EP3556942B1 - Cutter for making a diaphragma wall and method of making such wall - Google Patents

Description

The invention relates to a trench wall cutter for creating a milling slot in the ground with a milling frame, at least one pair of milling wheels which are rotatably mounted and driven on the milling frame, each milling wheel having a plurality of milling teeth along its outer circumference, and a discharge device with at least one discharge pump for discharging a milling fluid from the milling slot in the area of the milling wheels, according to the preamble of claim 1.

Furthermore, the invention relates to a method for creating a milling slot in the ground with such a trench cutter, the milling wheels being driven in rotation in a milling operation and the trench cutter being sunk into the ground and ground material being milled, the milling slot being created in the ground, in accordance with the preamble of Claim 11.

Such trench wall cutters are used to create so-called trench walls or sealing walls, which are required for securing or sealing construction pits, for example. Using a trench cutter, a first milling slot is created, which is filled with a hardenable mass. This mass cures to form a diaphragm wall segment. By lining up several diaphragm wall segments, a diaphragm wall of the desired size can be created.

From the EP 1 452 645 A1 shows a trench cutter to create a trench wall in the floor. A feed device opens between the two pairs of milling wheels, by means of which a settable liquid can be introduced into the milling slot in the area between the milling wheels. The supplied settable liquid is mixed by the rotary movement of the milling wheels with the milled soil material to form a hardenable mass, which then harden to form the diaphragm wall segment can. In this known method, the milled soil material is mixed directly in situ in the milling slot to form the hardenable mass.

Another method for producing a diaphragm wall segment in the floor is shown in FIG DE 41 41 629 A1 forth. In the trench wall cutter used for this purpose, a discharge device is provided between the cutter wheels, by means of which the milled soil material is sucked off immediately afterwards with the supporting liquid in the cutter slot. The suctioned-off suspension can be stripped of soil material in a separating device and returned to an upper area of the milling slot. The suspension can be prepared in such a way that it constitutes a hardenable mass which hardens in the milling slot to form the slot wall segment.

The shows further EP 0 253 726 A a trench cutter according to the preamble of claim 1.

When creating a milling slot using a trench cutter, there is basically the problem that when milling in cohesive soils, e.g. in clay, silt, claystone etc., the soil removed by the milling wheels adheres to the milling teeth of the milling wheels and can thus stick the milling wheels. This can lead to the bond being so strong that the trench cutter must be pulled out of the trench slot to mechanically clean the trimming wheels. Since milling slots can reach a depth of 80 meters and more, this is very time-consuming and therefore an economic disadvantage. The daily milling performance of a diaphragm wall milling machine can be markedly reduced as a result.

For loosening adhering soil material between annular rows of milling teeth on a milling wheel, it is approximately from the EP 2 685 007 A1 known to attach so-called reamer plates to the cutter wheel frame, which protrude into the spaces between the annular rows of cutter teeth. However, the scraper plates must maintain a certain distance from the cutting wheels and the cutting teeth, so that this can only partially remove adhering soil material.

From the generic EP 0 730 064 A1 shows a trench wall cutter, in which an injection device for injecting a liquid onto the cutting teeth of the cutting wheel is provided directly on the discharge device.

The invention has for its object to provide a trench wall cutter and a method for creating a milling slot in the ground, with which a milling slot can be produced particularly efficiently.

The object is achieved according to the invention by a trench cutter with the features of claim 1 or by a method with the features of claim 11. Preferred embodiments of the invention are specified in the respective dependent claims.

The trench wall cutter according to the invention is characterized in that a switchover device is provided, which is designed to switch the discharge device into a rinsing mode, in which a liquid flow generated by at least one discharge pump of the discharge device is generated on at least one milling wheel for flushing the milling wheel.

A basic idea of the invention is to use the discharge device for removing the milling fluid, i.e. the milled soil material with the surrounding supporting fluid, at least partially for generating a fluid flow which is directed towards one, preferably all milling wheels in order to rinse them free of adhering soil material . A switchover device is provided with which the discharge device can be switched over to a rinsing operation. As a result, the constructional and mechanical outlay on a trench wall cutter can be kept low, although at the same time good and reliable flushing of the cutting wheels is achieved.

