EP3725949B1 - Hand-guided implement with decoupled drawbar support - Google Patents

Description

The invention relates to a hand-held implement, in particular an implement for soil compaction.

The implement can in particular be designed as a vibrating machine, in particular as a soil compacting device.

Soil compaction devices, in particular vibrating plates or vibrating rollers, are known. They essentially consist of a lower mass with a tool, for example a soil contact element, which is moved over the soil to be compacted and subjected to vibrations generated by a vibration exciter. The vibration exciter is usually an imbalance exciter in which, for example, two counter-rotating imbalance shafts generate a resulting force that causes the desired vibration.

Provided above the lower mass is an upper mass which is movable relative to the lower mass and has a drive, for example an internal combustion engine, a machine frame and optionally a drawbar for guiding the vibration plate. The upper mass usually also includes a fuel tank, a starter battery, control elements and - if present - parts of a hydraulic system.

Larger vibratory plates are usually controlled with the help of remote controls to protect the operator from vibration influences. In the case of smaller vibrating plates, a guide drawbar is usually provided, with the help of which the operator can guide and control the vibrating plate. Many operators prefer towbars, even with larger vibratory plates, because the direct control makes it easier to control.

Despite highly developed vibration decoupling measures between the lower mass and the upper mass, strong vibrations still act on the upper mass, which can accordingly also be transmitted to the drawbar. In order to reduce the vibrations acting on the operator handling the tiller, it is made, for example, from the DE 20 2009 004 301 U1 It is known to divide the drawbar into a mounting part and a guide part which is decoupled in terms of vibration from the mounting part.

The internal combustion engines provided for driving the vibration exciters on the upper mass can usually be started via electric starters with starter batteries. The starter batteries can consist, for example, of grid plate accumulators that are designed for motor vehicles to participate in road traffic. However, the vibration amplitudes occurring in the vibration machines are orders of magnitude higher than those occurring in normal road traffic. In practice, the problem often arises that the grid structure of the vibration-sensitive starter batteries can be damaged due to the vibrations, so that the starter batteries fail.

For vibration-decoupled storage of a starter battery, it is from the DE 198 28 600 C1 known to specify a holding device for the starter battery, on the wall of which several rubber spring elements are arranged.

Although great efforts have already been made in the prior art to keep the vibrations affecting an electrical energy store, which is used e.g. which can damage the electrical energy store or the starter battery or put an excessive strain on the operator.

Out of DE 10 2011 104269 A1 , WO 2012/084074 , EP 2 980 316 A1 , WO 2013/050102 A1 hand-held tools are known in each case in which an electrical energy store is arranged on a handlebar or a drawbar in order to protect the energy store from the effects of high vibrations.

The invention is therefore based on the object of specifying a hand-held working device in which the vibrations acting on the starter battery and the operator are as low as possible.

The object is achieved according to the invention by a hand-held tool with the features of claim 1. Advantageous configurations are specified in the dependent claims. A vibration plate for soil compaction is particularly suitable as a working device.

A hand-held tool is specified, with a lower mass, which is a tool and a working device for effecting a working movement of the tool has; with an upper mass which is movable relative to the lower mass and has a drive component for the working device; with a first vibration decoupling device arranged between the lower mass and the upper mass for vibrationally decoupling the upper mass from the lower mass; with a guide tongue for guiding the implement by an operator; and with an electrical energy store for Providing electrical energy for the drive component; a drawbar carrier being provided, which is carried by the upper mass and which is connected to the upper mass via a second vibration decoupling device; wherein the guide tongue is attached to the tongue carrier; and wherein the energy store is carried by the drawbar carrier.

The lower mass is essentially formed by the working device and the tool. The working device can be, for example, an imbalance exciter that drives a ground contact plate that is used as a tool or causes it to vibrate (working movement).

The upper mass has at least one drive component, which can be designed, for example, as a drive motor for the working device, in particular as an internal combustion engine. The drive component can also be designed as a control component. Increasingly, construction machines are also being driven electrically by means of accumulators. The drive component can therefore also be designed as an additional battery (also referred to below as a traction battery), electric motor, voltage and/or frequency converter, electronic controller and/or circuit breaker.

