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 compactor 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. State of the art

[0002] Attachment compactors of the type described here typically comprise an upper carriage and an undercarriage elastically connected to the upper carriage, which includes a compactor plate, as well as a drive for a vibration exciter. The latter is designed to cause the compactor plate, which is elastically coupled to the upper carriage, to vibrate. The attachment compactor comprises a fastening device by means of which it can be attached, preferably to an arm of a construction or agricultural machine. Attached to an arm, the attachment compactor can be moved to a location to be compacted and, if necessary, pressed onto the subsoil to be compacted using a pressure force exerted by the attached machine. Attachment compactors are therefore ideally suited for compacting difficult-to-access 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 add-on compactor can preferably be operated via a hydraulic connection that is usually 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 a hydraulic fluid can be directed in alternating flow directions, for example to open or close an excavator bucket.

[0005] The hydraulic pressure generated by the construction machine is applied to the hydraulic lines in one or the other flow direction via a multi-way valve, which can be operated, for example, via a control lever located in the operator's cab of the construction machine. Depending on the attached attachment, this can cause an excavator bucket to open or close, a grab to rotate left or right, a lift to raise or lower, or similar operations.

[0006] When operating an add-on compressor, the variable-direction volume flow is typically used to drive the vibration exciter, whereby its direction of rotation is irrelevant to its basic function. However, as described in DE102010021961A1, for example, the two different directions of rotation can be used to generate two vibrations of different intensity and amplitude.

[0007] For this purpose, the vibration exciter can be equipped with a so-called reversing weight, which can assume two different positions depending on the direction of rotation of an unbalanced shaft. This can increase or decrease the imbalance that determines the vibration amplitude depending on the direction of rotation. The add-on compressor can thus operate in two modes.

[0008] However, as described in DE102010021961A1, the handling weight can also assume an indifferent position in arrangements operating according to this basic principle, whereby the position in which the handling weight 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 add-on compactor that is improved compared to the prior art.

[0010] 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.

[0011] According to the invention, an attachment compactor for compacting a subsoil is provided, with a fastening device by means of which it can be connected as an attachment to a construction machine, in particular an excavator, with a compactor plate which is arranged for compacting a subsoil, with a hydraulic connection via which a directionally variable volume flow of a hydraulic fluid can be supplied by the construction machine and with a vibration exciter which is arranged and configured to cause the compactor plate to vibrate and which can be driven via the hydraulic connection by means of the volume flow, wherein the add-on compactor has a hydraulic circuit which comprises a hydraulic rectifier and is designed such that a first part H of the directionally variable volume flow which can be supplied via the hydraulic connection is directed in the same direction as its flow direction to a drive of the vibration exciter, and a second part N of the directionally variable volume flow which can be supplied is directed in a non-rectified manner to a device for adjusting the amplitude of the vibration exciter.

[0012] In other words, it is provided that a portion N of a volume flow that can be provided via the hydraulic connection is branched off in the form of a secondary flow, which is fed to a device for amplitude adjustment. A portion H, which can, for example, comprise the entire volume flow minus the secondary flow, or after being combined with the previously branched secondary flow, even the entire volume flow, is fed in the form of a main flow to the drive of the vibration exciter, which is preferably designed as a hydraulic motor. In special cases, portions N and H can also be identical, so that the volume flow first flows through the device for amplitude adjustment and then the drive of the vibration exciter, or in the reverse order if the flow direction is reversed. In this special case, a main branch is interrupted behind the branching of the secondary flow into a secondary branch.Even in this special case, the hydraulic rectifier can be connected upstream of the drive.

[0013] The add-on compressor according to the invention has the advantage that the drive and the amplitude adjustment are separate from each other. By means of an amplitude adjustment device driven by a separate volume flow, an amplitude adjustment is possible that is essentially independent of the main flow and thus of the operation of the vibration exciter drive. Adjusting the amplitude can generally be achieved by a targeted or guided shift of the handling weight and / or by another method known from the prior art.

[0014] With a device fed by a secondary flow for adjusting the amplitude of the vibration exciter, the add-on compressor has the property of being able to decouple an adjustment of the amplitude of the vibration exciter from a drive of the vibration exciter.

