EP3543408B1 - Slurry wall mill and method for creating a milled slit in the ground - 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 feed and / or Discharge device for feeding a milling liquid into or out of 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 trench in the ground with such a trench wall cutter, wherein the cutting wheels are driven to rotate and the trench wall cutter is sunk into the ground and soil material is milled off, the milling slot being created in the soil, according to the preamble of claim 12.

A trench wall cutter of the generic type with a cleaning device for the cutting wheels is based on the EP 2 703 565 A1 emerged.

Such trench wall cutters are used to create so-called diaphragm walls or sealing walls, which are required for securing or sealing construction pits, for example. A trench wall cutter is used to create a first cut slot which is filled with a hardenable compound. This mass hardens to form a diaphragm wall segment. By stringing together several diaphragm wall segments, a diaphragm wall can be created in a desired size.

From the EP 1 452 645 A1 Another diaphragm wall cutter emerges for creating a diaphragm wall in the ground. A feed device opens between the two pairs of cutting wheels, by means of which a settable liquid can be introduced into the cutting slot in the area between the cutting wheels. The liquid which can be set is supplied with the milled soil material by the rotary movement of the milling wheels mixed to a hardenable mass, which can then harden to the slit wall segment. 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 ground is based on DE 41 41 629 A1 emerged. In the trench wall cutter used for this purpose, a discharge device is provided between the cutting wheels, with which the milled soil material is sucked off above ground directly with the support liquid located in the milling slot. The extracted suspension can be depleted of soil material in a separating device and returned to an upper area of the milling trench. The suspension can be prepared in such a way that it represents a hardenable mass which hardens in the milling slot to form the slit wall segment.

When creating a milling slot using a trench wall cutter, there is a fundamental problem that when milling in cohesive soils, e.g. in clay, silt, mudstone, etc., the soil removed by the milling wheels adheres to the milling teeth of the milling wheels and can thus stick the milling wheels together. This can lead to the sticking being so strong that the trench wall cutter has to be pulled out of the cutting slot to mechanically clean the cutting wheels. Since milling trenches can reach a depth of 40 meters and more, this represents a high expenditure of time and thus an economic disadvantage. The daily milling performance of a trench wall cutter can be significantly reduced as a result.

For loosening adhering soil material between ring-shaped rows of cutting teeth on a cutting wheel, it is about from the EP 2 685 007 A1 known to attach so-called scraper plates on the milling wheel frame, which protrude into the spaces between the annular rows of milling teeth. However, the clearing plates must maintain a certain distance from the cutting wheels and the cutting teeth, so that only a partial removal of adhering soil material can be achieved in this way.

The invention is based on the object of specifying 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 wall cutter with the features of claim 1 and by a method with the features of claim 12. Preferred embodiments of the invention are given in the dependent claims.

In the trench wall cutter according to the invention it is provided that a cleaning device for cleaning the milling wheels in milling operation with a cleaning fluid is provided at a distance from the feed and / or discharge device and that the cleaning device has a plurality of cleaning nozzles which are directed at the outer circumference of at least one milling wheel and are designed for injecting the cleaning fluid to loosen adhering soil material.

One aspect of the invention consists in providing a cleaning device at a distance from or separately from the feed and / or discharge device for a milling fluid, by means of which the milling wheels can be cleaned during milling by means of a cleaning fluid. By means of a cleaning fluid, the milling wheels and in particular the milling teeth can be cleaned particularly reliably and without substantial wear in the milling operation, in which the milling wheels rotate and cut off soil material.

It is one aspect of the invention that the cleaning device has a plurality of cleaning nozzles which are directed at the outer circumference of at least one milling wheel and are designed to inject the cleaning fluid to loosen soil material adhering to the milling teeth. The cleaning fluid can be a liquid or a gas or a gas-liquid mixture. The cleaning nozzles are at a distance from the feed device for milling fluid, which feeds a relatively large amount of milling fluid into the milling slot in a milling process with in situ mixing in order to operate the milling machine. By arranging a large number of cleaning nozzles, which are specifically aligned with the milling wheels and in particular the milling teeth and tooth holders, a targeted detachment of adhering soil material can be achieved. As a result, the milling wheels have a largely consistently high milling performance even with longer operating times when milling cohesive soil material, without the milling operation having to be interrupted for cleaning the trench wall cutter for days. This not only increases the daily milling performance of a milling machine, but also leads to an improved quality of the hardenable Mass in the milling slot, since the milling slot can preferably be machined in one stroke of the trench wall cutter. In addition, the milling resistance and thus the energy consumption are reduced.

