Power tool with disc-shaped tool and method for fastening or releasing the tool
By generating torque pulses through the drive unit of the power tool, and utilizing standard fastening nuts and an electronically commutated motor, the problem of needing auxiliary tools when tightening and loosening disc-shaped tools is solved, achieving efficient and stable tool connection and disassembly, and reducing construction delays and costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HILTI AG
- Filing Date
- 2021-06-08
- Publication Date
- 2026-06-05
AI Technical Summary
In the prior art, the disc-shaped tool requires additional auxiliary tools when tightening and loosening on the power tool, which leads to the easy loss of the tool and delays on the construction site. In addition, the cost of quickly clamping nuts is high and it takes up space.
The drive unit of the power tool generates torque pulses, which are used to tighten or loosen the disc tool without the need for auxiliary tools by using a standard commercial fastening nut. The electric commutator motor outputs torque pulses with a frequency of 1Hz to 10Hz, and the nut status is monitored by a sensorless feedback device.
It enables quick and stable tightening or loosening of disc-shaped tools without the use of additional tools, avoiding tool loss and construction delays, reducing costs and improving operational efficiency.
Smart Images
Figure CN115666855B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a power tool having a disc-shaped tool, wherein the tool can be fastened to the drive shaft of the power tool by means of a fastening nut, wherein the drive shaft is configured to transmit torque from a drive mechanism to the tool. The power tool is characterized in that it is configured to loosen or tighten the fastening nut by means of at least one torque pulse from the drive mechanism of the power tool. In a second aspect, the invention relates to a method for fastening a disc-shaped tool to the drive shaft of a power tool, and in another aspect, to a method for releasing a disc-shaped tool from the drive shaft of a power tool. In yet another aspect, the invention relates to the use of torque pulses generated by the drive mechanism of a power tool for tightening or loosening the fastening nut for fastening a disc-shaped tool to the power tool. Background Technology
[0002] Power tools with a disc-shaped design are known in the prior art. Examples of these power tools are angle grinders or cutting grinders, by which surfaces can be ground or substrates cut. Disc-shaped tools are particularly used for grinding or cutting discs to perform the corresponding work. Grinding or cutting discs may be inlaid with diamond fragments to further improve cutting performance.
[0003] Typically, such grinding or cutting discs are secured to power tools using fastening nuts. To ensure high operational reliability, these fastening nuts must be tightened with considerable force. This often necessitates the use of auxiliary tools from the power tool manufacturer, such as socket wrenches or spiral wrenches, to secure the grinding or cutting discs to the power tool. These auxiliary tools are usually designed to be particularly small and compact, and are custom-made for the nuts to be tightened. However, a lesson learned in life is that such extra auxiliary tools are often lost, especially if they are small. This loss is particularly annoying and causes considerable trouble, as it often results in only one suitable wrench being available on-site to loosen or tighten the fastening nut. Therefore, re-obtaining the appropriate auxiliary tool to loosen or tighten the fastening nut can cause significant delays and time losses on-site.
[0004] To address the need to carry auxiliary tools, quick-clamp nuts have been proposed in the prior art for securing grinding or cutting discs to power tools without the need for additional tools. However, such quick-clamp nuts are expensive and require additional installation space. Therefore, using such quick-clamp nuts can be challenging, particularly with compact equipment. Furthermore, quick-clamp nuts can be lost on-site, requiring the carrying of replacement nuts. However, this is infrequent due to cost considerations, resulting in delays and time losses.
[0005] The object of this invention is to provide a power tool in which a disc-shaped tool can be fastened without the use of additional auxiliary tools. Furthermore, it will be appreciated by those skilled in the art that standard, commercially available, cost-effective, and readily available fastening nuts can be used to fasten the tool, thereby effectively avoiding delays and time losses on construction sites.
[0006] This objective is achieved through the subject matter of the independent claim. Advantageous embodiments relating to the subject matter of the independent claim can be found in the dependent claims. Summary of the Invention
[0007] This objective is achieved by a power tool having a disc-shaped design, wherein the tool can be fastened to the drive shaft of the power tool by means of a fastening nut, wherein the drive shaft is configured to transmit torque from a drive mechanism to the tool. The power tool is characterized in that it is configured to loosen or tighten the fastening nut by means of at least one torque pulse from the drive mechanism of the power tool. In other words, the fastening nut can be loosened or tightened by means of torque pulses from the drive mechanism of the power tool. Preferably, the fastening nut can be loosened or tightened by means of at least one torque pulse from the drive mechanism of the power tool, wherein the torque pulses are particularly output at a frequency of 1 Hz to 10 Hz. In the context of this invention, it is preferred that the power tool and its drive mechanism be configured to output rapidly successive torque pulses, wherein the output frequency can be in the range of 1 Hz to 10 Hz.
