Patent Application
20240175237
The present application claims priority to German Patent Application No. 10 2022 131 341.7 filed on Nov. 28, 2022. The entire contents of the above-listed application are hereby incorporated by reference for all purposes.
The present disclosure relates to a trench cutter and to a carrier device having such a trench cutter.
Trench cutters are used to create trenches in the ground for the construction of diaphragm walls in a wide variety of construction projects and are available in different designs and sizes. They are usually mounted on mobile carriers such as mobile cranes or cable excavators and have several milling wheels with cutting tools to remove soil material to create a trench in the ground. The milling wheels are typically rotatably mounted on one or more bearing plates, wherein the bearing plates can be located on the underside of a milling frame. A common configuration comprises two pairs of milling wheels, wherein each pair of milling wheels is mounted on its own bearing plate, with one milling wheel on each side of the bearing plate.
The problem with such trench cutters with milling wheels arranged on the side of a bearing plate is that soil material below and to the side of the bearing plate cannot be worked off directly by the milling wheels. This material protrusion between the milling wheels or to the side and below the bearing plate can be removed in known trench cutters by using hinged teeth, which are used when rotating the milling wheels between a folded-in position, in which they do not collide with the bearing plate, and a folded-out position, in which they protrude into the region of the material protrusion to be removed to the side and below the bearing plate.
Hinged teeth known from the prior art have several sensing fingers, which are mounted as separate components at the front and rear of a pivoting base body of the hinged tooth and ensure that the hinged tooth moves from the folded-out position into the folded-in position by contacting a surface or a control strip of the bearing plate when the milling wheel is rotated. However, this solution has a number of disadvantages. On the one hand, this arrangement of the sensing fingers on the base body means that the hinged tooth is in contact with the bearing plate for longer and can therefore be folded into the initial position comparatively late—namely only when the rear sensing finger in the direction of movement no longer touches the bearing plate. This can cause the problem that soil material on the side of the bearing plate (i.e. in the region of the side diaphragm walls) is not sufficiently cleared away. This material overhang can lead to a reduction in the clearance between the trench cutter and the side diaphragm walls. This results in a deterioration of the sliding properties of the trench cutter, which leads to increased wear and poorer controllability of the trench cutter. On the other hand, sensing fingers mounted on the base body can break off during operation due to the high mechanical loads.
The object of the present disclosure is therefore to further develop trench cutters of the type mentioned at the outset in an advantageous manner and to overcome the aforementioned disadvantages. In particular, the aim is to improve the controllability of the trench cutter in the trench in the ground and reduce wear on the hinged teeth.
According to the disclosure, this object is achieved by a trench cutter s described herein.
Accordingly, the trench cutter proposed according to the disclosure comprises a bearing plate on which at least one milling wheel for crushing soil material is rotatably mounted. At least one adjustable cutting tool, for example a hinged tooth, is arranged on the at least one milling wheel. The adjustable cutting tool comprises a base body that interacts with the bearing plate in such a way that the adjustable cutting tool automatically moves between a folded-in position and an unfolded position when the milling wheel is rotated, depending on the angle of rotation. The adjustable cutting tool can be moved from the folded-out position into the folded-in position via a first guide element, wherein the first guide element makes contact with the bearing plate. The contact therefore automatically aligns the adjustable cutting tool in a specific angular range of the milling wheel.
According to the disclosure, the first guide element is formed integrally with the base body and projects from the base body in the direction of the bearing plate on a side facing the bearing plate. Thanks to the one-piece design, the first guide element cannot tear off the base body, which extends the service life of the adjustable cutting tool. In addition, it can be integrated into the geometry of the base body, in particular the welded construction of the base body, which enables a compact design and improves the kinematics of the cutting tool. Thanks to the reduced size, the adjustable cutting tool can also be moved to the folded-out position much earlier, in particular before reaching the “3 o'clock” position on the milling wheel. This means that the adjustable cutting tool can be brought into the folded-out position at an early stage, allowing soil material that is radially or laterally adjacent to the bearing plate to be removed more effectively.
A gearbox (or part thereof) can be arranged within the bearing plate to drive the at least one milling wheel, such that the bearing plate can also be referred to as a gearbox plate.