If a drive motor is mentioned, both combustion and electric motors are meant.

A fuel tank, an engine cooling device, a cooling fan, a protective frame or a centrifugal clutch, for example, can also be arranged on the upper mass.

The energy store carried by the drawbar carrier can be defined as the first energy store, wherein the drive component can have a second energy store, which can be arranged on the upper mass. In this case, the drive motor can also be part of the drive component and can therefore be arranged on the upper mass. In one variant, however, the drive motor can also not be part of the drive component and can be arranged, for example, on the lower mass, for example directly on the working device (e.g. the vibration exciter). The second energy store can serve to supply the drive motor arranged on the upper mass or on the lower mass.

A transmission device can be provided for transmitting the drive power of the drive motor arranged on the upper mass to the working device be. This can be, for example, a belt drive or a hydraulic coupling, for example to drive the unbalance exciter on the lower mass. The drive motor can be arranged on the upper mass, with its drive power being able to be transmitted to the lower mass with the named transmission device. Alternatively, the drive motor can be arranged on the lower mass. In this case, the use of an electric motor is preferred, which can be coupled to a vibration exciter.

The energy store (possibly also referred to below as the first energy store) can be, for example, a starter battery, for example for an electric starter provided on the internal combustion engine.

In a variant with an electric motor as the drive motor, the energy store (or the first energy store) can also be a secondary battery for providing electrical energy, e.g. for control devices of the motor, or also part of the traction battery that supplies the electric motor with drive energy . In this case, the electric motor can be supplied with drive energy, for example, by both energy stores, namely the first energy store and the second energy store. The electrical energy required for the electric motor is then stored in a distributed manner in the two energy storage devices.

The drawbar carrier is connected to the upper mass via the second vibration decoupling device. The drawbar carrier can be movable relative to the upper mass within certain limits that are specified by the second vibration decoupling device.

Both vibration decoupling devices can be formed with the help of an elastic bearing and in this way allow relative mobility of the components coupled to one another (lower mass - upper mass; upper mass - drawbar carrier) in order to prevent or at least reduce the transmission of vibrations from one component to the other.

The first vibration decoupling device and the second vibration decoupling device are functionally connected in series between the lower mass (and thus the location where the vibrations occur) and the components to be protected (battery; guide pole). This adds up Vibration decoupling effect of the two vibration decoupling devices.

Due to the two vibration decoupling devices, the energy store carried by the drawbar carrier or the first energy store (e.g. the battery, starter battery, traction battery, part of the traction battery) and the guide drawbar are vibrationally decoupled from the actual place of vibration generation, namely the working device in the lower mass. The vibrations on the lower mass are effectively damped or reduced by the vibration decoupling devices connected in series with respect to the battery and the guide tongue in order to protect the battery and the guide tongue from high vibration effects. Accordingly, the operator is also protected from excessive vibration when grasping the drawbar at its end to guide the work implement with his hands.

The drawbar carrier can be arranged in an area of the upper mass that faces the operator. This means that the drawbar carrier can be arranged in particular in the rear, rear part of the upper mass, seen in the forward direction of travel. Accordingly, a suitable recess for the drawbar support and the second vibration decoupling device is to be provided in the rear part of the upper mass.

The guide pole can be pivoted relative to the pole carrier. In particular, it can be achieved that the guide pole can be pivoted either upwards for a transport position or downwards for an operating position. For this purpose, the guide pole can be fastened to the pole carrier via a rotary bearing, for example an axle.

In the lower position of the guide pole (operating position), it can be advantageous if a resilient stop is provided in order to support the guide pole in this lower position. The stop can be realized, for example, by a rubber or plastic buffer.

The second vibration decoupling device can have several connection points between the drawbar carrier and the upper mass. The connection points allow on the one hand the reliable mechanical coupling between Drawbar carrier and upper mass. On the other hand, they also ensure vibration decoupling between the two components.

