Patent Application
20240175228
The present application claims priority to German Patent Application No. 10 2022 131 161.9 filed on Nov. 24, 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 to a carrier machine having such a trench cutter.
Trench cutters are used to prepare trenches for the construction of slurry walls in a wide variety of construction projects and are available in various designs and sizes. They are typically mounted on mobile carrier machines such as mobile cranes or cable excavators and comprise a plurality of cutting wheels with cutting tools for removing soil material in order to produce a trench. The cutting wheels are typically rotatably mounted on one or more bearing shields, wherein the bearing shields can be located on the underside of a cutter frame. A conventional configuration comprises two pairs of cutting wheels, wherein each pair of cutting wheels is mounted on its own bearing shield, with one cutting wheel on either side of the bearing shield.
Such trench cutters usually have a suction box in the area between the cutting wheel pairs, the primary purpose of which is to suck the waste material or soil material out of the trench. To this end, a series of suction openings are typically provided on the suction box, through which liquid containing waste material is sucked in via a pump. Further tasks can include breaking up the soil material loosened by the cutting wheels.
The problem with trench cutters of this kind, with cutting wheels arranged laterally on a bearing shield, is that soil material underneath and to the sides of the bearing shield cannot be processed directly by the cutting wheels. In known trench cutters, the removal of this excess material between the cutting wheels and/or to the sides of and underneath the bearing shield can be carried out using hinged teeth which, as the cutting wheels rotate, move between a folded-in position in which they do not collide with the bearing shield and a folded-out position in which they project laterally and underneath the bearing shield into the area of the excess material to be removed.
However, owing to the kinematics of such hinged teeth, it is not possible to remove all of the material between the cutting wheels and instead a residual “ridge” of soil material remains, the size of which is determined inter alia by the length of the hinged teeth. One reason for this is that the maximum length of the hinged teeth is limited by the fact that they must be able to be moved past the suction box, which typically happens when they are still in the folded-out position or in the transition between the folded-out and folded-in position, without collision.
The presence of soil material to the sides of the bearing shield (i.e. in the vicinity of the lateral slurry walls) reduces the clearance between the trench cutter and the lateral slurry walls. This leads to a worsening of the sliding properties of the trench cutter, resulting in increased wear and poorer controllability of the trench cutter.
The object of the present disclosure is therefore to develop trench cutters of the aforementioned type in an advantageous manner and to overcome the disadvantages referred to above. In particular, the wear on such trench cutters should be reduced and the control inside the trench made easier.
This object is achieved in accordance with the disclosure by a trench cutter having the features as described. Advantageous embodiments of the disclosure are derived from from the following description.
Thus, the trench cutter proposed in accordance with the disclosure comprises at least one bearing shield, on which at least one cutting wheel for breaking up soil material is rotatably mounted, and a suction box arranged radially adjacent to the cutting wheel for sucking up liquid containing soil material or waste material. At least one adjustable cutting tool, such as a hinged tooth, is arranged on the at least one cutting wheel and is designed in such a way that the adjustable cutting tool moves systematically between a folded-in position and a folded- out position as the cutting wheel rotates. In particular, the adjustable cutting tool is arranged on the outer circumference of the cutting wheel. In the folded-in position, there is an axial distance between the adjustable cutting tool and the bearing shield to enable it to move past the bearing shield without collision. By contrast, in the folded-out position, the adjustable cutting tool projects into an area lying radially adjacent to the bearing shield, i.e. in the folded-out position, looking at the outer circumference of the cutting wheel, the adjustable cutting tool projects in particular beyond the edge of the end face of the cutting wheel that faces the bearing shield.
In the present case, the designations “axially” and “radially” relate to the rotary axis of the cutting wheel, i.e. the axial distance denotes a distance parallel to the cutting wheel rotary axis and the radial distance denotes a distance perpendicular to the cutting wheel rotary axis. In addition, a direction that is perpendicular to the cutting wheel rotary axis and is horizontal when the trench cutter is oriented vertically is defined as the longitudinal direction of the trench cutter.
The term “cutting tool” is not intended to have a limiting effect and requires no actual cutting action or the presence of a blade. Rather, it can denote any element which can be used to break up or cut away soil material, such as a cutting tooth with a conical tip.