A preferred embodiment of the invention consists in that at least one discharge pump is designed as an adjustable pump, which can be adjusted from a milling operation, in which the discharge pump sucks milling liquid from the cutting wheels, into the flushing operation, in which the discharge pump reverses liquid to the Promotes milling wheels. The adjustable pump is also referred to as a so-called swivel pump, which can reverse the direction of delivery. The switchover device is essentially an electrical or electronic control device for changing the pump setting. This embodiment is structurally particularly simple.

An advantageous further development consists in the fact that the discharge device has a discharge line which extends from the at least one discharge pump extends above, and that the switching device comprises a control valve on the discharge line, with the control valve opening a suction opening on the discharge line. The control valve first ensures that the discharge line is blocked at the top and that material that has already been conveyed upwards is not conveyed back downwards from the discharge line. In normal milling operation, the discharge line is used primarily to pump up the milled soil material together with the supporting liquid as a suspension, in particular over days, whereby the milling liquid can be filtered and processed and then returned to the slot.

In a second function, an intake opening is formed above the discharge pump with the control valve. In this way, milling fluid in the slot, which is not or only barely mixed with milled soil material, can be sucked in and conveyed to the milling wheels by the switched-over discharge pump. In this way, the pump is protected.

According to a development of the invention, it is advantageous that two pairs of milling wheels are provided, that a suction element of the discharge device is arranged in the middle between the two milling wheels, and that liquid flows out of the suction element in the direction of the milling wheels in the flushing mode. The milling wheels are preferably rotatably mounted about a common axis of rotation. The axis of rotation is in particular arranged horizontally in milling operation. The axes of rotation of the two pairs are arranged in parallel or in the same axis. The discharge device is arranged in the middle between the two milling wheels, so that the milling fluid can be removed in the middle and then fed in the middle in the rinsing mode.

A further preferred embodiment variant of the invention consists in that a flush line arrangement with at least one flush outlet is provided for flushing the at least one milling wheel. In this embodiment, a special flushing line arrangement with at least one flushing outlet is therefore provided in addition to or instead of the existing discharge line. At least one rinsing outlet, preferably a plurality of rinsing outlets, are preferably provided on all milling wheels. In this way, there is no need or no central inflow when flushing via the switched-over suction element. Rather, a flush line arrangement with a specific number of flush outlets can be provided in a targeted manner.

It is particularly preferred that the switchover device comprises a switchover valve which connects a discharge line of the discharge device to the flushing line arrangement in the flushing operation. With such an arrangement, the discharge pump can maintain its normal conveying direction of the milling operation. Through the changeover valve, the upward flow in the discharge device can be deflected into the flushing line arrangement, which then directs the liquid flow downward. This training variant is particularly simple and robust.

A particularly good rinsing performance is achieved according to a development of the invention in that at least one second pump is provided which in the rinsing mode conveys liquid via the rinsing line arrangement to the at least one milling wheel. The at least one second pump or a plurality of pumps can be used to generate a particularly intensive rinsing flow, with which particularly reliably adhering soil material is rinsed free of the milling wheels.

In this case, a particularly advantageous embodiment variant is achieved in that the second pump is connected to the discharge line and in the milling operation conveys up milling fluid and that in the flushing operation the second pump is connected to the flushing line arrangement via an adjustment valve of the switching device.

In milling operation, the second pump can support the removal of milled soil material upwards through the discharge line. In the flushing mode, the second pump can be used specifically for flushing, this being achieved by means of a corresponding adjustable or swiveling pump or solely by means of an adjustment valve.

A particularly good flushing is also achieved according to a development of the invention in that a plurality of flushing outlets are provided, which are arranged in a fan shape in the region of the at least one milling wheel. In particular when milling cohesive soils, milling wheels are used in which the milling teeth are arranged in axially offset annular rows of milling teeth on the outer circumference of a milling wheel. Annular spaces are formed between the annular rows of milling teeth, into which the nozzle-like rinsing outlets are directed. The rinsing outlets can have one or more nozzle openings, so that targeted nozzle jets on the milling teeth and in particular the gaps can be directed between the rows of milling teeth. A large number of flushing outlets can be provided in a fan-like manner in accordance with the number of annular spaces.

