Slot wall cutter

Abstract

Diaphragm wall cutter (1) comprising: a milling frame (2) for receiving at least one component of the diaphragm wall cutter (1), characterized by a center of gravity compensation device (3) for varying the center of gravity in the diaphragm wall cutter (1) in order to avoid tilting of the suspended diaphragm wall cutter (1).

Description

The present invention relates to a slot wall cutter which has a center of gravity compensation device for varying the center of gravity of the slot wall cutter in order to compensate for an inclination of the suspended cutter and to prevent drifting during the milling process. Diaphragm wall cutters are frequently used in specialist foundation engineering to create narrow, deep trenches in the ground, which are later filled with concrete. However, different attachments, variable cutting tools, or changing drilling configurations alter the cutter's center of gravity, often leading to undesirable tilting or lateral displacement of a suspended diaphragm wall cutter. This impairs the milling result and necessitates additional corrective measures. With a conventional, unbalanced trench cutter, which is typically attached to a crane or boom and lowered vertically into the ground, this can significantly impair the milling process. First, the cutter tends to tilt because its center of gravity shifts with every change of tools or attachments, without any means of compensation. This tilt not only affects the precise guidance of the cutter in the trench but is also exacerbated during operation by the forces acting upon it, ultimately degrading the milling result and, in extreme cases, even bringing work to a standstill. Simultaneously, there is a risk that the cutter will drift laterally if it is not properly balanced, because an unevenly distributed mass creates a constant lateral force that is transmitted to the cutting tools.This not only results in uneven stress on the milling tools but also causes faster wear and thus more frequent maintenance intervals. In practice, this is compounded by more difficult handling and safety risks, as an uneven position promotes pendulum action and potential tipping moments of the suspended milling machine, placing an additional strain on the operator. Furthermore, poorly milled slots lead to higher follow-up costs because either extensive rework is required or additional stabilizing measures must be taken to ensure the desired shape. Conventional diaphragm wall milling machines therefore exhibit reduced precision and cost-effectiveness of the milling process and also have limited flexibility in their use, as any change to the design and configuration is problematic with regard to the above-explained disadvantageous shift in the center of gravity. The present invention aims to solve or at least mitigate some or all of the aforementioned problems. This is achieved with a working machine according to the invention as defined in claim 1. Further advantageous embodiments are specified in the dependent subclaims. The slot wall milling machine according to the invention comprises a milling frame for receiving at least one component of the slot wall milling machine and is characterized by a center of gravity compensation device for varying the center of gravity in the slot wall milling machine in order to avoid tilting of the suspended slot wall milling machine. The integrated center of gravity compensation device in the trench cutter ensures that the cutter is always vertically aligned, thus preventing tilting of the suspended cutter. This results in a more precise milling pattern, as no disruptive lateral forces act on the cutting or milling tools. At the same time, operation becomes safer for personnel because the pendulum and tilting behavior of the cutter is significantly reduced. According to an optional further development of the present invention, it can be provided that the center of gravity compensation device is arranged on an inside side of the milling frame. Positioning the center of gravity compensation device on the inside of the milling frame offers the advantage of optimal protection against external influences such as impacts, shocks, or dirt during operation. Furthermore, the outer contour of the trench cutter remains largely unchanged, which facilitates transport and insertion into the trench. The internal position also allows for a compact design, increasing the frame's stability. According to a further advantageous modification of the present invention, it can be provided that the milling frame has a substantially cuboid basic structure, in which at least one milling element is provided on a first end face and a lifting device for lifting the slot wall milling machine is provided on a second end face opposite the first end face. The essentially cuboid design of the milling frame, with the milling element positioned at one end and a lifting device at the opposite end, facilitates weight balance, as the main mass of the at least one milling element and the suspension of the slot wall cutter are clearly separated. This clear division into a milling and a lifting zone simplifies assembly and maintenance and allows for precise adjustment of the center of gravity. Preferably, the center of gravity compensation device can be arranged on a connecting surface that joins the first end face and the second end face. In particular, the center of gravity compensation device is arranged in the half of the milling frame facing the at least one milling element, and especially in the third of the milling frame adjacent to the milling