Abstract
The invention relates to a trench cutter for producing a cut trench in the soil with a cutter frame, at least one pair of cutting wheels which are supported and driven in a rotatable manner on a lower end of the cutter frame, wherein each cutting wheel has a plurality of cutting teeth along its external circumference, and a discharge means with at least one discharge pump for discharging a cutting fluid from the cut trench in the region of the cutting wheels. According to the invention a switchover means is provided which is designed for switching the discharge means over to a flushing operation, in which a fluid flow generated by at least one discharge pump of the discharge means is generated onto at least one cutting wheel for flushing out the cutting wheel.
Claims
1. A trench cutter for producing a cut trench in the soil with a cutter frame, at least one pair of cutting wheels which are supported and driven in a rotatable manner on a lower end of the cutter frame, wherein each cutting wheel has a plurality of cutting teeth along its external circumference, and a discharge means with at least one discharge pump for discharging a cutting fluid from the cut trench in the region of the cutting wheels, wherein a switchover means is provided which is designed for switching the discharge means over to a flushing operation, in which a fluid flow generated by at least one discharge pump of the discharge means is generated onto at least one cutting wheel for flushing out the cutting wheel.
2. The trench cutter according to claim 1, wherein at least one discharge pump is designed as an adjustable pump which can be adjusted from a cutting operation, in which the discharge pump sucks off cutting fluid from the cutting wheels, to the flushing operation, in which the discharge pump conveys fluid in the reverse direction to the cutting wheels.
3. The trench cutter according to claim 1, wherein the discharge means has a discharge line which extends upwards from the at least one discharge pump, and in that the switchover means comprises a positioning valve on the discharge line, wherein a suction opening on the discharge line is opened with the positioning valve.
4. The trench cutter according to claim 1, wherein two pairs of cutting wheels are provided, in that a suction element of the discharge means is arranged in a center between the two cutting wheels and in that in the flushing operation fluid flows from the suction element in the direction of the cutting wheels.
5. The trench cutter according to claim 1, wherein a flushing line arrangement with at least one flushing outlet for flushing out the at least one cutting wheel is provided.
6. The trench cutter according to claim 5, wherein the switchover means comprises a switchover valve which connects a discharge line of the discharge means to the flushing line arrangement in the flushing operation.
7. The trench cutter according to claim 5, wherein at least one second pump is provided which conveys fluid via the flushing line arrangement to the at least one cutting wheel in a flushing operation.
8. The trench cutter according to claim 7, wherein the second pump is attached to the discharge line and in the cutting operation conveys cutting fluid away in the upward direction and in that in the flushing operation the second pump is connected via an adjustment valve of the switchover means to the flushing line arrangement.
9. The trench cutter according to claim 5, wherein several flushing outlets are provided which are arranged in a fan-shaped manner in the region of the at least one cutting wheel.
10. The trench cutter according to claim 5, wherein the at least one flushing outlet is designed as an adjustable nozzle.
11. A method for cutting a cut trench in the soil, in particular with the trench cutter according to claim 1, wherein in a cutting operation the cutting wheels are driven in a rotating manner and the trench cutter is sunk into the soil and soil material is cut off, wherein the cut trench is produced in the soil, wherein in a flushing operation the trench cutter is raised and the cutting wheels are spaced from a cutting base of the soil and in that in the raised position of the cutting wheels a fluid flow is generated in the direction of the cutting wheels for flushing-out.
12. The method according to claim 11, wherein on an upper end of the trench cutter a rope or a bar is fixed, with which the trench cutter is suspended and adjusted vertically on a carrier implement.
13. The method according to claim 11, wherein by means of a control means an injection pressure and/or an injection quantity of the fluid for flushing out the cutting wheels are set in the flushing operation.
Description
[0030] In the following the invention is set out in greater detail by way of preferred embodiments illustrated schematically in the drawings, wherein show:
[0031] FIG. 1 a schematic front view of a first trench cutter according to the invention;
[0032] FIG. 2 an enlarged detailed view of the trench cutter of FIG. 1 in a cutting operation;
[0033] FIG. 3 a view of the trench cutter of FIG. 2 in a flushing operation;
[0034] FIG. 4 a schematic view of a further trench cutter according to the invention in the cutting operation;
[0035] FIG. 5 a view of the trench cutter of FIG. 4 in a flushing operation;
[0036] FIG. 6 a schematic view of a third trench cutter according to the invention in a flushing operation;
[0037] FIG. 7 a schematic view of a fourth trench cutter according to the invention in the cutting operation and
[0038] FIG. 8 a view of the trench cutter of FIG. 7 in the flushing operation.
