Method for loosening or tightening a screw connection between a core drill and a core bit, and core drill
Patent Information
- Application Number
- EP2023729109
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-07
- Filing Date
- 2023-05-26
- Publication Date
- 2025-04-16
AI Technical Summary
Conventional screw connections between core drilling devices and drill bits are difficult to loosen due to high forces required, especially when corrosion occurs, and existing methods like using wrenches, easy-release rings, or lubricants have drawbacks such as tool loss, reduced system rigidity, or contamination.
A method involving a core drilling device with a motor that generates a counter-torque during tool change to simplify the loosening or tightening of the screw connection between the core drilling device and the drill bit, using controlled motor operation to increase torque difference and requiring only one additional tool, such as a wrench.
Enables easy and efficient loosening or tightening of the screw connection without additional tools or lubricants, reducing contamination and material consumption, and simplifying the process of attaching or detaching the drill bit from the core drilling device.
Smart Images
Figure 1.1
Abstract
Description
[0001] Method for loosening or tightening a screw connection between a core drilling machine and a core bit, and core drilling machine
[0002] The present invention relates to a method for tightening or loosening a screw connection between a core drilling machine and a drill bit, wherein the core drilling machine comprises a drill bit and a motor, wherein the drill bit can be caused to move in a first rotational direction, while a counter torque is generated by controlling the motor during the tool change in order to tighten or loosen the rotary lock between the core drilling machine and the drill bit. In a second aspect, the invention relates to a core drilling machine for carrying out the proposed method. By controlling the motor of the core drilling machine, the motor can be caused to work against the movement of the drill bit in the first rotational direction. As a result, a difference between the torque in the first rotational direction and the counter torque can be significantly increased by controlling the motor.
[0003] Background of the invention:
[0004] Core drilling machines are known in the art, which can be used to cut essentially cylindrical cores from substrates to be processed, such as masonry, sand-lime brick, or concrete. Cables or pipes, for example, can then be laid or installed in the essentially cylindrical boreholes. The core drilling machines can be connected to core bits, with the core bits being driven into the subsurface to cut out the core.
[0005] Conventional drilling systems consisting of a core drill and core bit use screw connections to attach the core bit to the core drill. Due to the high forces applied during drilling, such a screw connection may be very difficult to loosen. This can be particularly true if corrosion also occurs and the core bit has not been removed from the core drill for an extended period.
[0006] There are essentially three known approaches to releasing such difficult-to-remove connections between a core drilling machine and a core bit. For example, it is known in the art to use multiple tools, such as wrenches with long levers, to generate the forces required to separate the core drilling machine and the core bit. A wrench is applied to the core drilling machine and a wrench is applied to the core bit, and the leverage can be improved by additionally using pipes or rods. This approach has the obvious disadvantage that the corresponding tools must be carried along and can easily be lost.
[0007] Another way to facilitate the loosening of a screw connection between the core drilling machine and the core bit is to use so-called "easy-release rings." These are copper and / or rubber discs that can be placed between the core drilling machine and the core bit. However, such easy-release rings have the disadvantage that their use reduces the rigidity of the drilling system consisting of the core drilling machine and the core bit. Reduced system rigidity can lead to difficulties when starting the drilling process.
[0008] A third option for facilitating the loosening of a screw connection between the core drilling machine and the core bit is the generous application of lubricant. However, due to obvious disadvantages such as material consumption and contamination, this method is not suitable as a long-term, satisfactory technical solution for separating the core bit from the core drilling machine.
[0009] The object underlying the present invention is therefore to overcome the above-described deficiencies and disadvantages of the prior art and to provide a method and a core drilling machine that enable particularly simple tightening or loosening of the core drilling machine and core bit. The solution should, in particular, be easy to handle and not lead to additional contamination of the construction site. Above all, the invention should enable the connection or release of the core bit from the core drilling machine with as few additional tools as possible, such as wrenches and / or pipes.
[0010] The problem is solved by the subject matter of the independent claims. Advantageous embodiments of the subject matter of the independent claims can be found in the dependent claims.
