DE102008000937A1 - Electric hand tool with flatwave shaft spring - Google Patents

Abstract

The invention relates to an electric hand tool, with at least one first component and at least one second component, wherein a spring between the two components - is directly or indirectly supporting this - arranged. It is provided that the spring (2) is designed as a flat-wire shaft spring (1).

Description

The The invention relates to an electric hand tool, in particular a drill and / or chisel hammer with at least one first component and at least one second component Component, with a spring between the two components - to this directly or indirectly supporting - arranged is.

State of the art

in the The state of the art becomes cylindrical in the construction of electric hand tools Round wire springs, in particular helical compression springs, as damping, Switching and / or Control springs and used as biasing elements. For example in rotary hammers they serve, in the handle built-in, the damping of vibrations and Bumps from be transferred to the electric hand tool to the user. Continue to serve to the for the application of force, for example, couplings or for preloading of components such as the hammer mill. Depending on the particular field of application and therefore required spring stiffness Take these round wire springs / helical compression springs a considerable Volume, whereby the design freedom, at least in terms the space requirements is limited. Especially in applications of vibration or shock absorption, especially in the area of the housing of the electric hand tool, therefore, a relatively large amount of space is claimed and also by the relatively large one Extension of such springs a partially undesirable formation of cavities for Recording such springs provided. This undesirably increases the risk of breakage of such housing parts.

task The invention is to provide an electric hand tool, in the one for these applications required space, especially for recording of springs for damping or control purposes or to form biasing, very clear can be reduced.

Disclosure of the invention

For this an electric hand tool is proposed, with at least one first component and at least one second component, wherein a Spring between the two components - to this directly or indirectly supporting - arranged is. It is provided that the spring as a flat wire shaft spring is trained. Unlike in the prior art, no round wire spring, in particular, no helical compression spring used, but a so called flatwave shaft spring. A flat wire wave spring is hereby such a spring, which is formed of flat wire, wherein the flat wire to achieve the desired Spring stiffness and spring force has wave peaks. While at classic round wire springs the spring stiffness and thus the spring force directly from the mean spring diameter and the middle spring wire diameter depend, can in flat wire springs at given mean spring diameter the desired Spring stiffness in a large Bandwidth can be achieved by the number and arrangement of Wave crests formed on the spring diameter vary become. Thus, adjustments are the spring stiffness and spring force to the respectively desired Requirements and applications very easy. For example can flat wire shaft springs by training a larger number harder at wave mountains while at a lower number of wave crests softer. It is not necessary, the spring diameter And so to change the spring space, it is not required, the starting sheet thickness and the material specification to change. By forming more or less wave crests of the flatwave shaft springs can the desired Spring stiffness can be adjusted in a very wide range.

In an embodiment is the flat wire wave spring as a closed ring, in another embodiment it is designed as an open ring. In the embodiment as a closed ring can be the flat wire wave spring form stiffer, since no open ends present, which can avoid the application of force. In the embodiment as an open ring is indeed compared to the closed ring the Spring stiffness slightly reduced, the embodiment, however a higher one Easy to install due to its higher radial and axial Flexibility on, thereby mounting, especially in tight and / or complicated geometries. For example can the embodiment as an open ring by means of a so-called Seegerringzange widened or also be narrowed, which through the two open ends and the between them remaining gap is possible and a slight Assembly allowed.

Several Feathers can as a flat wire shaft spring assembly of open and / or closed Rings are formed; be several flatwave shaft springs consequently joined together, to form the flat wire shaft spring assembly. Here is the Use of open and closed rings also in different proportions possible, to the desired Spring stiffness and the desired To obtain size.

In one embodiment, the flat wire wave spring assembly is a flat wire wave spring package. The individual flat-wire shaft springs are arranged in such a way that they assume different, even arbitrary, angles to one another; it is not required to lie in planes that are at least approximately parallel to each other, for example. In particular, it is possible in this case to carry out the flat-wire shaft spring package as a coil-like container, with the advantage that the flat-wire shaft spring package unfolds a spring action in all directions, that is, it is not limited to a specific force direction with regard to the exertion of the spring action. It is therefore possible, for example, to absorb shocks and / or vibrations in different directions and planes.