In one embodiment, at least four connection points can be provided between the drawbar carrier and the upper mass, with three of the four connection points spanning an imaginary (virtual) plane and the fourth connection point having a perpendicular distance from the plane that corresponds to at least half of the smallest distance that having the fourth connection point to the nearest one of the other three connection points. In the ideal case, the four connection points can thus be arranged in a kind of tetrahedron in order to achieve a particularly stable and effective arrangement in space and to reliably hold the drawbar carrier with the guide drawbar on the upper mass.

In particular, the second vibration decoupling device must be suitable for reliably transmitting the steering and control forces, which the operator brings in with his hands at the end of the guide pole, to the upper mass and thus to the lower mass. In particular, this results in tilting and torques which are introduced by the operator via the guide pole into the pole carrier and which are to be transmitted by the second vibration decoupling device. The arrangement of the four connection points ensures a broad base of moments in order to introduce the executives and moments directly into the upper mass and thus into the implement.

The fourth connection point is outside the plane that is spanned by the three other connection points. The distance between the fourth connection point and the plane should be as large as possible in order to make the imaginary (virtual) tetrahedron as large as possible.

In one embodiment, six connection points are provided between the drawbar carrier and the upper mass, with at least two of the six connection points being arranged at a different height level than the remaining connection points, based on an intended position of use of the implement in a horizontal plane. In this embodiment with six connection points, it is also possible to arrange connection points outside of imaginary planes, so that the advantageous tetrahedron arrangement described above can be achieved by four of the six connection points in each case.

To define the height level, it is assumed that the implement is horizontal in its position of use. In this case, the difference in height level can be, for example, at least 50% of the smallest distance between the remaining connection points. Here, too, it is important to pull the connection points as far apart as possible in order to achieve a broad base of moments for absorbing the executives and moments.

The connection points can each be formed by buffer elements and can be realized, for example, as rubber buffers or plastic buffers. The buffer elements should have at least a low level of elasticity in order to be able to develop the vibration-decoupling effect.

The buffer elements can each have a central axis in their longitudinal direction, with the central axes of the buffer elements of all connection points being able to extend in at least three different spatial directions. The buffer elements are constructed in a manner known per se and can, for example, have two metal plates (plates, discs) spaced apart from one another, between which an elastic rubber or plastic element is provided. The respective forces are introduced via the plates provided at the end and are elastically absorbed by the rubber or plastic element. The rubber or plastic element thus also serves as a spring and damper element.

The central axes of the buffer elements should therefore deviate from one another and extend in three different spatial directions. As a result, the central axes are at an angle to one another or are skewed. Of course, it can make sense to arrange the buffer elements in pairs in such a way that the best possible accommodation of the active executives can also be achieved here.

The buffer elements can be arranged in such a way that they are subjected to pressure and/or shear during operation of the implement, but not to tension. Accordingly, the fastenings of the buffer elements on the drawbar carrier and the upper mass are to be designed so that no tensile effects can be brought about in the buffer elements with normal force effects due to the prevailing vibrations and the executive forces introduced by the operator.

A protective frame can be provided which is rigidly connected to the upper mass. The protective frame then represents part of the upper mass.

In one variant, the protective frame can be rigidly connected to the drawbar carrier instead of to the upper mass. In this case, the protective frame is separate from the upper mass and is not part of the upper mass.

The guide pole can have an elongate extension, with a handle bar being provided on an end facing away from the upper mass or the pole carrier for gripping by the operator. The operator can grip the handle not only to guide the implement. Likewise, it is also possible to design the handlebar as a control element for setting the running direction of the implement, for example a vibrating plate. For this purpose, the handlebar can be pivoted relative to the end of the drawbar, with the pivoting movement of the handlebar being detected in a suitable manner and transmitted to an imbalance exciter in the lower mass. The function and effect of such a vibrating plate control is known per se and will therefore not be discussed in greater detail at this point.

The implement can in particular be a vibrating plate for soil compaction.

Fig. 1

eine perspektivische Draufsicht auf eine als Arbeitsgerät dienende Vibrationsplatte;

Fig. 2

eine Seitenansicht zu der Vibrationsplatte von Fig. 1;

Fig. 3

eine perspektivische Teilansicht eines Deichselträgers mit Führungsdeichsel; und

Fig. 4

eine Variante zu der Vibrationsplatte von Fig. 2.