The term “cutting tool” is not to be understood restrictively and does not require actual cutting or the presence of a blade. Rather, it can refer to any element that can be used to crush or mill off soil material, for example a milling tooth with a conical tip.
In one possible embodiment, the adjustable cutting tool is designed in such a way that it is axially spaced from the bearing plate in the folded-in position and can be moved past it without collision. In the folded-out position, however, the adjustable cutting tool protrudes into a region radially adjacent to the bearing plate, i.e. in the folded-out position, the adjustable cutting tool protrudes beyond the edge of the end face of the milling wheel facing the bearing plate when viewed from the outer circumference of the milling wheel, in particular. This allows the adjustable cutting tool to remove soil material in the folded-out position on the bearing plate. The adjustable cutting tool is preferably arranged on the outer circumference of the milling wheel.
In the present case, the terms “axial” and “radial” refer to the axis of rotation of the milling wheel, i.e. the axial distance refers to a distance parallel to the axis of rotation of the milling wheel and the radial distance refers to a distance perpendicular to the axis of rotation of the milling wheel. Furthermore, a direction running perpendicular to the milling wheel's axis of rotation and horizontally when the trench cutter is aligned vertically is referred to below as the longitudinal direction of the trench cutter.
In a further possible embodiment, it is provided that the adjustable cutting tool is pivotably mounted on the milling wheel. In particular, the base body of the adjustable cutting tool is pivotably mounted on the milling wheel. The movement process between the folded-in position and the folded-out position can preferably be a folding process or a pivoting movement, wherein the adjustable cutting tool is folded outwards in the axial direction in the folded-out position and projects in the direction of the bearing plate.
In a further possible embodiment, it is provided that the base body has a chamfer that extends at least partially onto the first guide element. The first guide element is therefore at least partially integrated into the chamfer of the base body or the base body and the first guide element can share a common chamfer. This results in a compact design of the adjustable cutting tool, as the chamfer already provided on the base body, which can be used for crushing soil material, for example, can also serve as a chamfer for making the first contact between the first guide element and the bearing plate. The chamfer of the base body can be widened in the region of the first guide element and/or have a different angle than in a region next to the first guide element.
Preferably, the chamfer is located on a front edge of the base body in the direction of rotation during milling operation, i.e. on an edge that forms the front of the base body during normal milling operation and therefore comes into contact with soil material first.
In a further possible embodiment, the base body is provided with a holder for a replaceable milling tooth. The milling tooth, which is subject to heavy wear, can therefore be replaced quickly and easily. To do this, the milling tooth is removed from the base body of the cutting tool and a new milling tooth is installed. The milling tooth can have any shape, for example a flat, round or conical geometry. In milling operation, the first guide element is arranged in front of the holder in the direction of rotation, i.e. in normal operation, the first guide element reaches the bearing plate earlier than the holder, for example. Preferably, the holder comprises a recess for receiving the milling tooth, which extends in the direction of a pivot axis of the base body. The milling tooth can be inserted into the recess and preferably locked or held in place in a releasable manner.
In a further possible embodiment, it is provided that the first guide element is arranged on a front portion of the base body in the direction of rotation during milling operation, i.e. it is located in particular in the region of a leading front side or front edge of the base body. As a result, the first guide element leaves the region of the bearing plate early, so that the adjustable cutting tool can be moved into the folded-out position earlier than if a guide element or sensing finger were located in a rear region of the base body, which would remain in contact with the bearing plate for longer.
In a further possible embodiment, it is provided that only one unique first guide element is provided for moving the adjustable cutting tool from the folded-out position into the folded-in position. This means that the adjustable cutting tool can be moved into the folded-out position earlier than if there were another guide element or sensing finger on the base body. In particular, this compact design makes it possible to move the adjustable cutting tool into the folded-out position well before “3 o'clock” (this refers to a position in which the adjustable cutting tool is rotated 90° to the side by turning the milling wheel in the milling direction when the trench cutter is aligned vertically). This allows the soil material on the bearing plate to be removed more effectively, which minimises the remaining material web in the longitudinal direction of the trench cutter and therefore improves its controllability in the trench in the ground. In addition, with this solution, the adjustable cutting tool is already in the folded-out position when it comes into contact with the soil material to be removed, which has a positive effect on the load acting on the adjustable cutting tool and on the load curve.
