Mounted compactor

Abstract

The invention relates to an attachment compactor (1) for compacting a subsoil, with a fastening device (2) by means of which it can be connected as an attachment to a construction machine, in particular an excavator, with a compaction plate (3) which is arranged for compacting a subsoil, with a hydraulic connection (4) via which a directionally variable volume flow of a hydraulic fluid can be supplied from the construction machine and a vibration exciter (8) which is arranged to set the compaction plate (3) into vibration and which can be driven via the hydraulic connection (4) by means of the volume flow.According to the invention, the attached compressor (1) has a hydraulic circuit comprising a hydraulic rectifier (11-12-13-14) and is designed such that a first part of the variable-flow volume flow that can be supplied via the hydraulic connection (4) is directed in the same direction as the flow to a drive (15) of the vibration exciter (8), and a second part of the variable-flow volume flow that can be supplied is directed in a different direction to a device (10) for adjusting the amplitude of the vibration exciter (8).

Description

[0001] The invention relates to an attachment compactor with a compaction plate for compacting a subsoil, which can be connected as an attachment to a construction machine, in particular an excavator, by means of a fastening device and is basically known from the generic document DE10 2009018490 A1. State of the art

[0002] Attachment compactors of the type described here typically consist of an upper carriage and an elastically connected lower carriage containing a compaction plate, as well as a drive for a vibration exciter. The latter is designed to set the elastically coupled compaction plate into vibration. The attachment compactor has a mounting device by means of which it can preferably be attached to an arm of a construction machine or agricultural machine. Attached to an arm, the attachment compactor can be moved to the area to be compacted and, if necessary, pressed down onto the ground to be compacted by means of a pressure force exerted by the connected machine. Attachment compactors are therefore very well suited for compacting hard-to-reach areas, such as the subsoil in a narrow trench.

[0003] The drive of the vibration exciter is usually designed as a hydraulic motor, so that the attached compressor can preferably be operated via a hydraulic connection that is usually already present on the construction machine.

[0004] The hydraulic connection is usually designed in the form of two hydraulic lines and an optional leak line, through which a volume flow of hydraulic fluid can be directed in alternating flow directions, for example to open or close an excavator bucket.

[0005] The hydraulic lines are pressurized with hydraulic pressure generated by the construction machine, directing the flow in one direction or the other, via a multi-way valve, which can be operated, for example, by a control lever located in the operator's cab of the construction machine. Depending on the attached attachment, this allows for opening or closing an excavator bucket, rotating a grapple left or right, raising or lowering a lift, or similar actions.

[0006] When operating an attachment compressor, the variable-direction volume flow is generally used to drive the vibration exciter, the direction of which is irrelevant for its basic function. However, as described, for example, in DE102010021961A1, the two different directions of rotation can be used to generate two vibrations of different intensities and amplitudes.

[0007] The vibration exciter can incorporate a so-called counterweight, which assumes two different positions depending on the direction of rotation of an unbalanced shaft, thus increasing or decreasing the imbalance that is crucial for the vibration amplitude, depending on the direction of rotation. The attached compressor can therefore be operated in two modes, so to speak.

[0008] As described in DE102010021961A1, the counterweight in arrangements operating according to this basic principle can also assume an indifferent position, which means that the position in which the counterweight increases the imbalance of the unbalance shaft cannot be reliably guaranteed. Disclosure of the invention

[0009] The object of the present invention is to provide a solution for an attachment compactor that is improved compared to the prior art.

[0010] The problem is solved according to the invention by the features of the independent claim. Advantageous embodiments of the invention are specified in the dependent claims.

[0011] According to the invention, an attachment compactor for compacting a subsoil is provided, comprising a mounting device by means of which it can be connected as an attachment to a construction machine, in particular an excavator, a compaction plate arranged for compacting a subsoil, a hydraulic connection through which a directionally variable volume flow of hydraulic fluid can be supplied from the construction machine, and a vibration exciter which is arranged and configured to set the compaction plate into vibration and which can be driven via the hydraulic connection by means of the volume flow, wherein the attachment compactor has a hydraulic circuit which includes a hydraulic rectifier and is designed such that a first part H of the directionally variable volume flow supplied via the hydraulic connection is directed in the same direction as the flow to a drive of the vibration exciter.and a second part N of the supplyable variable-direction volume flow is not directed in the same direction to a device for adjusting the amplitude of the vibration exciter.

