A tightening device for tightening a series of nuts pre-threaded on a bolt
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-03-10
- Publication Date
- 2026-03-17
AI Technical Summary
Existing solutions for automatically tightening bolts in wind turbine flange connections are costly and complex due to the need for powerful electromagnets for propulsion, which increases the complexity and expense of the robot systems.
A fastening device with a continuous drive mechanism that operates on the top surface of nuts, eliminating the need for electromagnets by using a chain or belt drive that can grip the edges of the nuts for traction, thus providing a robust and reliable propulsion system that is simpler and less expensive to manufacture.
The solution enables efficient and reliable automatic tightening of bolts in wind turbine flange connections, reducing manufacturing costs and complexity while maintaining robust propulsion, thus facilitating faster and more economical construction of wind turbine towers.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a tightening device for tightening a set of nuts pre-threaded onto a bolt according to the preamble of claim 1. [Background technology]
[0002] In the field of modern energy production, wind turbines play a crucial role in providing renewable, sustainable, and clean energy for the energy market. A wind turbine comprises a tower on which a rotor connected to a generator is mounted. The tower can reach heights of 100 meters, 150 meters, or even more, depending on the specific requirements arising from the wind turbine's location, among other factors. The tower consists of several tube segments, e.g., 20 or 30 meters long. These segments are connected by circular flange connections on both sides of the tube segments. During on-site assembly of a wind turbine, the tube segments are fitted together and connected to the circular flange joints using bolts and nuts. A large number of large bolts, typically numbering in the hundreds, are required to establish the required stiffness and strength of the joints. To achieve the appropriate, specified stiffness and strength of the joints, all bolts must be tightened according to a specific bolt tightening pattern with a predetermined preload or torque.
[0003] Previously, this task was performed manually using a torque wrench or similar tool. Therefore, the construction of wind turbine towers required a significant amount of labor. To speed up construction, robots have been developed to automatically perform the bolting sequence. EP2607685A1 discloses a robot for tightening a series of nuts and bolts on a circular flange connection of a wind turbine joint. The robot includes at least two wheels and a drive for transporting the robot along the series of nuts and bolts, and a tool for tightening the nuts and bolts to a predetermined torque. The drive used in this robot is a belt drive that interacts with the tower's sidewall to propel itself forward. To achieve sufficient friction with the sidewall, several electromagnets are provided to press the belt drive against the sidewall. Using the sidewall as a means of propelling the robot is beneficial because it prevents obstacles, such as metal shavings, other tools, or additional obstacles, from colliding with the sidewall. This design therefore provides reliable propulsion for the robot. The drawback of this solution is that these electromagnets require significant power for the robot to operate, increasing the complexity and cost of the robot. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] EP2607685A1 Summary of the Invention [Problem to be solved by the invention]
[0005] The technical problem of the present invention is therefore to provide a means for automatically tightening bolts in a flange connection that is cheaper and easier to manufacture than previous solutions, while still providing a reliable driving force along the flange connection. [Means for solving the problem]
[0006] This problem is solved by providing a tightening device according to the subject matter of claim 1. The tightening device according to the invention is configured to tighten a series of nuts that are pre-threaded onto bolts. The bolts are arranged in a linear or curved flange connection, and each nut has an upper surface located at one end of the nut. The upper surface is arranged in a nut plane of the flange connection, and the tightening device comprises a propulsion unit for moving the tightening device along the flange connection. The propulsion unit of the device comprises a continuous drive. According to the invention, in the operating state of the tightening device, the continuous drive is essentially arranged in the nut plane of one or more upper surfaces of one or more of the nuts.
[0007] The upper surface of the nut is always located within the nut plane, even when the nut is not yet tightened, because the weight of the bolt ensures that the nut always abuts the flange connection of the respective tube segment of the tower. Therefore, the nut plane always provides a horizontal surface on which the continuous drive device can operate. Furthermore, the upper surface of the nut is always free of obstacles that could impede the movement of the tightening device. Furthermore, the use of a continuous drive device provides the advantage that the continuous drive device interacts with the nut in such a way that it can grasp the edges of the nut and utilize these edges to provide a grip. Furthermore, the continuous drive device is very robust and durable. The tightening device structure according to the present invention therefore offers the advantage of a reliable and robust propulsion means that does not require any additional mechanism for attaching the continuous drive device to the drive surface, and is therefore less complex and less expensive to manufacture than known solutions in the prior art.
