Power tool
By applying a friction reduction device to the sliding bearing surface of the power tool, the torque range problem of the power tool when installing the holder is solved, simple and low-cost correct installation and reduced vibration transmission are achieved, and the safety and reliability of use are improved.
Patent Information
- Application Number
- CN202480005995.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-02-15
- Filing Date
- 2024-02-02
- Publication Date
- 2025-07-22
AI Technical Summary
When installing additional retainers, existing power tools are prone to cause the sliding bearing to be stuck or the retainer to be improperly assembled due to excessive torque or low torque, which affects the reliability and health and safety of use.
Using a sliding bearing with friction reduction device, the allowable torque range of the fastening clamp is extended to ensure the correct installation of the retainer by applying friction reduction devices such as microcapsules and solid lubricants on the sliding surface.
This enables simple and low-cost expansion of the torque range of the fastener clamp without the need for additional measuring equipment, ensuring the correct installation of the holder, reducing vibration transmission, and improving safety and reliability of use.
Smart Images
Figure CN120359106A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a power tool, which includes a drive and a housing shell. Among them, the drive is mounted on the housing shell via at least one sliding bearing. The drive can be, for example, an electric-pneumatic drive. The power tool can be a handheld power tool. Background Art
[0002] It is usually necessary to attach an additional holder, such as an auxiliary handle, to this type of power tool. The holder can have a fastening clip, by means of which the holder can be fastened to the power tool.
[0003] For example, in the case of a handheld power tool, for ergonomic and functional reasons, it is recommended to fasten the holder to the housing shell in the area of the sliding bearing. However, in this case, the user should carefully ensure that the fastening clip is tightened with a torque within a narrowly defined torque range. If the torque is too high, the sliding bearing may be over-preloaded and may, for example, become jammed as a result. If the torque is too low, the holder will not be properly mounted on the housing shell.
[0004] During the normal use of a power tool having such a holder, it usually leads to failures or malfunctions. For example, if the user is subjected to excessive vibrations thereby, this may also damage the health of the user of the power tool. Summary of the Invention
[0005] Therefore, the object of the present invention is to provide a power tool of the type described at the beginning, which enables an additional holder to be properly installed in a particularly simple manner. In particular, it is desirable that the power tool can be produced at low cost.
[0006] This object is achieved by a power tool, which includes a drive (such as an electric-pneumatic drive) and a housing shell. Among them, the drive is mounted on the housing shell via at least one sliding bearing, and the sliding bearing has a friction reducing device.
[0007] This makes it possible to significantly expand the allowable torque range in a surprisingly simple and particularly low-cost manner to properly fasten the fastening clip of a holder or the like to the housing shell. For example, the friction reducing device allows the body (such as the power tool spindle) installed in the sliding bearing to slide, even if the fastening clip exerts a relatively high pressure on the sliding bearing.
[0008] Tests have shown that in the case of power tools, the allowable torque range can be extended to such an extent that the user can tighten the fastening clip without additional measuring devices etc. while still remaining within the allowable torque range. Additionally, the user can generally detect too low a torque since in this case the user recognizes that the fastening clip is mounted on the housing shell too loosely (e.g. can be moved easily).
[0009] This provides a particularly simple and convenient way of fitting an additional holder (e.g. an auxiliary handle) to the power tool. Thus, no additional measuring devices or special training measures for the user are required.
[0010] Furthermore, a sliding bearing can be used to support the drive. The advantages associated with the sliding bearing are maintained, such as good dust and dirt protection and low production costs. In particular, certain other types of bearings, such as ball bearings or roller bearings, are not required. Significant additional costs resulting from such a change can be avoided.
[0011] In principle, friction reducing devices are available at very low cost. Thus, although the power tool offers increased convenience, it can still be produced at low cost.
[0012] Furthermore, it has been found and is explained in more detail below that at least one of the basic functions of the sliding bearing, in particular minimizing the vibration transfer from the drive to the housing shell and thus from the housing shell to any holder (in particular an auxiliary handle) fitted, is further improved.
[0013] The sliding bearing can have a sliding surface. The friction reducing device can be applied to the sliding surface.
[0014] Accordingly, a particularly advantageous power tool can have a holder which is arranged on the housing shell in a detachable, in particular tool-free detachable, manner via a fastening part. For example, the holder can be an additional side handle. While maintaining or improving the basic function of the sliding bearing, the holder provides an additional way of safely guiding the power tool. This may be necessary especially in the case of particularly powerful power tools (such as hammer drills or power chisels).
[0015] The fastening part can have a fastening clip and thus enables the fastening part to be adapted in a flexible manner to the different dimensions of different embodiments of the power tool. The fastening clip also enables the holder to be arranged on or removed from the power tool non-destructively.
[0016] Advantageously, the friction reducing device remains in the sliding bearing for a relatively long time and / or under high and / or long-term continuous loads. In addition, the friction reducing device should be as robust as possible against dust or dirt, which is always desirable, for example, at a construction site.
[0017] For the same reason, it is advantageous if the friction reducing device includes a solid lubricant, and in particular, the friction reducing device is a solid lubricant.
