DE202019101967U1 - Soil compactor with freewheel mode - Google Patents

Abstract

A soil compaction apparatus (1) comprising a compression plate (14) which is vibratable by an exciter unit (2) and which has a hydraulic circuit (3) with a hydraulic pump (4) and at least one hydraulic motor (5), said hydraulic pump (4) being characterized by a hybrid electric Power drive (6) is drivable, the at least one hydraulic motor (5) by the hydraulic pump (4) is drivable and the exciter unit (2) by the hydraulic motor (5) is drivable, wherein the soil compaction device (1) is adapted to the exciter unit ( 2) by a hydraulic short circuit of the hybrid electric power drive (6) to decouple.

Description

The invention relates to a soil compacting device with a compacting plate which can be set into vibration by an exciter unit and which has a hydraulic circuit with a hydraulic pump and at least one hydraulic motor, by means of which the excitation unit can be driven.

State of the art

Soil compacting devices, including hand-guided soil compaction equipment such as rammers or vibratory plates, usually have a power drive, which includes an internal combustion engine and / or an electric drive. If a soil compaction device is driven by an internal combustion engine, then in the drive train between the internal combustion engine and the drive, e.g. a drive axle or in this case the exciter unit, usually arranged a clutch.

The clutch allows separation of the engine and the drive, so that the drive can be taken out of service for the purpose of stopping without having to switch off the internal combustion engine.

Known embodiments of such, usually mechanically executed clutch are often used in vehicles disc clutches or often used in small equipment centrifugal clutches, such as in the DE 10 2017 105117A1 described.

Both coupling variants require a minimum of space and have a correlating with their dimensions weight. Both sizes are to be kept as low as possible in the construction of small-sized, suitable for manual operation soil compaction equipment.

Disclosure of the invention

Object of the present invention is to provide a comparison with the prior art improved solution, in particular with regard to a compact feasibility and low weight.

The object is achieved according to the invention by the features of the independent claim. Advantageous embodiments of the invention are specified in the subclaims.

According to the invention, a soil compacting device is provided with a compression plate which can be set into vibration by an exciter unit and which has a hydraulic circuit with a hydraulic pump and at least one hydraulic motor, wherein the hydraulic pump can be driven by a hybrid-electric power drive, the at least one hydraulic motor can be driven by the hydraulic pump, the exciter unit the hydraulic motor is drivable, and wherein the soil compaction device is adapted to decouple the excitable by the hydraulic motor exciter unit by a hydraulic short circuit of the power drive.

Such a soil compaction device has the advantage of enabling a propulsion-free idling or freewheeling of the power drive while at the same time dispensing with a mechanical coupling.

In this case, the hydraulic short-circuit causes a hydraulic fluid delivered or discharged by the hydraulic pump to be returned almost lossless directly to the hydraulic pump on an almost resistance-free short-circuit path. By appropriate dimensioning of the short-circuit path, power losses of the circulating hydraulic fluid can be kept low, so that the hydraulic pump is quasi freewheeling.

In an advantageous embodiment of a soil compacting device, the power drive and the hydraulic pump can thus be coupled to each other without coupling, in order to stop propulsion of the soil compacting device while the power drive is running.

Advantageously, the hydraulic circuit to a parallel to the hydraulic pump valve arranged so that the hydraulic short circuit can be achieved by opening the valve. Advantageously, the valve is designed as a directional control valve, which allows a deflection of the hydraulic fluid from one path to another. If the valve is designed as a directional control valve, the hydraulic fluid can be recycled altematively into the hydraulic circuit or to the hydraulic pump.

In a further alternative, the short-circuit valve may be arranged parallel to the hydraulic motor. This variant is advantageous if other components of the hydraulic circuit should not be short-circuited.

The generation of the hydraulic short circuit by opening a valve offers the advantage that a valve occupies much less space compared to a mechanical coupling and also has lower weight. Due to constructive flexibility in the installation of hydraulic hoses, the positioning of the valve within the soil compaction device can be chosen relatively freely and thus space-optimizing.