A preferred embodiment of the trench wall cutter according to the invention consists in that two pairs of cutting wheels are provided and that the feed and / or discharge device is arranged in a center between the two cutting wheels. The milling wheels of a pair are rotatably mounted about a common axis of rotation. The axis of rotation is preferably arranged horizontally in the milling mode. The axes of rotation of the two pairs are arranged in parallel. The feed and / or discharge device is arranged in the middle between the two milling wheels, so that the milling liquid can be fed or discharged centrally. The cleaning device with the cleaning nozzles for the individual milling wheels are each arranged at a distance from the center laterally to the respective milling wheels.

In a simple embodiment, fixed cleaning nozzles can be provided. In particular for adjustment to changed floors and tooth arrangements, it is preferred according to a further development of the invention that the cleaning nozzles are adjustable. For example, ball nozzles can be provided that can be clamped in a set position by means of a corresponding union nut.

According to a further embodiment of the invention, it is advantageous that the cleaning device has nozzle rails, one nozzle rail being arranged along the outer circumference of each milling wheel and running approximately parallel to the axis of rotation of the milling wheel. In principle, several nozzle rails can also be provided for each milling wheel. A nozzle rail can be referred to as a so-called common rail, which is supplied with cleaning fluid via a supply line from a central pressure generating device, in particular an injection pump. Using corresponding adjustment valves on the individual cleaning nozzles or the nozzle rails, different injection quantities and injection pressures can also be provided and set on the individual cleaning nozzles.

Such a trench wall cutter is preferably developed in that rod-shaped cleaning rails are attached to the nozzle rail and that the cutting teeth are attached a milling wheel are arranged in annular rows of milling teeth which are axially spaced from one another to form annular interspaces, and that the rod-shaped cleaning nozzles protrude into the annular interspaces. In particular when milling cohesive soils, milling wheels are used in which the milling teeth are arranged in axially offset annular milling tooth rows on the outer circumference of a milling wheel. Between the annular rows of milling teeth, annular spaces are formed into which the rod-shaped cleaning nozzles protrude. The rod-shaped cleaning nozzles extend from the respective nozzle rail in the direction of the milling wheel center. The rod-shaped cleaning nozzles can have one nozzle opening or also several nozzle openings, so that targeted nozzle jets can be directed onto the milling teeth in the milling teeth rows or the outer circumference of the milling wheels. Adjustable nozzles can be provided at the cleaning openings.

A particularly good cleaning is achieved according to the invention in that clearing plates are arranged on the milling frame for stripping off adhering soil material from the milling wheels. Clearing plates are basically known from the prior art. These are mechanical stripping devices which preferably extend into the annular gaps between the annular rows of milling teeth in order to scrape soil material located there from the gaps. However, the mechanical clearing plates must be arranged at a certain distance from the rows of milling teeth in order to avoid collisions during milling that could occur due to vibrations of the individual machine parts during operation. In addition to this mechanical cleaning, remaining floor material can be removed by the cleaning fluid with the cleaning device according to the invention.

According to the invention it is provided that the cleaning nozzles are integrated into the scraper plates or are attached close to them. Thus, the scraper plates themselves can be designed as hollow plates, the cavity serving as a supply of cleaning fluid to the cleaning nozzles on the scraper plates. Alternatively, the rod-shaped cleaning nozzles in particular can be attached to a

Be attached to the outside of the scraper plates to remove any remaining soil material from the cutting teeth.

According to a variant embodiment of the invention, particularly good cleaning is achieved in that the nozzle rails are connected via feed lines to at least one injection pump with which the cleaning fluid can be injected under pressure. The injection pump can be arranged above ground or on the milling frame of the trench wall cutter.