In a further possible embodiment, it is provided that the first guide element comprises a flat portion pointing towards the bearing plate, i.e. arranged laterally on the base body, in the folded-in position, which preferably adjoins a chamfer of the base body. The flat portion can transition abruptly or via an edge or continuously or curved into the chamfer. In particular, the flat portion is the part of the first guide element that contacts the bearing plate and thus presses the adjustable cutting tool into the folded-in position. In the folded-in position, the flat portion can run parallel or essentially parallel to a side surface of the bearing plate. The flat portion is preferably flat, but can alternatively also have a convex or concave shape. The flat portion can be adjacent to a holder for a milling tooth.
As the first guide element protrudes from the base body, the flat portion in the folded-in position has, in particular, a smaller axial distance to the bearing plate than the remaining part of the base body or the adjustable cutting tool.
In a further possible embodiment, it is provided that the adjustable cutting tool comprises a second guide element that is designed in such a way that when the bearing plate is contacted by the second guide element, the adjustable cutting tool moves from the folded-in position to the folded-out position. The first guide element is therefore used to move the adjustable cutting tool into the folded-in position, while the movement into the folded-out position is effected by the second guide element.
The second guide element is preferably spaced apart from the first guide element in the radial direction, i.e. it is located closer to the milling wheel than the first guide element. As a result, the first guide element contacts the bearing plate (or an optionally provided control bar or control surface on the bearing plate) at a greater distance from the milling wheel axis of rotation than the second guide element. In particular, the second guide element is arranged on a side of a pivot axis or joint of the base body opposite the first guide element, i.e. the pivot axis lies between the two guide elements. During the movement between the folded-in and folded-out position, the adjustable cutting tool pivots about the aforementioned pivot axis in particular.
In a further possible embodiment, it is provided that a control guide is provided on the bearing plate, which interacts with the adjustable cutting tool, in particular with said first and/or second guide element, such that it moves automatically between the folded-in position and the folded-out position when the milling wheel is rotated at certain angles of rotation, i.e. depending on the angle of rotation. The control guide can comprise one or more control bars (for example in the form of a cam bar) and/or control surfaces, which are arranged on the side of the bearing plate at the height of the adjustable cutting tool.
In a further possible embodiment, it is provided that the control guide comprises a control bar arranged on the bearing plate, which extends in a first angular region around the axis of rotation of the milling wheel or partially surrounds it. Looking at the side surface of the bearing plate, the control bar can form an arc. The control bar can be designed as a cam bar or control cam, which in particular has a constant height above the bearing plate. The control bar is designed in such a way that the adjustable cutting tool moves from the folded-in position to the folded-out position by contacting the control bar. In particular, the control bar is contacted by a guide element of the adjustable cutting tool. The guide element preferably runs along a contact surface of the control bar, which has a certain axial distance from the side wall of the bearing plate.
The control bar preferably has a chamfer sloping down towards the bearing plate at at least one end, in particular at both ends, which counteracts a jerky movement of the adjustable cutting tool between the folded-in position and the folded-out position and ensures a gradual, smooth transition.
In a further possible embodiment, it is provided that the control bar comprises a control surface (this refers in particular to a surface portion of the side wall of the bearing plate, which may comprise a part of the side wall and/or a plate attached thereto) or a second control bar, which extends in a second angular region around the axis of rotation of the milling wheel. If the adjustable cutting tool is located in the first angular portion, contacting a first control bar preferably ensures a movement into the folded-out position, while contacting the control surface or second control bar ensures a movement into the folded-in position when the adjustable cutting tool is located in the second angular portion.
The first angular portion can be larger than the second angular portion such that the folded-in position is only limited to the immediate region of the bearing plate and the adjustable cutting tool is in the folded-out position immediately before and after the bearing plate in order to remove any excess material on the bearing plate as completely as possible.
Said control surface or second control bar is thus designed in such a way that the adjustable cutting tool moves automatically from the folded-out position into the folded-in position when the control surface or second control strip is contacted by the first guide element.
Preferably, the control surface or second control bar is contacted by the first guide element and the first control bar is contacted by the aforementioned second guide element.
