EP2229261B1 - Power tool - Google Patents

Description

The invention relates to a power tool according to the preamble of patent claim 1 or 2.

The electric hand tool may be impact drills, impact wrenches, saber saws, grinders, or the like.

Such power tools have a housing and an electric motor located in the housing. Furthermore, there are in the housing electrical and / or electronic components, such as an electrical and / or electronic switch, electronics for controlling the electric motor o. The like., Wherein the electrical and / or electronic assembly is attached to one or more receptacles in the housing.

Power tools in particular for the mechanical processing of materials, such as impact drills and reciprocating saws, and those for use in fastening technology, such as Impact impact wrench, are sometimes subject to very high mechanical stresses in the form of vibrations that are generated specifically to the effectiveness and Increase efficiency of the tool. For this purpose, find a vibration generating device, such as a striking mechanism, use in the power tool. Thus, the magnitude or magnitude of the impact amplitude and the magnitude of the impact acceleration, which also serve as a measure of the performance of a percussion drill or a hammer drill and / or a drill bit, constantly optimized and / or amplified. This in turn increases the demands on the power tool, its components and its parts in terms of durability and robustness against such strong vibrations. So far, sponges rubber foam between switches and handles of the power tool are occasionally pressed to reduce the negative impact of high vibration on the power tool, but this is only a moderate success. Furthermore, powered by a battery power tools from the GB 2 432 036 A as well as the WO 2004/096500 A1 known, in which a damping element between the battery and the housing of the power tool is arranged.

Vibration resistance is today and will increasingly be an important technical challenge in the future. Without further measures with regard to the vibration resistance can lead to massive impairment of the function of the power tool, to dissolve connections and contacts to the partial destruction of individual parts. For example, closed power contacts lose their contact reliability, swinging electronic components or metal heatsinks detach from the fixture.

The invention has for its object to largely prevent such impairments caused by vibrations in the power tool, but at least to reduce. In particular, an effective mechanical damping of electromechanical and / or electronic switching elements is to be realized within the tool grip of the power tool.

This object is achieved in a generic power tool by the characterizing features of claim 1 or 2.

In the power tool according to the invention a vibration decoupling between the receptacle in the housing and the electrical and / or electronic assembly is arranged. As a result, an effective damping for the assembly is achieved, whereby an optimization of the robustness of the assembly is achieved, which increases their reliability even with hard use of the power tool.

The electrical and / or electronic assembly may be an electrical switch having an electromechanical contact system. The module may just as well be an electronic switch in which the switching function is realized electronically by means of semiconductors. The switch has a switch housing for receiving these switch components. Optionally, in the switch housing, an electronics for controlling and / or regulating the electric motor are, so for example, the speed, torque o. The like. The power tool adjustable is. It is then arranged the vibration decoupling of the recording facing the switch housing, whereby the electrical switch is largely protected from the influence of vibrations of the power tool. Although the vibration decoupling can be arranged loosely on the switch housing, it is expediently attached to the switch housing.

The electrical and / or electronic module may be electronics which serve to control and / or regulate the electric motor. For example, with the help of electronics, the speed of the power tool, the rate of impact of the power tool o. The like. Be adjustable. The electronics has a printed circuit board, a carrier o. The like. To accommodate the components. It is then the vibration decoupling of the recording facing the circuit board, the carrier o. The like. Arranged, whereby the electronics is largely protected from the influence of vibrations of the power tool. Although the vibration decoupling can be arranged loosely on the printed circuit board, the carrier or the like, it is expediently attached to the printed circuit board, the carrier or the like.

Further embodiments of the invention are the subject of the dependent claims.

In the usual way, the switch housing, the circuit board, the carrier o. The like. At least partially made of plastic. Likewise, the housing of the power tool and / or the receptacle in the housing made of plastic. The plastic is a thermoplastic and / or a thermosetting plastic. Although the vibration decoupling may be made of rubber or other elastic material, it is preferred that a plastic is also used as the material for vibration decoupling. Suitable for this is an elastic polymer or a thermoplastic elastomer.

In one embodiment, the vibration decoupling from an at least partial Um- and / or gating of the electrical and / or electronic assembly with the elastic polymer. In a further embodiment, the vibration decoupling from an at least partial coating of the electrical and / or electronic assembly with elastic fluids, such as paints and / or paints. These embodiments are characterized by simple and cost-effective manufacturability. In another embodiment, the vibration decoupling consists of a damping part, wherein the damping part of the simple assembly for half in and / or on the recording and / or can be locked. Of course, the damping member may also be attached to corresponding housing receivers or housing recesses on the switch housing. Furthermore, the vibration decoupling can consist of a mechanical spring element, which offers itself above all under high loads. Furthermore, it is also possible to design a housing which serves to enclose the electrical and / or electronic assembly from resilient housing halves for vibration decoupling. Finally, the receptacle for vibration decoupling can be designed to be elastic, in particular in that the receptacle is encapsulated with an elastic polymer and / or coated with an elastic fluid. In this case, the electrical and / or electronic assembly can then be designed in a conventional manner.