[0039] FIG. 1 shows an overall view of a trench cutter 10 according to the invention with a box-like cutter frame 12, at the lower end of which two pairs of cutting wheels 14 are arranged. By way of a drive motor, not depicted, the cutting wheels 14 can be driven in a rotating manner about horizontal axes of rotation that are parallel to each other. On the external sides of the drum-shaped cutting wheels 14 releasable cutting teeth 16 are arranged in a known manner via plate-shaped holders, with which in-situ soil material can be cut off at the base of the trench in the cutting operation. In the cutting operation the cut trench is filled with a stabilizing fluid not shown in FIG. 1. Together with surrounding stabilizing fluid the cut-off soil material is sucked off as cutting fluid via a suction element 24 of a discharge means 20, which is arranged centrally between the cutting wheels 14.
[0040] Via a lower discharge line 26a the suction element 24 is connected to a discharge pump 22 of the discharge means 20, which is arranged on the frame. The discharge pump 22 generates the suction pressure for sucking the cutting fluid in. Via the discharge pump 22 the sucked-in cutting fluid is then removed further upwards via an upper discharge line 26c from the cut trench. The cutting fluid can be treated above ground in a corresponding facility, in particular being depleted of cut-off soil material. The treated cutting fluid can then be returned as stabilizing fluid into the trench.
[0041] At the upper end of the cutter frame 20 a holding means 18 is arranged. With the holding means 18 the trench cutter 10 can be fixed on a rope or a guide bar of a carrier implement, not shown in greater detail, and through this displaced vertically in particular. The trench cutter 10 illustrated in FIG. 1 has, by way of example, a box-shaped cutter frame 12 that is provided with lateral guide elements. Through this the trench cutter 10 is able to guide itself in the trench. Alternatively, the cutter frame 12 can also be designed in a compact way and substantially without guide elements for contact guidance. In this case guidance takes place from the outside of the cut trench by the carrier implement via a guide bar fixed on the holding means 18.
[0042] In the cutting operation, in particular when cutting off cohesive soil material, this can adhere to the cutting teeth 16 with the plate-shaped holders on the cutting wheels 10. As a result, the cutting performance of the trench cutter 10 can be markedly reduced. To counteract clogging-up of the cutting wheels 14 by adhering soil material the trench cutter 10 is provided in accordance with the invention with a switchover means 40, with which, in the illustrated embodiment, the trench cutter 10 can be switched from a cutting operation over to a flushing operation for flushing out the cutting wheels 14.
[0043] In the first embodiment of a trench cutter 10 according to the invention illustrated in FIGS. 1 to 3 the switchover means 40 has a positioning valve 42 between a middle discharge line 26b and the upper discharge line 26c of the discharge means 20. Through the positioning valve 42 the upper discharge line 26c lying above the positioning valve 42 is blocked and at the same time a suction opening 44 on the positioning valve 42 is cleared. The suction opening 44 is preferably located above the discharge pump 22 in an upper region of the cutter frame 12 that is spaced from the cutting wheels 14.
[0044] Furthermore, in the embodiment according to FIGS. 1 to 3 the discharge pump 22 is designed as an adjustable pump, also referred to as a bidirectional pump. Simultaneously with the actuation of the positioning valve 42 the discharge pump 22 is changed over in its conveying direction. Thus, on opening the suction opening 44 the discharge pump 22 is switched over from a cutting operation, in which the discharge pump 22 conveys cutting fluid from the cutting wheels 14 in the upward direction, as illustrated graphically with arrows in FIG. 2, to a flushing operation according to FIG. 3.
[0045] In the cutting operation according to FIG. 2 cutting fluid is sucked in via the central suction element 24 with openings 25 and pumped upwards via the discharge line 26. In this cutting operation the suction opening 44 is closed by the positioning valve 42. On switching over to the flushing operation according to FIG. 3 the changed-over discharge pump 22 causes cutting fluid to be sucked in through the opened suction opening 44 from an upper region of the cut trench and conveyed via the middle discharge line 26b and the lower discharge line 26a to the cutting wheels 14. In doing so, the fluid exits with a settable pressure and a settable conveying quantity via the openings 25 of the suction element 24 in both directions towards the cutting wheels 14. The setting can take place via a control means in the carrier implement. In this flushing operation the trench cutter 10 is raised so that the cutting wheels 14 are spaced from the in-situ trench base. On continued rotation of the cutting wheels 14, which rotate, in particular, in opposed directions so that the cutting teeth 16 move from below towards the suction element 24, adhering soil material is loosened on the external side of the cutting wheels 14 by the outflowing fluid. After flushing-out a switch-back to the cutting operation can be effected by the control means, in which case the cutter is then lowered back onto the trench base in order to cut off further soil material.
[0046] In FIGS. 4 and 5 a second embodiment of a trench cutter 10 according to the invention is shown. FIG. 4 shows the trench cutter 10 in the cutting operation, in which the trench cutter 10 functions according to the previously described first embodiment. Soil material stripped off by the cutting wheels 14 is sucked off by the discharge means 20 with the discharge pump 22 via the suction element 24 and is conveyed away upwards.