In another embodiment the flat wire wave spring assembly is a flat wire wave spring cylinder. Preferably, it is provided that the flat wire shaft spring cylinder from flatwire shaft springs disposed substantially concentrically about a longitudinal axis is formed. The individual flat wire shaft springs, in particular in their execution as open or closed rings, are therefore substantially one above the other and / or each other, so that one by their respective extent and height resulting in addition expansion.

In a preferred embodiment have the flat wire shaft springs to form the flat wire shaft spring assembly at least in sections a connection to each other. By means of Connection can be ensured that the individual flatwave shaft springs do not solve each other, causing the flat wire shaft spring composite affected or dissolved could.

Especially Preferably, the compound is an adhesive connection, so for example a weld, soldering or a bond. The material connection is in such areas of the Flat wire shaft springs provided, which lie opposite each other in contact position.

In another embodiment is the flat wire wave spring assembly, in particular namely a Flat wire wave spring cylinder, wound from an endless flat wire. This embodiment has the advantage that on the compounds described above can be dispensed with, the production so once again simplified and cheaper can be configured. Next is advantageously avoided that individual flat wire shaft springs are released from the composite and so to speak can jump out, because the entire composite consists of a single component.

In an embodiment the flat-wire shaft spring consists of a metallic material, for example made of spring steel.

In another embodiment If the flatwave shaft spring is made of a non-metallic material, for what, in particular Plastics in different material composition and texture be considered. Here, the flatwave shaft spring can not only act mechanically, but also, for example, the tasks take over an electrical insulator or in electrically critical areas of the electric hand tool be used.

In preferred embodiments are the components in which the Spring supports, Housing components. This makes it possible individual housing components with regard to occurring vibrations and / or vibrations decouple.

Prefers the first component is a housing handle and the second component is a housing shell. In particular, namely in applications in which a handle to be held by the operator of the electric hand tool vibration damped and / or vibration decoupled accomplished should be, for example, over a one-sided axial / swivel / movable storage and other a sprung storage / suspension, are so far with great Space expenditure helical compression springs, cylindrical steel springs used, which creates a for many applications undesirable size Training this damping element results. In particular, relatively large gaps are invading To seal dust, especially in construction site equipment, for operational safety the damping sure. Advantageously, with the flat-wire shaft springs according to the invention or flat wire shaft spring assemblies a very significant reduction in the amount required for the spring Installation space / volume can be achieved.

Further is provided that the components Abstützausnehmungen and / or support surfaces for support or have at least partially receiving the spring. To support the Spring on the components are provided support surfaces, these as Abstützausnehmungen can be trained So as such designs, such as wells, the one allow at least partially introducing the spring so that the spring is on the Abstützausnehmung not just as supported on a support surface, but at the same time is held, for example, an axial and radial emigration to avoid. This leaves in particular, a very simple installation by a certain and guided Receiving the spring in at least one of the components.

In another embodiment, the components are components of a drilling and / or impact mechanism of the electric hand tool. In particular in drilling or hammering of Elektrohandwerkzeu Feathers are used. They serve to control and / or the damping of such components.

Also leave here with the embodiments according to the invention the spring a very significant reduction in the required space to reach.

In an embodiment the first component is a hammer tube and the second component is a Axial securing and / or storage of the hammer tube. The spring is supported Consequently, on the hammer tube on the one hand and its axial securing and / or storage on the other hand. It thus causes a dampening Fixation of the hammer tube.

Prefers the spring is a biasing spring acting between the components. For vibration reduction must different masses, namely the Components, if possible be braced axially. In rotating pipes, such as hammer tubes, This is currently only insufficiently achieved. By means of the flat wire shaft springs according to the invention however, an axial clamping is easy and very space-saving possible by for example, the storage on the one hand and a supporting this On the other hand, component are acted upon by the spring according to the invention. For example Is it possible, as storage a radial bearing, for example a ball bearing, and to provide a sleeve receiving this as another component, wherein a ball bearing facing bottom or top side of the Sleeve of the spring is acted upon, on the other hand, the this floor or the lid facing surface the ball bearing on the other hand, in particular end face, acted upon. Such bearings are, for example, as cup-shaped training the sleeve with a breakthrough for a shaft or the hammer tube executed, wherein in the pot storage lies. Between storage and breakthrough Part of the pot, for example pot base, the spring according to the invention is therefore arranged and thereby allows in a very simple and space-saving manner the tension of the shaft or the hammer tube.