According to the disclosure, the suction box has a recess which is designed in such a way that, in the folded-out position or in the transition between the folded-in position and the folded-out position, the adjustable cutting tool moves through, i.e. projects into, the recess. In this way it is possible to make the adjustable cutting tool longer than has hitherto been the case with the same arrangement of the suction box, without the adjustable cutting tool colliding with the suction box, so that soil material to the sides of and/or underneath the bearing shield can be removed more effectively.
The greater removal of material increases the longitudinal clearance of the trench cutter in the trench (i.e. the clearance in the longitudinal direction adjacent to the bearing shield) and thus improves the controllability of the trench cutter. In particular, the inventive recess in the suction box maximises the removal of material, even if a thick bearing shield is used, making the shield universally usable, so a single bearing shield can be used for trench cutters of different sizes, for example.
A gearbox (or part of one) for driving the at least one cutting wheel can be arranged inside the bearing shield, so the bearing shield can also be described as a gearbox shield.
The term “recess” can be interpreted broadly and can include inter alia an actual material cut-out and/or an indentation and/or a narrowing of the suction box.
In one possible embodiment, it is provided that, as the cutting wheel rotates, an end of the adjustable cutting tool spaced radially apart from the cutting wheel describes a trajectory which passes through the recess, i.e. partly inside the notional extension of the outer contour of the suction box extending over the recess. Thus, as it describes the trajectory arising from the rotation of the cutting wheel, the adjustable cutting tool dips into the recess. The end of the adjustable cutting tool can be formed by a blade or a cutting edge or by the tip of a tooth. The trajectory preferably crosses a notional radial extension of the bearing shield.
The axial distance between the trajectory and a median plane of the bearing shield preferably differs in different angular ranges, wherein the axial distance is shorter when the adjustable cutting tool is in the folded-out position. Looking at the end face of the cutting wheel, the shape of the trajectory can be substantially circular. It is also possible, however, for the trajectory to deviate from a circular shape due to the movement (such as a pivoting movement) of the adjustable cutting tool between the folded-in and folded-out positions.
In a further possible embodiment, it is provided that when the trench cutter is in cutting mode (i.e. when the cutting wheels are rotating “forwards” in the conventional manner), the recess is positioned ahead in the direction of rotation of the cutting wheel with respect to a first angular sector in which the adjustable cutting tool is in the folded-in position. The movement from the folded-out position to the folded-in position can take place entirely or partly inside the recess or after passing through the recess. In a second angular sector the adjustable cutting tool is in the folded-out position. The second angular sector can be larger than the first angular sector.
In a further possible embodiment, it is provided that the adjustable cutting tool is pivotably mounted on the cutting wheel. In particular, the movement between the folded-in and folded-out position can be a folding operation or a pivoting movement, wherein in the folded-out position the adjustable cutting tool is folded outwards in the axial direction and projects towards the bearing shield.
In a further possible embodiment, it is provided that, in addition to the at least one adjustable cutting tool, the cutting wheel has at least one fixed, i.e. non-adjustable cutting tool, which is preferably a greater axial distance from the bearing shield than the at least one adjustable cutting tool.
The cutting wheel preferably has a plurality of fixed cutting tools and/or a plurality of adjustable cutting tools, which are distributed around the circumference of the wheel.
In a further possible embodiment, it is provided that the at least one adjustable cutting tool is longer than the at least one non-adjustable cutting tool. In the folded-out position, the at least one adjustable cutting tool preferably has a greater radial length than the at least one non-adjustable cutting tool, i.e. in the folded-out position it projects radially further from the outer circumferential surface of the cutting wheel than the at least one non-adjustable cutting tool. The adjustable cutting tool is longer than the fixed cutting tool(s) because its primary purpose is in particular to clear away soil material surrounding the bearing shield. As the fixed cutting tools are shorter, they can be moved past the suction box without collision and without having to dip into the recess.