[0047] In this second embodiment of a trench cutter 10 according to the invention the conveying direction of the discharge pump 22 remains unchanged in the flushing operation illustrated schematically in FIG. 5. In the second embodiment the switchover means 40 has a switchover valve 48. When switching over to the flushing operation the switchover valve 48 blocks the upper discharge line 26c of the discharge means 20 and connects the middle discharge line 26b to a flushing line arrangement 60. The flushing line arrangement 60 has one or several flushing lines 62 which lead from the switchover valve 48 in the downward direction to the cutting wheels 14. The flushing lines 62 end in nozzle-like flushing outlets 64, with which the cutting fluid conveyed by the discharge pump 22 is fed back to the cutting wheels 14 in the region of the cutting teeth 16 in order to loosen adhering soil material. Hence, in this second embodiment a simple discharge pump 22 can still be used.
[0048] A third embodiment of a trench cutter 10 according to the invention is shown in FIG. 6 in a flushing operation. In the cutting operation, not depicted, the trench cutter 10 according to FIG. 6 functions like the two embodiment variants described beforehand. Together with surrounding fluid soil material stripped by the cutting wheels 14 is sucked in via the suction element 24 by a discharge pump 22 of a discharge means 20 and discharged via a lower discharge line 26a in the upward direction via an upper discharge line 26c.
[0049] In the flushing operation according to FIG. 6 the discharge pump 22 is changed over in its conveying direction in line with the first embodiment according to FIGS. 1 to 3. Hence, the discharge pump 22 is also designed as an adjustable or bidirectional pump. Via the discharge line 26 fluid from an upper region of the trench or from the treatment facility itself is then flushed via the discharge pump 22 and the suction element 24 back towards the cutting wheels 14. To assist flushing-out provision is made in the third embodiment of a trench cutter 10 according to the invention for a second pump 30 on the cutter frame 12. In the flushing operation this second pump 30 can additionally convey fluid via a flushing line arrangement 60 with several flushing lines 62 and flushing outlets 64 in the direction of the cutting wheels 14 and flow adhering soil material loose. In this embodiment a flushing-out therefore takes place both from the direction of the suction element 24 and by additional flushing outlets 64 of the flushing line arrangement 60.
[0050] A fourth embodiment of a trench cutter 10 according to the invention is illustrated in FIGS. 7 and 8. The trench cutter 10 according to FIG. 7 is thereby in the cutting operation, in which, similar to the previously described embodiments, soil material cut off by the cutting wheels 14 is sucked in together with fluid via the suction element 24 by a discharge pump 22 of a discharge means 20 and conveyed away upwards via a lower, middle and upper discharge line 26a, b, c. In addition, between the middle discharge line 26b and the upper discharge line 26c a second pump 30 is attached via a lower additional line 28a and an adjustment valve 52 of a switchover means 40 according to the invention. In the cutting operation conveying-away of the sucked-in cutting fluid can therefore be effected not only via the discharge pump 22 but also via the second pump 30 that conveys the sucked-in cutting fluid away in the upward direction via the upper additional line 28b. In this way, particularly high conveying rates can be reached, as is especially advantageous in the case of deep cut trenches. In this double-pump arrangement the upper discharge line 26c is blocked by the adjustment valve 52 in the cutting operation.
[0051] Via the adjustment valve 52 of the switchover means 40 the additional line 28 can be connected to a flushing line arrangement 60 with flushing lines 62. In the cutting operation according to FIG. 7, however, there is no line connection between the additional line 28 and the flushing line arrangement 60.
[0052] On switching over to a flushing operation according to FIG. 8 the adjustment valve 52 connects the additional line 28 of the second pump 30 to the flushing line arrangement 60. At the same time, the second pump 30 which is designed as an adjustable pump is changed over in its conveying direction by the switchover means 40. This enables the second pump 30 to feed fluid via the additional line 28 from above to below into the flushing line arrangement 60 that leads to the cutting wheels 14. Via corresponding flushing outlets 64 at the end of the flushing lines 62 a targeted incident flow onto an external side of the cutting wheels 14 can be effected to flush out adhering soil material.
[0053] At the same time, the adjustment of the adjustment valve 52 disconnects the line connection between the middle discharge line 26b from the discharge pump 22 to the additional line 28. Moreover, in the position for the flushing operation according to FIG. 8 the adjustment valve 52 connects the lower discharge line 26a and the middle discharge line 26b to the upper discharge line 26c so that the discharge pump 22 still sucks in cutting fluid from the region of the cutting wheels 14 that preferably continue rotating. Through this, in particular loosened soil material from the cutting wheels 14 can be directly sucked in by the suction element 24 and conveyed away upwards via the discharge line 26.
[0054] Especially with the trench cutter 10 according to the fourth embodiment pursuant to FIGS. 7 and 8 a cleaning and flushing-out of the cutting wheels 14 can also take place during ongoing cutting operation.
