WO2004016399A1

WO2004016399A1 - Housing unit

Info

Publication number: WO2004016399A1
Application number: PCT/DE2003/001384
Authority: WO
Inventors: Rudolf Fuchs
Original assignee: Robert Bosch Gmbh
Priority date: 2002-07-30
Filing date: 2003-04-30
Publication date: 2004-02-26
Also published as: DE10259518A1

Abstract

The invention relates to a housing unit (2) consisting of a first material, which encloses a component of a hand tool. According to the invention, the housing unit (2) has a component (8, 10, 12, 16, 20, 26, 30) consisting of a second material, which is more elastic than the first material, said first material being joined to the second material by means of a material bond in an injection moulding method.

Description

Housing inlet

State of the art

The invention is based on a housing unit.

Known hand-held power tools usually have a housing unit which encompasses some or all of the components of the hand-held power tool. Such a housing unit performs different tasks. It serves to protect the components arranged in it and is therefore usually made of a strong, less elastic material. Part of the housing insert also serves as a handle, which should have a certain slip resistance in addition to an ergonomic shape. Furthermore, a housing unit has fastening elements which are used for fastening or receiving a component of the handheld power tool, for example a bearing. For good fastening and for damping vibrations, the fastening elements can have an elastic component that softly clamps the component. In order to provide a housing unit with all the desired properties, it is common to equip the housing unit with various elements.

Advantages of the invention

The invention is based on a housing unit made of at least a first material, which encompasses a component of a hand tool. It is proposed that the housing unit have a component made of a second material which is more elastic than the first material, the first material being integrally connected to the second material by an injection molding process.

With a multi-component injection molding process, a housing unit of a handheld power tool can be manufactured from several materials in a simple and inexpensive manner. The materials can have different properties and colors and are firmly and durable connected by the injection molding process. In addition to a first impact and impact-resistant material for protecting the components located in the housing unit, the housing unit can also comprise a second material which has material properties adapted to a further task.

The housing unit encompasses one or more components of the handheld power tool. The component can be the machine part of the hand machine tool, a handle, a battery pack of the hand machine tool or a charger for the battery pack of the hand machine tool. However, it is equally possible that the housing unit completely encloses all components of the hand machine tool, apart from the necessary openings and passages.

In an advantageous embodiment of the invention, the component supports an element of the handheld power tool. Such supportive recording can be done by clamping or fastening the element in or on the component. It is also possible to support the element between two components by clamping or fastening. Due to the elasticity of the second material, the element is elastically supported in the housing unit by the component. Vibrations, vibrations or impacts are thus only damped from the element to the housing unit or vice versa. In addition to vibration damping and thus comfortable guidance of a handheld power tool, it is also possible to reduce noise during the operation of the handheld power tool. The handheld power tool is easy to operate and quiet.

The element can be a bearing seat with which a bearing of the handheld power tool is arranged in a fixed position on the housing unit. The element can also be a bearing flange receptacle that firmly positions a flange of a bearing or a pole shoe receptacle for firmly holding the motor within the Housing unit of the hand machine tool. The elements are positioned firmly and yet are kept soft so that they are only subjected to a slight acceleration, for example due to impacts or impacts, during the operation of the hand tool. This reduces wear on the elements and increases their reliability and service life.

The elasticity of the second material may allow the second material to conform to the shape of the element. This counteracts slipping or twisting of the element in the component. In addition, the surface of the second material can be made non-slip than the surface of the first material. In this way, a particularly secure positioning of the element in or on the component or between the components is achieved.

The element is expediently kept separate from the first material by the component. Vibration can therefore only be transmitted indirectly from the element via the component to the first material or vice versa. Due to the elasticity of the second material, noise generated by the handheld power tool due to vibration can be kept low. The separation between the element and the first material is expediently ensured even when the housing unit is subjected to the usual bumps or knocks during operation. Rattling caused by the element bumping against the first material can thus be effectively avoided.