[0008] According to a preferred embodiment of the clamping device according to the invention, the propulsion unit comprises a guide element which, in the operating state of the clamping device, preferably faces one side of one or more of the nuts or bolts of the flange connection. The guide element reduces the risk that the continuous drive device will move away from the upper surface of the nut during operation of the clamping device. This is particularly advantageous when operating the clamping device at high speeds.
[0009] The continuous drive preferably comprises a chain of interlocking chain segments, one or more of which preferably comprises a friction element oriented toward the nut plane in the operating state, the friction element preferably being made of rubber or plastic material. The friction element increases the friction of the continuous drive against the upper surface of the nut. The friction element is also preferably replaceable. By replacing the friction element, the life of the continuous drive can be extended. The friction element may also be glued to the chain segment. According to a preferred embodiment of the tightening device of the present invention, each of the chain segments comprises at least one friction element. The chain is essentially positioned on the nut plane of one or more upper surfaces of one or more of the nuts in the operating state of the tightening device. According to an alternative embodiment, the continuous drive may comprise a drive belt, which may have a circular or flat cross section, and is essentially positioned on the nut plane of one or more upper surfaces of one or more of the nuts in the operating state of the tightening device.
[0010] The propulsion unit may preferably comprise a swivel joint for pivotally supporting the continuous drive, the swivel joint enabling the continuous drive to adapt to different curvatures and radii of the flange connection.
[0011] According to a preferred embodiment, the tightening device also includes a positioning unit adapted to control the continuous drive device according to the positioning information. The positioning unit preferably includes a camera configured to capture image data of the flange connection in an operating state of the tightening device, and the positioning unit configured to extract the positioning information from the image data. By using the positioning unit, the tightening device may automatically tighten the nuts of the flange connection according to a predetermined tightening sequence. Furthermore, the positioning device ensures that each nut to be tightened is aligned with the tightening device according to specifications.
[0012] The tightening device may also include a nut tightening unit and two propulsion units arranged essentially on either side of the nut tightening unit, with each continuous drive of each propulsion unit essentially positioned on a nut plane of one or more upper surfaces of one or more of the nuts when the tightening device is in an operating state. By providing two continuous drives on either side of the tightening device, the smoothness of the movement of the tightening device can be improved.
[0013] The propulsion unit may also include two guide elements that face opposite sides of one or more of the nuts or bolts of the flange connection when the tightening device is in operation, thereby improving the guiding effect when the tightening device is operated at high speeds.
[0014] Furthermore, the continuous drive may comprise two chains, each of which, in the operating state of the tightening device, is essentially positioned opposite at least one bolt on the nut plane of one or more upper surfaces of one or more of the nuts, so that an increased surface area can be utilized for traction of the continuous drive.
[0015] The clamping device according to the present invention, as well as preferred and alternative embodiments, will now be described with reference to the drawings. [Brief explanation of the drawings]
[0016] [Figure 1] 1 shows a front view of a clamping device according to the present invention; [Figure 2] 1 shows a clamping device according to the invention in a perspective view; [Figure 3] 1 shows a cross-sectional view of a clamping device according to the invention; [Figure 4] 1 shows a front view of a propulsion unit of a clamping device according to the invention; [Figure 5] 5 shows a side view of the propulsion unit of FIG. 4. [Figure 6]5 shows a thrust unit of the tightening device according to FIG. 4 placed on a series of nuts of a flange connection. [Figure 7] 7 shows a side view of the propulsion unit of FIG. 6. DETAILED DESCRIPTION OF THE INVENTION
[0017] A tightening device 1 according to the present invention is shown in a preferred embodiment in a front view in FIG. 1 and in an operational perspective view in FIG. 2. The tightening device 1 is designed to tighten a series of nuts 2 pre-threaded onto bolts 3, which are arranged in a straight or curved flange connection 4. Each nut 2 has an upper surface 5 located at one end of the nut 2, which upper surface 5 is arranged in a nut plane 6 of the flange connection 4. The tightening device 1 is equipped with a propulsion unit 7 for moving the tightening device 1 along the flange connection 4. According to the present invention, the propulsion unit 7 includes a continuous drive 8, which, in the operational state of the tightening device 1, is essentially positioned on the nut plane 6 of one or more upper surfaces 5 of one or more of the nuts 2. This is shown in more detail in FIGS. 6 and 7. The continuous drive 8 thus uses the upper surfaces 5 of the nuts 2 as a drive surface for propelling the tightening device 1 in either direction along the flange connection 4. The upper surfaces 5 naturally align with the nut plane 6 due to the weight of the bolt 3 crossing the flange connection 4, providing a horizontal drive surface. By using the continuous drive devices 8 according to the present invention, these upper surfaces 5 can be used to advance the tightening device 1. The upper surfaces 5 are naturally also free of obstacles, such as tools or other equipment, that could impede the movement of the tightening device. By using the continuous drive devices 8, the spaces between the nuts 2 can also be easily filled, thereby enabling smooth movement of the tightening device 1. To fill these gaps or spaces between the nuts 2, the continuous drive devices 8 preferably have a length greater than the width of the gap between two adjacent nuts 2. The continuous drive devices 8 also have the advantage of being able to grip the edges of the nuts 2, thereby increasing the traction force on the nuts 2. The structure of the tightening device 1 according to the present invention therefore provides a reliable and robust propulsion means for the tightening device 1, which is simple and easy to assemble.