A particularly preferred solution is that realized at the receiving points of the built-in tool handle shell assemblies, such as a power tool switch as a whole assembly or an electronic module with and / or without plastic housing or parts of a power tool switch, a mechanical vibration decoupling between the tool handle shell and the module becomes. The vibration decoupling dampens the vibrations coming from outside as well as from the power tool, reduces the critical natural vibrations by reducing the mechanical degrees of freedom to a minimum and compensates for mechanical tolerances. For this function, damping and / or elastic material and shape properties are exploited whose elasticity and hardness can be adapted to the respective requirements.

There are several embodiments, which are explained in more detail below.

The vibration decoupling can be realized by encapsulation of the assembly with elastic polymer. This variant, preferably produced in multicolour or multi-component injection molding, is characterized in that the "hard" Body of the assembly is partially encapsulated at the mounting points to the tool grip shell with elastic plastic. In this case, several, located at one part receiving points can be encapsulated in an injection molding operation simultaneously. For optimum adhesion of the elastomer, appropriate precautions, such as undercuts or adhesion-optimized surface contours, can be attached. As an alternative to multicolor injection molding, an application of an elastomeric material, for example an elastically crosslinking silicone, can be effected subsequently by dispenser. For optimum adhesion wells with / without undercuts are also advantageous here.

The vibration decoupling can be done by coating the assemblies with elastic fluids, such as paints and / or paints. The receiving points and / or the receiving areas on the modules can be coated in a spraying, dipping or printing process with an elastically hardening fluid. When installing the module, this area is correspondingly pressed with excess, wherein the elastomer is thereby compressed and thus acts damping effect in the subsequent period. Even without excess, the elastomer has a dampening effect.

The vibration decoupling can be done by mounting and / or snapping a damping member at the receiving points. An existing of elastic plastic additional part is up or engaged at the corresponding receiving points. The advantage here is the significantly reduced tooling costs compared to the multi-color injection molding. The elastic additional part can be standardized and therefore universally applicable. The adaptation of the additional part to the basic assembly can be done either by releasing and / or snapping, by gluing or a similar connection technique both detachable or non-detachable.

As a vibration isolation can also be used spring elements for mechanical damping. The spring elements can be performed either as a solid or as a resilient component of the plastic housing of the ENSTprechenden assembly, or in the form of one or more additional spring element components. Examples include compression springs, spring rings and spring washers made of metal or plastic, which are positively and / or non-positively attached to the assembly and in its installation the Damping function meet. These spring elements can be used both on assemblies with housing enclosure, such as switches, but also in electronics modules, such as populated printed circuit boards.

Furthermore, resilient housing halves can be used for vibration decoupling. The housing of electromechanical assemblies, such as the switch housing of switches, can be performed as a whole or partially to the relevant for installation in the tool handle receiving points in the installation direction resiliently to each other. The existing in the non-installed state mechanical excess is compressed during installation in the tool grip shell due to the suspension tolerance independent, so that a permanently existing, spring force-dependent pressing system without mechanical degree of freedom arises. Thus, critical natural vibrations are prevented and at the same time, due to the resilient system, dampened by the power tool coming vibration. This suspension can be realized by the corresponding execution of one or both halves of the housing itself or by incorporating additional spring elements between them.

Finally, the solutions described can be realized in the same way on the "counterpart to the assembly", ie on the handles or mold halves of the housing for the power tool and / or at the receiving points within these tool halves. A particularly preferred solution consists in the encapsulation of the receptacle for the switch or for assemblies in the handle shell with an elastic polymer. This variant, which is preferably produced in the multi-color injection molding process, is characterized in that the "hard" main body of the tool handle shell at the receiving points for switch assembly or other electromechanical assemblies, such as electronics, mechanical actuators, contacting assemblies, electrical and / or electronic elements, such as sensors or capacitors, power semiconductors with heat sinks o. The like., Is partially encapsulated with elastic plastic. In this case, optionally existing external encapsulation on the handles, for example, rubber coatings for optical and / or mechanical-damping enhancement of the power tool, injection technology can be designed so that these simultaneously with the inner, for supporting assemblies serving elastic-damping areas can be produced in one operation. For optimal adhesion of the elastomer appropriate precautions such as undercuts or adhesion-optimized surface contours can be attached. As an alternative to multicolor injection molding, an application of an elastomeric material, for example an elastically crosslinking silicone, can be effected subsequently by dispenser. For optimum adhesion, depressions with and / or without undercuts are also advantageous here.