[0011] Description of the invention: According to the invention, a method for tightening or loosening a screw connection between a core drilling machine and a drill bit is provided, the method comprising the following method steps: a) Providing a core drilling machine with
[0012] - a core bit which is attached to the core drilling machine by means of a screw connection when the core drilling machine is in operation, and
[0013] - a motor configured to generate a torque to drive the core bit, b) movement of the core bit in a first direction of rotation, while controlling the motor generates a counter torque to tighten or loosen the screw connection between the core drilling machine and the core bit.
[0014] The basic idea of the invention is based on the interaction between the movement of the drill bit in a first direction of rotation A, which is opposite to a direction B of the counter torque. The counter torque, which in the sense of the invention is preferably also referred to as counter-holding torque, is preferably generated by controlling the motor of the core drilling machine during the tool change. The term «tool change» in the context of the present invention preferably refers to the detachment of the drill bit from the core drilling machine, for example in order to replace the drill bit. When changing the tool, the screw connection between the drill bit and the core drilling machine is preferably loosened, whereby the screw connection between the drill bit and the core drilling machine is also preferably referred to as a «twist lock» in the context of the present invention.By controlling the core drilling rig's motor, which generates the counter torque, a simplified separation of the core bit from the core drilling rig can be provided. A key advantage of the proposed method is that the screw connection between the core drilling rig and the core bit can be loosened using only one additional tool, such as a wrench. Furthermore, the proposed separation method eliminates the need for excessive use of lubricant, thus contributing to cost and material savings on the construction site. Furthermore, unnecessary contamination by the lubricant is avoided, thus preventing extensive cleanup work on the construction site.
[0015] In addition to loosening the screw connection between a core drilling machine and a core bit, the proposed method can also be used to connect the core bit to the core drilling machine. This process is referred to in the context of the present invention as "tightening the screw connection." Tightening the screw connection also takes advantage of the fact that the drive of the machine tool does not perform a rotary movement, but rather is blocked, so that tightening the screw connection can also be significantly simplified with the invention.
[0016] The invention further departs from conventional separation methods known from the prior art in that the motor is blocked by a targeted control and the core bit can then be loosened using a tool such as a wrench. In the context of the present invention, the motor is preferably blocked by setting a target speed of 0 revolutions per minute (rpm) for the motor when controlling the motor. This technical solution departs, for example, from other separation methods in which a deliberate change in the direction of rotation of the motor is effected in order to utilize a flywheel mass of the core bit when stopping and / or braking the motor in order to loosen the screw connection or the twist lock between the core drilling device and the core bit.
[0017] It is preferred in the sense of the invention that when changing tools, the screw connection or the rotary lock between the core drilling device and the drill bit is released or loosened by causing the drill bit to move in a first direction of rotation, while a counter torque is generated by controlling the motor, with which the drill bit can be released or loosened.
[0018] It is preferred within the meaning of the invention that the control of the motor of the core drilling machine causes the motor to work against the movement of the drill bit in the first direction of rotation. As a result, the motor of the core drilling machine attempts to prevent any rotational movement of the drill bit; in other words, the control of the motor prevents any rotational movement of the drill bit. In this way, a mechanical locking of the rotary drive of the drill bit is advantageously achieved, which advantageously results in the locking mechanism of the drill bit being able to be closed. Closing the locking mechanism of the drill bit advantageously prevents the motor of the core drilling machine from rotating in the first direction of rotation. Instead, in the context of the present invention, the control of the motor causes the motor to work against the movement of the drill bit in the first direction of rotation.By having the core drilling machine's motor work against the movement of the core bit in the first direction of rotation, the difference between the torque directed in the first direction of rotation and the counter-torque generated by controlling the motor can advantageously be increased. This increased torque difference can make loosening the screw connection between the core drilling machine and the core bit significantly easier, thus making it possible in the first place. Thus, the invention can support and significantly facilitate a process that is usually performed manually, such as removing a core bit from the core drilling machine, by cleverly utilizing technical possibilities such as controlling a motor or technically generating a counter-torque or counter-holding torque.