[0012] In other words, it is intended that a portion N, in the form of a bypass flow, is diverted from a volume flow supplied via the hydraulic connection and fed to an amplitude adjustment device. A portion H, which may, for example, comprise the entire volume flow minus the bypass flow, or, after merging with the previously diverted bypass flow, the entire volume flow, is fed as a main flow to the drive of the vibration exciter, which is preferably a hydraulic motor. In a special case, portion N and portion H can also be identical, so that the volume flow first passes through the amplitude adjustment device and then through the drive of the vibration exciter, or, in the reverse order if the flow direction is reversed, through the drive. In this special case, a main branch is interrupted downstream of the branch where the bypass flow splits into a secondary branch.Even in this special case, the hydraulic rectifier can be connected upstream of the drive.

[0013] The attachment compressor according to the invention has the advantage that the drive and the amplitude adjustment are separated from each other. By means of a device for amplitude adjustment, driven by a separate volume flow, an amplitude adjustment that is in principle independent of the main flow and thus of the operation of the vibratory exciter drive is possible. An adjustment of the amplitude can, in principle, be effected by a targeted or guided displacement of the conveying weight and / or by another method known from the prior art.

[0014] With a device powered by a bypass current for adjusting the amplitude of the vibration exciter, the attached compressor has the property of being able to decouple an adjustment of the amplitude of the vibration exciter from a driving of the vibration exciter.

[0015] This decoupling makes it possible to always rotate the vibration exciter drive in the same direction. For this purpose, the hydraulic circuit can advantageously include a hydraulic rectifier, through which the portion H of the variable volume flow is supplied to the vibration exciter drive in the same direction.

[0016] Operating the vibration exciter with a rectified flow rate offers several advantages. With a non-rectified drive of a vibration exciter according to the state of the art, switching from a first operating mode with a low vibration amplitude and, for example, a high vibration frequency to a second operating mode with a higher vibration amplitude and, for example, a lower vibration frequency, always involves a change in the direction of rotation of the hydraulic drive. This change of direction usually occurs abruptly; a temporary pause in a rest position between a "counterclockwise" and a "clockwise" rotation is not standard practice. The abrupt change of direction is therefore quite stressful for the mechanism. If this mechanism also has a counterweight, it usually strikes a drive element rotating in the opposite direction with a loud, clearly audible bang.Overall, the design of the attachment compactor is subjected to extreme stress due to the rapid switching between operating modes.

[0017] This type of stress is eliminated with an attachment compressor that has a rectified flow rate. An otherwise similarly designed mechanism exhibits significantly less wear and tear, resulting in a considerably longer service life.

[0018] In an advantageous embodiment of the add-on compressor, it features four backflow preventers for rectifying the variable flow rate. These preventers are arranged in the form of a Graetz bridge rectifier or an electrical bridge rectifier. Such a hydraulic rectifier design can be achieved with cost-effective components and without high pressure losses.

[0019] Furthermore, in an advantageous embodiment of the attachment compressor, the amplitude adjustment device can assume at least two different positions, the adoption of which depends alternately on the direction of the variable volume flow. The two amplitude settings can be adjusted independently of the flow rate, solely depending on the flow direction.

[0020] Furthermore, the attached compressor can be designed such that the vibration exciter has at least two coupled, synchronously or counter-rotating eccentric shafts, the phase of which of the first shafts can be adjusted relative to the second shaft by up to half a rotation. This phase adjustment can be continuous or quasi-digital, each assigned to a specific flow direction. This can be achieved such that, with a volume flow in a first flow direction, the eccentric shafts remain unadjusted relative to each other, while with a volume flow in a second, opposite flow direction, the eccentric shafts are adjusted relative to each other by half a rotation.

[0021] With a continuous adjustment of the phase, adjustment angles of less than half a turn would of course also be conceivable, so that the imbalances of the unbalance shafts only add up proportionally.