[0018] Alternatively or additionally, it is conceivable that the friction reducing device includes a liquid lubricant. In this case, the liquid lubricant can be understood to mean a lubricant that is liquid at room temperature (e.g., 18°C to 25°C, especially 20°C) or at a typical operating temperature (e.g., an operating temperature in the range from 30°C to 130°C, such as 80°C).
[0019] In one class of embodiments, a lubricant reservoir can be provided. Thus, even over long periods, such as 5 years, 10 years, or 20 years, the sliding bearing can be supplied with the friction reducing device.
[0020] The friction reducing device can include a plurality of particles, especially lubricant-filled particles. The particles can serve as lubricant reservoirs.
[0021] In this case, it is particularly advantageous if the particles can already be in their desired position of action. Thus, the particles can release the lubricant directly in situ. In addition, it is particularly advantageous here that: under the high loads that can occur, for example, when tightening a clamping clip with high torque, a particularly large number of particles can open and release their lubricant inclusions. Thus, the friction reducing device can be supplied to the sliding bearing in a particularly demanding manner.
[0022] In the case of a power tool with an impact function, the drive (e.g., an electro-pneumatic drive) generates impacts along its longitudinal axis and thus particularly severe vibrations. Effective vibration damping is particularly important for these power tools. Thus, if such a power tool is designed with an impact function in the manner described herein, the risk to the health of a user, for example, when assembling and using an auxiliary handle on the power tool, is reduced or even completely avoided.
[0023] The power tool can be arranged on a construction robot. The construction robot can be configured to perform construction work on a ceiling, wall, and / or floor. The construction robot can have a manipulator. An end effector can be formed at the free end of the manipulator. The power tool can be arranged and / or capable of being arranged on the end effector.
[0024] The manipulator can be designed as a robotic arm. The manipulator can also have a lifting device. The lifting device can increase the size of the overall volume that the manipulator can reach. The manipulator can have at least three degrees of freedom. In particular, the manipulator can have at least six degrees of freedom.
[0025] The construction robot can also have a mobile platform. The mobile platform can include a wheeled chassis and / or a tracked chassis. The mobile platform can have at least two degrees of freedom. The construction robot can have a total of at least eight, for example ten, degrees of freedom.
[0026] In the case of a conventional power tool, the vibration of the power tool can be transmitted to the end effector of the construction robot. As a result, the end effector is also set into vibration, and thus the construction work of the construction robot can only be performed with low precision. The end effector, manipulator, and / or mobile platform of the construction robot are also subject to particularly high mechanical loads due to the vibration. Therefore, it is particularly advantageous for the construction robot to have a power tool of the type described above, such that a holder can be mounted on the power tool, which enables the power tool to be optionally additionally held, thereby ensuring that no or only very slight vibration is transmitted to the construction robot.
[0027] Alternatively or additionally, it is conceivable to design the power tool as a hand-held power tool. On such a power tool, for example, an auxiliary handle can be mounted, through which only a slight degree of vibration is transmitted during the operation of the power tool. The risk to health (e.g., to the user's hand) due to excessive vibration load can be avoided or at least significantly reduced.
[0028] Generally, the power tool can be designed for performing construction work at a building construction site and / or a civil engineering construction site. In particular, the power tool can be designed for working on masonry (e.g., concrete). It is precisely for working on masonry that a power tool with an impact function and a particularly high individual impact energy is used. In order to be able to safely guide the power tool despite its high individual impact energy, it is recommended to use an auxiliary handle, such that the above advantages can be particularly significantly realized in the case of such a power tool.
[0029] Further features and advantages of the present invention emerge from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings, as well as from the claims, which show the essential details of the present invention. The features shown therein are not necessarily considered to be in true scale, but are presented in a manner that enables the special features according to the present invention to be clearly visualized. In variants of the present invention, the various features can be implemented individually in themselves or in any combination.
[0030] Exemplary embodiments of the present invention are shown in the schematic diagrams and will be explained in detail in the following description. Description of the Drawings
[0031] Figure 1 A side view of a power tool with an auxiliary handle is shown, and Figure 2 A longitudinal sectional view of the sliding bearing of the power tool is shown.
[0032] In the following description of the drawings, understanding of the present invention is facilitated by using the same reference numerals for the same or functionally corresponding elements in each case. Detailed Description of the Invention
[0033] Figure 1 The power tool 10 is shown. The power tool 10 is designed as a hand-held power tool. In particular, the power tool 10 is designed as a hammer drill. Accordingly, the power tool has an impact function.
[0034] Figure 1 A side view of a part of the power tool 10 is shown. The figure shows the housing shell 12, on which the auxiliary handle 14 is mounted via a fastening part 16. The fastening part 16 has a fastening clip 18. The fastening clip 18 surrounds the front region of the housing shell 12.
[0035] The power tool 10 has a drive 20. The drive 20 is located within the housing shell 12 and is thus only Figure 1 shown schematically in.