These and other advantages and features of the invention are explained in more detail below using examples with the aid of the accompanying figures. Show it:

1

a perspective plan view of a working device serving as a vibrating plate;

2

a side view of the vibration plate of 1 ;

3

a perspective partial view of a drawbar carrier with guide pole; and

4

a variant of the vibration plate from 2 .

1 shows a vibration plate driven by an internal combustion engine for soil compaction as an example of a working device according to the invention in a perspective view from above. 2 shows the vibration plate from 1 in side view. While in the presentation of 2 the vibration plate with a is equipped with the protective frame explained later, this is in the view of 1 removed for better display.

The vibration plate has a lower mass 1 and an upper mass 2 arranged above the lower mass 1.

A part of the lower mass 1 is a soil contact plate 3 which is used as a tool and is moved with its underside over the soil to be compacted. On the ground contact plate 3, a vibration exciter 4 is arranged, which can be designed, for example, as a known imbalance exciter. The imbalance exciter has, for example, two imbalance shafts rotating in opposite directions, on each of which an imbalance mass is arranged. The counter-rotation generates a resulting force vector that forms the desired vibration. Due to the rigid coupling between the vibration exciter 4 and the soil contact plate 3, the vibration is introduced directly into the soil contact plate 3 and can therefore be used effectively for soil compaction.

Fastening devices 5 are also provided on the lower mass 1, on each of which buffer elements 6 made of a rubber or plastic material are arranged. The buffer elements 6 are part of a first vibration decoupling device, which decouples the vibrations of the upper mass 2 from the lower mass 1, which vibrates strongly during operation.

A protective frame 7 is arranged on the upper mass 2 as part of the upper mass 2 ( 2 ), which however - as mentioned above - in 1 is not shown.

A drive motor (not shown) for driving the vibration exciter 4 is also part of the upper mass 2. This can in particular be an internal combustion engine. However, it is also possible to implement the drive motor as an electric motor.

In order to transmit the drive power of the drive motor to the vibration exciter 4, a transmission device, also not shown, is also provided, which can be realized, for example, as a belt drive or as a hydraulic drive.

The upper mass 2 can also include the other components: for example a fuel tank, control components, engine cooler, cooling fan, a centrifugal clutch, a protective frame.

A drawbar carrier 8 is held on the upper mass 2 . For this purpose, a corresponding cutout 9 can be formed in the upper mass, in which the drawbar carrier 8 is inserted ( 1 ).

3 shows the drawbar carrier 8 fastened to the upper mass 2 in a perspective partial view.

The drawbar carrier 8 is vibrationally decoupled from the upper mass 2 . For this purpose, a second vibration decoupling device is provided between the drawbar carrier 8 and the upper mass 2, which has a plurality of buffer elements 10. At the in the Figures 1 to 3 A total of six buffer elements 10 are arranged between the upper mass 2 and the drawbar carrier 8 as an example of the vibration plate shown as an example. The buffer elements 10 are in 2 shown in respective outbreaks.

Each of these buffer elements 10 has a plate (sheet metal, disk, etc.) on the face side. The actual buffer material, for example a rubber or plastic material, is arranged between the two end plates. In principle, the buffer elements 10 can have a similar design as the buffer elements 6 between the upper mass 2 and lower mass 1. These are generally components that are available and can be purchased on the open market, for example rubber buffers.

Three of the buffer elements 10 are arranged on one side of the drawbar support 8 and spaced apart, like the Figures 1 to 3 show.

The respective central axes of the buffer elements 10 extend in different directions in space, as also in FIGS Figures 1 to 3 good to see. In this way, different preferred directions of action of the buffer elements 10 are achieved in order to load the buffer elements 10 as far as possible only in compression or shear (or torsion), but not in tension.

The drawbar carrier 8 is box-shaped and has a plateau-shaped area 11 which is delimited by side walls 12 ( 3 ).

