Abstract:
A motor-powered machine tool includes a drum-like tool-changing magazine having tool chambers. The magazine is arranged inside a housing, and when the tool is in a change position, one of the tool chambers of the tool-changing magazine is aligned with a tubular tool holder. The tool further includes a sliding element configured to slide a tool from the tool-changing magazine into the tool holder and from the tool holder back into the tool-changing magazine. The sliding element is movable in a longitudinal direction of the tool holder. In at least one embodiment, the sliding element is coupled with a gearbox system which includes at least one toothed gear. The rotational motion of the toothed gear is translated into linear movement of the sliding element.

Description:
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2011/067812, filed on Oct. 12, 2011, which claims the benefit of priority to Serial No. DE 10 2010 044 061.2, filed on Nov. 17, 2010 in Germany, the disclosures of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     The disclosure relates to a motor-powered machine tool, in particular a hand-held machine tool, in accordance with the description below. 
     A machine tool of this type is already known from DE 10 2006 059 688 A1 from the applicant. The known machine tool has a drum-like tool magazine, in which in each case one tool is arranged in a tool chamber. The tool magazine can be rotated in its longitudinal axis, with the result that a tool chamber can be arranged in alignment with a tubular sliding channel, via which a required tool can be slid into a receptacle of the machine tool or can be moved back into the tool chamber again from the tool receptacle. A manually actuable sliding element serves this purpose, which sliding element is of substantially pin-shape configuration and can be actuated by means of a handle which penetrates the housing in the housing upper side. On account of the relatively long displacement path, the handle which can be actuated by the operator requires a relatively long displacement path on the housing upper side. As a result, the housing also has a relatively large or elongate opening for the handle, which aids the entry of dirt or contaminants into the housing interior. Moreover, the configuration of the housing upper side is restricted and/or other operating elements have to be arranged at other locations of the housing. 
     SUMMARY 
     Proceeding from the prior art which is shown, the disclosure is based on the object of developing a motor-powered machine tool, in particular a hand-held machine tool, in accordance with the description below in such a way that it is configured to be as compact as possible at least in the region of the sliding device which penetrates the housing. This object is achieved in a motor-powered machine tool having the features described below. Here, the disclosure is based on the concept of coupling the sliding element to a gear-mechanism device which comprises at least one gearwheel, the rotational movement of which is converted into a linear movement of the sliding element. A configuration of this type makes the advantage possible that displacement paths which are as large as desired can be realized with a relatively low space requirement for the manually actuable operating element. In particular, it is made possible as a result to configure the manually actuable operating element in the form of a rotary knob or rotary disk which requires only a relatively small cutout in the housing, with the result that the outer configuration of the housing on the housing upper side can be configured more freely than in the prior art, satisfactory and simple sealing of the housing in the region of the operating element being made possible at the same time. 
     Advantageous developments of the motor-powered machine tool according to the disclosure are specified in the description below. All combinations of at least two of the features which are disclosed in the description below, the description and/or the figures fall under the scope of the disclosure. 
     One embodiment is preferred, in which the at least one gearwheel is coupled to a manually actuable adjusting element. Here, the adjusting element can be configured, as already explained, in particular, as a rotary switch or rotary knob, or else as a sliding switch. A configuration of this type of the adjusting element can be produced relatively inexpensively and requires a relatively low space requirement in comparison with a motor-actuable drive. 
     It is provided here, in particular, that the adjusting element penetrates an opening of the housing. This makes simple gripping of the adjusting element from the outside by the operator possible. 
     It is very particularly preferable that the adjusting element is arranged such that it is sealed with respect to the housing. As a result, the entry or the ingress of dirt, dust or the like into the housing interior is prevented, with the result that the machine tool operates particularly reliably over its entire service life. 
     In order to convert the rotary movement of the gearwheel into a linear movement of the sliding element, it is provided in one preferred structural refinement of the disclosure that the sliding element is configured at least in regions as a toothed rack. As a result, a mechanically relatively simple construction is made possible which can be produced inexpensively and operates reliably. 
     Furthermore, one embodiment is particularly preferred, in which a plurality of gearwheels are provided which produce a displacement transmission ratio of the adjusting element on the sliding element. In other words, this means that a relatively large displacement travel on the sliding element is produced, for example, with a relatively small rotational movement on the adjusting element. As a result, the handling is facilitated for the operator to the extent that, for example, it is not necessary to reach around the adjusting element, in order to produce a defined displacement travel. 
     Furthermore, it is particularly preferred if the sliding element is arranged so as to be in engagement by way of a toothing system on mutually opposite sides with in each case one gearwheel. As a result, particularly satisfactory or defined guidance of the sliding element is made possible. 