In a further embodiment of the invention, the component is a bumper arranged on an edge of the outside of a housing part. As a result, the wear of the housing unit at particularly exposed locations can be considerably reduced. Due to the elasticity of the second material, the bumper can considerably reduce impacts from the outside of the housing. This also reduces the wear on the components of the handheld power tool arranged within the housing unit. The bumper may be attached to or around the edge as a layer of the second material. It is also possible to design the bumper so that Safe storage or convenient storage of the hand tool is achieved. An edge is understood to mean those points of a housing part which have a convex curvature with a radius of curvature which is less than 2 cm. The housing unit can consist of one or more housing parts.

The housing unit expediently comprises a bumper at a point at which a housing part is provided for contact with a further housing part. Impacts caused by the collision of the housing parts can thus be dampened. Such a point at which two housing parts meet is, for example, a point at which a battery pack touches a housing part of the machine part or handle of the hand tool. A charger also has points at which a battery pack can come into connection with the charger when it is plugged into the charger.

The component is advantageously a grip zone sprayed onto a housing part. The elasticity of the second material has a vibration-damping effect, so that the handheld machine tool can be handled more comfortably and safely in the grip zone. In addition, the surface of the second material can be made non-slip than the surface of the first material. As a result, the handheld power tool can be gripped particularly securely.

A particularly quiet mounting of a housing part of a handle can be achieved by the component holding this housing part. Vibrations or impacts from a striking mechanism generated by rotating parts of the hand tool are dampened by the component on their way to the handle. The handle is therefore very quiet in the operator's hand.

In another embodiment variant of the invention, the component forms a kink protection for a power cable. At the place where a power cable emerges from the housing unit of the hand machine tool, it is subject to a strong kink. exposed to stress. This stress is usually reduced by a kink protection plugged into the housing unit. With a kink protection molded onto the first material, the assembly effort of the hand machine tool can be reduced.

The component expediently forms a receptacle for an anti-kink protection for a power cable. A kink protection usually has a high elasticity so that it can be bent with a power cable. At a point where an edge made of the first material touches the kink protection, the kink protection is subjected to high stress. This stress can be reduced in that at least part of the receptacle made of second and elastic material comes to lie between the kink protection and at least one edge made of the first material.

In a further embodiment variant of the invention, the component is a label. Such labeling is not worn out during normal use of the hand-held power tool, as is the case, for example, with printed labeling. In addition, a label made of a second material, which has a different color than the first material, is clearly visible on the housing unit. The disadvantage of a label relief made of only the first material that is difficult to recognize is avoided. An additional advantage can be achieved if the second material is made translucent. A light source arranged inside the housing unit, such as a light-emitting diode, can be easily recognized outside the housing. The lettering can be designed as a letter, number or symbol.

The component is expediently arranged between a first and a second housing part, wherein it is connected to the first housing part and is designed separately from the second housing part. A connection between two housing parts is usually arranged a distance away from the edges of a housing part. As a result, the housing parts rest relative to one another at a connection point. which, however, can perform relative movements to one another at the edges during operation of the hand-held power tool due to a certain elasticity of the housing parts. This can lead to the edges hitting each other. A component made of second material arranged between the first and the second housing part has a damping effect and can effectively reduce rattling of the two housing parts against one another.

A particularly stable connection between the first material and the second material can be achieved by the component completely penetrating a housing part from the inside to the outside. As a result, the entire thickness of the first material is used to anchor the component. The visibility of the component from outside the housing unit can be regarded as an additional advantage, since an operator of the handheld power tool can recognize the component arranged inside the housing insert and can thereby obtain information if necessary.

In an advantageous development of the invention, the housing unit comprises a third material which is integrally bonded to at least one of the other two materials by an injection molding process. The third material can differ from the other two materials in its elasticity, toughness, hardness, temperature resistance or color. In this way, the advantages mentioned above can be further increased, for example by a combination of the three materials reducing vibrations even further than would be possible with only two materials. It is possible, for example, to injection-mold a receptacle for a buckling shot made of the second material onto the first material and to integrally spray the buckling protector made of the third and even more elastic material onto the second material. There are also different color markings for different functions, such as off / on, open / close, left / right, slow / fast, in a clear and simple manner. drawing

Further advantages result from the following description of the drawing. In the drawing, an embodiment of the invention is shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations.