[0018] According to a preferred embodiment of the tightening device 1 of the present invention, the propulsion units 7 are provided with guide elements 9 which, in the operating state of the tightening device 1, preferably face one side of one or more of the nuts 2 or bolts 3 of the flange connection 4. As can be seen in Figures 1 and 2, the guide elements 9 are arranged facing the sides of the bolts 3. Preferably, two guide elements 9 are provided on each propulsion unit 7, which are arranged on either side of the nut 2 and / or bolt 3 in the operating state of the tightening device 1. The provision of one or more guide elements 9 ensures that the continuous drive 8 is aligned with the curved portion of the flange connection 4 during operation or movement of the tightening device 1.
[0019] The continuous drive 8 preferably comprises a chain 10 of interlocking chain segments, which are not shown in detail in the figures. The chain 10 can be seen, for example, in FIG. 6. These chain segments function similarly to tank chains or excavator chains. One or more of these chain segments preferably comprise friction elements oriented toward the nut plane 6 when the tightening device 1 is in operation. The friction elements are preferably made of rubber or plastic material. The friction elements increase the traction of the continuous drive 8 on the upper surface 5 of the nut 2 and further reduce wear and tear on the continuous drive 8. Preferably, each chain segment comprises at least one friction element. The friction elements may be replaceable or permanently fixed to the chain segment. They may be, for example, glued or riveted to the chain segment. The replaceable friction elements increase the usable life of the continuous drive 8, and the permanently fixed friction elements reduce the risk of losing one or more of the friction elements during operation of the tightening device 1. The chain 10 is essentially arranged on the nut plane 6 of the one or more upper surfaces 5 of one or more of the nuts 2 in the operating state of the tightening device 1. According to an alternative embodiment, the continuous drive 8 may comprise a drive belt, which may have a circular or flat cross section, and which is essentially arranged on the nut plane 6 of the one or more upper surfaces 5 of one or more of the nuts 2 in the operating state of the tightening device 1.
[0020] As can be seen in Figures 1 and 4, the propulsion unit 7 of the tightening device 1 according to the present invention, according to a preferred embodiment, comprises a swivel joint 11 that pivotally supports the continuous drive device 8. The swivel joint 11 ensures that the continuous drive device 8 can follow the narrow curves of the flange connection 4. The swivel joint 11 may also comprise a locking mechanism or lock plate 12 for locking the movement of the swivel joint 11, if necessary. The lock plate 12 is shown in Figures 4 and 5.
[0021] The continuous drive device 8 may also include a tensioning mechanism 13, as shown in FIG. 6 . Furthermore, the tightening device 1 may also include a positioning unit, which is adapted to control the continuous drive device 8 according to the positioning information. The positioning unit may also include a camera 14, as shown in FIGS. 1 , 2, and 3 , which is configured to capture image data of the flange connection 4 when the tightening device 1 is in operation, and which is configured to extract the positioning information from the image data. The positioning unit enables the tightening device 1 to accurately position itself above a specific nut 2 and tighten the nut 2. Furthermore, the positioning unit enables the tightening device 1 to tighten the nut 2 according to a specific tightening sequence.