In a further possible embodiment, it is provided that a milling wheel is arranged on opposite sides of the bearing plate, wherein the milling wheels are coaxially mounted and each have at least one adjustable cutting tool, wherein the trench cutter preferably has two bearing plates, each having a pair of milling wheels. The milling wheels arranged on a particular side of the different bearing plates are, in particular, radially adjacent to each other.
A suction box can be arranged between the milling wheels of the two bearing plates. The suction box is primarily used to extract the overburden or soil material from the trench in the ground. For this purpose, a series of suction openings can be provided on the suction box, in particular on the suction sides facing the respective milling wheels and preferably tapering towards each other, through which liquid containing overburden can be extracted by means of an overburden pump. In particular, the adjustable cutting tools of the respective milling wheels are designed and have such a length that they can be guided past the suction box without collision.
In general, in addition to the at least one adjustable cutting tool, the milling wheel can have at least one fixed, i.e. non-adjustable cutting tool, which preferably has a greater axial distance to the bearing plate than the at least one adjustable cutting tool. Preferably, the milling wheel has a plurality of fixed cutting tools and/or several adjustable cutting tools distributed around the circumference of the wheel.
The disclosure further relates to an adjustable cutting tool for a trench cutter according to the disclosure. This obviously results in the same properties and advantages as for the trench cutter according to the disclosure, so that repetitive explanations are dispensed with at this point. In particular, the adjustable cutting tool can be a hinged tooth.
The disclosure further relates to a carrier device with a trench cutter according to the disclosure. This also results in the same properties and advantages as for the trench cutter according to the disclosure. The carrier device can be a cable excavator, in particular, but also a mobile crane or hydraulic excavator. The carrier device preferably comprises a mobile undercarriage, for example with caterpillar tracks, and an upper carriage mounted on the undercarriage such that it can rotate about a vertical axis, with a pivoting boom. In particular, the trench cutter is suspended from the carrier device by a cable, which is guided to a winch on the upper carriage via one or more deflection pulleys at the end of the boom.
Further features, details and advantages of the disclosure result from the following exemplary embodiment explained with the help of the figures. In the drawings:
At the lower end of the milling frame 11 are two pairs, each with two milling wheels 14 (shown here only schematically) for removing and crushing soil material. The milling wheels 14 shown are arranged next to each other in a radial direction. There is another pair of milling wheels on the rear side, which is not visible here because it is concealed. The milling wheels 14 are rotatably mounted on bearing plates 12, that are attached to the underside of the milling frame 11.
A suction box 20 is located in a region between the milling wheels 14 of a pair of milling wheels and above the horizontal plane formed by the axes of rotation of the milling wheels 14 (when the trench cutter 10 is upright). This has an elongated shape and runs parallel to the axes of rotation of the milling wheels 14 from one side of the trench cutter 10 with one pair of milling wheels to the opposite side with the other pair of milling wheels. In the exemplary embodiment shown here, there is a bearing plate 12 with two coaxially arranged milling wheels 14 on each side of the suction box 20, which is primarily used to suck the overburden-liquid suspension out of the trench in the ground by means of an overburden feed pump (not shown). The suction box 20 has a box-shaped, symmetrical structure and is preferably mounted on the underside of the milling frame 11 via a mounting plate.
Several cutting tools are arranged on the outer circumferential surfaces of the milling wheels 14, which are used to remove and crush soil material. These cutting tools can also be referred to as crushing tools and each comprise a base body 31 and a replaceable milling tooth mounted therein (not shown). In the present exemplary embodiment, the base bodies 31 and the milling teeth have a flat shape, wherein other geometries (e.g. conical cutting tools or milling teeth) are also conceivable.
The cutting tools must be moved past the bearing plate 12 without colliding when the respective milling wheel 14 is rotated. In order to also be able to remove soil material between the milling wheels 14, in a region adjacent to the narrow sides of the bearing plate 12, the outer cutting tools 30, which run directly past the bearing plate 12, are not fixed, i.e. immovably arranged on the milling wheel 14, but are adjustable. A preferred exemplary embodiment of such an adjustable cutting tool 30 without an inserted milling tooth is shown in
The adjustable cutting tool 30 can pivot about an axis of rotation formed by a joint 37 between a folded-in position and a folded-out position and is therefore also referred to as a hinged tooth 30 (in the following, both terms are used synonymously). In the folded-in position, the adjustable cutting tool 30 is pivoted away from the bearing plate 12 so that it can be moved past it without collision. In the folded-out position, the adjustable cutting tool 30 is pivoted out or folded out in the direction of the bearing plate 12 such that the milling tooth protrudes into the region next to or under the bearing plate 12 and can remove any soil material present there.