The advantages achieved by the invention are in particular that a targeted reduction in the switch or in the assembly "initiated" vibrations is achieved by mechanical decoupling. At the same time, a compensation of the mechanical tolerances takes place, namely already during the assembly of the power tool, and thus also the avoidance of critical natural vibrations. It is therefore increased in a cost effective manner, the reliability and the life of the power tool.

Fig. 1

schematisch ein Elektrowerkzeug mit einem Gehäuse, das teilweise aufgebrochen dargestellt ist, gemäß einem ersten Ausführungsbeispiel,

Fig. 2

schematisch ein Elektrowerkzeug gemäß einem weiteren zweiten Ausführungsbeispiel,

Fig. 3a, 3b

ein Schaltergehäuse eines elektrischen Schalters mit einer Vibrationsentkopplung in einer Ausgestaltung,

Fig. 4a, 4b

das Schaltergehäuse eines elektrischen Schalters mit einer Vibrationsentkopplung in einer weiteren Ausgestaltung,

Fig. 5a, 5b

das Schaltergehäuse eines elektrischen Schalters mit einer Vibrationsentkopplung in einer nochmals weiteren Ausgestaltung,

Fig. 6a, 6b

das Schaltergehäuse eines elektrischen Schalters mit einer Vibrationsentkopplung in einer wiederum weiteren Ausgestaltung,

Fig. 7a, 7b

das Schaltergehäuse eines elektrischen Schalters mit einer Vibrationsentkopplung in einer abermals weiteren Ausgestaltung und

Fig. 8a bis 8d

eine Leiterplatte für ein Elektronik-Modul mit einer Vibrationsentkopplung.

Embodiments of the invention with various developments and refinements are illustrated in the drawings and will be described in more detail below. Show it

Fig. 1

1 schematically shows a power tool with a housing, which is shown partially broken away, according to a first exemplary embodiment,

Fig. 2

schematically a power tool according to a further second embodiment,

Fig. 3a, 3b

a switch housing of an electrical switch with a vibration decoupling in one embodiment,

Fig. 4a, 4b

the switch housing of an electrical switch with a vibration decoupling in a further embodiment,

Fig. 5a, 5b

the switch housing of an electrical switch with a vibration decoupling in a still further embodiment,

Fig. 6a, 6b

the switch housing of an electrical switch with a vibration decoupling in yet another embodiment,

Fig. 7a, 7b

the switch housing of an electrical switch with a vibration decoupling in a yet further embodiment and

Fig. 8a to 8d

a circuit board for an electronics module with a vibration isolation.

In Fig. 1 is a power tool 1 with an electric motor 2 to drive a tool 3 to see. It may be a cordless and / or mains power tool. Is exemplary in the Fig. 1 a percussion drill as a power tool 1 shown. Of course, the power tool 1 can also be an impact wrench, a saber saw, a grinder or the like. With the electric motor 2 or in any other way with the tool 3 is a vibration generating device 9, such as a percussion, in connection.

In the housing 4 of the power tool 1, a switch 5 is arranged. The switch 5 is received in the housing 4 such that a manually movable by the user actuator 6 of the switch 5 protrudes from the housing 4. The switch 5 has a contact system 7, which acts on the actuator 6 for switching, so that the power tool 1 by means of the actuator 6 on and / or off. Finally, the switch 5 is associated with an electrical circuit arrangement for controlling and / or regulating the electric motor 2. The circuit arrangement serves as an electronic control unit 8 for speed variation of the electric motor 2. In a simple manner, a microprocessor 8 can be used. Of course, the control electronics 8 and / or other electronics may also be housed separately from the switch 5 in the housing 4, as shown in the Fig. 1 is indicated schematically. The switch 5 and / or the electronics 8 are thus an electrical and / or electronic assembly, which are fastened to corresponding receptacles 10 in the housing 4. Between the receptacles 10 in the housing 4 and The electrical and / or electronic assembly 5, 8, a vibration decoupling 11 is arranged, which can be designed in different ways.

As in Fig. 1 is shown with reference to the electrical and / or electronic assembly 5, the vibration decoupling 11 consists of an encapsulation 11a with elastic polymer. The vibration decoupling 11 for the electrical and / or electronic assembly 8 consists of a coating 11b with elastic fluids, such as paints and / or paints. As can further be seen by means of the electrical and / or electronic assembly 5, the vibration decoupling 11 can consist of an attenuation part 11c, wherein the damping part 11c is attached to the receptacles 10 and / or latched. Finally, a vibration decoupling consisting of a mechanical spring element 11d is also shown on the electrical and / or electronic assembly 5.