[0008] In the context of this invention, it is preferred that the drive mechanism of the power tool includes a motor. The inventors have recognized that, particularly in the case of drive mechanisms including electronically commutated motors, power tools can generate torque pulses strong enough to tighten or loosen preferred standard commercially available fastening nuts. In this respect, the present invention utilizes the capabilities of power tools to solve a technical problem that has remained unresolved until now. Until now, those skilled in the art have not considered the torque pulses for tightening or loosening fastening nuts that can be generated by a power tool with a drive mechanism as described herein. Instead, those skilled in the art have previously assumed that additional auxiliary tools specifically provided for this purpose must be used to tighten or loosen fastening nuts, or that auxiliary tools specifically provided for this purpose can be omitted only when using cost-effective quick-clamping nuts to tighten grinding or cutting discs. The present invention offers the possibility that disc-shaped tools can be tightened using preferred standard commercially available, cost-effective, and readily available fastening nuts without the need for special auxiliary tools. Therefore, the present invention directly contradicts the prior art and the prejudices of those skilled in the art.
[0009] According to the invention, a grinding or cutting disc can be fastened to the drive shaft of a power tool using a standard commercially available fastening nut. Here, the drive shaft is configured to transmit torque from the drive mechanism to the tool. It is also proposed that the drive mechanism of the power tool includes a motor, which generates torque to drive the disc-shaped tool. Preferably, this torque can be transmitted to the tool using the drive shaft. In a very particularly preferred embodiment of the invention, the motor is preferably an electronically commutated motor constituting a brushless drive mechanism of the power tool. The inventors have recognized that electronically commutated motors, in particular, are capable of generating torque pulses to tighten or loosen the fastening nut. In particular, the torque pulses generated by a brushless motor exhibit sufficiently large power transmission or sufficiently large torque to ensure that the standard commercially available fastening nut can be securely and stably tightened, or conversely, to ensure that a secure and stable connection between the fastening nut and the power tool can be released by means of the generated torque pulses.
[0010] In the context of this invention, it is preferable that a fastening nut can be loosened or tightened solely by means of the torque pulses of the power tool's drive mechanism without the use of auxiliary tools. This capability represents a fundamental advantage of the invention. The motor of the power tool is preferably an electronically commutated motor. The drive mechanism of the power tool is preferably configured to output rapidly successive torque pulses.
[0011] In the context of this invention, it is preferred that the pulses or torque pulses are used to generate a torque greater than the counter-torque generated by the mass inertia of the nut and the disc-shaped tool connected to the nut, the connection preferably being achieved through frictional engagement. Depending on the configuration of the drive unit, pulses can be output several times per second. In the context of this invention, it is preferred that the pulses be output at a frequency in the range of 1 Hz to 10 Hz. In other words, for example, pulses can be output 1 to 10 times per second. Furthermore, the power tool or its drive unit can be configured to output rapidly successive torque pulses.
[0012] In a preferred embodiment of the invention, the power tool has at least one sensor for monitoring torque pulses. In other words, in the context of the invention, it is preferred that the power tool has a sensor for monitoring the output of torque pulses. Preferably, in the context of the invention, the output torque pulses are generated in a sensor-monitored manner, i.e., using a sensor. The sensor is preferably an incremental encoder, an absolute encoder, an accelerometer, and / or a Hall sensor, but is not limited thereto. Hall sensors and absolute encoders are preferably designed to determine the rotational position of the motor. The at least one sensor is particularly designed to determine changes in the rotational position of the motor.
[0013] In the context of this invention, it is also preferable to include a sensorless feedback device in the motor, which can be used to determine how energy is introduced to cause a specific angular change in the motor. In other words, a sensorless feedback device can be used to detect the interaction or dependence between the introduced energy and the resulting angular change in the motor.
[0014] Based on the time curves of these variables, it can be determined whether the nut has been tightened or may have loosened. In particular, changes in the rotational position or angle of the motor can be used to infer whether the nut is tightened to the power tool or not. The inventors have recognized that the change in total inertia depends on whether the disc-shaped tool is connected to the output shaft or has been released from it. An advantage associated with using a sensorless feedback device is that no sensors are required and the complexity of the power tool is limited.