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

[0016] Operating the vibration exciter drive 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; temporarily remaining in a rest position between "left rotation" and "right rotation" is not in line with everyday practice. The abrupt change of direction is correspondingly stressful for the mechanical system. If the system also has a reversing weight, this usually strikes a driver rotating in the opposite direction with a loud, clearly audible bang.Overall, the design of the add-on compressor is subjected to extreme stress by rapid switching of operating modes.

[0017] Such stress is eliminated with an add-on compressor with a unidirectional flow rate. A similarly designed mechanism exhibits much lower wear and thus a significantly longer service life.

[0018] In an advantageous embodiment of the add-on compressor, it has four backflow preventers arranged in the form of a Graetz circuit or an electrical bridge rectifier to rectify the variable-direction volume flow. Such a hydraulic rectifier design can be achieved with cost-effective components without high pressure losses.

[0019] Furthermore, in an advantageous embodiment of the add-on compressor, the device for adjusting the amplitude can assume at least two different positions, the assumption of which alternates depending on the direction of the variable-flow volume. The two amplitude settings can be adjustable independently of the flow rate and solely dependent on the flow direction.

[0020] Furthermore, the add-on compressor can be designed such that the vibration exciter has at least two interconnected, synchronously or counter-synchronously rotating unbalanced shafts, the phase of a first of which can be adjusted relative to a second by up to half a turn. The phase adjustment can be continuous or quasi-digital, each associated with a flow direction. This can be done such that, for a volume flow in a first flow direction, the unbalanced shafts are not adjusted relative to each other, and for a volume flow in a second flow direction opposite to the first, the unbalanced shafts are adjusted relative to each other by half a turn.

[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 unbalanced shafts only add up proportionally.

[0022] If the volume flow can be controlled not only in its direction but also in its pressure or volume, for example, an adjustment angle between the unbalance shafts could be reduced at the same time as the volume flow increases, so that both the vibration frequency and the vibration amplitude could be increased in parallel.

[0023] If such control is not available on the construction machine, the amplitude adjustment can be very simple and stable digitally provided for two alternating settings, one of which allows the unbalanced shafts to rotate relative to each other without rotation, and the other to rotate by half a turn. In terms of its effect, this essentially corresponds to that of a handling weight, with the advantage that the weight cannot move freely and no undefined, random intermediate positions of the weight can occur. The unbalanced shafts can rotate in two defined states, advantageously, for example, adding or subtracting each other.

[0024] In an advantageous embodiment, the add-on 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 that is adjusted 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 adjusting the amplitude, have a phase position that is adjusted by half a turn compared to a second position of the device for adjusting the amplitude.

[0025] The unbalanced shafts can advantageously be coupled via a spindle or a spiral sleeve, whereby an adjustment of the phase position between the unbalanced shafts can be achieved by rotating the spindle or the spiral sleeve. In this way, a rotational rotation can be achieved by a translational displacement. For this purpose, an adjusting pin can engage in a groove in the spindle or in a spiral groove in 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 achieve an adjustment of the phase position between the unbalanced shafts.

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

[0027] Alternatively, the opposite is also possible: with an adjusting pin that is fixed axially against movement along the shaft axis, the spiral sleeve can be displaced and thus a translational movement can be converted into a rotational rotation.

[0028] In a further 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 twist can be achieved by an axial displacement of the adjusting pin and the spindle or spiral sleeve in opposite directions to each other.

[0029] Furthermore, the add-on compressor can also have more than two unbalanced shafts. For example, to reduce mechanical loads, such as those on the shaft bearings, the add-on compressor can have a plurality of smaller unbalanced shafts with comparatively smaller imbalances instead of a few shafts each with a relatively large imbalance. The sizes of the imbalances are advantageously selected such that the cumulative effect of one or more unbalanced shafts is unequal to the cumulative effect of the one or more remaining unbalanced shafts in their phase position relative to the one or more other unbalanced shafts that can be adjusted.