[0022] If the volume flow is controllable not only in its direction but also in its pressure or volume, then, for example, with increasing volume flow, an adjustment angle between the unbalanced shafts could be reduced at the same time, so that both vibration frequency and vibration amplitude could be increased in parallel.

[0023] If the construction machine lacks such controllability, the amplitude adjustment can very simply and reliably provide two alternating digital settings. In one setting, the unbalanced shafts have no rotation relative to each other, while in the other, they rotate by half a turn. This essentially corresponds to the effect of a counterweight, with the advantage, however, that the weight cannot move freely and no undefined, random intermediate positions can occur. The unbalanced shafts can rotate in two defined states, advantageously, for example, summing or subtracting each other.

[0024] In an advantageous embodiment, the attachment compressor can thus be designed such that the two unbalanced shafts in a first of the positions of the device for adjusting the amplitude have a phase position offset by half a turn compared to a second position, that an adjustment of the phase position of the unbalanced shaft can be effected by means of the device for adjusting the amplitude, and that the two unbalanced shafts in a first position of the device for amplitude adjustment have a phase position offset by half a turn compared to a second position of the device for amplitude adjustment.

[0025] The unbalanced shafts can advantageously be coupled via a spindle or a spiral sleeve, whereby a rotation of the spindle or the spiral sleeve allows for an adjustment of the phase relationship between the unbalanced shafts. In this way, a rotational rotation can be effected by a translational displacement. For this purpose, an adjusting pin can engage in a groove of the spindle or in a spiral groove of the spiral sleeve, whereby an adjustment of the adjusting pin along a parallel axis of the spindle or on an axis within the spiral sleeve can effect an adjustment of the phase relationship between the unbalanced shafts.

[0026] In the case of a spindle or spiral sleeve fixed against axial displacement, bidirectional adjustment of the adjusting pin along a parallel axis to the spindle, or along the axis within the spiral sleeve, by means of the changing volume flow, can be achieved very easily, for example by pistons or cylinder pistons.

[0027] Alternatively, conversely, with an adjusting pin fixed axially against movement along the shaft axis, a displacement of the spiral sleeve can occur, thus converting a translational movement into a rotational twist.

[0028] In another variant, both the spindle or spiral sleeve on the one hand and the adjusting pin on the other hand can be designed to be axially displaceable, and a rotational twisting can be achieved by an opposing axial displacement of the adjusting pin and the spindle or spiral sleeve.

[0029] Furthermore, the attachment compressor can also have more than two unbalanced shafts. For example, to reduce mechanical stress, such as that on the shaft bearings, the attachment compressor can have several smaller unbalanced shafts with comparatively smaller imbalances instead of a few shafts each with a relatively large imbalance. The magnitudes of the imbalances are advantageously selected such that the cumulative effect of one or more unbalanced shafts, in their phase relationship to the other one or more adjustable unbalanced shafts, is not equal to the cumulative effect of the other one or more unbalanced shafts.

[0030] To balance the hydraulic flow rates and to protect the components, such as the drive motor and the cylinders for amplitude adjustment, the attached compressor can advantageously have one or more throttles and one or more pressure limiters.

[0031] In an advantageous embodiment of the add-on compressor, it features a pressure limiter located downstream of the bridge rectifier, between the pressure line and the return line. Downstream of the bridge rectifier, the flow rate is always in the same direction, making it possible to limit the pressure throughout the entire add-on compressor cost-effectively with a single pressure limiter that closes on one side and opens when a predetermined maximum pressure is exceeded. This allows pressure peaks from the hydraulic system of the machine to which the add-on compressor may be connected to be limited by directly diverting the corresponding volumes into the return line.

[0032] A pressure limiter arranged in this way is particularly advantageous for limiting the pressure in a section of the hydraulic circuit with the same direction of travel. A further advantage is the option of positioning the pressure limiter in close proximity, virtually parallel to the drive motor, thus providing good protection for the drive motor.

[0033] In an advantageous embodiment of the add-on compressor, the add-on compressor has at least one, preferably variable, throttle, which, from the perspective of the hydraulic connection, is arranged in series with the drive downstream of the bridge rectifier. A throttle arranged downstream of the bridge rectifier is also located downstream of any branching and division of the flow rate into a portion H, the main flow, and a portion N, the bypass flow. With the aid of a throttle arranged at this point, two functions can be achieved with only one component: one of which is the potentially necessary or desirable throttling of the motor power of the drive, and the other of the potentially necessary hydraulic balancing of the flow rates between the main flow and the bypass flow.

