DE202013005537U1 - Pounding device with electrodynamic stamping unit - Google Patents

Abstract

Tamping device for soil compaction, with - an upper mass (1); - a bottom contact element (2) which has a ground contact element (8) and is movable relative to the upper mass (1); and with - a drive acting between the upper mass (1) and the lower mass (2) drive; wherein - the drive comprises a linear drive (4) with a stator (5) and an axially reciprocable linear rotor (6); - The stator (5) is provided on the upper mass (1); and wherein - the linear rotor (6) with the lower mass (2) is positively coupled.

Description

The invention relates to a tamping device for soil compaction, in particular a vibration tamper and a method for operating such a tamping device.

Usually, a tamper comprises a drive having an upper mass and a ground contact element having, movable relative to the upper mass lower mass. Between the upper mass and the lower mass acts a drivable by the drive ramming system (vibration exciter device), with which the working movement of the ground contact element can be effected in order to achieve the soil compaction effect.

The padfoot having the ground contact element (lower mass) is connected via a double-acting spring assembly to a plunger connected to the connecting rod. By coupling the springs on the one hand a part of the kinetic energy is stored and on the other hand, the drive with the transmission of the hard bumps of the impacting padfoot decoupled.

Rammers for soil compaction are usually driven by rotating motors, wherein by means of a transmission, for example a crank gear, the rotational movement of the motor is converted into the linear motion required for the ramming process. In electric strippers usually the rotational movement of the electric motor is first translated at high speed via a gear in the slow and then converted via a crank mechanism with connecting rod in an oscillating linear motion.

The translation of the high speed of the electric motor and the conversion of the rotational movement in the oscillating linear motion requires a considerable mechanical effort. The mechanically predetermined connection of the padfoot via the crank mechanism to the rotational movement of the motor means that the stamping cycle during operation is difficult to change as a result of the inertia of the moving components and due to the predetermined lifting height of the crank mechanism. An adaptation of the ramming system to different soils or changes in soil properties during the compression process (ramming) is not possible or only with considerable additional effort.

3 shows a schematic representation of an example of a known from the prior art rammer.

The rammer has an upper mass 21 and a lower mass 22 on. The lower mass 22 is relative to the upper mass 21 movable and with this over a bellows 23 connected. A stable guidance of the lower mass 22 relative to the upper mass 21 is through guide tubes 24 guaranteed.

At the lower mass 22 , which is also referred to as pest foot, is a ramming plate as a ground contact element 25 intended.

At the upper mass 21 an unrepresented drive is provided, for example an internal combustion engine or an electric motor, which is a crankshaft 26 rotating drives. Over a connecting rod 27 becomes a pestle 28 back and forth or - in 3 - moved up and down.

A plunger plate 29 is at its two end faces by springs 30 supported, in turn, on the lower mass 22 are supported. In this way, the reciprocating motion of the plunger 28 on the lower mass 22 and thus the ground contact element 25 transferred to generate the pitching motion.

From the DE 10 2010 052 243 A1 a tamping device with a synchronization device is known in which a manipulation device is provided between the upper mass and the lower mass in order to influence the movement behavior of upper mass and lower mass relative to one another. This makes it possible to control the ramming behavior of the rammer.

From the CN 101196003 A is a stamper device with an electrodynamic Stampfwerk known. The tamping device has an upper mass and a base contact element having, movable relative to the upper mass lower mass. An acting between the upper mass and the lower mass drive is designed as a linear drive and has a stator on the upper mass and a linear rotor. The movement of the linear rotor is transmitted via a plunger and two spring assemblies on the lower mass or the padfoot.

The invention has for its object to provide a ramming device for soil compaction, which requires little mechanical effort and allows variability of the pitch dynamics or the ramming behavior.

The object is achieved by a tamping device according to claim 1. Advantageous embodiments are defined in the dependent claims.

It is given a ramming device for soil compaction, with an upper mass, a bottom contact element having, movable relative to the upper mass lower mass, and with a drive acting between the upper mass and the lower mass, wherein the drive has a linear drive with a stator and an axially reciprocable linear rotor, the stator is provided on the upper mass, and wherein the linear rotor is positively coupled to the lower mass.