In a further possible embodiment, it is provided that the suction box comprises a suction surface facing the outer circumference of the cutting wheel and comprising at least one suction opening, wherein liquid containing soil material or waste material can be sucked in through the at least one suction opening. To this end, the trench cutter preferably comprises a mud pump for sucking the suspension through the at least one suction opening. The inventive recess permitting the collision-free passage of the at least one adjustable cutting tool is formed at least partly, in particular entirely, on the suction surface. A plurality of suction openings arranged side by side in the axial direction are preferably arranged on the suction surface to enable the suspension to be effectively sucked in over the entire length of the suction box.
In a further possible embodiment, it is provided that in the circumferential direction the recess is arranged in the vicinity of the at least one suction opening. One or more suction openings can also be provided in the recess to ensure that the suction efficiency is not reduced by the recess. Alternatively, suction openings can be arranged above and/or below the recess, since the suction function and the enabling of the collision-free passage of the at least one adjustable cutting tool are independent of one another.
In a further possible embodiment, it is provided that the recess is at the axial height of the bearing shield, wherein a notional median plane running through the centre of the bearing shield preferably divides the recess symmetrically. This symmetrical arrangement is particularly advantageous for trench cutters in which a cutting wheel is arranged on either side of the bearing shield. In this way, a common recess can be used for the adjustable cutting tools of both cutting wheels.
In a further possible embodiment, it is provided that the recess is substantially rectangular in shape, wherein preferably at least two edges of the recess are bevelled or have chamfers. In principle, however, the recess can also be any other shape.
In a further possible embodiment, it is provided that the trench cutter comprises an adjusting device with which the at least one adjustable cutting tool can be moved or adjusted between the folded-in position and the folded-out position as the cutting wheel rotates. This adjustment preferably occurs automatically and passively, i.e. without an active drive. The adjusting device can in particular include a control cam, which is arranged on the bearing shield and makes indirect or direct contact with the adjustable cutting tool as it passes, thereby moving it into the folded-in or folded-out position. The control cam can be designed as a rail or guide which runs partly around the rotary axis of the cutting wheel and has a contact face for contacting the adjustable cutting tool. The control cam is preferably bevelled in a run-in area and/or in a run-out area to avoid an abrupt transition between the folded-in and folded-out position of the adjustable cutting tool. The control cam thus fixes the axial position of the adjustable cutting tool depending on the rotation angle.
In a further possible embodiment, it is provided that the trench cutter comprises two bearing shields arranged side by side, each having at least one rotatably mounted cutting wheel, wherein the cutting wheels of the different bearing shields are arranged radially side by side and the suction box is arranged between the radially adjacent cutting wheels. In this embodiment, the suction box has at least two recesses, each facing one of the cutting wheels of the different bearing shields.
In a further possible embodiment, it is provided that a cutting wheel is arranged on each opposing side of the at least one bearing shield, so that at least two cutting wheels are provided per bearing shield. In this case, the cutting wheels are coaxially mounted and each have at least one adjustable cutting tool. The adjustable cutting tools of the cutting wheels serve to clear away soil material from between the cutting wheels on the bearing shield. The recess in the suction box maximises the removal of material from between the cutting wheels, even with a thick gearbox shield, making the shield universally usable, i.e. for different slurry wall dimensions.
In a further possible embodiment, a common suction box is provided for the cutting wheels arranged on opposite sides of the bearing shield, wherein the suction box preferably has a common recess for the adjustable cutting tools of the coaxial cutting wheels. Alternatively, a plurality of recesses, each associated with the respective cutting wheels, can also be provided.
The disclosure further relates to a carrier machine having a trench cutter according to the disclosure. The carrier machine can in particular be a cable excavator, but it can also be a mobile crane or a hydraulic excavator. The carrier machine preferably comprises a mobile chassis, with a caterpillar track for example, and a superstructure, which is mounted on the chassis for rotation about a vertical axis and has a pivotable boom. In particular, the trench cutter is suspended from the carrier machine by a cable, which passes over one or more deflection rollers at the end of the boom to a winch on the superstructure.
Further features, details and advantages of the disclosure can be found in the exemplary embodiments below, illustrated by way of the figures. In the figures:
At the bottom end of the cutter frame 11 there are two pairs of cutting wheels 14 (shown only schematically here) for removing and breaking up soil material. The cutting wheels 14 shown here are arranged side by side in the radial direction. There is an additional pair of cutting wheels on the rear side, which is not visible here because it is concealed. The cutting wheels 14 are rotatably mounted on bearing shields 12, which are attached to the underside of the cutter frame 11.