element. Positioning the center of gravity compensation device at the connection surface between the first and second end faces allows for efficient force transmission, as it can effectively influence the center of gravity. This prevents misalignments that could occur if the center of gravity is shifted laterally relative to the longitudinal direction of the milling frame. Furthermore, by mounting the center of gravity compensation device in the lower section of the frame, specifically in the lower third, the resulting lever arm to the suspension point allows for a weight-efficient center of gravity correction, ensuring that the machine remains stable and guided straight within the floor slot throughout the entire milling process. According to a further optional modification of the present invention, the center of gravity compensation device can be designed to attach at least one weight element or a plurality of weight elements to the milling frame, preferably wherein the at least one weight element is a sheet metal part. The ability to attach at least one or more weight elements to the milling frame allows for flexible adjustment of the center of gravity to different working conditions and milling configurations. Since these weight elements can preferably be made of sheet metal, they are cost-effective to manufacture and robust enough to withstand the rigors of construction site use. Furthermore, the modular design allows for incremental changes to the overall mass, ensuring that the diaphragm wall cutter operates as close as possible to its ideal balance. This makes it possible to adjust the number of weight elements to achieve the required shift in the center of gravity. According to a further optional development of the present invention, it can be provided that the center of gravity compensation device comprises a receiving device for the defined arrangement of at least one weight element on the milling frame. The mounting device for the defined arrangement of the weight elements creates a structured and repeatable attachment method on the milling frame. This not only simplifies the mounting of individual weights but also ensures that the weights cannot shift uncontrollably during operation of the diaphragm cutter. This precise positioning allows the user to quickly and reliably adjust the center of gravity without having to perform extensive measurements or readjustments. Advantageously, the receiving device may have at least one centering pin protruding from the milling frame, which serves to interact with the at least one weight element in order to arrange it on the milling frame in a predetermined manner. A centering pin projecting inwards or outwards from the milling frame enables the secure and intuitive placement of the weight elements, as they are automatically positioned correctly thanks to the guide provided by the centering pin. This simplifies handling the weight elements and prevents unintentional twisting or slippage, ensuring reliable balance of the center of gravity even during operation of the trench cutter. According to a further advantageous embodiment of the present invention, the receiving device may include at least one recess formed in the milling frame in which an internal thread is provided to provide a screw connection for fastening the at least one weight element. The recess with internal thread formed in the milled frame offers an additional option for fixing the weight elements using screw connections. This allows for even more secure fastening, making loosening of the weights unlikely or impossible, even under high vibrations or impacts. This type of fastening is also universally applicable, as standard screw systems can be used, and quick assembly and disassembly are possible. Furthermore, according to a further advantageous modification of the present invention, it can be provided that the at least one weight element has a contour or a shape that is adapted to the receiving device in order to enable the at least one weight element to be attached to the receiving device. If at least one weight element has a contour or shape that is matched to the mounting device, a precise and play-free connection between the weight and the milling frame is achieved. This precise alignment contributes to increased stability, as the forces are distributed evenly and no unwanted movement can occur. Furthermore, the clear design facilitates changing the weights, as the position is immediately fixed without time-consuming alignment. According to a further advantageous embodiment of the present invention, the receiving device can be designed to attach a plurality of adjacent weight elements, in particular weight elements stacked relative to each other, to the milling frame. The design of the mounting device for a large number of adjacent, especially stacked, weight elements significantly increases the modularity of the slot wall cutter. By arranging multiple plates without play, the user can incrementally increase or decrease the total mass, enabling extremely precise adjustment of the slot wall cutter's center of gravity. At the same time, the cutter's dimensions remain compact, as the weights are placed in a space-saving, stacked arrangement or in a position with no play relative to each other. According to a further embodiment of the present invention, it can be provided that each weight element has a weight that is no heavier than 35 kg, preferably no heavier than 28 kg and preferably no heavier than 20 kg. Weight elements weighing 35 kg or less can still be handled by a single person and thus meet ergonomic