In Fig. 2 is to be seen as a further embodiment, a power tool 1 with a tool 3, wherein the power tool 1 comprises a housing 4 in which an electric motor 2 and a vibration generating device 9 are located. In the handle of the housing 4 is an electrical switch 5 with an outstanding from the housing 4 actuator 6. The switch 5 has a switch housing 12, which is received in corresponding receptacles 10 in the housing 4. In the switch housing 12 is an electromechanical contact system 7, to which the actuating member 6 acts switching to turn on and / or off the power supply for the electric motor 2. Instead of an electromechanical contact system 7, the switch 5 can also switch the power supply to the electric motor 2 by means of power transistors, which is then an electronic switch. Furthermore, located in the housing 4 of the power tool 1, an electronic unit 8 for controlling and / or regulating the electric motor 2 on a printed circuit board 13 or other carrier, so that the actuator 6 in the manner of a "gas-Gebe-switch" manually from the user Setting the speed of the electric motor 2 is movable. The electronics 8 is also fixed in corresponding receptacles 10 in the housing 4. Of course, the electronics 8 for controlling and / or regulating the electric motor 2 may also be located in the known manner in the switch housing 12, which is not shown here.

The vibration decoupling 11 is facing the receptacle 10 facing the switch housing 12 and the receptacle 10 facing the printed circuit board 13 and the carrier. Various embodiments of the arrangement and / or attachment of the vibration decoupling 11 on the switch housing 12 and on the circuit board 13 are shown below.

In Fig. 3a the switch 5 can be seen, wherein at the corners of the switch housing 12, an elastomer as a vibration decoupling 11a, 11b is mounted. As in Fig. 3b is indicated, carried out at the corresponding locations of the existing plastic switch housing 12, an elastomer application in multi-component injection molding or an order of an elastomeric ink layer to produce the vibration decoupling 11a, 11b. In Fig. 4a the switch housing 12 is shown with a strip-shaped vibration decoupling 11a. As based on Fig. 4b can be seen, the production of the strip-shaped vibration decoupling 11a takes place by applying an elastomer paste at the corresponding points of the switch housing 12 or by an elastomer application by means of a multi-component injection molding.

In Fig. 5a, 5b shows the subsequent attachment of a vibration decoupling 11d in the manner of mechanical spring elements on the finished switch 5 or on one or more of its individual parts. How out Fig. 5a shows, a circular compression spring 11d 'made of elastomer or other plastic on the broad side of the switch housing 12 is arranged. Elongated leaf springs 11d "made of elastomer or plastic are located on the rear side of the switch housing 12. Of course, this may also be a conventional compression spring 11d 'or leaf spring 11d" made of spring steel. According to Fig. 5b the compression spring 11d 'and the leaf spring 11d "inserted into corresponding housing receptacles 14 on the switch housing 12.

In Fig. 6a is a damping member 11c made of elastomer or plastic located at the vertices of the switch housing 12. According to Fig. 6b the damping member 11c is subsequently mounted in corresponding housing recesses 15 on the switch housing 12 on the otherwise completed switch 5. Fig. 7a shows on the switch housing 12 mounted elastomeric form elements as vibration decoupling 11c, not only in the switch housing 12 but also in corresponding handle shell contours of the housing 4 in Power tool 1 can protrude, allowing this almost ideal-elastic mounting of the switch 5 in the housing 4. For this purpose, according to Fig. 7b one or more of these damping members 11 c inserted into corresponding housing recesses 15 or alternatively introduced a thermoplastic elastomer by multi-component injection molding in the housing recesses 15.

In Fig. 8a is the circuit board 13 for the electronics 8 to see. The circuit board 13 is according to Fig. 8b provided at the edges and on the surface with a strip-shaped vibration decoupling 11a. The vibration decoupling 11a is produced by applying a viscoelastic, crosslinking elastomer paste on and / or on the printed circuit board 13 or by elastomer application by means of a multi-component injection molding process. According to Fig. 8c is on the side edge of the circuit board 13, a vibration decoupling 11b by coating with an elastic fluid, an elastic paint, an elastic paint, a multi-component medium o. The like. Attached. Finally, according to Fig. 8d Also, mechanical damping parts 11c may be attached to the printed circuit board 13. Such damping parts 11 c can also be retrofitted to the finished, already assembled circuit board 13.