In another, preferred embodiment the components are coupling elements of a clutch, in particular an overload clutch. clutches of electric hand tools, especially overload clutches, solve overload against a closing one Spring force off. Slip clutches, for example, have clutch discs on, which are held by the spring in clutch engagement. Preferred may these clutch discs a toothing with tooth flanks and these responsive Have interventions, the release of the steepness of Tooth flanks dependent is. As long as overload does not occur, the tooth flanks remain with the shape-responsive Intervention in the form-fit, wherein in blocking, for example, a Tool in a workpiece, so in case of overload, the teeth due to the skew the tooth flanks are released from the intervention and this opposite the spring force the clutch is opened. Again, by means of the flat wire wave spring according to the invention a very space-saving training possible.

In another embodiment forms at least one spring with at least one of the components Spring-mass system off. Spring-mass systems serve as vibration dampers.

Prefers the components are components of a vibration absorber or wise such an on.

Especially Preferably, the Vibrationstilger is associated with a percussion tube of the electric hand tool, In particular, he embraces such at least in certain areas. In The training as a spring-mass system is one of the components, for example annular formed, with its volume and weight of one of him at least partially enclosing percussion tube and the desired Effective range of vibration absorber, ie frequency and amplitude of Vibration is adapt. The component is on both sides of springs according to the invention, in particular of flat wire shaft spring cylinders, biased so that results in the described spring-mass system.

Especially Preferably, the vibration damper is a longitudinal vibration damper. Especially in the arrangement of hammer works electric rotary hammers occur depending on the principle of longitudinal vibrations, which is unpleasantly over the machine housing report. It is advantageous in this way, such longitudinal vibrations already on Origin, namely in the hammer mill itself, as far as possible to dampen or eradicate. With the flat wire wave composite according to the invention, In particular flat wire wave spring cylinder, the application is very high and very effective spring forces also possible in a small space, so that such longitudinal vibrations also great Amplitude effectively suppressed can be.

Further is provided that the spring is a control spring of a hammer mill or striking mechanism of the electric hand tool. The spring is used here the control, in the broadest sense an impulse-giving drive, a part of the hammer mechanism or percussion, for example a firing pin.

In another embodiment, the spring is a damping spring, in particular damping spring of a percussion or hammer mill.

Further advantageous embodiments emerge from the dependent claims and combinations thereof.

The The invention is explained in more detail below with reference to exemplary embodiments, without but limited to these to be.

Brief description of the drawings

It demonstrate

1 a flat wire wave spring in its geometric dimensions;

2 the flat wire wave spring to explain its principle of action in side view;

3 a flat wire shaft spring assembly formed as a flat wire wave spring cylinder;

4 a flat wire wave spring assembly for vibration damping in a housing handle of a power hand tool;

5 a Vibrationstilger with two flat wire shaft spring assemblies;

6 the flat wire wave spring as a biasing spring for clamping a radial bearing and

7 a flat wire shaft spring assembly consisting of two flat-wire shaft springs for applying force to a safety / friction clutch.

Embodiment (s) the invention

1 shows a flatwave shaft spring 1 trained pen 1 in their geometric dimensions 3 , for the sake of clarity, as a virtual ring 4 are drawn. The flatwave shaft spring 1 is here as a ring spring 5 trained, namely as an open ring 6 that has a ring opening 7 having. The flatwave shaft spring 1 is from a flat wire 8th formed out of an original, level education with wave mountains 9 was brought into an altitude extent. The spring stiffness of the flatwave shaft spring 1 depends on the material 10 of the flat wire 8th and from the number and height h as the amount of elevation of the wave crests 9 towards a top 11 and a bottom 12 the flatwave shaft spring 1 , The more wave mountains 9 on the flatwave shaft spring 1 are formed and the higher they are, the stiffer the flat wire wave spring 1 ,

2 shows the flatwave shaft spring 1 in side view to illustrate an application in support between two components 13 namely, a first component 14 and a second component 15 , The second component 15 is here on a pad 16 stored while the first component 14 receives a force F, such as a load. The spring effect is in this case by the height h of the flatwave shaft spring 1 and number and education of the wave mountains 9 determined, in a sense, as a rejection out of the flat plane. By number and training of the wave mountains 9 can be the desired spring force of the flatwave shaft spring 1 set in a wide range.