[0019] It is preferred according to the invention that the control of the motor of the core drilling machine comprises a speed control, wherein a target speed for the motor of the core drilling machine is 0 revolutions per minute (rpm). In this way, the difference between the torque in the first direction of rotation and the counter torque can preferably be increased by controlling the motor of the core drilling machine. It is preferred according to the invention that only one additional tool, such as a wrench, is required to loosen the screw connection between the core drilling machine and the core bit. This tool can be a wrench, for example. With the help of the additional tool, the twist lock of the core bit can advantageously be tightened or loosened, so that the core bit can be removed from the core drilling machine.Advantageously, the wrench can be applied to the core bit to detach the core bit from the core drilling machine or to connect the core bit to the core drilling machine.
[0020] In a second aspect, the invention relates to a core drilling machine, wherein the core drilling machine is configured to perform the method according to one of the preceding claims. The terms, definitions, and technical advantages introduced for the separation method preferably apply analogously to the core drilling machine. The proposed core drilling machine can provide a technical solution that reduces the number of tools required for tool changes.
[0021] According to the invention, it is preferred that the core drilling machine comprises a motor, wherein the motor of the core drilling machine is configured to generate a torque for driving the core bit, causing the core bit to move in a first direction of rotation, while controlling the motor can generate a counter-torque to loosen the screw connection between the core drilling machine and the core bit. The core bit can be connected to the core drilling machine during operation of the core drilling machine, while the core bit can be kept or stored separately, for example, when the core drilling machine is not in operation. The core bit is therefore not a fixed component of the core drilling machine, like the motor, but rather the core bit is preferably configured to be connected to the core drilling machine.Thus, the core bit can be connected to the core drilling machine to perform core drilling and cut essentially cylindrical cores from the subsurface. The motor is controlled to generate the counter torque, particularly during tool changes, i.e., when the core bit is removed from the core drilling machine to which it is connected during operation. Furthermore, the motor can be controlled to generate the counter torque when tightening the screw connection between the core bit and the core drilling machine.
[0022] According to the invention, it is preferred that a direction in which the counter torque is oriented or points is opposite to the first direction of rotation of the core bit. Preferably, the motor of the core drilling machine is controlled such that a target speed for the motor is 0 revolutions per minute (rpm). The unit "revolutions per minute" is called "rounds per minute" in English and is abbreviated to "rpm." This advantageously generates the counter torque, which opposes the movement of the core bit in the first direction of rotation, so that tightening or loosening the screw connection or the twist lock between the core drilling machine and the core bit can be made considerably easier.
[0023] According to the invention, it is preferred that the motor of the core drilling machine be controllable such that the motor operates counter to the movement of the drill bit in the first direction of rotation. To control the motor, the core drilling machine may comprise a control device or control electronics, wherein the control device and the control electronics are configured to control the motor of the core drilling machine such that a target speed for the motor of the core drilling machine is 0 revolutions per minute (rpm). Alternatively or additionally, the control device and the control electronics may be configured to control the motor of the core drilling machine such that a difference between the torque in the first direction of rotation and the counter torque is increased.
[0024] The core drilling machine is preferably enabled to perform the proposed separation process by specifically controlling the core drilling machine's motor, which generates a counter-torque that significantly facilitates tool changes. Further advantages are evident from the following description of the figures. The figure, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and combine them into further meaningful combinations. They show:
[0025] Fig. 1 View of a preferred embodiment of the invention
[0026] Implementation examples and figure descriptions:
[0027] Figure 1 shows a proposed core drilling machine 1 with which the proposed method for connecting or disconnecting a core bit 2 from a core drilling machine 1 can be carried out. The connection between the core drilling machine 1 and the core bit 2 is formed in particular by a screw connection 6. During its operation, i.e. when it is used to cut out cores from a subsoil, the core drilling machine 1 is connected to a core bit 2, wherein the core bit 2 is driven into the subsoil in order to cut out the core. For this purpose, the core bit 2 is caused to rotate by a motor 5 of the core drilling machine 1. It is provided that the core bit 2 is rotated in a first direction of rotation A during the tool change in order to detach the core bit 2 from the core drilling machine 1.In addition, the rotary movement of the motor 5 of the core drilling machine 1 can also be used to tighten the screw connection between the core bit 2 and the core drilling machine 1, i.e. to connect the core bit 2 to the core drilling machine 1. In the sense of the invention, this preferably means that the core bit 2 rotates, for example, in a clockwise direction. During the tool change, control of the motor 5 of the core drilling machine 1 is provided, wherein the control of the motor 5 generates a counter torque, wherein the counter torque is oriented in a second direction of rotation B or points in a second direction of rotation B. Possible examples of a first direction of rotation A and a second direction of rotation B are indicated schematically by arrows in Fig. 1. In the actual implementation of the invention, the directions of rotation A, B can of course also be interchanged.