[0034] In another or the same advantageous embodiment of the add-on compressor, the add-on compressor has at least one, preferably adjustable, pressure limiter in the non-coordinated secondary branch, which is arranged parallel to a pressure cylinder of the amplitude adjustment device, and / or a, preferably variable, throttle, which is arranged in series with the amplitude adjustment device.

[0035] These components can, on the one hand, provide protection for the amplitude adjustment device and, on the other hand, enable or support hydraulic balancing between the main flow and the secondary flow.

[0036] Relief and / or leakage flows from the pressure limiters can advantageously be routed via backflow preventers into the hydraulic line serving as the return line. This can be achieved particularly advantageously using the same backflow preventers that also form part of the bridge rectifier, thus enabling them to serve a dual purpose and be carried by both the bypass flow from the amplitude adjustment and the main flow from the drive. Drawings

[0037] The invention is explained in more detail below with reference to the attached schematic drawings and preferred embodiments. They show

[0038] Fig. 1 a perspective drawing of an embodiment of the described attachment compressor; Fig. 2 an embodiment of a hydraulic circuit of the described attachment compressor; Fig. 3 a view from below into an open drive housing of an embodiment of the attachment compressor; Fig. 4 a structure of a device for amplitude adjustment with two cylinders, a spiral sleeve with adjusting pin and an unbalanced shaft with weights.

[0039] Out of Fig. 1 An exemplary embodiment of the described attachment compactor is shown in perspective.

[0040] Fig 1 Figure 1 shows an attachment compactor 1 for compacting a subsoil, with a fastening device 2 by means of which it can be connected as an attachment to a construction machine, in particular an excavator, and with a compaction plate 3 which is arranged for compacting a subsoil.

[0041] Not shown for the sake of clarity, the attachment compactor 1 has a hydraulic connection 4 through which a directionally variable volume flow of hydraulic fluid can be supplied by the construction machine, which is also not shown.

[0042] The attachment compressor 1 has a superstructure 5, on which the mounting device 2 is arranged, and a substructure 6 coupled to the superstructure 5 via damping elements 7. In the substructure 6, a vibration exciter 8 with three unbalanced shafts 91, 92 is arranged on the compressor plate 3, one of which a central unbalanced shaft 92 can be adjusted in its phase by half a turn by means of a device 10 to adjust the amplitude.

[0043] Out of Fig. 2 A hydraulic circuit of the attached compressor 1 is shown, which includes a hydraulic rectifier 11-12-13-14 and is designed such that a first part H of the variable-flow volumetric flow supplied via the hydraulic connection 4 is directed in the same direction as the flow to a drive 15 of the vibration exciter 8, and a second part N of the variable-flow volumetric flow (not in the same direction) is directed to a device 10 for adjusting the amplitude of the vibration exciter 8. The four backflow preventers 11, 12, 13 and 14 for rectifying part H of the variable-flow volumetric flow are arranged in the form of a Graetz bridge rectifier, i.e., in the form of an electrical bridge rectifier.

[0044] The amplitude adjustment device 10 can assume two positions, the position of which alternates depending on the direction of the variable volume flow. If a line connected to connection point A of hydraulic port 4 is pressurized, a cylinder connected to connection point D can push a piston in the direction of 17. If a line connected to connection point B of hydraulic port 4 is pressurized, a cylinder connected to connection point C can push a piston in the direction of 18. In this process, the respective relief flows can be returned to the hydraulic port 4 via the adjustable pressure relief valves 19 and 20 and via the non-return valves 13 and 14, which are also part of the bridge rectifier 11-12-13-14.

[0045] Almost parallel to the hydraulic connection 4, but aligned on the pressure side via the non-return valves 21 and 22 and on the return side via the non-return valves 13 and 14, the attachment compressor 1 has an adjustable pressure limiter 23, which protects the units of the attachment compressor 1, in particular the hydraulic motor 15 and the cylinders of the amplitude adjustment 10.