3 shows a flat wire shaft spring assembly 17 , which consists of several in the form of a flat wire shaft spring cylinder 18 arranged, individual flat wire shaft springs 1 is formed. The individual flatwave shaft springs 1 are superimposed in such a way that their wave crests 9 each in opposite direction touch, so troughs 19 (namely, down-facing peaks 9 below an average level) on the one hand with wave crests 9 on the other hand (increases above the average level) in touching contact 20 to step. At the touch contacts 20 have the superimposed flatwave shaft springs 1 at least in sections a connection 21 on, for example, a material connection 22 such as a weld 23 , which is very easy to produce, for example by means of a welding laser or by means of a known from the prior art spot welding. It is not necessary that all touch contacts 20 the individual flatwave shaft springs 1 a connection 21 have one another; it is sufficient if so many connections 21 between the individual flatwave shaft springs 1 exist that the flat wire shaft spring assembly, in particular, for example, the arrangement of a flat wire shaft spring cylinder 18 , retained in its geometry and even under load (unilateral or bilateral force) the individual flatwave shaft springs do not emigrate from the flat wire shaft spring assembly, for example, slide away to the side. About the connections 21 The spring forces are under the individual flatwave shaft springs 1 defined passed, whereas contact contacts 20 that have no connections 21 have, a sliding of Berührkontakte 20 is possible. Also in this way can be very advantageous to adjust the spring action of the flat wire shaft spring assembly within very wide limits and open up a wider, more effective application.

4 shows one of flat wire shaft springs 1 formed Flachdrahtwellenfederverbund 17 between two components 13 , where the components 13 housing components 24 an electric hand tool 25 , namely a hammer drill 26 are. The first component 14 Here is a case handle 27 of the electric hand tool 25 while the second component 15 a housing shell 28 of the electric hand tool 25 is. The housing handle 27 is about a bearing axis 29 on the housing shell 28 articulated pivotally in a certain range. It essentially forms the shape of a U, one leg of which 30 the bearing axis 29 for pivotable connection with the housing shell 28 includes while the other leg 31 on the flat wire shaft spring assembly 17 which is supported in a flexible dust cover 32 stores and over, for example, a support element 33 on the housing shell 28 supported. From the housing shell 28 outgoing vibrations and vibrations are therefore of the flat wire wave spring assembly 17 recorded and not or only slightly on the housing handle 27 and thus transferred to the hand of the operator of the electric hand tool. For advantageous and easy introduction and storage of the flat wire shaft spring assembly 17 is in the housing handle 27 a Abstützausnehmung 34 introduced, in which the flat wire wave spring assembly 17 engages in sections. This facilitates the assembly and its spatial fixation. Essentially transverse to a longitudinal axis 35 of the flat wire shaft spring assembly (as a flat wire shaft spring cylinder 18 is formed) are both on the housing handle 27 as well as on the housing shell 28 or the support element 33 support surfaces 36 educated.

5 shows a vibration damper 37 in a simplified representation. A component 13 is as a mass tube 38 formed and on both sides end to its end faces 39 each of a flat wire shaft spring assembly 17 namely, each a flat wire wave spring cylinder 18 applied. The flatwave shaft spring cylinder 18 relies either on each a second component 15 (here only schematically drawn) from or has up to the second component 15 still a free distance w. The vibration damper 37 This is from the mass tube 38 and the two him each end associated with flat-wire shaft spring cylinders 18 educated. For example, it encompasses a percussion tube 40 an electric hand tool not shown here 25 , For example, a hammer drill 26 , The mass tube 38 slides on the percussion tube 40 axially displaceable, wherein it by impulse loading during operation of the hammer mechanism of the hammer drill, not shown 26 each performs a forward and backward movement in response to the impactor induced pulses. Each end is its movement of the flat wire wave spring cylinder 18 recorded, which then on the one hand to the second component 15 and on the mass tube 38 as the first component 14 supported, whereby the existing kinetic energy in the mass tube by the spring action of the flat wire shaft spring cylinder 18 at least predominantly consumed. In this way, a very good Vibrationstilgung can be achieved, especially in training as a longitudinal vibration damper 41 , Vibrations and vibrations, in the longitudinal direction of the electric hand tool, ie in axial extent as the striking mechanism tube 40 occur, can be damped or eradicated in an advantageous manner, so that the operator a pleasant work with the electric hand tool 25 is possible.