[0030] To balance the hydraulic volume flows and to protect the units, such as the drive motor and the cylinders for amplitude adjustment, the add-on 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 has a pressure limiter, which, from the perspective of the hydraulic connection, is located downstream of the bridge rectifier between the pressure line and the return line. Downstream of the bridge rectifier, the volume flow is always directed in the same direction, making it possible to cost-effectively limit the pressure in the entire add-on compressor with just one pressure limiter that blocks on one side and opens when a specified maximum pressure is exceeded. This allows pressure peaks from a hydraulic system of the machine to which the add-on compressor may be connected to be limited by directly diverting corresponding volumes into the return line.

[0032] A pressure limiter arranged in this way can advantageously limit the pressure in a parallel section of the hydraulic circuit. Another particularly advantageous feature is the option of arranging the pressure limiter in close proximity, virtually parallel to the drive motor, so that the pressure limiter offers effective protection, especially 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 downstream of the bridge rectifier in series with the drive. A throttle arranged downstream of the bridge rectifier is also arranged downstream of any branching and division of the volume flow into a part H, the main flow, and a part N, the secondary flow. With the help of a throttle arranged at this point, two tasks can be achieved with just one component: one of which is a possibly necessary or desirable throttling of the motor power of the drive, and the other is a possibly necessary hydraulic balancing of the volume flows between the main flow and the secondary flow.

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

[0035] On the one hand, these components can provide a protective effect for the amplitude adjustment device and, on the other hand, enable or support a hydraulic balancing between the main flow and the secondary flow.

[0036] Relief and / or leakage currents from the pressure limiters can advantageously be channeled via non-return valves into the hydraulic line serving as the return line. This can be done particularly advantageously via the same non-return valves that also form part of the bridge rectifier, so that they have dual use and are flowed through by both the secondary flow of the amplitude adjustment and the main flow of the drive. Drawings

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

[0038] It shows Fig. 1 shows a perspective drawing of an embodiment of the described add-on compressor; Fig. 2 shows an embodiment of a hydraulic circuit of the described add-on compressor; Fig. 3 shows a view from below into an opened drive housing of an embodiment of the add-on compressor; Fig. 4 shows the 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 embodiment of the described add-on compressor is shown in perspective.

[0040] Fig 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 compactor plate 3, which is arranged for compacting a subsoil.

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

[0042] The attachment compactor 1 comprises an upper carriage 5, on which the fastening device 2 is arranged, and an undercarriage 6 coupled to the upper carriage 5 via damping elements 7. In the undercarriage 6, a vibration exciter 8 with three unbalanced shafts 91, 92 is arranged on the compactor plate 3. Of these, a central unbalanced shaft 92 can be adjusted in phase by half a turn by means of a device 10 for adjusting the amplitude.

[0043] Out of Fig. 2 a hydraulic circuit of the add-on compressor 1 can be seen, which comprises a hydraulic rectifier 11-12-13-14 and is designed such that a first part H of the directionally variable volume flow that can be supplied via the hydraulic connection 4 is directed in the same direction of flow to a drive 15 of the vibration exciter 8, and a second part N of the directionally variable volume flow that can be supplied (not rectified) 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 directionally variable volume flow are arranged in the form of a Graetz circuit, i.e. in the form of an electrical bridge rectifier.

[0044] The amplitude adjustment device 10 can assume two positions, the positions of which alternate depending on the direction of the variable-direction flow. If a line connected to connection point A of the hydraulic connection 4 is pressurized, a cylinder connected to connection point D can push a piston in direction 17. If a line connected to connection point B of the hydraulic connection 4 is pressurized, a cylinder connected to connection point C can push a piston in direction 18.

[0045] In this case, respective relief flows can be returned to the line serving as a return line to the hydraulic connection 4 via the adjustable pressure relief valves 19 and 20 as well as via the non-return valves 13 and 14, which are also part of the bridge rectifier 11-12-13-14.

[0046] Almost parallel to the hydraulic connection 4, but 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 add-on compressor 1 has an adjustable pressure limiter 23 which protects the units of the add-on compressor 1, in particular the hydraulic motor 15 and the cylinders of the amplitude adjustment 10.

[0047] From the perspective of the hydraulic connection 4, the pressure limiter 23 is arranged behind the bridge rectifier 21-22-13-14 between the pressure line, also called the supply line, and the return line.