The hinged tooth 30 comprises a base body 31, which is pivotably attached to the outer circumference of the milling wheel 14 via a joint 37. In the radial direction above the pivot axis or the joint 37 (i.e. the upper part of the hinged tooth 30 in
In
On a side surface of the first portion 33, namely on the side facing the bearing plate 12, the base body 31 has a first guide element 40, which is formed in one piece with the base body 31 and is integrated into its welded construction and into the chamfer 35 of the first portion 33. The first guide element 40 comprises a flat portion 42, which in the exemplary embodiment shown extends flat and parallel to the side surface of the first portion 33. The flat portion 42 merges into the chamfer 35, which can be wider in the region of the first guide element 40 than, for example, in the region of the front edge 38 between the first guide element 40 and the joint 37.
The first guide element 40 or its flat portion 42 protrudes from the side surface of the base body 31, such that contact with the bearing plate 12 is only made via the first guide element 40 and not via another portion of the base body 31. No such guide element 40 is provided on the other side of the base body 31; instead, the first portion 33 is flat on this side (see
In the radial direction below the pivot axis or the joint 37 (i.e. the lower part of the hinged tooth 30 in
The length of the adjustable milling teeth 30 and the thickness of the bearing plate 12 determine how much material can be removed in the region between the milling wheels 14 and how large the remaining, non-removed “web” of soil material is. The thickness of the bearing plate 12 is determined in particular by the intended use and the static requirements of the system. The pivoting hinged tooth 30 is provided to reduce this material protrusion to a minimum. This is forced into different pivot positions and axial distances at certain angles of rotation via a control guide (not shown) provided on the side of the bearing plate 12 when the milling wheel 14 is rotated.
In order to guide the hinged tooth 30 past the bearing plate 12 without collision, the hinged tooth 30 is pivoted or folded into a folded-in position shortly before reaching the bearing plate 12, in which the upper flat portion of the base body 31 is aligned essentially parallel to the side surface of the bearing plate 12. This is achieved by the first guide element 40 contacting the bearing plate 12, which causes the base body 31 to pivot away from the bearing plate 12. For this purpose, the bearing plate 12 preferably has a control surface that is contacted and swept by the first guide element 40. The bearing plate 12 can have bevelled or tapered edges in the inlet and outlet regions in order to guide the first guide element 40 to the control surface and thus achieve a gradual or gentle folding process. Alternatively, a control or cam bar can be provided instead of the control surface.
In order to be able to remove the excess material radially next to or to the side of the bearing plate 12, the hinged tooth 30 is pivoted into a folded-out position after leaving the region of the bearing plate 12, in which the milling tooth projects into the region to be removed next to the bearing plate 12. For this purpose, the second guide element 50, which acts as a driver, contacts a corresponding control bar, which is circularly formed on the bearing plate 12 (not shown) and is contacted or swept over by the second guide element 50. The ends of the control bar, also known as the control cam, are bevelled towards the bearing plate 12 in order to achieve a continuous transition between the folded-in and folded-out positions.
The first guide element 40 thus assumes the function of known sensing fingers, wherein in this exemplary embodiment only a single guide element 40 is provided on the base body 31, namely in the front portion 33 of the hinged tooth 30. This allows the hinged tooth 30 in the outlet region to be moved into the folded-out position earlier after the end of the bearing plate 12, as the single first guide element 40 leaves the bearing plate 12 earlier than the rear portion 34 of the base body 31. In particular, this makes it possible to pivot the hinged tooth 30 into the folded-out position well before “3 o'clock” and thus better remove excess material in the longitudinal direction of the trench cutter 10. This increases the clearance of the trench cutter 10 in the trench in the ground and thus its controllability. With this geometry, it is also possible to move the hinged tooth 30 into the folded-out position when turning the milling wheel 14 backwards.
The integration of the first guide element 40 into the base body 31 and its front chamfer results in a particularly robust and compact design and thus less wear and improved kinematics of the hinged tooth 30.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2022 131 341.7 | Nov 2022 | DE | national |