Similar designs are also conceivable as control springs 42 (dashed line drawn here), in which the spring arrangement is not the damping of vibrations, but the pulse return of an axially displaceable mass 43 (dash-dotted line drawn here), which applies the impact energy to a tool holder, not shown, and ultimately to the tool.

The mass tube 38 forms with the flat wire shaft spring cylinders 18 a spring-mass system 44 from, the same applies to the exemplary drawn design as control springs 42 with the axially displaceable mass 43 ,

6 shows the flatwave shaft spring 1 as a biasing spring 45 between a radial bearing 46 namely a ball bearing 47 , and a wave 48 , in particular a hammer tube 49 a rotary hammer, not shown. The radial bearing 46 is the hammer tube 49 assigned, for example, blown up, and allows its rotation. The radial bearing 46 is in an axial fuse 50 for the hammer tube 49 introduced, with the axial securing 50 as a sleeve 51 in the form of a pot 52 with a bottom of the pot 53 to the passage of the hammer tube 49 is trained. The flatwave shaft spring 1 rests on a radial bearing end face 54 on the one hand and on one of these facing pot bottom inside 55 on the other hand. In this way it is very easy and with very little space overhead a very good tension of the hammer tube 49 enable. The radial bearing 46 namely slides axially displaceable within the pot 52 and is by the biasing spring 45 held in the desired position and braced.

7 shows an overload clutch 56 namely, a slip clutch 57 the electric hand tool, not shown. This has coupling elements 58 on, the components 13 are (a component 13 , at which the flat wire wave spring composite 17 is not shown here for the sake of clarity, this component is above the flange shown here 59 by means of the shown, on the flange 59 arranged screws 60 to support the flat wire shaft spring assembly). At the flange 59 will with the screws 60 not shown here, for supporting serving another component 13 attached, that at the here visible visible area of the flat wire shaft spring assembly 17 supports and axially on the flange 59 sliding coupling element 58 by means of the spring force of the flat wire shaft spring assembly 17 on the further, substantially cup-shaped coupling element 58 , namely the coupling counterpart 61 , imprinted, so that there is a frictional connection.

Preferably, the coupling counterpart 61 interventions 62 as open-edged recesses 63 on, in the not here shown, shape-related teeth of the coupling element 58 as a clutch disc 64 is trained, intervene. The teeth are created by the pressure of the flat wire shaft spring assembly 17 engaged in the coupling counterpart 61 held. In case of overload, ie in particular when blocking a tool in a workpiece, the spring force of the flat wire shaft spring assembly is sufficient 17 no longer to the twisting of the coupling counterpart 61 relative to the clutch disc 64 over tooth flanks 65 to counteract the interventions and the teeth, not shown; the friction is canceled as well as the positive connection and it comes to a slippage, a "Rätschen" of the clutch, whereby the power flow between the flange 59 and the coupling counterpart 61 is interrupted. Again, in contrast to the prior art, a very space-saving design possible because of the here of two individual flat wire shaft springs 1 formed Flachdrahtwellenfederverbund 17 a highly effective Federkraftbeaufschlagung the clutch disc 64 to effect a clutch engagement 66 effect.