A battery 13 is set up on the plateau-shaped area 11 , the position of which is fixed by a locking element 14 . In this way, the battery 13 is reliably held in its position even when the vibration plate is in operation. The Battery 13 serves in particular to store and provide electrical energy, which can be supplied to an electric starter on the drive motor as required. In addition, other control devices of the vibration plate can also be supplied with electrical energy from the battery 13 .

If the drive motor is implemented as an electric motor in one variant, the battery 13 can also serve as part of a traction battery that supplies the electric motor with the necessary electric drive energy. Another part of the traction battery can be provided directly on the upper mass than not - like the battery 13 - on the drawbar support 8, which is vibrationally decoupled from the upper mass.

Because the battery 13 is mounted on the drawbar carrier 8, it is effectively decoupled from the vibrations in the lower mass 1 in terms of vibration. The vibrations in the lower mass 1 are significantly reduced due to the first vibration decoupling device (buffer elements 6) and second vibration decoupling device (buffer elements 10) connected in series with respect to the battery 13 and the drawbar carrier 8, so that the battery 13 is well protected.

On the drawbar carrier 8, a drawbar receptacle 15 is provided in the rear region, on which a guide drawbar 16 is pivotably mounted. The lower end of the guide pole 16 is attached to the pole receptacle 15 and can be pivoted about a pivot axis 16a between an upper position and a lower position shown in the figures when the operator moves a pole head 17 formed at the end of the guide pole 16 upwards or downwards presses down.

A stop device 18 with a height adjustment 19 is provided on the guide pole 16 . A buffer element 20 is arranged at the lower end of the stop device 18 and can be struck against a stop 21 formed on the drawbar receptacle 15 when the guide drawbar 16 is in the position shown in FIG 2 shown lower position.

With the help of the height adjustment 19, the angle of the guide pole 16 can be adjusted in the lower position relative to the pole mount 15 and thus the rest of the vibrating plate in order to set the pole head 17 to a comfortable height for the height of the operator.

A handle bar 22 is arranged on the tiller head 17, which also serves as a switching bar. Accordingly, the robustly designed handle bar 22 can be gripped by the operator on the one hand, in order to apply appropriate forces to the vibration plate and to control and steer it. In addition, the handle bar 22 can be pivoted relative to the tiller head 17 - if it is also designed as a switching bar. The pivoting of the handle bar 22 is detected by a transmission device (not shown) and transmitted to the vibration exciter 4 . In particular, a hydraulic transmission device can be provided, with the help of which the relative position of the imbalance shafts in the vibration exciter 4 and thus their phase position can be changed in order to adjust the direction of the resulting vibration vector and thus the direction of travel.

In this way, forward and reverse movement of the vibrating plate can be realized. The vibration plate can also carry out a stationary vibration when it is stationary. The control options described have been known for a long time and therefore do not need to be explained in more detail at this point.

4 shows another embodiment of a vibrating plate serving as a working device according to the invention.

As far as similar or identical components are used, as in the embodiment of Figures 1 to 3 , the same reference symbols are also used.

This vibrating plate also has a lower mass 1 and an upper mass 2 , with a first vibration decoupling device in the form of the buffer elements 6 being provided between the lower mass 1 and the upper mass 2 .

A drive motor 23 is also attached to the upper mass 2 and 4 shown.

In this variant, the drawbar carrier 8 is designed to be significantly larger and extends over the entire base area of the upper mass 2, with cutouts also being possible. Accordingly, the drawbar carrier 8 is vibrationally decoupled from the upper mass 2 via the buffer elements 10, which serve as a second vibration decoupling device.

In addition, a protective frame 24 is carried by the drawbar carrier, which frame spans the vibration plate in a manner known per se in the manner of a housing. Of both Figures 1 to 3 The protective frame 7 shown is thus replaced by the protective frame 24 .

Because the protective frame 24 is part of the drawbar carrier 8 or is rigidly attached to it, the total mass of the drawbar carrier 8 is increased, as a result of which the effect of reducing vibration is further intensified. Accordingly, it is possible to greatly reduce the vibration applied to the battery 13 supported by the drawbar beam 8 . The guide pole 16 is also held by the pole carrier 8 so that the vibrations (hand-arm vibrations) transmitted to the operator via the guide pole 16 can also be kept small.