According to one embodiment of the invention, it is preferred that a control device is provided with which the injection pressure and / or an injection quantity of the cleaning fluid can be set. Here, depending on the adhesion property of the soil material to be milled, a sufficient injection pressure and a sufficient injection quantity of cleaning fluid can be set in order to reliably clean the milling teeth of soil material. At the same time, the control device can also be used to set a desired pressure in the area of the milling wheels, which can have a positive effect on milling and mixing of milled soil material with milling fluid.

In principle, a gas or any liquid can be used as the cleaning fluid. According to a development of the invention, it is particularly advantageous that the cleaning fluid corresponds to the milling fluid. In particular, the cleaning fluid can be a hardenable suspension, in particular a cement suspension, which is used to remove soil material. The cleaning fluid injected under pressure can at the same time support mixing of the milled soil material, so that a particularly good hardenable suspension for forming the diaphragm wall element is established, particularly in the case of an in situ method. Water can also be provided as the cleaning fluid in order, for example, at the end of an operating day to clean the milling wheels by the cleaning device outside the milling slot.

Another preferred embodiment of the invention is that the feed device has a feed pump for feeding the milling liquid, the milling liquid and the cleaning fluid being mixed with the milling wheels in the milling slot with milled soil material to form a hardenable suspension. In such a trench wall cutter for an in situ milling and mixing process is preferably used as Cleaning fluid uses the milling fluid. The feed pump on the milling frame can convey both the milling fluid to the feed device and the cleaning fluid to the cleaning nozzles. A particularly efficient construction of the trench wall cutter can be achieved in this way.

Alternatively, according to a further development of the invention, it can be provided that the discharge device has a suction pump with which milling liquid with the cleaning fluid and milled soil material is sucked out of the milling slot. In this milling process, a so-called suction box at the lower end of the trench wall cutter is used to suck off milling fluid from the milling slot below the milling frame by means of the suction pump and the discharge device, which has one or more suction openings.

Furthermore, it is preferred in a trench wall cutter according to the invention that a rope or a rod is attached to an upper end of the milling frame, with which the trench wall cutter is suspended from a carrier device and vertically adjustable. The milling wheels can be cleaned during milling operation both when milling the ground material and during a lifting movement by means of the rope or the rod.

The method according to the invention for milling a milling trench in the ground with the aforementioned trench wall milling machine is characterized in that a cleaning fluid is sprayed onto the outer circumference of the milling wheels during milling via a cleaning device, whereby soil material adhering to the milling wheels is loosened. With the method according to the invention, the advantages described above can be achieved when using a trench wall cutter according to the invention.

Fig. 1

eine perspektivische Ansicht eines unteren Teiles einer erfindungsgemäßen Schlitzwandfräse mit den Fräsrädern;

Fig. 2

eine Vorderansicht der Schlitzwandfräse von Fig. 1;

Fig. 3

eine Seitenansicht der Schlitzwandfräse der Figuren 1 und 2;

Fig. 4

eine Ansicht der Schlitzwandfräse von den Figuren 1 bis 3 von unten; und

Fig. 5

eine perspektivische Ansicht eines Teils der Reinigungsvorrichtung für die Fräsräder.

The invention is described in more detail below with reference to a preferred exemplary embodiment which is shown schematically in the figures. In the figures show:

Fig. 1

a perspective view of a lower part of a trench wall cutter according to the invention with the cutting wheels;

Fig. 2

a front view of the trench wall cutter of Fig. 1 ;

Fig. 3

a side view of the trench wall cutter of Figures 1 and 2 ;

Fig. 4

a view of the trench wall cutter from the Figures 1 to 3 from underneath; and

Fig. 5

a perspective view of part of the cleaning device for the milling wheels.