Claims (26)

Electric hand tool, with at least one first component and at least one second component, wherein a spring between the two components - is arranged on these directly or indirectly supporting -, characterized in that the spring ( 2 ) as a flat wire wave spring ( 1 ) is trained. Electric hand tool according to claim 1, characterized in that the flatwave shaft spring ( 1 ) is designed as a closed ring. Electric hand tool according to one of the preceding claims, characterized in that the flatwave shaft spring as an open ring ( 6 ) is trained. Electric hand tool according to one of the preceding claims, characterized in that the spring ( 2 ) as Flachdrahtwellenfederverbund ( 17 ) from open ( 6 ) and / or closed rings is formed. Electric hand tool according to one or more of the preceding claims, characterized in that the flat wire shaft spring assembly ( 17 ) is a flat wire wave spring package. Electric hand tool according to one or more of the preceding claims, characterized in that the flat wire shaft spring assembly ( 17 ) a flat wire wave spring cylinder ( 18 ). Electric hand tool according to one or more of the preceding claims, characterized in that the flat-wire shaft spring cylinder ( 17 ) substantially concentrically about a longitudinal axis ( 35 ) arranged flatwave shaft springs ( 2 ) is formed. Electric hand tool according to one or more of the preceding claims, characterized in that the flat wire shaft springs ( 2 ) for the formation of the flat wire shaft spring assembly ( 17 ) at least in sections a connection ( 21 ) exhibit. Electric hand tool according to one or more of the preceding claims, characterized in that the connection ( 21 ) a material connection ( 22 ). Electric hand tool according to one or more of the preceding claims, characterized in that the spring ( 2 ) as a wound from an endless flat wire flat wire shaft spring assembly ( 17 ), in particular flat-wire shaft spring cylinders ( 18 ), is trained. Electric hand tool according to one or more of the preceding claims, characterized in that the flatwave shaft spring ( 1 ) consists of a metallic material. Electric hand tool according to one or more of the preceding claims, characterized in that the flatwave shaft spring ( 1 ) consists of a non-metallic material. Electric hand tool according to one or more of the preceding claims, characterized in that the components ( 13 ) Housing components ( 24 ) are. Electric hand tool according to one or more of the preceding claims, characterized in that the first component ( 13 . 14 ) a housing handle ( 27 ) and the second component ( 13 . 15 ) a housing shell ( 28 ). Electric hand tool according to one or more of the preceding claims, characterized in that the components ( 13 ) Outrigger tions ( 34 ) and / or support surfaces ( 36 ) for supporting or at least partially receiving the spring ( 2 ) exhibit. Electric hand tool according to one or more of the preceding claims, characterized in that the components ( 13 ) Components of a drilling and / or impact mechanism of the electric hand tool ( 25 ) are. Electric hand tool according to one or more of the preceding claims, characterized in that the first component ( 13 . 14 ) a hammer tube ( 49 ) and the second component an axial fuse ( 50 ) and / or storage of the hammer tube ( 49 ). Electric hand tool according to one or more of the preceding claims, characterized in that the spring ( 2 ) one between the components ( 13 ) acting biasing spring ( 45 ). Electric hand tool according to one or more of the preceding claims, characterized in that the components ( 13 ) Coupling elements ( 58 ) a clutch, in particular an overload clutch ( 56 ), are. Electric hand tool according to one or more of the preceding claims, characterized in that the overload clutch ( 56 ) a slip clutch ( 57 ), which has clutch plates, which by means of the spring ( 2 ) are held in clutch engagement. Electric hand tool according to one or more of the preceding claims, characterized in that at least one spring ( 2 ) with at least one of the components ( 13 ) a spring-mass system ( 44 ) trains. Electric hand tool according to one or more of the preceding claims, characterized in that the components ( 13 ) Components of a vibration absorber ( 37 ) or have such. Electric hand tool according to one or more of the preceding claims, characterized in that the vibration damper ( 37 ) a percussion tube ( 40 ) of the electric hand tool ( 25 ), in particular such at least partially surrounds. Electric hand tool according to one or more of the preceding claims, characterized in that the vibration damper ( 37 ) a longitudinal vibration damper ( 41 ). Electric hand tool according to one or more of the preceding claims, characterized in that the spring ( 2 ) a control spring ( 42 ) of a hammer mechanism or impact mechanism of the electric hand tool ( 25 ). Electric hand tool according to one or more of the preceding claims, characterized in that the spring ( 2 ) is a damper spring, in particular damper spring of a percussion drilling or a hammer mill, is.