Thus, the tamping device has an electrodynamic stamping unit with the linear drive. The stator of the linear drive is provided on the upper mass or may in particular be positively connected to the upper mass. The belonging to the linear actuator linear motion, however, is positively coupled with the lower mass, so that the electrodynamic driving action directly between the upper mass (with the stator) and the lower mass (with the linear rotor) takes place. An additional spring device between the upper mass and lower mass is not absolutely necessary. But it can - as will be explained later - be helpful.

The tamping device has compared to known from the prior art devices relatively few components, which reduces the mechanical complexity and thus the cost. In addition, the stamper can be realized due to the unnecessary mechanical components with less weight. The few moving parts reduce the maintenance and also reduce the vibrations during operation of the rammer.

The fact that there are fewer mechanical components on the upper mass than in the prior art, it is possible to lower the center of gravity of the rammer, which improves the maneuverability of the rammer and reduces the risk of tipping.

Due to the direct form-fitting coupling of the linear drive with the lower mass, it is possible to influence directly by controlling the linear drive and the movement behavior of the lower mass. In this way, the ramming behavior of the rammer can be adapted from case to case, for example, to take account of different soil properties.

The linear rotor may be guided by the stator radially at its circumference in the upper mass.

On at least one end face, but in particular on both opposite end faces of the linear rotor can be provided in each case a rotor spring means for supporting the reverse movement of the linear rotor in the reversal points.

This means that the linear rotor in the working direction, that is axially at least one side, but preferably supported on both sides via a spring system (the rotor spring means) against the upper mass. The rotor spring device can have springs, for example made of steel, plastic or air. This part of the kinetic energy of the drive system is stored and supports the necessary reversal of direction of the linear rotor in its reversal points for the oscillation (reciprocation). Furthermore, a defined center position of the upper mass is ensured at a standstill, so that the rammer does not collapse, in contrast to known from the prior art rammers with crank mechanism.

In a sibling claim, a tamping device is specified in which the linear rotor does not necessarily have to be positively coupled to the lower mass (but can). In this case, other types of coupling, for example via springs are possible, as will be explained later. However, according to the independent claim, the tamping device comprises the at least one rotor spring device or also both opposing rotor spring devices, in order to assist the reversal movement of the linear rotor in the reversal points.

In one variant, a plunger spring device can be provided in the force flow between the linear rotor and the lower mass for transmitting the movement of the linear rotor to the lower mass. In this variant, the linear rotor is thus not form-fitting, but coupled via the plunger-spring device with the lower mass. The plunger-spring device can be realized in a conventional manner, such as from the CN 101196003 A known.

The plunger-spring device causes a relief of the linear rotor, since the linear rotor is coupled in this way elastically with the Stampffuß or the ground contact element and the lower mass. In this case, the plunger-spring device can be designed either relatively stiff to achieve a mere interception of shock peaks, or - according to the stamping ram design of today's rammer - in a softer design with large energy buffering serving as a coupling element spring device.

The one or both runner spring means may be operatively provided between the linear runner and the upper mass. In this way, the linear rotor is supported in operation against the upper mass and is moved by the arranged at its two end faces rotor spring means back and forth. By supporting the runner spring devices of the actual linear drive are dimensioned weaker, especially since he does not have to completely cause the reverse movement of the linear rotor from its own power.

The rotor spring device and / or the plunger spring device can each have a variable spring characteristic. By changing the spring characteristic, it is possible to change the movement behavior between upper mass and lower mass and thus the damping properties of the rammer. For example, it is possible to adjust the spring characteristic by the operator himself or by a controller present in the tamping device.

The linear drive may be an electric motor selected from the group reluctance motor or brushless DC motor. The reluctance motor, in particular a switched reluctance motor can have a rotor, which consists of a laminated core, which is very robust against impact. Also, a brushless DC motor (BLDC) is conceivable, where he should also be carried out correspondingly robust.

The tamping device may comprise a vibration detection device for detecting the movement behavior of at least one component of the tamping device, wherein the component is selected from the group of upper mass, lower mass, relative movement between upper mass and lower mass and attached to the upper mass guide bracket for guiding the tamping device.

With the help of the vibration detection device, it should thus be possible in a suitable manner to draw conclusions about the working behavior of the rammer. The movement of the rammer or its components is considered a suitable criterion. Device, for example, the rammer on an already heavily compacted soil "out of tact", the upper mass performs much stronger vibrations than in normal operation. A similar movement behavior can also be observed for the lower mass. In addition, the relative movement between the upper mass and lower mass is considered a helpful criterion for detecting the movement behavior of the rammer and thus his way of working.