In an advantageous embodiment, the valve is designed as a solenoid valve. Electrically switchable solenoid valves are very common and therefore cheap available in numerous variants. An electrical controllability allows almost any positioning within the soil compaction device.

Further advantageously, the hybrid electric power drive has an electric drive which can be operated as a generator and a further drive unit, by means of which the electric drive operable as a generator can be driven. In this case, the soil compaction device advantageously has an operating mode in which the generator can be driven by the further drive unit and the exciter unit can be decoupled by a hydraulic short circuit.

For Bodenverdichtungsgeräte with a hybrid running power drive is the requirement to perform all components as easily and physically small construction in particular, since two or more drive units are to be arranged in about the same space. In this case, such hybrids usually have a hybrid electric power drive with an internal combustion engine and an electric drive.

In an advantageous embodiment, such a soil compacting device also has an electrical energy store, which can be loaded in an operating mode designed as a charging mode via the electric drive which can be operated as a generator. In this case, the excitation unit can be decoupled from the power drive by a hydraulic short circuit in this charging mode.

In a further or one of the above-described embodiments, the soil compacting device is set up for manual guidance. For this purpose, it advantageously has a guide tongue with a control device, wherein the control device is advantageously set up for actuating the valve.

list of figures

The invention will be explained in more detail below with reference to the attached, schematic drawings based on preferred embodiments.

• 1 eine Schaltskizze zum Prinzip des Bodenverdichtungsgeräts mit hybridelektrischem Antrieb und einer durch einen hydraulischen Kurzschluss entkoppelbaren Erregereinheit;
• 2 ein Ausführungsbeispiel eines Bodenverdichtungsgeräts mit hybridelektrischem Antrieb und einer durch einen hydraulischen Kurzschluss entkoppelbaren Erregereinheit.

Show it

• 1 a circuit diagram of the principle of soil compaction device with hybrid electric drive and a decoupled by a hydraulic short excitation unit;
• 2 An embodiment of a soil compaction device with hybrid electric drive and a decoupled by a hydraulic short excitation unit.

1 shows a circuit diagram to the principle soil compactor 1 , The soil compactor 1 has an exciter unit 2 on, through which one out 2 apparent compaction plate 12 is capable of vibrating for soil compaction.

A hydraulic circuit 3 has a hydraulic pump 4 and at least one hydraulic motor 5 on. The hydraulic pump 4 is by a hybrid electric power drive 6 drivable. At least one hydraulic motor 5 is through the hydraulic pump 4 drivable, and the exciter unit 2 is through the hydraulic motor 5 drivable.

The hydraulic motor 5 is together with the exciter unit 2 in an undercarriage 12 of the soil compactor 1 and the drive 6 and the hydraulic pump 4 are in an uppercarriage 11 of the soil compactor 1 arranged.

The soil compactor 1 is set up, the exciter unit 2 by a hydraulic short circuit of the hybrid electric power drive 6 to decouple. For this purpose, the hydraulic circuit 3 a valve arranged in this embodiment 7 on. The hydraulic short circuit is by opening the short-circuit valve 7 achievable. An opening of the short-circuit valve 7 leads to a drop in hydraulic pressure in the hydraulic circuit 3 through which the hydraulic motor 5 is taken out of service. A hydraulic fluid of the hydraulic circuit 3 is thus pumped without resistance in a circle, the hydraulic pump 4 is idle.

If the valve is designed as a directional control valve, this is arranged at the branch point, which is located in 1 in relation to a flow direction of the hydraulic fluid upstream of the valve 7 located. It allows at this position an alternative switching the paths of the hydraulic fluid in a short path back to the hydraulic pump 4 or in a work path to the hydraulic motor 5 ,

Switching the directional control valve from the working path to the short-circuit path results in a volume flow at the hydraulic motor 5 bypassed and pumped without pressure into the tank. The hydraulic motor 5 is completely pressure-free in this embodiment variant.