[0036] The drive 20 has an electro-pneumatic motor unit 22. The motor unit 22 drives the tool spindle 24. In particular, the tool spindle 24 can be driven to rotate, perform a striking motion, and / or a rotary striking motion. The tool spindle 24 can include steel. In particular, the tool spindle can be formed of steel. The tool spindle 24 terminates at a tool fitting 26. A tool can be mounted in the tool fitting 26. For example, the tool can be a chiseling tool or a hammer drill tool.
[0037] The fastening clip 18 has a clamping screw 28. By means of the clamping screw 28, the length of the fastening clip 18 and thus its diameter can be adjusted. Accordingly, the pressure on the housing shell 12 can be increased or decreased according to the torque by which the clamping screw 28 is tightened. In this way, the hardness of the seat on which the fastening clip 18 is mounted on the housing shell 12 can also be adjusted.
[0038] Figure 2 Now, details of the power tool 10 in region II according to Figure 1 are shown. For the sake of simplicity of the illustration, the auxiliary handle 14, its fastening clip 18, and the housing shell 12 are not shown here (see in each case Figure 1).
[0039] In particular, Figure 2 a three-dimensional partial sectional view of the shown region II is shown. Here, the tool spindle 24 is also not shown (see also Figure 1 ). Thus, an internal view of the housing 12 in the shown region II is obtained. In particular, the sliding bearing 32 can be seen. Thus, the sliding bearing 32 is located between the housing 12 and the tool spindle 24. Thus, the sliding bearing 32 supports the tool spindle 24 on the housing 12. The support can be direct or indirect. In the case of direct support, the tool spindle 24 can rest on the sliding bearing 32. In an alternative embodiment with indirect support, the tool spindle 24 can be surrounded at least in a radially circumferential manner by the drive housing. Then, the drive housing can rest on the sliding bearing 32, and thus the tool spindle 24 is indirectly supported on the sliding bearing 32 via the drive housing.
[0040] The sliding bearing 32 has a plurality of sliding surfaces 34. For the sake of simplicity of illustration, only a single one of these sliding surfaces 34 is provided with a reference numeral. The sliding surfaces 34 are designed, for example, to be equally spaced from one another over the entire inner surface of the sliding bearing 32. The sliding surfaces 34 can be formed of a polymer. The friction reduction means 36 is located outside and / or inside the sliding surfaces 34.
[0041] An example of a suitable friction reduction means 36 can comprise the following components: As a base material, polyoxymethylene (e.g., a material known as "Hostaform C9021") can be provided, which contains microcapsules based on polyurethane (PU), for example, in an amount of 10% to 15% by weight, for example, 12.5% by weight of the friction reduction means 36.
[0042] The microcapsules contain a lubricant. The lubricant contained in the microcapsules can be a mixture of substances.
[0043] Its capsule wall can be based on polyurethane and is in particular formed of polyurethane. Generally, the capsule wall can comprise a plastic, in particular a polymer.
[0044] The total amount of the lubricant contained in the microcapsules can be at least 50% by weight of the weight of the microcapsules, for example, in the range of 50% to 95% by weight, for example, in the range of 75% to 85% by weight, in particular 80% by weight.
[0045] The diameter of the microcapsules can be in the range of 20 µm to 250 µm. For example, the median diameter thereof can be in the range from 1 µm to 100 µm, in particular 20 µm to 50 µm.
[0046] Thus, the friction reducing device 36 has microcapsules 38. Again, for reasons of simplification, only one of these microcapsules 38 is indicated by reference numerals in Figure 2 the drawings. The microcapsules 38 can be designed as microparticles or nanoparticles.
[0047] The friction reducing device 36 can also include a solid lubricant, such as based on MoS2 or PTFE.
[0048] List of reference numerals 10 Power tool 12 Housing shell 14 Auxiliary handle 16 Fastening part 18 Fastening clip 20 Driver 22 Motor unit 24 Tool spindle 26 Tool fitting 28 Clamping screw 32 Sliding bearing 34 Sliding surface 36 Friction reducing device 38 Microcapsule II Region
Claims
1. A power tool (10) comprising a drive (20), such as an electro-pneumatic drive (20), and a housing (12), wherein, The drive (20) is mounted on the housing (12) via at least one sliding bearing (32). It is characterized in that the sliding bearing (32) has a friction reducing device (36).
2. The power tool (10) according to the previous claim, characterized in that, The power tool (10) has a holder, such as an auxiliary handle (14), which is arranged on the housing (12) in a detachable manner, in particular without tools, via a fastening part (16).
3. The power tool (10) according to any one of the preceding claims, characterized in that, The fastening part (16) has a fastening clip (18).
4. The power tool (10) according to any one of the preceding claims, characterized in that, The friction reducing device (36) comprises a solid lubricant and / or a liquid lubricant.
5. The power tool (10) according to any one of the preceding claims, characterized in that, The friction reducing device (36) comprises a plurality of particles, in particular lubricant-filled particles.
6. The power tool (10) according to any one of the preceding claims, characterized in that, The power tool (10) has an impact function.
7. The power tool (10) according to any one of the preceding claims, characterized in that, The power tool (10) is designed as a hand-held power tool.