In a simple embodiment, the flushing outlets can be fixed. In particular for adjustment to modified floors and tooth arrangements, it is preferred according to a development of the invention that the at least one rinsing outlet is designed as an adjustable nozzle. For example, a ball nozzle can be provided, which can be clamped in a set position by means of a corresponding union nut.

The method according to the invention is characterized in that, in a flushing operation, the trench wall cutter is raised and the cutting wheels are spaced apart from a cutting base of the floor and that in the raised position of the cutting wheels a flow of liquid is generated in the direction of the cutting wheels for flushing. The method can in particular be carried out with the trench wall cutter according to the invention described above. The advantages described above can be achieved.

The cutter is raised to interrupt the milling operation and thereby spaced from the milling base. This means that the milling operation is interrupted. Subsequently, in the rinsing mode, in particular in the case of milling wheels rotating further, the liquid flow in the direction of the milling wheels can be generated, as a result of which the milling wheels are rinsed free of adhering soil material.

To retract the trench cutter, it is particularly preferred that a rope or a rod is attached to an upper end of the trench cutter, with which the trench cutter is suspended on a carrier device and adjusted vertically. This enables an efficient lifting movement of the trench cutter.

Furthermore, according to an embodiment variant of the method according to the invention, it is advantageous for an injection pressure and / or an injection quantity of the liquid to be flushed out of the cutting wheels by means of a control device in the flushing operation. The flushing can be effected in particular with an increased pressure which is between 2 bar and 40 bar. In principle, higher pressures can also be set depending on the soil material to be milled. By adjusting the injection pressure and / or the injection quantity, the milling wheels can be cleaned in the most efficient manner.

The result of the flushing can be determined and checked by means of the control device by determining the change in the drive power required for the milling wheels.

The control device can also transmit free drive power of the cutting wheels to the at least one pump in the flushing mode.

Fig. 1

eine schematische Vorderansicht einer ersten erfindungsgemäßen Schlitzwandfräse;

Fig. 2

eine vergrößerte Detailansicht der Schlitzwandfräse von Fig. 1 in einem Fräsbetrieb;

Fig. 3

eine Ansicht der Schlitzwandfräse von Fig. 2 in einem Spülbetrieb;

Fig. 4

eine schematische Ansicht einer weiteren erfindungsgemäßen Schlitzwandfräse im Fräsbetrieb;

Fig. 5

eine Ansicht der Schlitzwandfräse von Fig. 4 in einem Spülbetrieb;

Fig. 6

eine schematische Ansicht einer dritten erfindungsgemäßen Schlitzwandfräse in einem Spülbetrieb;

Fig. 7

eine schematische Ansicht einer vierten erfindungsgemäßen Schlitzwandfräse im Fräsbetrieb und

Fig. 8

eine Ansicht der Schlitzwandfräse von Fig. 7 im Spülbetrieb.

The invention is explained in more detail below on the basis of preferred exemplary embodiments which are shown schematically in the drawings. The drawings show:

Fig. 1

is a schematic front view of a first trench cutter according to the invention;

Fig. 2

an enlarged detail view of the trench cutter from Fig. 1 in a milling shop;

Fig. 3

a view of the trench cutter from Fig. 2 in a flushing facility;

Fig. 4

a schematic view of a further trench cutter according to the invention in milling operation;

Fig. 5

a view of the trench cutter from Fig. 4 in a flushing facility;

Fig. 6

a schematic view of a third trench cutter according to the invention in a flushing operation;

Fig. 7

a schematic view of a fourth trench cutter according to the invention in milling operation and

Fig. 8

a view of the trench cutter from Fig. 7 in the rinsing mode.

The Fig. 1 shows an overall view of a trench cutter 10 according to the invention with a box-like milling frame 12, at the lower end of which two pairs of milling wheels 14 are arranged. The milling wheels 14 are rotating via a not shown Drive motor can be driven to rotate around horizontal axes of rotation that are parallel to one another. On the outer sides of the drum-shaped milling wheels 14, detachable milling teeth 16 are arranged in a known manner via plate-shaped holders, with which soil material present in the slot base can be milled off during milling operation. In the milling operation, the milling slot is filled with a support liquid, which in Fig. 1 is not shown. The milled soil material is sucked off together with the surrounding supporting liquid as milling liquid via a suction element 24 of a discharge device 20 arranged centrally between the milling wheels 14.