The valve 7 is designed as a solenoid valve and the power drive 6 and the hydraulic pump 4 are coupled with each other without coupling.

2 shows an embodiment of a soil compaction device 1 , where the power drive 6 hybrid is executed and operated as a generator electric drive 8th and another drive unit 9 has, by which the operable as a generator electric drive 8th is drivable.

The further drive unit 9 is designed as an internal combustion engine and how out 1 visible with a coupling 10 with the electric drive 8th separably connected.

The soil compactor 1 has an operating mode in which the electric drive 8th as a generator through the further drive unit 9 driven and in the undercarriage 12 concealed exciter unit 2 can be decoupled by a hydraulic short circuit.

Furthermore, the soil compaction device 1 an electrical energy storage 13 on which preferably in an operating mode designed as a charging mode combustion engine via the electric drive operated as a generator 8th is loadable. In this mode of operation also the exciter unit 2 be operated, wherein a non-driving required part of the power generated by the engine for charging the electrical energy storage 13 is usable.

Furthermore, the soil compaction device 1 preferably an exclusive charging mode, in which an electrical energy storage 13 via the electric drive which can be operated as a generator 8th is loadable and in which the exciter unit 2 by a hydraulic short circuit of the power drive 6 is decoupled.

The soil compactor 1 is set up to guide by hand and has a guide bar 15 with a control device 16 on. The control device 16 is for actuating the valve 7 set up.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102017105117 A1 [0004]

Claims (9)

A soil compacting apparatus (1) comprising a compression plate (14) vibratable by an exciter unit (2) and having a hydraulic circuit (3) with a hydraulic pump (4) and at least one hydraulic motor (5), the hydraulic pump (4) being characterized by a hybrid electric Power drive (6) is drivable, the at least one hydraulic motor (5) by the hydraulic pump (4) is drivable and the exciter unit (2) by the hydraulic motor (5) is drivable, wherein the soil compaction device (1) is adapted to the exciter unit ( 2) by a hydraulic short circuit of the hybrid electric power drive (6) to decouple. Soil compactor (1) after Claim 1 , characterized in that the hydraulic circuit (3) to the hydraulic pump (4) arranged in parallel valve (7) and the hydraulic short circuit by opening the valve (7) can be achieved. Soil compactor (1) after Claim 1 , characterized in that the hydraulic circuit (3) has a directional control valve, by which a volume flow of the hydraulic pump (4) alternatively on a short circuit path back to the hydraulic pump or on a working path to the at least one hydraulic motor (5) can be fed. Soil compactor (1) according to one of the preceding claims, characterized in that the valve (7) is designed as a solenoid valve Soil compacting device (1) according to one of the preceding claims, characterized in that the electro-hybrid power drive (6) and the hydraulic pump (4) are coupled to each other without coupling. Ground compacting device (1) according to one of the preceding claims, characterized in that the electro-hybrid power drive (6) has an electric drive (8) which can be operated as a generator and a further drive unit (9), by means of which the electric drive (8) which can be operated as a generator can be driven is, and the soil compaction device (1) has an operating mode in which the generator by the further drive unit (9) drivable and the exciter unit (2) is decoupled by a hydraulic short circuit. Soil compactor (1) after Claim 6 , characterized in that the soil compacting device (1) has an electrical energy store (13) which can be charged in an operating mode carried out as a charging mode via the electric drive (8) which can be operated as a generator and in which the excitation unit (2) is connected by a hydraulic short circuit the power drive (6) is decoupled. Ground compacting device (1) according to one of the preceding claims, characterized in that it is set up for guidance by hand. Soil compacting device (1) according to one of the preceding claims, characterized in that it comprises a guide tongue (15) with a control device (16) and the control device (16) is arranged for actuating the valve (7).

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