Also, the guide bracket is suitable for observing the working behavior of the rammer, since its movement behavior allows conclusions about the operation of the rammer.

The movement of the rammer or the component of the rammer can be detected in the form of a vibration, an acceleration, a speed or as a movement path.

A control device may be provided for controlling the frequency and / or the amplitude of the linear drive, that is to say in particular of the linear rotor. The control device thus enables a drive control for changing the ramming or motor parameters. In particular, the single impact energy can be changed by adjusting the frequency and / or the amplitude of the linear rotor.

The tax measures of z. B. a motor controller having control device can be specified by the operator. However, it is also possible that the control takes place automatically on the basis of corresponding specifications. In this case, on the one hand, the adjustment or control measure relatively rarely, for example, be made before the start of a work, or on the other hand be extremely sensitive, so that, for example, each individual shock or shock of the ground contact element is selectively controlled.

If the control device is actuated by the operator, for example, it is possible for the operator to make presettings due to the soil to be compacted (soft, cohesive, hard, already pre-compacted, etc.), so that the ramming behavior of the rammer is then adapted to the ground conditions ,

The control device can be embodied as a control device for monitoring a movement behavior of the tamping device on the basis of the actual movement behavior of the corresponding component of the tamping device detected by the vibration detection device, whereby a deviation of the actual movement behavior from a predetermined desired movement behavior can be recognized by the control device, and by the control device the frequency and / or amplitude of the movement of the linear rotor is controllable to reduce the deviation.

If the control device is designed as a control device, it is possible to automatically adapt the movement behavior of the tamping device to the ground conditions, in particular to changing ground properties. With the help of the vibration detection device while the movement behavior of the corresponding selected component of the tamping device, so for example, the upper mass or the lower mass detected. This actual movement behavior is compared with a predetermined desired movement behavior. If a deviation is detected or the deviation exceeds a permissible limit, the control device can take appropriate control measures to reduce or minimize the deviation. In particular, the controller may measure the frequency and / or or change the amplitude of the linear drive or the movement of the linear rotor in order to reduce the deviation.

For example, if it is determined by the vibration detecting means that the upper mass undergoes unduly high vibration (which may be an indication that the tamping device is bouncing on a hard, already fully compacted bottom), the control means may, for example, alter the amplitude simultaneously increase the frequency of the linear actuator cause. The same applies if other components of the tamping device are relevant for detecting the movement behavior.

With the aid of the control device, the stroke and speed of the linear actuator can be changed or programmed as desired within the physical limits. As a result, the single impact energy and the impact number are determined independently. Due to suitable criteria, adaptation to the ground, in particular to the soil to be compacted, is possible. For example, if the return is very high, this indicates an already well-compacted bottom so that the amplitude can be reduced. At the same time, it may be useful, for example, to increase the frequency of the stroke, so that the rammer can be guided faster from the well-compacted area into the area still to be compacted, so that working time can be saved.

Even individual, for the operator difficult to predict and thus difficult to control high jumps, for example, when hitting a large stone, can be actively counteracted by the subsequent Hubanregung lower. Thus, a constant, uniform pitching movement, adaptive adapted to the underground behavior, reachable.

The rammer is in this way much better and above all safer to guide. The hand-arm vibrations improve, since the vibrations of the ramming system and thus the suggestions of the handle system or the guide bracket by random shocks or overload operation on a hard surface, each with high amplitudes, are reduced or not even occur. A further advantage, in particular with battery-operated rammers, is that no energy is unnecessarily introduced into an already compacted soil.

For operating a tamping device, as stated above, the linear drive can be controlled such that it is operated over a predetermined period of time according to a predetermined characteristic with at least one variable parameter. It is thus possible, for example, to start up the linear drive along the characteristic curve in order to start the stamping process safely.

In one embodiment, the variable parameter is the frequency and / or the amplitude of the linear rotor, so that the linear drive is operated over the predetermined period of variable frequency and / or amplitude.

The change of frequency or amplitude can be suitable in particular for starting up, ie starting the rammer. It can first be started with a low amplitude at a high frequency to then - for example, after a predetermined period or slowly increasing - to go from this operating condition in the typical tamping operation with high amplitude at low frequency. The operator can adjust to the resulting movements and forces in this starting period. A surprise of the operator by sudden high forces or fast movements is excluded.