guidelines on construction sites. This reduces the risk of injury and saves time, as no additional lifting aids or special equipment are required for assembly. Furthermore, the relatively low weight, which can be handled by a single operator, allows for easy disassembly and storage, enabling the trench cutter to be flexibly adapted to different conditions without the need for an additional lifting device for the weight element. According to a further optional modification of the present invention, it can be provided that the at least one weight element is a weight plate which preferably has at least one recess or at least one opening for manual gripping of the weight plate and / or at least one recess or at least one opening for interaction with at least one centering pin of the receiving device. Equipping the weight plate with at least one opening for manual gripping and / or interaction with the centering pin greatly simplifies the entire assembly and disassembly process. Thanks to these openings, a person can securely grip the plate without having to resort to improvised aids, thus speeding up workflows. At the same time, the recesses, which interact with the centering pin, ensure that the plate fits precisely into its intended position, guaranteeing stable and correct center of gravity balancing. It may also be provided that the recesses / openings for gripping the weight plate are identical to the recesses / openings for interacting with the at least one centering pin. According to a further optional development of the present invention, it can be provided that the several weight elements are identical to each other. The identical design of several weight elements results in high interchangeability and reduces the number of different parts that need to be kept on the construction site. This simplifies logistics, as only a single type of weight element needs to be stocked. Furthermore, assembly errors are virtually eliminated because each weight element is attached to the mounting device using the same systematic method. Furthermore, according to an advantageous embodiment of the present invention, it can be provided that the multiple weight elements are weight plates which can interact with the receiving device both in a first orientation, in which a first flat side faces the milling frame, and in a second orientation, in which a second flat side faces the milling frame, preferably wherein several weight plates arranged in the receiving device are arranged with a respective orientation which is designed to alternate with each other, so that engagements for easier disassembly of the multiple weight plates from each other are created. If the weight plates can be mounted in both a primary and secondary orientation, installation flexibility increases considerably. This alternating orientation, combined with a specific design of identically shaped weight plates, creates gaps or spaces within a stack of weight plates arranged without play. These gaps act as grips and lever points, allowing for the reliable removal of rusted or stuck plates, even after extended use. This ensures safe removal of the plates without special tools, even after months or years. In harsh environments, especially those containing salt water, closely spaced weight plates tend to form a strong bond due to corrosion, which cannot be easily broken. In such cases, it is advantageous if each stacked weight plate has at least one section extending beyond the adjacent plate, allowing leverage to be applied with a tool to separate the individual plate. Preferably, it can be provided that the multiple weight plates, which are identical to each other, assume a different support contour relative to the milling frame after being turned from the first flat side to the second flat side in the receiving device. The different support contour of a reversed weight plate on the holding device makes it possible to provide corresponding sections for attaching a tool for separating a single plate when several plates are stacked and arranged without play on the holding device. If a plate connected to the centering pin of the mounting device is turned over, with the turned plate then again in operative contact with the centering pin, a contact contour is created on the milling frame that differs from the contact contour of the unturned weight plate. This difference in the contact contour forms a lever section for releasing the plate. Further features, details, and advantages of the invention will become apparent from the following description of the figures. These show: Fig. 1: a schematic side view of a slot wall milling machine according to the invention; Fig. 2: an enlarged area from Fig. 1, showing the center of gravity compensation device; Figs. 3a-d: schematic representations of the center of gravity compensation device in various states with and without weight elements; Figs. 4a-c: a top view of the respective Figs. 3b-3d; Fig. 5: a schematic view of a weight plate; and Fig. 6: a perspective view of the receiving device with a plurality of weight plates arranged without play relative to one another. Fig. 1 shows a schematic side view of a slot wall milling machine 1 according to the invention. The milling frame 2 is visible, which generally has a cuboid-shaped base and on whose lower side (the lower end face 7) two milling elements 4 are arranged. A lifting device 5 is provided on the upper side, the upper end face 6 of the milling frame 2, which is spaced apart from the lower side and enables the slot wall milling machine 1 to be raised by a lifting device. Furthermore, a