[0046] From the perspective of the hydraulic connection 4, the pressure limiter 23 is located behind the bridge rectifier 21-22-13-14 between the pressure line, also called the supply line, and the return line.

[0047] Furthermore, the attached compressor 1 has an orifice or throttle 24, 25 in each of the pipe branches serving as pressure lines. These orifices or throttles allow for speed limitation and / or hydraulic balancing between branches H and N, depending on the flow direction. The orifices or throttles 24, 25 can be of different sizes to adjust for different vibration frequencies. Additionally, and / or in conjunction with these, hydraulic balancing can be achieved by the pressure limiters 19 and 20 located in the non-parallel branch N.

[0048] Fig. 3 The figure provides a view into the drive housing of the attached compressor 1, which is opened from below. Three unbalanced shafts 91, 92, synchronously coupled via equally sized gears, are visible inside. These shafts can be driven by the hydraulic motor 15 connected to one of the unbalanced shafts 91 and together form the vibration exciter 8. The outer unbalanced shafts 91 each have two semi-circular weights 31, and the inner unbalanced shaft 92 has two semi-circular weights 32. During rotation, the sum of the centrifugal forces generated by the weights 31 is greater than the sum of the centrifugal forces generated by the weights 32. In the present illustration, the unbalanced shafts 91, 92 have no phase shift relative to each other; all weights 31, 32 are located in the same phase position on the back side of the shafts. Fig. 3 Although not immediately apparent, the unbalance shaft 92, connected to the central gear via a spiral groove, is rotatable by half a turn relative to the unbalance shafts 91. Since the sum of the centrifugal forces generated by the weights 31 is greater than the sum of the centrifugal forces generated by the weights 32, the effect of the inner unbalance shaft 92, whose phase relationship relative to the outer unbalance shafts 91 is adjustable, is not equal to the sum of the effects of the outer unbalance shafts 91.

[0049] Fig. 4 shows the structure of a device for amplitude adjustment 10 with two cylinders 51, 52, a spiral sleeve 40 with adjusting pin 42 and an unbalance shaft 92 with weights 32.

[0050] The in Fig. 4The structure shown allows for two modes of operation, which differ in how the adjusting pin 42 and the spiral sleeve 40 are moved relative to each other. Basically, the unbalance shaft 92 is synchronously coupled to the centrally shown gear and thus to the outer unbalance shafts 91 via a spiral sleeve 40.

[0051] In a first embodiment, the spiral sleeve 40 has an external spiral groove 41 in which an adjusting pin 42, connected to the gear, engages. When the sleeve 40 is displaced axially by the cylinders 51 or 52, the spiral groove 41 causes the spiral sleeve 40 to rotate relative to the driving gear. This allows the phase position of the weights 32 to be changed by up to half a rotation relative to the phase position of the weights 31. With the adjusting pin 42 axially fixed and the cylinders 51 and 52 alternately subjected to the hydraulic pressure of the changing volume flow, an axial adjustment of the spiral sleeve 40, and thus a phase change of the unbalance shaft 92 relative to the outer unbalance shafts 91, can be achieved.

[0052] Alternatively, in a second variant, the spiral sleeve 40 can be axially fixed and rigidly connected to the gear and have an internal spiral groove 41. An adjusting pin 42 can engage in this groove from the inside, which is rotated by the spiral groove 41 when the unbalance shaft 92 is displaced along it. The adjusting pin 42, guided in an elongated hole in the unbalance shaft 92, thus rotates the unbalance shaft 92 without displacing it axially. However, this causes a phase shift of the unbalance shaft 92 relative to the gear and the coupled unbalance shafts 91. In this variant, the phase shift is achieved by means of the cylinders 51 and 52 through the axial displacement of the adjusting pin 42.