Not shown in the drawings is a vibration decoupling, which is realized in that the switch housing 12 consists of resilient housing halves. Finally, the receptacle 10 in the housing 4 of the power tool 1 can also be designed to be elastic for vibration decoupling, for which purpose the receptacle 10 is encapsulated with an elastic polymer and / or coated with an elastic fluid.

The invention is not limited to the described and illustrated embodiments. On the contrary, it also encompasses all professional developments within the scope of the invention defined by the claims. Thus, the invention can not only be used with power tool switches, but can also be found on other switches, such as those for household electrical appliances, electrical gardening equipment, machine tools o. The like., Use and for the mechanical recording of switches, individual switch parts, electronic assemblies, printed circuit boards o. be used.

Reference numeral list:

1:

power tool

2:

electric motor

3:

Tool

4:

casing

5:

Switch / assembly

6:

actuator

7:

Contact system

8th:

Control electronics / electronics / assembly

9:

Vibration generating device

10:

Recording (in the case)

11:

vibration isolation

11a:

encapsulation

11b:

coating

11c:

damping part

11d:

spring element

11d ':

compression spring

11d "

leaf spring

12:

switch housing

13:

circuit board

14:

housing receptacle

15:

housing recess

Claims (13)

1. An electric tool, such as a percussion drilling machine, impact screwdriver, sabre saw or sander, comprising a housing (4), comprising an electric motor (2) located in the housing (4), and comprising an electric and/or electronic assembly (5, 8) which is located in the housing (4) and fastened to at least one receptacle (10) in the housing (4), characterised in that the electric and/or electronic assembly (5) is an electric and/or electronic switch, that the switch (5) has a switch housing (12), that a vibration decoupling (11) is arranged between the receptacle (10) in the housing (4) and the electrical and/or electronic assembly (5, 8), and that the vibration decoupling (11) is arranged facing the receptacle (10) on the switch housing (12).
2. An electric tool, such as a percussion drilling machine, impact screwdriver, sabre saw or sander, comprising a housing (4), comprising an electric motor (2) located in the housing (4), and comprising an electric and/or electronic assembly (5, 8) which is located in the housing (4) and is fastened to at least one receptacle (10) in the housing (4), characterised in that the electric and/or electronic assembly (8) is an electronic unit, that the electronic unit (8) has a circuit board (13) or a carrier, that a vibration decoupling (11) is arranged between the receptacle (10) in the housing (4) and the electrical and/or electronic assembly (5, 8), and that the vibration decoupling (11) is arranged facing the receptacle (10) on the circuit board (13) or the carrier.
3. An electric tool according to claim 1 or 2, characterised in that the switch housing (12) or the circuit board (13) or the carrier is made at least partially of plastic, that the housing (4) and/or the receptacle (10) in the housing (4) is made of plastic, and that the plastic is a thermoplastic and/or thermosetting plastic material.
4. An electric tool according to any one of claims 1 to 3, characterised in that the vibration decoupling (11) is made of plastic or of an elastic polymer or of a thermoplastic elastomer.
5. An electric tool according to any one of claims 1 to 4, characterised in that the vibration decoupling (11) is made of an at least partial extrusion coating and/or injecting (11a) of the electric and/or electronic assembly (5, 8) with the elastic polymer.
6. An electric tool according to any one of claims 1 to 5, characterised in that the vibration decoupling (11) is made of an at least partial coating (11b) of the electric and/or electronic assembly (5, 8) with elastic fluids, such as lacquers and/or paints.
7. An electric tool according to any one of claims 1 to 6, characterised in that the vibration decoupling (11) is made of a damping part (11c).
8. An electric tool according to any one of claims 1 to 7, characterised in that the vibration decoupling (11) is made of a mechanical spring element (11d).
9. An electric tool according to any one of claims 1 to 8, characterised in that a housing for the electric and/or electronic assembly (5, 8) is made of resilient housing halves for the vibration decoupling.
10. An electric tool according to any one of claims 1 to 9, characterised in that the receptacle (10) for the vibration decoupling is designed elastically.
11. An electric tool according to any one of claims 1 to 10, characterised in that an electronic unit for controlling and/or regulating the electric motor (2) is located in the switch housing (12) or that the electronic unit (8) is used to control and/or regulate the electric motor (2).
12. An electric tool according to any one of claims 1 to 11, characterised in that the damping part (11c) is snapped into and/or onto the receptacle (10) in the housing (4) or a housing receptacle (14) on the switch housing (12) or a housing recess (15) on the switch housing (12).
13. An electric tool according to any one of claims 1 to 12, characterised in that the receptacle (10) is extrusion-coated with an elastic polymer and/or is coated with an elastic fluid.

Images