To stop the operation of a tamping device, the linear drive for stopping the movement of the linear rotor can be operated electromagnetically. As a result, the ramming can be switched off quickly. Since the moving masses are small in comparison to a ramming system driven by a rotary motor, the ramming process can be brought to a standstill clearly within one cycle, which is particularly important in dangerous situations. In contrast, conventional rammers often require trailing several strokes (for example, three to four strokes) until they finally come to a halt.

These and other advantages and features will be explained in more detail below by way of example with the aid of the accompanying figures. Show it:

1 a stamping device according to the invention in a schematic representation;

2 a variant of the stamper; and

3 a known from the prior art tamping device.

1 shows a stamper, with an upper mass 1 and a lower mass, also referred to as stamp foot 2 , The lower mass 2 is relative to the upper mass 1 linearly movable back and forth to effect a ramming movement for soil compaction.

At the upper mass 1 is a guide handle 3 attached as a guide device for an operator. The guide handle 3 For example, it may be configured as a guide bracket relative to the upper mass 1 is swinging, so that the guide handle 3 from the vibrations of the upper mass 1 is decoupled. In this way, the operator can conveniently perform the tamping device (also referred to as rammer) in a proven manner.

Between the upper mass 1 and the lower mass 2 acts an electrodynamic linear drive 4 , The linear drive 4 is designed as a linear electric motor and has a stator 5 and an axially back and forth, so oscillating movable linear rotor 6 on. The stator 5 is at the upper mass 1 attached and as far as part of the upper mass 1 , In contrast, the linear rotor 6 on a pestle 7 attached, in turn, with serving as a ramming plate for soil compaction bottom contact element 8th is positively coupled or rigidly coupled. Thus exists between the linear rotor 6 over the pestle 7 a positive or rigid coupling with the ground contact element 8th , The linear rotor 6 can therefore be considered part of the lower mass 2 be understood.

The linear drive 4 can be designed as a switched reluctance motor, in which the linear rotor 6 consists of a laminated core, which is very robust against impact. In addition, it is also possible to use the linear drive 4 to design as a brushless DC motor, which must then be carried out according to robust.

At the upper end of the linear rotor 6 is an upper spring device 9 arranged, which is the linear rotor 6 against the upper mass 1 , for example, a corresponding, to the upper mass 1 belonging housing 10 supported. Accordingly, on the opposite end face of the linear rotor 6 a lower spring device 11 provided with the bottom of the linear rotor 6 against the case 10 the upper mass 1 is supported.

The upper spring device 9 and the lower spring means 11 together form a rotor spring device, with the direction reversal of the linear rotor 6 in its extreme points is supported by the oscillating reciprocating motion of the linear motor 6 to enable. With the help of the rotor spring means considerable electrical energy in the operation of the linear drive 4 be saved.

Due to the rigid coupling of the linear rotor 6 with the ground contact element 8th is it possible to control the movement of the linear rotor 6 directly on the ground contact element 8th transferred to. With appropriate control of the linear drive 4 Thus, any or at least variable movement forms of the ground contact element can 8th be achieved. In particular, the frequency or the amplitude of the stroke of the linear rotor 6 and thus the ground contact element 8th be adjusted during operation to the movement behavior of the ground contact element 8th to adapt to the soil to be compacted. If, for example, the soil is already highly compacted and thus correspondingly hard, the amplitude of movement of the linear rotor can 6 or the ground contact element 8th be reduced to avoid jumping of the rammer. On the other hand, the movement frequency can be increased, for example, to move the rammer quickly across the already compacted soil.

For a soft ground z. B. a large amplitude of motion can be adjusted to achieve a good tamping and thus compaction effect.

With the help of a controller, not shown, it is possible to use the linear drive 4 z. B. via a motor controller in a suitable manner. The adjustment can be made by the operator from the outside. Additionally or alternatively, it is possible to form the controller as a control device, so that with the help of suitable detectors, for example with the aid of acceleration sensors, the behavior of the rammer can be monitored, so that subsequently automatically adjusting the ramming parameters by adjusting the linear drive 4 is feasible.

2 shows a variant of the rammer of 1 ,

While with the rammer of 1 the linear rotor 6 is rigidly or positively coupled to the ground contact element is in the embodiment of 2 between the linear rotor 6 carrying pestle 7 and the lower mass 2 with the ground contact element 8th a plunger-spring device 12 intended. The plunger spring device 12 is known in its operation in principle from the prior art. The pestle 7 carries a pestle plate 13 , on whose end faces in each case a spring device 14 . 15 is provided. The spring devices 14 . 15 are opposite a guide tube 16 the lower mass 2 supported.