center of gravity compensation device 3 can be seen, which is arranged in the half of the cuboid-shaped basic structure of the milling frame 2 facing the two milling elements 4. If, in an exemplary configuration of the slot wall cutter 1, the center of gravity is shifted to the left as shown in Fig. 1, the center of gravity can be shifted towards a balanced state by arranging weight plates 9 in the center of gravity compensation device 3 or the receiving device 10. Fig. 2 shows an enlarged view of the center of gravity compensation device 3 from Fig. 1, in which it can be seen that several weight elements 9 are attached to the receiving device 10 arranged on the milling frame 2 by means of a centering pin 11. Figures 3a to 3d show different states of the center of gravity compensation device and the receiving device 10. In Fig. 3a, the milling frame 2 is provided with recesses 12 of the receiving device 10, which have an internal thread for screwing in appropriately designed fastening screws. Fig. 3b shows two centering pins 11, which simplify the insertion of the at least one weight plate 9, so that fixing with screws does not have to be done simultaneously with holding the respective weight plate 9 or several weight plates 9. The respective centering pins 11 can also be attached to the milling frame via the screw connection of the mounts 12 of the mounting device 10. Fig. 3c shows a state of the receiving device 10 in which several weight plates 9, but not yet the maximum number of weight plates 9, have been inserted into the receiving device 10. It can be seen that the weight plates 9 are held by means of the two centering pins 11, so that after a sufficient number of weight plates 9 have been arranged, they can be fastened in a subsequent step using appropriate screws 17. Thus, each weight plate 9 can be attached to the centering pins 11 before, after reaching the desired number of weight plates 9, the weight plates are attached to the milling frame 2. Furthermore, it can be seen that the identically designed weight plates 9 are not inserted into the receiving device 10 in exactly the same orientation, but rather that directly adjacent weight plates are rotated in their orientation relative to each other. This creates engagement areas 15 due to the specific design of the weight plate 9, which simplify the disassembly of the weight plates that are stuck together. Fig. 3d shows an almost maximum or maximum number of weight plates 9 interacting with the receiving device 10. The adjacent weight plates 9 have such dimensions that the centering pin 11 can no longer hold another weight plate 9, since the cumulative thickness of the multiple weight plates has reached the longitudinal dimension of the centering pin 11. For easier handling of each weight plate 9, a recess 13 for manual gripping can be provided, which simplifies the insertion or removal of a weight plate 9 from the receiving device 10 for an operator. Figures 4a-4c show corresponding representations of Figures 3b-3d described above in a top view. In Fig. 4a, it can first be seen that the two centering pins 11, which are aligned parallel to each other, are inserted into a recess of the receiving device 12, in particular screwed in. In Fig. 4b, it can be seen that a certain number of weight plates 9 are hooked into the respective centering pins 11 and are attached to the milling frame 2 with a screw connection 15 (not visible in this Fig.). Fig. 4c shows an even larger number of weight plates 9 inserted into the receiving device 10, where almost the maximum number, or even the maximum number, of possible weight plates 9 has been reached. The individual weight plates 9 are arranged in a kind of stack relative to each other, with their flat sides aligned without any play. Fig. 5 shows a schematic perspective view of a weight plate 9, which interacts with the center of gravity compensation device 3 or the receiving device 10. The plate-like structure of the weight plate and the recess 14 for interaction with a respective centering pin 11 are immediately apparent. Several openings 16 for the insertion of a fastening element, which can be used to fix the weight to the milling frame, are also visible. As an example, a screw is shown here passing through the opening, engaging with a corresponding internal thread on the milling frame 2. The grip recess 13, which significantly simplifies the handling of the weight plate 9 and allows for easy gripping by an operator, is also visible. Furthermore, the dimensions of the weight plate 9 are designed such that when it is turned over and subsequently hooked onto the centering pins 11, a contour is created that differs from that of a non-turned weight plate also hooked onto the centering pins. This creates, in the case of a stack of weight plates 9 where every second weight plate 9 is turned over, indentations 15 that can be used to more easily detach weight plates 9 that are stuck together. Fig. 6 shows a perspective view of the center of gravity compensation device 3, in which a plurality of weight plates 9 are attached to the centering pin 11 of the receiving device 10 on the milling frame 2. The invention provides a solution to the problem described above by providing an adjustable ballast system with easily mounted weight plates 9. These weight plates 9 can be slid onto centering bolts 11 and are firmly fixed to the milling frame 2 by means of screws 17. To ensure uncomplicated (dis)assembly and efficient reusability, the weight plates 9 are designed to rotate alternately, while tabs or engagements 15 and handle