[0022] The tightening device 1 further comprises a nut tightening unit 15 for tightening the nuts 2 and preferably two propelling units 7 with continuous drives 8 arranged essentially on either side of the nut tightening unit 15, as can be seen in Figure 1. In the operating state of the tightening device 1, according to this embodiment, each continuous drive 8 is arranged essentially on the nut plane 6 of one or more upper surfaces 5 of one or more of the nuts 2. By providing two separate continuous drives 8, the smoothness of movement of the tightening device 1 can be improved and an increased drive surface for propelling the tightening device 1 can be used.
[0023] The propulsion unit 7 according to the preferred embodiment as shown in the figures may also comprise two guide elements 9, as shown in Figure 2, which face opposite sides of one or more of the nuts 2 or bolts 3 of the flange connection 4 in the operating state of the tightening device 1. This is shown, for example, in Figures 5 and 7. This improves the guiding effect when the tightening device is operated at high speeds.
[0024] Furthermore, the continuous drive 8 may comprise two chains 10, each of which, in the operating state of the tightening device, is essentially arranged on the opposite side of at least one bolt 3 on the nut plane 6 of one or more upper surfaces 5 of one or more of the nuts 2. This allows an increased surface area to be utilized for traction of the continuous drive 8. This configuration of the chains 10 is shown, for example, in Figures 5 and 7. One or both of these chains 10 may be replaced by a belt according to an alternative embodiment.
Claims
1. A tightening device (1) for tightening a series of nuts (2) pre-screwed onto a bolt (3), wherein the bolt (3) is arranged on a straight or curved flange connection portion (4), each nut (2) has an upper surface (5) located at one end of the nut (2), the upper surface (5) is located within the nut plane (6) of the flange connection portion (4), and the tightening device (1) includes a propulsion unit (7) for moving the tightening device (1) along the flange connection portion (4), The propulsion unit (7) comprises a continuous drive device (8), and in the operating state of the fastening device (1), the continuous drive device (8) is essentially positioned on the nut plane (6) of one or more of the upper surfaces (5) of one or more of the nuts (2), the fastening device (1).
2. The fastening device (1) according to claim 1, wherein the propulsion unit (7) comprises a guide element (9), and the guide element (9) preferably faces one side of one or more of the nuts (2) or bolts (3) of the flange connection portion (4) in the operating state of the fastening device (1).
3. The fastening device (1) according to claim 1 or 2, wherein the continuous drive device (8) comprises a chain (10) of connected chain segments, and one or more of the chain segments preferably comprises a friction element oriented toward the nut plane (6) in the operating state, and the friction element is preferably made of rubber or plastic material.
4. The clamping device (1) according to claim 3, characterized in that the friction element is replaceable.
5. The fastening device (1) according to claim 3, characterized in that the friction element is bonded to the chain segment.
6. The fastening device (1) according to claim 3, characterized in that each of the chain segments comprises at least one friction element.
7. The clamping device (1) according to claim 1 or 2, characterized in that the propulsion unit (7) is provided with a swivel joint (11) that pivotably supports the continuous drive device (8).
8. The fastening device (1) according to claim 1 or 2, characterized in that it comprises a positioning unit adapted to control the continuous drive device (8) according to positioning information.
9. The fastening device (1) according to claim 8, characterized in that the positioning unit includes a camera (14), the camera (14) is configured to capture image data of the flange connection portion (4) in the operating state of the fastening device (1), and the positioning unit is configured to extract the positioning information from the image data.
10. The fastening device (1) according to claim 1 or 2, comprising a nut fastening unit (15) and two propulsion units (7) essentially arranged on both sides of the nut fastening unit (15), wherein in the operating state of the fastening device (1), each continuous drive unit (8) of each propulsion unit (7) is essentially arranged on the nut plane (6) of one or more upper surfaces (5) of one or more of the nuts (2).
11. The propulsion unit (7) comprises two guide elements (9), the two guide elements (9) facing one or more opposing sides of the nut (2) or bolt of the flange connection portion (4) in the operating state of the fastening device (1), as described in claim 1 or 2.
12. The fastening device (1) according to claim 1 or 2, wherein the continuous drive device (8) comprises two chains (10) of connected chain segments, and in the operating state of the fastening device (1), each chain (10) is essentially positioned opposite at least one bolt (3) on the nut plane (6) of one or more upper surfaces (5) of the nuts (2).