The oscillating linear motion of the linear rotor 6 is thus above the plunger 7 and the pestle plate 13 on the spring devices 14 . 15 which, in turn, transfer the movement to the lower mass 2 with the ground contact element 8th pass on. In this way it is possible to use the linear rotor 6 mechanically relieve, by using the stamp foot, that is, the lower mass 2 is elastically coupled.

The spring devices 14 . 15 the plunger-spring device 12 can be designed to be relatively stiff in order to achieve only interception of impact peaks, so that the linear rotor 6 is protected from overheating. However, it is also possible, the plunger-spring device 12 softer or more elastic, to provide a tamping plunger construction as in rammers known from the prior art ( 3 ) with high energy buffering in the spring coupling elements (spring devices 14 . 15 ) to reach.

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 102010052243 A1 [0011]
• CN 101196003 A [0012, 0024]

Claims (10)

Tamping device for soil compaction, with - an upper mass ( 1 ); One of a ground contact element ( 8th ), relative to the upper mass ( 1 ) movable lower mass ( 2 ); and with - one between the upper mass ( 1 ) and the lower mass ( 2 ) acting drive; where - the drive is a linear drive ( 4 ) with a stator ( 5 ) and an axially reciprocable linear rotor ( 6 ) having; - the stator ( 5 ) at the upper mass ( 1 ) is provided; and where - the linear rotor ( 6 ) with the lower mass ( 2 ) is positively coupled. Tamping device according to claim 1, characterized in that at least on one end face, in particular on both opposite end faces of the linear rotor ( 6 ) each have a rotor spring device ( 9 . 11 ) is provided for assisting the reverse movement of the linear rotor ( 6 ) in the reversal points. Tamping device for soil compaction, with - an upper mass ( 1 ); One of a ground contact element ( 8th ), relative to the upper mass ( 1 ) movable lower mass ( 2 ); and with - one between the upper mass ( 1 ) and the lower mass ( 2 ) acting drive; where - the drive is a linear drive ( 4 ) with a stator ( 5 ) and an axially reciprocable linear rotor ( 6 ) having; - the stator ( 5 ) at the upper mass ( 1 ) is provided; - the linear rotor ( 6 ) with the lower mass ( 2 ) is coupled; and wherein - at least on one end face, in particular on both opposite end faces of the linear rotor ( 6 ) each have a rotor spring device ( 9 . 11 ) is provided for assisting the reverse movement of the linear rotor ( 6 ) in the reversal points. Pounding device according to claim 3, characterized in that in the power flow between the linear rotor ( 6 ) and the lower mass ( 2 ) a plunger-spring device ( 12 ) is provided for transmitting the movement of the linear rotor ( 6 ) on the lower mass ( 2 ). Tamping device according to one of the preceding claims, characterized in that the one rotor spring device ( 9 . 11 ) or the two rotor spring devices ( 9 . 11 ) functionally between the linear rotor ( 6 ) and the upper mass ( 1 ) are provided. Tamping device according to one of the preceding claims, characterized in that the rotor spring device ( 9 . 11 ) and / or the plunger spring device ( 12 ) have a variable spring characteristic. Tamping device according to one of the preceding claims, characterized in that the linear drive ( 4 ) is an electric motor selected from the group reluctance motor, brushless DC motor. Tamping device according to one of the preceding claims, characterized by a vibration detection device for detecting the movement behavior of at least one component of the tamping device, wherein the component is selected from the group of upper mass ( 1 ), Lower mass ( 2 ), Relative movement between upper mass ( 1 ) and lower mass ( 2 ), at the upper mass ( 1 ) attached guide device ( 3 ) for guiding the tamping device by an operator. Tamping device according to one of the preceding claims, characterized by a control device for controlling the frequency and / or the amplitude of the movement of the linear rotor ( 6 ). Tamping device according to one of the preceding claims, characterized in that the control device is designed as a control device for monitoring a movement behavior of the tamping device due to the detected by the vibration detection device actual movement behavior of the component of the tamping device, wherein - by the control device, a deviation of the actual movement behavior of a predetermined Target movement behavior is recognizable, and - by the control device, the frequency and / or the amplitude of the movement of the linear rotor ( 6 ) is controllable to reduce the deviation.

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