[0048] Furthermore, the add-on compressor 1 has an orifice or throttle 24, 25 in each of the line branches serving as pressure lines, with which a speed limitation and / or hydraulic balancing between branches H and N can be achieved depending on the flow direction. To adjust different oscillation frequencies, the orifices or throttles 24, 25 can be designed in different sizes. In addition to and / or in mutual coordination with these, hydraulic balancing can be achieved by the pressure limiters 19 and 20 arranged in the non-rectified secondary branch N.

[0049] Fig. 3 provides a view of the drive housing of the add-on compressor 1, opened from below, in which three unbalanced shafts 91, 92 are visible, synchronously coupled via equally sized gears. These are 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 in the same phase position on the back of the shafts. Fig. 3 Not visible, however, the unbalanced shaft 92, which is connected to the central gear via a spiral groove, can be rotated by half a turn relative to the unbalanced 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 unbalanced shaft 92, whose phase position is adjustable relative to the outer unbalanced shafts 91, is not equal to the cumulative effect of the outer unbalanced shafts 91.

[0050] 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.

[0051] The 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 unbalanced shaft 92 is synchronously coupled via a spiral sleeve 40 to the gear shown in the center and thus to the outer unbalanced shafts 91.

[0052] In a first variant, the spiral sleeve 40 has an external spiral groove 41, in which an adjusting pin 42 connected to the gear engages. If the sleeve 40 is displaced in the axial direction by the cylinders 51 or 52, the spiral groove 41 causes the spiral sleeve 40 to rotate relative to the driving gear. As a result, the phase position of the weights 32 can be changed by up to half a turn 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 directionally variable volume flow, an axial adjustment of the spiral sleeve 40 and thus a phase change of the unbalanced shaft 92 relative to the outer unbalanced shafts 91 can be effected.

[0053] 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 from the inside and is rotated by the spiral groove 41 upon displacement along the unbalanced shaft 92. The adjusting pin 42, guided in a slot in the unbalanced shaft 92, thus rotates the unbalanced shaft 92 without axially displacing it. However, it causes a phase change of the unbalanced shaft 92 relative to the gear and the unbalanced shafts 91 coupled to it. 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. 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 compactor 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 with a vibration exciter (8) which is designed to set the compactor plate (3) in vibration and which can be driven via the hydraulic connection (4) by means of the volume flow, characterized in thatthe add-on compressor (1) has a hydraulic circuit which comprises a hydraulic rectifier (11-12-13-14) and is designed such that a first part of the directionally variable volume flow which can be supplied via the hydraulic connection (4) is directed in the same direction in its flow direction to a drive (15) of the vibration exciter (8), and a second part of the directionally variable volume flow which can be supplied is directed in a non-rectified manner to a device (10) for adjusting the amplitude of the vibration exciter (8).

2. Attachment compressor (1) according to claim 1, characterized in that the add-on compressor (1) has four non-return valves (11), (12), (13), (14) for rectifying the directionally variable volume flow, which are arranged as bridge rectifiers (11-12-13-14) in the form of a Graetz circuit.

3. Attachment compressor (1) according to one of the preceding claims, characterized in thatthe device for adjusting the amplitude (10) can assume at least two positions, the assumption of which depends alternately on the direction of the direction-variable volume flow.

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

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

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

7. Attachment compressor (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. Attachment compressor (1) according to claim 7, characterized in that- with an 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 an axially fixed adjusting pin (42), an axial adjustment of the spindle or spiral sleeve (40), - or an axial displacement of the adjusting pin (42) and spindle or spiral sleeve (40) in opposite directions, can be effected bidirectionally by means of the directionally variable volume flow.

9. Attachment compressor according to one of claims 5 to 8, characterized in that in the case of more than two unbalanced shafts (91), (92), the cumulative effect of one or more unbalanced shafts (92) whose phase position is adjustable relative to the other one or more unbalanced shafts (91) is not equal to the cumulative effect of the other one or more unbalanced shafts (91).

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

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

13. Attachment compressor (1) according to one of the preceding claims, characterized in thatLeakage flows and / or relief flows are directed via non-return valves (13), (14) into the hydraulic line serving as the return.

14. Attachment compressor (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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