A trench wall cutter 10 according to the invention with a milling frame 12 is in the Figures 1 to 4 shown in the different views. At a lower end of the milling frame 12, which is only partially shown, first milling wheels 14 are mounted in pairs on a first gear plate 11a so that they can rotate about a common axis of rotation and on a second gear plate 11b a pair of second milling wheels 15 are rotatably mounted together about another axis of rotation. The milling wheels 14, 15 each have a drum-shaped hub 17, on the outer circumference of which a multiplicity of milling teeth 20 with milling tooth holders 18 are attached. The milling teeth 20 are detachably mounted in the milling tooth holders 18. The milling tooth holders 18 with the milling teeth 20 are arranged along the outer circumference of each milling wheel 14, 15 in annular rows of milling teeth 22, as illustrated in FIGS Figures 3 and 4 emerges. The individual rows of milling teeth 22 are axially spaced from one another, so that annular spaces 24 are formed between them.

In the milling operation, soil materials can adhere to the milling teeth 20, the milling tooth holders 18 and in the spaces 24 between the milling teeth 20 and the milling tooth holders 18, in particular when milling cohesive soil, such as clay. In order to remove adhering soil material, plate-shaped clearing plates 50 are attached to the underside of the milling frame 12 and engage in a comb-like manner in the annular spaces 24 between the cutting teeth 20 in order to mechanically scrape off adhering soil material. The clearing plates 50 are attached to both sides of a central discharge device 30, which is designed to suck off milling fluid from the milling slot that has been created. The discharge device 30 has a suction box 32 which extends parallel to the axes of rotation and tapers downwards. On its underside, the suction box 32 is provided with a plurality of suction openings 34, as can be seen Fig. 3 can be found.

The ones in the Figures 1 to 4 The trench wall cutter 10 shown here is designed to carry out a milling process in which the removed soil material together with the surrounding support or milling fluid from the working area of the milling wheels 14, 15 is sucked off and removed after days. Alternatively, instead of the discharge device 30, a corresponding feed device 30 can also be provided, through which milling liquid is fed into the area between the milling wheels 14, 15. Such a trench wall cutter 10 would be designed to carry out a milling process in which the removed soil material is mixed in situ in the milling slot together with the milling liquid to form a suspension, which preferably hardens after the trench wall cutter 10 has been removed from the milling slot and thus becomes a diaphragm wall segment or diaphragm wall panel for a Diaphragm wall hardens.

According to the invention, a cleaning device 40 with cleaning nozzles 46, which are directed towards the outer circumference of the milling wheels 14, 15, is arranged on both sides at a distance from the discharge device 30. A part of the cleaning device 40 is enlarged in FIG Fig. 5 shown. The cleaning device 40 has two clamp-like holding frames 41, one of which is holding frame 41 in FIG Fig. 5 is shown. At the lower end of the U-shaped holding frame 41, a nozzle rail 42 is attached, which is spaced from the discharge device 30 and is directed parallel to the axes of rotation of the milling wheels 14, 15. The two nozzle rails 42 of two opposite milling wheels 14, 15 are connected to a feed pump (not shown) via a feed line 44, which is only partially shown. A cleaning fluid, in particular a liquid under pressure, can be supplied via the supply pump via the supply lines 44 to the nozzle rails 42.

On an underside of the nozzle rails 42, adjustable rod-shaped cleaning nozzles 46 are attached via clamping nuts 48. The cleaning nozzles 46 can be loosened by means of the clamping nuts 48 and their alignment can be changed at least in certain areas and thus adjusted to the respective arrangement of milling teeth 20 on the milling wheels 14, 15. The cleaning nozzles 46 have nozzle openings from which the cleaning fluid exits under pressure in order to loosen soil material adhering to the milling teeth 20 and the milling tooth holders 18 during the milling operation. The cleaning nozzles 46 engage in the annular intermediate spaces 24 in the manner of a comb.

The feed pump for injecting the cleaning fluid into the cleaning nozzles 46 can preferably be arranged on the milling frame 12 of the trench wall cutter 10. The milling fluid that is located in the milling slot can preferably be used as the cleaning fluid.

With the inventive trench wall cutter 10 described above, the previously described method for creating a milling slot in the ground can be carried out, with the cleaning device 40 being able to detach adhering soil material from the milling wheels 14, 15 during milling operation with the milling wheels 14, 15 turning.