The suction element 24 is connected via a lower discharge line 26a to a discharge pump 22 of the discharge device 20 arranged on the frame. The discharge pump 22 generates the suction pressure for sucking in the milling fluid. The sucked-in milling fluid is then removed further upward from the milling slot via the discharge pump 22 via an upper discharge line 26c. The milling fluid can be prepared for days in a corresponding system, in particular de-milled from soil material. The processed milling fluid can then be returned to the slot as a supporting fluid.

A holding device 18 is arranged at the upper end of the milling frame 20. With the holding device 18, the trench wall cutter 10 can be attached to a rope or a guide rod of a carrier device (not shown in any more detail) and in particular can thereby be moved vertically. In the Fig. 1 Diaphragm wall milling machine 10 shown has, for example, a box-shaped milling frame 12 which is provided with lateral guide elements. This allows the trench cutter 10 to guide itself in the slot. Alternatively, the milling frame 12 can also be compact and essentially without guide elements for contact guidance. The guide then takes place via a guide rod attached to the holding device 18 from outside the milling slot via the carrier device.

In milling operation, in particular when milling off cohesive soil material, it can adhere to the milling teeth 16 with the plate-shaped holders on the milling wheels 10. As a result, the milling performance of the trench cutter 10 can be markedly reduced. In order to counteract clogging of the cutting wheels 14 by adhering soil material, according to the invention the trench wall cutter 10 is a switching device 40 is provided, with which, in the exemplary embodiment shown, the trench wall cutter 10 can be switched from a milling operation to a flushing operation for flushing out the milling wheels 14.

In the in the Figures 1 to 3 First embodiment of a diaphragm wall milling machine 10 according to the invention, the switching device 40 has a control valve 42 between a central discharge line 26b and the upper discharge line 26c of the discharge device 20. The upper discharge line 26c located above the control valve 42 is shut off by the control valve 42 and at the same time a suction opening 44 on the control valve 42 is opened. The suction opening 44 is preferably located above the discharge pump 22 in an upper region of the milling frame 12 spaced apart from the milling wheels 14.

Furthermore, in the embodiment according to the Figures 1 to 3 the discharge pump 22 is designed as an adjustable pump, also called a swiveling pump. Simultaneously with the actuation of the control valve 42, the discharge pump 22 is changed in its delivery direction. Thus, when the suction opening 44 is opened, the discharge pump 22 is switched from a milling operation, in which the discharge pump 22 conveys milling liquid from the cutting wheels 14, as shown in FIG Fig. 2 is shown with arrows in a flushing operation according to Fig. 3 switched.

In milling operation according to Fig. 2 milling liquid is sucked in via the central suction element 24 with openings 25 and pumped upward via the discharge line 26. In this milling operation, the suction opening 44 is closed by the control valve 42. When switching to the rinsing mode according to Fig. 3 is removed by the converted discharge pump 22 through the opened suction opening 44 milling fluid from an upper region of the milling slot and conveyed via the middle discharge line 26b and the lower discharge line 26a to the cutting wheels 14. The liquid exits at an adjustable pressure and an adjustable delivery rate through the openings 25 of the suction element 24 in both directions to the cutting wheels 14. The setting can be made via a control device in the carrier device. In this flushing operation, the trench wall cutter 10 is raised, so that the cutting wheels 14 are spaced apart from the existing slot base. If the cutting wheels 14 continue to rotate, which in particular rotate in opposite directions, so that the cutting teeth 16 move towards the suction element 24 from below, the liquid flowing out becomes adherent Soil material loosened on the outside of the cutting wheels 14. After flushing, the control device can be used to switch back to the milling operation, in which case the milling machine is then lowered again onto the slot base for milling off further soil material.

In the Figures 4 and 5 A second embodiment of a trench cutter 10 according to the invention is shown. It shows Fig. 4 the trench cutter 10 in milling operation, in which the trench cutter 10 functions according to the previously described first embodiment. Soil material removed by the milling wheels 14 is sucked off by the discharge device 20 with the discharge pump 22 via the suction element 24 and conveyed upwards.