[0015] In a second aspect, the present invention relates to a method for fastening a disc-shaped tool to the drive shaft of a power tool. The proposed fastening method includes the following steps:
[0016] a) Provide power tools and disc-shaped tools for power tools;
[0017] b) Provide fastening nuts for securing the tool to the power tool;
[0018] c) Connect power tools to tools using fastening nuts;
[0019] d) The torque pulse is output through the drive unit of the power tool, thereby securing the tool to the drive shaft of the power tool by means of a fastening nut.
[0020] In the context of this invention, it is preferable that standard commercially available fastening nuts for fastening tools to power tools be provided and used within the framework of the proposed fastening method. The terminology, definitions, and technical advantages already introduced for power tools are preferably applicable to the proposed method and similarly to the proposed uses. A fundamental advantage of the proposed method and power tool is that the power tool can perform the method virtually without user assistance and without needing to hold an object or item. This allows the user of the power tool to optimally free their hands and perform other tasks with their free hands.
[0021] In another aspect, the present invention relates to a method for releasing a disc-shaped tool from the drive shaft of a power tool. The proposed release method includes the following steps:
[0022] a) Provide a power tool on which a tool is tightened by means of a tightening nut;
[0023] b) The power tool's drive unit outputs torque pulses, thereby loosening the fastening nut;
[0024] c) Separate the power tool from the tool.
[0025] In the context of this invention, it is preferred that standard commercially available fastening nuts be provided and used within the framework of the proposed release method. Preferably, the output torque pulse is generated in such a manner that the fastening nut can be released from the drive shaft without the need for additional auxiliary tools. In particular, the separation of the power tool from the control tool occurs without the need for tools or auxiliary tools.
[0026] In another aspect, the present invention relates to the use of torque pulses generated by the drive mechanism of a power tool for tightening or loosening fastening nuts for securing a disc-shaped tool to a power tool.
[0027] Further advantages will become apparent from the following description of the drawings. The drawings, description, and claims contain a number of combinations of features. Those skilled in the art will also readily consider these features individually and combine them to form useful further combinations. Attached Figure Description
[0028] In the accompanying drawings, identical and similar parts are indicated by the same reference numerals. In the accompanying drawings:
[0029] Figure 1A preferred embodiment of the proposed power tool is shown. Detailed Implementation
[0030] Figure 1 A preferred embodiment of the proposed power tool (1) is shown. The proposed power tool (1) can be, for example, an angle grinder or a cutting and polishing machine. The power tool (1) includes a disc-shaped tool (2), such as a cutting disc or a polishing disc. The tool (2) is fastened to the drive shaft (4) of the power tool (1) by means of a fastening nut (3), wherein the drive shaft (4) of the power tool (1) is configured to transmit torque of the drive mechanism of the power tool (1) to the tool (2). The drive mechanism of the power tool (1) particularly includes a motor (5), wherein, in a preferred embodiment of the invention, the drive mechanism may further include a gearbox (11). The motor (5) is preferably a brushless motor that can be designed, in particular, to be electronically commutated.
[0031] In the context of this invention, the power tool (1) is configured to loosen or tighten the fastening nut (3) by means of torque pulses from the drive mechanism of the power tool (1). In other words, the fastening nut (3) can be loosened or tightened by means of torque pulses from the drive mechanism of the power tool (1). In the context of this invention, tightening the fastening nut (3) preferably means that the fastening nut (3) is fastened or fixed to the power tool (1). Preferably, the tool (2) interacts with a tool assembly (7) configured to receive the tool (2) and fasten it to the power tool (1). In the context of this invention, the tool assembly (7) may also be referred to as an output shaft.
[0032] In a preferred embodiment of the invention, the power tool (1) may have at least one sensor (6) for monitoring the output of the at least one torque pulse. Preferably, when using the at least one sensor (6), the at least one torque pulse is output for releasing or tightening the tool (2). In the context of the invention, this preferably means that the sensor (6) of the power tool (1) is configured to monitor the output of the at least one torque pulse that causes the tool (2) to be released or tightened. The sensor (6) may detect position and / or acceleration in particular. In the context of the invention, it is preferred that the at least one sensor (6) is arranged between the motor (5) and the electronics (9). The at least one sensor (6) may be connected to the motor (5) of the power tool (1) or spatially located near it.
[0033] Preferably, the power tool (1) includes operator control elements (8) configured to initiate the release or tightening of the tool (2) using a fastening nut (3). Thus, the user advantageously gains the possibility of initiating the tightening or loosening of the tool (2) in a preferably unassisted manner. The power tool (1) may also include electronics (9) preferably configured to evaluate data determined by the at least one sensor (6), to evaluate inputs input via the operator control elements (8), and / or to control the motor (5) and its power supply. For this purpose, the power tool (1) may include electrical connections (10) configured to connect the operator control elements (8), the electronics (9), the at least one sensor (6), and / or the motor (5).