In an area between the cutting wheels 14 of a cutting wheel pair and above the horizontal plane formed by the rotary axes of the cutting wheels 14 (when the trench cutter 10 is in the upright position) there is a suction box 20. This has an elongated shape and runs parallel to the rotary axes of the cutting wheels 14 from one side of the trench cutter 10 with one pair of cutting wheels to the opposite side with the other pair of cutting wheels. A common suction box 20 is preferably used for both pairs of cutting wheels. In the exemplary embodiment shown here, there is a bearing shield 12 with two coaxially arranged cutting wheels 14 on either side of the suction box 20.
The suction box 20, an enlarged version of which is shown in
The suction box 20 has two lateral bevelled suction surfaces 24 which face the respective cutting wheels 14 and are located opposite the outer circumferential surfaces thereof. The suction surfaces 24 taper towards each other and can be oriented substantially tangentially to the respective cutting wheels 14. As can be seen in
As the respective cutting wheel 14 rotates, the cutting teeth 30, 32 must be moved past both the suction surface 24 of the suction box 20 and the bearing shield 12 without a collision occurring. The distance from the suction surface 24 to the outer circumferential surface of the cutting wheel 14 thus determines the maximum radial length of the cutting teeth 32. In order for soil material also to be removed from between the cutting wheels 14, in an area adjoining the narrow sides of the bearing shield 12, the outer cutting teeth 30, which run directly past the bearing shield 12, are not fixedly arranged on the cutting wheel 14 but instead are adjustable. These adjustable cutting teeth 30 can pivot about a rotary axis between a folded-in position and a folded-out position and can thus also be described as hinged teeth 30. By contrast, the other cutting teeth 32 are immovably or fixedly attached to the cutting wheel 14.
In the folded-in position, these adjustable cutting teeth 30 are pivoted away from the bearing shield 12 so they can be moved past it without collision. In the folded-out position, the adjustable cutting teeth 30 are pivoted out or folded out towards the bearing shield 12, so the blades 34 project into the area next to or below the bearing shield 12 and clear away soil material in that area. In
The length of the adjustable cutting teeth 30 and the thickness of the bearing shield 12 determine the quantity of material that can be removed in the area between the cutting wheels 14 and the size of the remaining “ridge” of soil material that is not removed. The thickness of the bearing shield 12 is determined in particular here by the intended use and the structural requirements of the system. The system-related excess soil material or ridge in the longitudinal direction of the trench cutter 10 (defined here as a direction parallel to the line connecting the rotary axes of the cutting wheels 14 arranged on either side of the suction box 20) leads to a reduction in the clearance between the trench cutter 10 and the lateral walls of the trench. This can lead to a reduction in the sliding properties of the trench cutter 10, leading to increased wear and poorer controllability of the trench cutter 10.
To minimise this excess material, the adjustable cutting teeth 30 are longer than the fixed cutting teeth 32, so they project further into the area next to or below the bearing shield 12 and remove more material in that area. Since this would lead to a collision with the suction box 20, the latter has, in accordance with the disclosure, a recess 22 (see
The recess 22 in the suction box 20 allows the adjustable cutting teeth 30 to be made significantly longer, so the removal of material from between the cutting wheels 14 or radially adjacent to the bearing shield 12 can be increased and the controllability of the trench cutter 10 can thus be improved. In particular, the recess 22 maximises the removal of material from between the cutting wheels 14, even with a thick bearing shield 12, making the shield universally usable (i.e. a single bearing shield 12 for multiple slurry wall dimensions).
In the exemplary embodiment shown in
In the exemplary embodiment of
In addition, in the embodiment shown here, a plurality of attachment elements 26 arranged on the side of the suction box 20 above the suction openings 25 serve for the attachment of additional elements (not shown here), such as dividing plates, to the suction box 20. These attachment elements 26 do not necessarily have to be present, however.
Instead of a design with a common suction box 20 for both pairs of cutting wheels, a separate suction box 20 can be provided for each pair of cutting wheels, each with its own recess 22 on each suction surface 24.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2022 131 161.9 | Nov 2022 | DE | national |