In this second exemplary embodiment of a trench wall cutter 10 according to the invention, the delivery direction of the discharge pump 22 remains in the rinsing mode, which in FIG Fig. 5 is shown schematically, unchanged. In the second exemplary embodiment, the switching device 40 has a switching valve 48. When switching over to the flushing mode, the changeover valve 48 blocks the upper discharge line 26c of the discharge device 20 and connects the middle discharge line 26b to a flushing line arrangement 60. The flushing line arrangement 60 has one or more flushing lines 62, which lead downward from the changeover valve 48 to the cutting wheels 14. The rinsing lines 62 end in nozzle-like rinsing outlets 64, with which the milling fluid conveyed by the discharge pump 22 is directed back to the milling wheels 14 in the region of the milling teeth 16 for loosening adhering soil material. In this second embodiment, a simple drainage pump 22 can continue to be used.

A third embodiment of a trench wall cutter 10 according to the invention is shown in FIG Fig. 6 shown in a flushing operation. In the milling operation, not shown, the trench cutter 10 functions in accordance with Fig. 6 like the two variants described above. Soil material removed from the cutting wheels 14 is sucked in together with the surrounding liquid via the suction element 24 by a discharge pump 22 of a discharge device 20 and discharged upward via a lower discharge line 26a via an upper discharge line 26c.

In the flushing mode according to Fig. 6 the discharge pump 22 according to the first embodiment according to the Figures 1 to 3 changed in their direction of funding. The discharge pump 22 is thus also designed as an adjustable or swiveling pump. In this case, liquid is now flushed out of an upper region of the slot or out of the processing system itself via the discharge pump 22 and the suction element 24 in the direction of the cutting wheels 14 via the discharge line 26. To support the flushing, a second pump 30 is provided on the milling frame 12 in the third embodiment of a trench cutter 10 according to the invention. In the flushing operation, this second pump 30 can additionally convey liquid in the direction of the cutting wheels 14 via a flushing line arrangement 60 with a plurality of flushing lines 62 and flushing outlets 64 and free-flowing soil material can flow out. In this embodiment, there is therefore a flushing out both from the direction of the suction element 24 and through additional flushing outlets 64 of the flushing line arrangement 60.

A fourth embodiment of a trench cutter 10 according to the invention is shown in FIGS Figures 7 and 8th shown. The trench cutter 10 is located according to FIG Fig. 7 in the milling operation, in which, similarly to the previously described embodiments, ground material milled off by the cutting wheels 14 together with liquid is sucked in via the suction element 24 by a discharge pump 22 of a discharge device 20 and upwards via a lower, middle and upper discharge line 26a, b, c is promoted. In addition, a second pump 30 is connected between the middle discharge line 26b and the upper discharge line 26c via a lower additional line 28a and an adjustment valve 52 of a switching device 40 according to the invention. In the milling operation, the sucked-in milling liquid can thus be discharged not only via the discharge pump 22, but also via the second pump 30, which pumps the sucked-in milling liquid upwards via the upper additional line 28b. In this way, particularly high discharge rates can be achieved, which is particularly advantageous with deep milling slots. In this double pump arrangement, the upper discharge line 26c is blocked by the adjusting valve 52 in the milling operation.

Via the adjustment valve 52 of the switching device 40, the additional line 28 can be connected to a flushing line arrangement 60 with flushing lines 62. In milling operation according to Fig. 7 however, there is no line connection between the additional line 28 and the flush line arrangement 60.

When switching to a flushing operation according to Fig. 8 the adjusting valve 52 connects the additional line 28 of the second pump 30 to the flushing line arrangement 60. At the same time, the switching device 40 changes the second pump 30, which is designed as an adjustable pump, in its delivery direction. Thus, the second pump 30 can conduct liquid via the additional line 28 from top to bottom into the flush line arrangement 60, which leads to the cutting wheels 14. Appropriate flushing outlets 64 at the ends of the flushing lines 62 can be used to specifically flow onto an outside of the milling wheels 14 for flushing away adhering soil material.

At the same time, the adjustment of the adjustment valve 52 releases the line connection between the middle discharge line 26b from the discharge pump 22 to the additional line 28. In addition, the adjustment valve 52 connects in the position for the flushing operation according to FIG Fig. 8 the lower discharge line 26a and the middle discharge line 26b with the upper discharge line 26c, so that the discharge pump 22 continues to draw in milling fluid from the area of the preferably rotating milling wheels 14. As a result, in particular detached soil material can be sucked in by the cutting wheels 14 directly through the suction element 24 and conveyed upward via the discharge line 26.