Claims (12)

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

   - a cutter frame (12),

   - at least one pair of cutting wheels (14, 15) which are supported and driven in a rotatable manner on a lower end of the cutter frame (12), wherein each cutting wheel (14, 15) has a plurality of cutting teeth (20) along its outer circumference, and

   - a supply and/or discharge means (30) for supplying or discharging a cutting liquid to or from the cut trench in the region of the cutting wheels (14, 15),

   - wherein spaced from the supply and/or discharge means (30) a cleaning device (40) is provided for cleaning the cutting wheels (14, 15) during the cutting operation with a cleaning fluid and

   - wherein the cleaning device (40) has a plurality of cleaning nozzles (46) which are directed onto the outer circumference of at least one cutting wheel (14, 15) and designed to inject the cleaning fluid to loosen adhering soil material,
   characterized in that

   - on the cutter frame (12) reamer plates (50) are arranged for scraping off adhering soil material from the cutting wheels (14, 15), and

   - in that the cleaning nozzles (46) are integrated into the reamer plates (50) or fixed close thereto.
2. Trench cutter according to claim 1,
   characterized in that
   two pairs of cutting wheels (14, 15) are provided and
   in that the supply and/or discharge means (30) is arranged in a center between the two cutting wheels (14, 15).
3. Trench cutter according to claim 1 or 2,
   characterized in that
   the cleaning nozzles (46) are supported in an adjustable manner.
4. Trench cutter according to any one of claims 1 to 3,
   characterized in that
   the cleaning device (40) has nozzle rails (42), wherein one nozzle rail (42) is in each case arranged along the outer circumference of each cutting wheel (14, 15) and runs approximately parallel to the axis of rotation of the cutting wheel (14, 15).
5. Trench cutter according to claim 4,
   characterized in that
   on the nozzle rail (42) bar-shaped cleaning nozzles (46) are fixed,
   in that the cutting teeth (20) on a cutting wheel (14, 15) are arranged in annular cutting tooth rows (22) which, by forming annular spaces (24), are spaced axially from each other, and
   in that the bar-shaped cleaning nozzles (46) protrude into the annular spaces (24).
6. Trench cutter according to any one of claims 4 or 5,
   characterized in that
   the nozzle rails (42) are connected via supply lines (44) to at least one injection pump, with which the cleaning fluid can be injected under pressure.
7. Trench cutter according to claim 6,
   characterized in that
   a control means is provided, with which the injection pressure and/or an injection quantity of the cleaning fluid can be set.
8. Trench cutter according to any one of claims 1 to 7,
   characterized in that
   the cleaning fluid corresponds to the cutting liquid.
9. Trench cutter according to any one of claims 1 to 8,
   characterized in that
   the supply means (30) has a supply pump for supplying the cutting liquid, wherein by way of the cutting wheels (14, 15) the cutting liquid and the cleaning fluid are mixed in the cut trench with cut-off soil material to a hardenable suspension.
10. Trench cutter according to any one of claims 1 to 9,
    characterized in that
    the discharge means (30) has a suction pump, with which cutting liquid, together with the cleaning fluid and cut-off soil material, is sucked out of the cut trench.
11. Trench cutter according to any one of claims 1 to 10,
    characterized in that
    on an upper end of the cutter frame (12) a rope or a rod is fixed, with which the trench cutter (10) is suspended and vertically adjustable on a carrier implement.
12. Method for cutting a cut trench in the soil with a trench cutter according to any one of claims 1 to 11,
    wherein the cutting wheels (14, 15) 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, and
    during cutting a cleaning fluid is sprayed via a cleaning device (40) onto the outer circumference of the cutting wheels (14, 15), wherein soil material adhering to the cutting wheels (14, 15) is loosened,
    characterized in that
    adhering soil material is scraped off from the cutting wheels (14, 15) by reamer plates (50) which are arranged on the cutter frame (12), and
    in that the cleaning fluid is sprayed onto the outer circumference of the cutting wheels (14, 15) by means of cleaning nozzles (46) which are integrated into the reamer plates (50) or fixed close thereto.

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