[0034] List of reference numerals
[0035] 1 Power tools
[0036] 2. Disc-shaped tools
[0037] 3. Tighten the nuts
[0038] 4 drive shafts
[0039] 5 motors
[0040] 6 sensors
[0041] 7. Tool assemblies
[0042] 8 Operator control elements
[0043] 9 Electronic devices
[0044] 10 Electrical connectors
[0045] 11 Gearbox
Claims
1. A power tool (1) having a disc-shaped tool (2), wherein the tool (2) can be fastened to a drive shaft (4) of the power tool (1) by means of a fastening nut (3), wherein the drive shaft (4) is configured to transmit the torque of a drive device to the tool (2). Its features are, The power tool (1) is configured to loosen or tighten the fastening nut (3) by means of at least one torque pulse output by the drive device of the power tool (1) at a frequency in the range of 1 Hz to 10 Hz, wherein a sensorless feedback device in the motor (5) is used to detect the interaction or dependence between the introduced energy and the resulting angle change in the motor, wherein the fastening nut (3) is a standard commercial fastening nut.
2. The power tool (1) according to claim 1. Its features are, The fastening nut (3) can be loosened or tightened by the torque pulse of the drive device of the power tool (1) without the use of auxiliary tools.
3. The power tool (1) according to claim 1 or 2. Its features are, The drive unit of the power tool (1) includes the motor (5), wherein the motor (5) is an electronically commutated motor.
4. The power tool (1) according to claim 1 or 2. Its features are, The drive unit is configured to output rapidly successive torque pulses.
5. The power tool according to claim 1 or 2, Its features are, The power tool (1) has at least one sensor (6) for monitoring the at least one torque pulse.
6. The power tool according to claim 1 or 2, Its features are, The power tool (1) includes a tool assembly (7) for receiving the tool (2).
7. The power tool according to claim 5, Its features are, The power tool (1) includes operator control elements (8) configured to initiate the use of the fastening nut (3) to release or tighten the tool (2).
8. The power tool according to claim 7, Its features are, The power tool (1) includes electronics (9) for evaluating data determined by the at least one sensor (6), for evaluating inputs input via these operator control elements (8), and / or for controlling the motor (5) and its power supply.
9. The power tool according to claim 8, Its features are, At least one sensor (6) is arranged between the motor (5) and the electronic device (9).
10. The power tool according to claim 8, Its features are, The power tool (1) includes electrical connectors (10) for connecting the operator control elements (8), the electronics (9), the at least one sensor (6), and / or the motor (5).
11. The power tool according to claim 1 or 2, Its features are, The sensorless feedback device of the motor (5) is used to detect the angle change of the motor (5).
12. A method for fastening a disc-shaped tool (2) to the drive shaft (4) of a power tool (1), Includes the following steps: a) Provide a power tool (1) and a disc-shaped tool (2) for the power tool (1); b) Provide a fastening nut (3) for fastening the tool (2) to the power tool (1), wherein the fastening nut (3) is a standard commercial fastening nut; c) The power tool (1) is connected to the tool (2) by means of the fastening nut (3); d) The drive mechanism of the power tool (1) outputs torque pulses with a frequency in the range of 1 Hz to 10 Hz, thereby fastening the tool (2) to the drive shaft (4) of the power tool (1) by means of the fastening nut (3). The sensorless feedback device in the motor (5) is used to detect the interaction or dependence between the introduced energy and the resulting angle change in the motor.
13. A method for releasing a disc-shaped tool (2) from a drive shaft (4) of a power tool (1), Includes the following steps: a) Provides a power tool (1) on which the tool (2) is fastened by means of a fastening nut (3), wherein the fastening nut (3) is a standard commercial fastening nut; b) The power tool (1) outputs a torque pulse with a frequency in the range of 1 Hz to 10 Hz through its drive device, thereby loosening the fastening nut (3); c) Separate the power tool (1) from the tool (2), The sensorless feedback device in the motor (5) is used to detect the interaction or dependence between the introduced energy and the resulting angle change in the motor.
14. The method according to claim 12 or 13, Its features are, The torque pulse is output using sensor (6).
15. The use of a torque pulse generated by the drive device of the power tool (1) according to any one of claims 1 to 11 for tightening or loosening a fastening nut (3) for fastening a disc-shaped tool (2) to the power tool (1).