The single figure shows a housing unit 2 of a hand tool in a simplified, sectional representation. The hand tool is a hand drill. In the fully assembled state of the hand drill, the housing unit 2 encompasses a number of components of the hand drill, not shown in the figure. The housing unit 2 comprises a plurality of housing parts 4, one of which is designed as a handle shell 6. The housing parts 4 and the handle shell 6 are produced from an impact-resistant plastic material in an injection molding process. A second material, which is more elastic than the first material, was sprayed onto this plastic material, referred to as the first material, in the same injection molding process. Components 8 designed as bearing seats are formed from this second material, in which a bearing (not shown in more detail in the figure) is accommodated in the fully assembled state of the hand drill. The bearing seats shown in the top view are shaped such that a bearing held by them is kept separated from the first material in a contactless manner, that is to say does not come into contact with a housing part 4 of the housing unit 2. A bearing is supported by the bearing seats in such a way that it is held in position by the bearing seats during operation of the hand drill. At the same time, the bearing seats absorb some of the vibrations emanating from the bearing, so that only some of these vibrations are transmitted to a housing part 4. Due to the elasticity of the second material, some of the vibrations are absorbed by the bearing seats. In addition to the bearing seats, further components 10, 12 are sprayed onto a housing part 4 made of the first material, namely a component 10 consisting of several individual elements, which serves as a pole shoe holder, and a component 12, which is designed as a bearing flange holder. The pole shoe receptacle supports the motor of the hand drill, not shown, and holds it firmly in position relative to a housing part 4. The bearing flange receptacle supports a flange of a bearing, so that the bearing is held at a distance from the housing part 4 made of the first material by a layer 14 made of second material. The bearing seats as well as the pole shoe receptacle and the bearing flange receptacle are introduced into the housing part 4 by the injection molding process and are thus integrally connected to it. The components 8, 10 configured as bearing seats and pole shoe receptacles are arranged inside the housing unit 2. They penetrate the housing part 4, with which they are integrally connected, completely to the outside, so that the components 8, 10 are clearly visible from the outside.

At the lower end of the housing unit 2, a component 16 designed as a receptacle for an anti-kink protection 18 is injection molded onto at least one of the housing parts 4. This receptacle is also formed from a second material and protects the kink protection 18 against excessive kinking at the location of sharp edges of the housing part 4. The kink protection 18 itself is made from a third material that is even more elastic than the second material. The third material of the kink protection 18 is sprayed onto the second material of the component 16 designed as a receptacle using the injection molding process, so that the third material is bonded to the second material. Due to the great elasticity of the third material, the kink protection 18 is particularly easy to bend, so that a power cable emerging from the housing unit 2 is essentially only gently bent even under strong tensile loads.

Also made of a third and very elastic material, components 20 serving as buffers are injection molded onto holding devices 22 of the handle shell 6 and are thus integrally connected to it. The buffers are separated, for example, by a glue or a plug-in or crimped connection with holding devices 24 of a housing part 4, so that they hold the handle shell 6 on the housing part 4. Vibrations generated by rotating parts of the hand drill are only partially transmitted to one or more housing parts 4 by the elastically designed bearing seats, the pole shoe receptacle and the bearing flange receptacle and are further dampened on their way to the handle shell 6 by the buffers. The handle shell 6 is therefore very calm in the hand of the operator of the hand drill even when there is a very strong vibration, which can be triggered, for example, by a hammer mechanism. In addition to a vibration-damping function, the components 8, 10, 12 and in particular also the components 26 perform a noise-damping function. In the area of the components 26, two housing parts 4 overlap one another. Due to the production-related or vibration-damping separation of the housing parts 4 from one another, the housing parts 4 can move to a small extent in the area of the components 26 relative to one another and collide with one another during operation of the handheld power tool. The components 26 are made of a third material and are arranged between the housing parts 4, each of the components 26 being injection molded onto only one housing part 4 and being designed separately from the other housing part 4. The components 26 serve as protection against rattling and prevent the two housing parts 4 from clattering against one another when vibrated.