In particular with the trench cutter 10 according to the fourth embodiment according to the Figures 7 and 8th The milling wheels 14 can also be cleaned and rinsed free during the milling operation.

Claims (13)

1. Trench cutter for producing a cut trench in the soil with

   - a cutter frame (12),

   - at least one pair of cutting wheels (14) which are supported and driven in a rotatable manner on a lower end of the cutter frame (12), wherein each cutting wheel (14) has a plurality of cutting teeth (16) along its external circumference, and

   - a discharge means (20) with at least one discharge pump (22) for discharging a cutting fluid from the cut trench in the region of the cutting wheels (14),

   characterized in that
   a switchover means (40) is provided which is designed for switching the discharge means (20) over to a flushing operation, in which a fluid flow generated by at least one discharge pump (22) of the discharge means (20) is generated onto at least one cutting wheel (14) for flushing out the cutting wheel (14).
2. Trench cutter according to claim 1,
   characterized in that
   at least one discharge pump (22) is designed as an adjustable pump which can be adjusted from a cutting operation, in which the discharge pump (22) sucks off cutting fluid from the cutting wheels (14), to the flushing operation, in which the discharge pump (22) conveys fluid in the reverse direction to the cutting wheels (14).
3. Trench cutter according to claim 2,
   characterized in that
   the discharge means (20) has a discharge line (26) which extends upwards from the at least one discharge pump (22), and
   in that the switchover means (40) comprises a positioning valve (42) on the discharge line (26), wherein a suction opening (44) on the discharge line (26) is opened with the positioning valve (42).
4. Trench cutter according to any one of claims 1 to 3,
   characterized in that
   two pairs of cutting wheels (14) are provided,
   in that a suction element (24) of the discharge means (20) is arranged in a center between the two cutting wheels (14) and
   in that in the flushing operation fluid flows from the suction element (24) in the direction of the cutting wheels.
5. Trench cutter according to any one of claims 1 to 4,
   characterized in that
   a flushing line arrangement (60) with at least one flushing outlet (64) for flushing out the at least one cutting wheel (14) is provided.
6. Trench cutter according to claim 5,
   characterized in that
   the switchover means (40) comprises a switchover valve (48) which connects a discharge line (26) of the discharge means (20) to the flushing line arrangement (60) in the flushing operation.
7. Trench cutter according to claim 5 or 6,
   characterized in that
   at least one second pump (30) is provided which conveys fluid via the flushing line arrangement (60) to the at least one cutting wheel (14) in a flushing operation.
8. Trench cutter according to claim 7,
   characterized in that
   the second pump (30) is attached to the discharge line (26) and in the cutting operation conveys cutting fluid away in the upward direction and
   in that in the flushing operation the second pump (30) is connected via an adjustment valve (52) of the switchover means (40) to the flushing line arrangement (60).
9. Trench cutter according to any one of claims 5 to 8,
   characterized in that
   several flushing outlets (64) are provided which are arranged in a fan-shaped manner in the region of the at least one cutting wheel (14).
10. Trench cutter according to claim 5 or 9,
    characterized in that
    the at least one flushing outlet (64) is designed as an adjustable nozzle.
11. Method for cutting a cut trench in the soil, in particular with a trench cutter (10) according to any one of claims 1 to 10,
    wherein in a cutting operation the cutting wheels (14) are driven in a rotating manner and the trench cutter (10) is sunk into the soil and soil material is cut off,
    wherein the cut trench is produced in the soil,
    characterized in that
    in a flushing operation the trench cutter (10) is raised and the cutting wheels (14) are spaced from a cutting base of the soil and
    in that in the raised position of the cutting wheels (14) a fluid flow is generated in the direction of the cutting wheels (14) for flushing-out.
12. Method according to claim 11,
    characterized in that
    on an upper end of the trench cutter (10) a rope or a bar is fixed, with which the trench cutter (10) is suspended and adjusted vertically on a carrier implement.
13. Method according to claim 11 or 12,
    characterized in that
    by means of a control means an injection pressure and/or an injection quantity of the fluid for flushing out the cutting wheels (14) are set in the flushing operation.

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