openings 13 always remain accessible. In this way, individual center of gravity adjustments can be made without having to carry out extensive modifications to the slot milling machine 1. The weight plates 9, which are essentially made of sheet metal components, provide a cost-effective solution that is both flexible and robust. The invention also allows for adaptation to various designs and sizes of the slot wall cutter 1, thus covering a wide range of applications. Reference symbol list 1 Slot wall cutter 2 Milling frame 3 Center of gravity compensation device 4 Milling element 5 Lifting arrangement 6 First end face 7 Second end face 8 Connecting surface 9 Weight element 10 Mounting device 11 Centering pin 12 Recess of the mounting device 13 Recess of the weight plate for manual gripping 14 Recess of the weight plate for interaction with the centering pin 15 Recesses for disassembly in a stacked arrangement of weight plates 16 Opening for insertion of a fastening element 17 Fastening element for interaction with recess 12

Claims

Diaphragm wall cutter (1) comprising: a milling frame (2) for receiving at least one component of the diaphragm wall cutter (1), characterized by a center of gravity compensation device (3) for varying the center of gravity in the diaphragm wall cutter (1) in order to avoid tilting of the suspended diaphragm wall cutter (1). Slot wall milling machine (1) according to the preceding claim 1, wherein the center of gravity compensation device (3) is arranged on an inside side of the milling frame (2). Slot wall milling machine (1) according to one of the preceding claims, wherein the milling frame (2) has a substantially cuboid basic structure, in which at least one milling element (4) is provided on a first end face (7) and a lifting device (5) for lifting the slot wall milling machine (1) is provided on a second end face (6) opposite the first end face (7). Slot wall cutter (1) according to the preceding claim 3, wherein the center of gravity compensation device (3) is arranged on a connecting surface (8) connecting the first end face (7) and the second end face (6). Slot wall milling machine (1) according to one of the preceding claims, wherein the center of gravity compensation device (3) is designed to attach at least one weight element (9) or a plurality of weight elements (9) to the milling frame (2), preferably wherein the at least one weight element (9) is a sheet metal part. Slot wall milling machine (1) according to one of the preceding claims, wherein the center of gravity compensation device (3) comprises a receiving device (10) for the defined arrangement of at least one weight element (9) on the milling frame (2). Slot wall milling machine (1) according to the preceding claim 6, wherein the receiving device (10) has at least one centering pin (11) projecting from the milling frame (2), which serves to cooperate with the at least one weight element (9) in order to arrange it on the milling frame (2) in a predetermined manner. Slot wall milling machine (1) according to one of the preceding claims 6 or 7, wherein the receiving device (10) comprises at least one recess (12) formed in the milling frame (2) in which an internal thread is provided to provide a screw connection for fastening the at least one weight element (9). Slot wall milling machine (1) according to one of the preceding claims 6 - 8, wherein the at least one weight element (9) has a contour or shape adapted to the receiving device (10) to enable the attachment of the at least one weight element (9) to the receiving device (10). Slot wall milling machine (1) according to one of the preceding claims 6 - 9, wherein the receiving device (10) is designed to attach a plurality of adjacent weight elements (9), in particular weight elements (9) stacked relative to each other, to the milling frame (2). Slot wall cutter (1) according to one of the preceding claims 5 - 10, wherein the at least one weight element (9) has a weight that is not heavier than 35 kg, preferably not heavier than 28 kg and preferably not heavier than 20 kg. Slot wall milling machine (1) according to one of the preceding claims 5 - 11, wherein the at least one weight element (9) is a weight plate which preferably has at least one recess (13) or at least one opening for manual gripping of the weight plate and / or has at least one recess (14) or at least one opening for cooperating with at least one centering pin (11) of the receiving device (10). Slot wall cutter (1) according to one of the preceding claims 5 - 12, wherein the multiple weight elements (9) are identical to each other. Slot wall milling machine (1) according to one of the preceding claims 5 - 13, wherein the multiple weight elements (9) are weight plates which can interact with the receiving device (10) both in a first orientation, in which a first flat side faces the milling frame (2), and in a second orientation, in which a second flat side faces the milling frame (2), preferably wherein several weight plates arranged in the receiving device (10) are arranged with a respective orientation which is designed to alternate with each other, so that engagements (15) are created for easier disassembly of the multiple weight plates from each other. Slot wall milling machine (1) according to the preceding claim 14, wherein the multiple weight plates, which are identical to each other, assume a different support contour relative to the milling frame (2) after being turned from the first flat side to the second flat side in the receiving device (10).

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