On the outside of one of the housing parts 4 of the housing insert 2, a grip zone 28 made of third material is sprayed onto the first material of the housing part 4. The grip zone 28 has a particularly non-slip surface and serves to ensure that the hand drill can be filled safely. Components 30 made of second material and serving as bumpers are also sprayed onto the outside of one of the housing parts 4. The components 30 are applied to the housing part 4 or the housing parts 4 at those points at which the housing unit 2 is exposed to particular mechanical stresses from the outside. This stress can be exerted by third-party as well as components of the hand tool machine go out yourself. When the hand-held power tool is designed as a battery-operated machine, the housing unit can be subjected to great stress at a point where a battery pack touches a housing part of the machine part or handle of the hand-held power tool. A charger also has points at which a battery pack can come into connection with the charger when it is plugged into the charger. Such bumpers are not explicitly shown in the figure, but are to be regarded as encompassed by them.

Inscriptions 32, 34 made of second material and fourth material, which are injected into a housing part 4, are essentially enclosed by the first material of a housing part 4. The inscription 32 made of second material shows the position of a selector lever of the hand drill, not shown in the figure. The second material has a color that is clearly different from the color of the first material. For example, the first material is kept dark green, whereas the second material has a dark red color. The inscription 32 is thus clearly visible even with only weak lighting and can still be recognized with the same clarity as in the beginning of the use of the hand drill even when subjected to heavy mechanical stress and long use of the hand drill.

The label 34 is made of a fourth material, which was injected into the first material by means of the injection molding process and was integrally connected to it. The fourth material also has a color that clearly stands out from the color of the first material, and additionally has the property that it is translucent. A light source arranged below the label 34 can thus be seen from outside the housing unit 2. The label 34 shows a symbol that indicates an operating state of the hand drill in connection with the light source. reference numeral

2 housing unit

4 housing part

6 handle shell

8, 10, component

12

14 layer

16 component

18 Kink protection

20 component

22, 24 holding device

26 component

28 grip zone

30 component

32, 34 lettering

Claims

Expectations

1. Housing unit (2) made of at least a first material, which encompasses a component of a hand tool, and a component (8, 10, 12, 16, 20, 26, 30) made of a second material, which is more elastic than the first material , wherein the first material is integrally connected to the second material by an injection molding process.

2. Housing unit (2) according to claim 1, characterized in that the component (8, 10, 12) receives an element of the handheld power tool supporting.

3. Housing unit (2) according to claim 2, characterized in that the element is kept contactlessly separated from the first material by the component (8, 10, 12).

4. Housing unit (2) according to one of the preceding claims, characterized in that the component (30) is a bumper arranged on an edge of the outside of a housing part (4).

5. Housing unit (2) according to one of the preceding claims, characterized in that the component forms an anti-kink protection (18) for a power cable.

6. Housing unit (2) according to one of the preceding claims, characterized in that the component (16) forms a receptacle for an anti-kink protection (18) for a power cable.

7. Housing unit (2) according to one of the preceding claims, characterized in that the component is a label (32, 34).

8. Housing unit (2) according to one of the preceding claims, characterized in that the component (26) is arranged between a first and a second housing part (4), wherein it is connected to the first housing part (4) and from the second housing part (4th ) is carried out separately.

9. Housing unit (2) according to one of the preceding claims, characterized in that the component (8, 10) completely penetrates a housing part (4) from the inside to the outside.

10. Housing unit (2) according to any one of the preceding claims, characterized by a third material which is integrally connected to at least one of the other two materials by an injection molding process.