In a further embodiment that is not shown, the battery 13 is an element of an electric drive of the implement. The electrical drive energy can be provided by means of a traction battery arranged on the upper mass and the battery 13 . In this respect, the battery 13 can represent a part of the traction battery or support it. For example, the energy of the traction battery and battery 13 can be combined to provide a higher total capacity. Alternatively, it is also conceivable to supply the electronic control by means of the battery 13 and to supply the electric drive motor by means of the traction battery, ie to assign separate tasks to each of the two batteries. In this case, the battery 13 can also be referred to as a secondary battery, since it is used to provide energy for secondary tasks that is not required directly to operate the electric motor.

Claims (13)

1. Hand-guided working apparatus having

   - a lower mass (1) which comprises a tool (3) and a working device for causing a working movement of the tool (3);

   - an upper mass (2) which is movable relative to the lower mass (1) and which comprises a drive component for the working device;

   - a first vibration decoupling device (6), disposed between the lower mass (1) and the upper mass (2), for decoupling the upper mass (2) from the lower mass (1) in terms of vibration;

   - a guide drawbar (16) for guiding the working apparatus by an operator; and having

   - an electrical energy store (13) for provision of electrical energy for the drive component;

   wherein

   - a drawbar carrier (8) is provided, which is carried by the upper mass (2) and which is connected to the upper mass (2) via a second vibration decoupling device (10) and

   - the guide drawbar (16) is attached to the drawbar carrier (8), characterised in that

   - the energy store (13) is carried directly and immediately by the drawbar carrier (8).
2. Working apparatus as claimed in claim 1, wherein the drive component comprises a drive motor for the working device.
3. Working apparatus as claimed in any one of the preceding claims, wherein

   - the energy store carried by the drawbar carrier is a first energy store; and wherein

   - the drive component comprises a second energy store which is disposed on the upper mass.
4. Working apparatus as claimed in any one of the preceding claims, wherein the drawbar carrier (8) is disposed in a rear, backward region of the upper mass (2) as seen in the forwards direction of travel.
5. Working apparatus as claimed in any one of the preceding claims, wherein the guide drawbar (16) is pivotably mounted relative to the drawbar carrier (8).
6. Working apparatus as claimed in any one of the preceding claims, wherein the second vibration decoupling device comprises a plurality of connection points (10) between the drawbar carrier (8) and the upper mass (2).
7. Working apparatus as claimed in claim 6, wherein

   - at least four connection points (10) are provided between the drawbar carrier (8) and the upper mass (2); and wherein

   - three of the four connection points (10) span an imaginary plane, and the fourth connection point is at a perpendicular distance from the plane, which corresponds at least to half the smallest distance which the fourth connection point has to the closest of the other three connection points.
8. Working apparatus as claimed in any one of claims 6 or 7, wherein

   - six connection points (10) are provided between the drawbar carrier (8) and the upper mass (2); and wherein

   - at least two of the six connection points (10) are disposed at a different height level than the remaining connection points, based on a provided usage position of the working apparatus in a horizontal plane.
9. Working apparatus as claimed in any one of claims 6 to 8, wherein the connection points are each formed by buffer elements (10).
10. Working apparatus as claimed in claim 9, wherein

    - the buffer elements (10) each comprise a central axis in their longitudinal direction; and wherein

    - the central axes of the buffer elements (10) of all connection points extend in at least three different spatial directions.
11. Working apparatus as claimed in any one of the preceding claims, wherein a protective frame (7, 24) is provided which is rigidly connected to the upper mass or to the drawbar carrier.
12. Working apparatus as claimed in any one of the preceding claims, wherein

    - the guide drawbar (16) has an elongate extension; and wherein

    - a gripping handle (22) to be gripped by the operator is provided at an end remote from the upper mass (2).
13. Working apparatus as claimed in any one of the preceding claims, wherein the working apparatus is a vibrating plate for ground compaction.

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