Claims

1. Mounted compactor (1) for compacting a ground, with a fastening device (2) by means of which it can be connected as an attachment to a construction machine, in particular an excavator, with a compaction plate (3) which is arranged for compacting a ground, with a hydraulic connection (4), via which a directionally variable volume flow of a hydraulic fluid can be supplied by the construction machine, and a vibration exciter (8), which is designed to set the compressor plate (3) into vibration, and which can be driven via the hydraulic connection (4) by means of the volume flow, characterized in that the compactor (1) has a hydraulic circuit, which includes a hydraulic rectifier (11-12-13-14) and is designed such that a first part of the directionally variable volume flow suppliable via the hydraulic connection (4), rectified in its flow direction, is directed to a drive (15) of the vibration exciter (8), and a second part of the directionally variable volume flow suppliable via the hydraulic connection (4), not rectified in its flow direction, is directed to a device (10) for adjusting the amplitude of the vibration exciter (8).

2. Mounted compactor (1) according to claim 1, characterized in that the mounted compactor (1) has four backflow preventers (11), (12), (13), (14) for rectifying the direction-changing volume flow, which are arranged as bridge rectifiers (11-12-13-14) in the form of a Graetz circuit.

3. Mounted compactor (1) according to one of the preceding claims, characterized in that the characterized in that the device for adjusting the amplitude (10) can assume at least two positions, the position of which alternately depends on the direction of the variable volume flow.

4. Mounted compactor (1) according to one of the preceding claims, characterized in that the vibration exciter (8) has at least two coupled, synchronously or counter-rotating synchronously unbalanced shafts (91), (92), of which a first one is adjustable in its phase by half a rotation relative to a second one.

5. Mounted compactor (1) according to claim 3 and claim 4, characterized in that an adjustment of the phase position of the first unbalance shaft (92) can be effected by means of the device for adjusting the amplitude (10), and that the two unbalance shafts (91), (92) in a first position of the device for adjusting the amplitude (10) have a phase position that is adjusted by half a turn compared to a second position of the device for adjusting the amplitude (10).

6. Mounted compactor (1) according to claim 5, characterized in that the unbalance shafts (91), (92) are coupled via a spindle or a spiral sleeve (40) and an adjustment of the phase position between the unbalance shafts (91), (92) can be achieved by rotating the spindle or the spiral sleeve (40).

7. Mounted compactor (1) according to claim 6, characterized in that an adjusting pin (42) engages in a groove of the spindle or in a spiral groove (41) of the spiral sleeve (40) and an adjustment of the phase position between the unbalance shafts (91), (92) can be achieved by a mutual axial adjustment of adjusting pin (42) and spindle or spiral sleeve (40).

8. Mounted compactor (1) according to claim 7, characterized in that - with axially fixed spindle or spiral sleeve (40), an adjustment of the adjusting pin (42) along an axis parallel to the spindle or along an axis in the spiral sleeve (40), or, - with axially fixed adjusting pin (42), an axial adjustment of the spindle or spiral sleeve (40), - or an opposing axial displacement of adjusting pin (42) and spindle or spiral sleeve (40), can be achieved bidirectional by means of the changing volume flow.

9. Mounted compactor (1) according to one of claims 5 to 8, characterized in that, in the case of more than two unbalance shafts (91), (92), the sum effect of one or more unbalance shafts (92) which are adjustable in their phase position relative to the other one or more unbalance shafts (91) is not equal to the sum effect of the one or more other unbalance shafts (91).

10. Mounted compactor (1) according to one of the preceding claims, characterized in that the mounted compactor (1) has a pressure limiter (23) which, from the perspective of the hydraulic connection (4), is arranged behind a bridge rectifier (21-22-13-14) between the pressure line and the return line.

11. Mounted compactor (1) according to one of the preceding claims, characterized in that the mounted compactor (1) has at least one, preferably variable, throttle (24), (25) which is arranged in series with the drive (15) from the perspective of the hydraulic connection (4) in or behind the bridge rectifier (21-22-13-14).

12. Mounted compactor (1) according to one of the preceding claims, characterized in that the mounted compactor (1) has at least one, preferably adjustable, pressure limiter (19), (20) in a non-coordinated secondary branch, which is arranged parallel to the device for amplitude adjustment (10).

13. Mounted compactor (1) according to one of the preceding claims, characterized in that leakage flows and / or relief flows are directed via backflow preventers (13), (14) into the hydraulic line used as the return flow.

14. Mounted compactor (1) according to claim 13, characterized in that these backflow preventers (13), (14) are part of the bridge rectifier (11-12-13-14).

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