[0028] After completion of the work or for transporting the core drilling machine 1, it may be necessary or desired to remove the core bit 2 from the core drilling machine 1. For this purpose, the present invention provides for the motor 5 of the core drilling machine 1 to be blocked by a targeted control with a target speed of 0 rpm. By specifically controlling the motor 5 of the core drilling machine 2, a difference between the torque, which points, for example, in the first direction of rotation A, and the counter-torque, which points, for example, in the second direction of rotation B, can be increased, so that separation of the core bit 2 from the core drilling machine 1 can be made considerably easier.
[0029] 1 core drilling machine
[0030] 2 core bits
[0031] 5 Motor of the core drilling machine 6 Screw connection
[0032] A first direction of rotation of the drill bit when changing tools
[0033] B second direction of rotation of the counter torque
Claims
Patent claims 1. Method for tightening or loosening a screw connection (6) between a core drilling device (1) and a drill bit (2) characterized by the following method steps: a) Provision of a core drilling device (1) with - a drill bit (2) which is attached to the core drilling machine (1) by means of a screw connection (6) when the core drilling machine (1) is in operation, and - a motor (5) configured to generate a torque to drive the drill bit (2), b) movement of the drill bit (2) in a first direction of rotation, while a control of the motor (5) generates a counter-torque to tighten or loosen the screw connection (6) between the core drilling device (1) and the drill bit (2).
2. Method according to claim 1, characterized in that the control of the motor (5) of the core drilling device (1) causes the motor (5) to work against the movement of the drill bit (2) in the first direction of rotation.
3. Method according to claim 1 or 2 characterized in that the control of the motor (5) of the core drilling device (1) comprises a speed control, wherein a target speed for the motor (5) of the core drilling device (1) is 0 revolutions per minute (rpm).
4. Method according to one of the preceding claims characterized in that a difference between the torque in the first direction of rotation and the counter-torque is increased by controlling the motor (5) of the core drilling device (1).
5. Method according to one of the preceding claims characterized in that for tightening or loosening the screw connection (6) between the core drilling device (1) and the drill bit (2) only requires an additional tool. Core drilling device (1) characterized in that the core drilling device (1) is configured to perform the method according to one of the preceding claims. Core drilling device (1) according to claim 6 characterized in that the core drilling device (1) comprises a drill bit (2) and a motor (5), wherein the motor (5) of the core drilling device (1) is configured to generate a torque for driving the drill bit (2) so that the drill bit (2) is caused to move in a first direction of rotation, while a counter-torque can be generated by controlling the motor (5) to tighten or loosen the screw connection (6) between the core drilling device (1) and the drill bit (2). Core drilling device (1) according to claim 6 or 7 characterized in that the motor (5) of the core drilling device (1) can be controlled in such a way that the motor (5) works against the movement of the drill bit (2) in the first direction of rotation.A core drilling device (1) according to any one of claims 6 to 8, characterized in that the motor (5) of the core drilling device (1) can be controlled such that a target rotation speed for the motor (5) of the core drilling device (1) is set to 0 revolutions per minute (rpm). A core drilling device (1) according to any one of claims 6 to 9, characterized in that the motor (5) of the core drilling device (1) can be controlled such that the difference between the torque in the first direction of rotation and the counter-torque is increased.