     The angularly correct feeding of the tool which is provided with an outer contour into the tool receptacle which is provided with a corresponding inner contour is critical when sliding tools into the tool receptacle. Jamming of the tool with respect to the tool receptacle can occur here, which makes the actuation more difficult, since the operation possibly has to be repeated until a corresponding angular position between the tool and the tool receptacle is reached. It is therefore proposed in one particularly preferred refinement of the disclosure that an inner contour is formed on the inner circumference of the tool receptacle and an outer contour is formed on the tool, which contours interact with one another and bring about a rotationally fixed arrangement of the tool at least in an axial end position of the tool in the tool receptacle, and that a region with at least one entry guide is formed on the inner circumference of the tool receptacle on the side which faces the sliding element, which entry guide, during sliding of the tool into the tool receptacle, brings about an angularly correct alignment of the tool with respect to the tool receptacle. 
     As an alternative, however, it is also conceivable that the tool receptacle has an inner contour and the tool has an outer contour, which contours interact with one another and bring about a rotationally fixed arrangement of the tool at least in an axial end position of the tool in the tool receptacle, and that the inner contour which is formed on the inner circumference of the tool receptacle has a plurality of longitudinal ribs with entry edges. 
     If longitudinal ribs are used, it can be provided structurally that the longitudinal ribs have a rounded or triangular cross section. Shapes of this type can be produced relatively simply and precisely and are therefore particularly suitable for use in the tool receptacle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, features and details of the disclosure result from the following description of preferred exemplary embodiments and using the drawing, in which: 
         FIG. 1  shows a simplified longitudinal section through a motor-powered machine tool according to the prior art, 
         FIG. 2  shows a simplified longitudinal section through a motor-powered machine tool according to the disclosure, 
         FIGS. 3 and 4  show parts of the machine tool according to  FIG. 2  in order to explain the functionality of the tool change magazine, in a simplified side view and longitudinal section, 
         FIG. 5  shows a first sliding mechanism according to the disclosure in a side view, 
         FIG. 6  shows a section in the plane VI-VI from  FIG. 5 , 
         FIG. 7  shows a second sliding mechanism according to the disclosure in a side view, 
         FIG. 8  shows a section in the plane VIII-VIII from  FIG. 7 , 
         FIG. 9  shows a third sliding mechanism according to the disclosure in a bottom view, 
         FIG. 10  shows the sliding mechanism according to  FIG. 9  in a side view, 
         FIG. 11  shows a tool receptacle in a longitudinal section, 
         FIG. 12  shows a section in the plane XII-XII from  FIG. 11 , 
         FIG. 13  shows a detail from  FIG. 11  in an enlarged illustration, 
         FIG. 14  shows a modified tool receptacle in a longitudinal section, 
         FIG. 15  shows a section in the plane XV-XV from  FIG. 14  in a first configuration variant, and 
         FIG. 16  shows a section in the plane XV-XV from  FIG. 14  in a configuration variant which is modified with respect to  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION 
     Identical components or components with the same function are provided with the same designations in the figures. 
       FIG. 1  shows a motor-powered machine tool  100  in the form of a hand-held machine tool according to the prior art, in a greatly simplified form. Here, the machine tool  100  is configured in the form of what is known as a “bit screwdriver” which is suitable for handling various tools  101  in the form of bit inserts. The tools  101  are arranged in chambers (not shown in  FIG. 1 ) of a turret-like tool magazine  102 , the tool magazine  102  being arranged in a mounted manner such that it can be rotated in a longitudinal axis  103 . Furthermore, the machine tool  100  has a tool receptacle  104  which has a tubular region  105 , into which the respective tool  101  to be used is pushed from the tool magazine  102 . In order to be exchanged for a new tool  101 , the tool receptacle  104  is rotated into congruence with an empty chamber of the tool magazine  102 . The tool receptacle  104  is coupled via a gear toothing system  106  to a drive motor  107  in order to drive the tool  101 , which drive motor  107  produces a corresponding rotational movement of the tool receptacle  104 , the tool  101  being arranged in a rotationally fixed manner in the tool receptacle  104  in the case of driving. 
     In the prior art, a tool  101  is pushed from the chamber of the tool magazine  102  into the tubular region  105  of the tool receptacle  104  by means of a sliding element  108  in the form of a slide  109 . Here, the slide  109  has a handle  110  which can be actuated manually by an operator and penetrates the housing  111  of the machine tool  100  in the region of an opening  112  of the housing  111 . That end of the slide  109  which faces the tool  101  is, for example, of magnetic configuration, in order to realize a magnetic attachment of the tool  101  to the slide  109 , which magnetic attachment is required, in particular, when the tool  101  is pulled back out of the tool receptacle  104  into the chamber of the tool magazine  102 . 
     Furthermore, the machine tool  100  has adjusting means (not shown) for rotating the tool magazine  102  in its longitudinal axis  103 , in order that that chamber of the tool magazine  102  which is equipped with the desired tool  101  can be rotated into alignment with the slide  109  or the tool receptacle  104 . With regard to further details of a machine tool  100  according to the prior art, moreover, reference is made to DE 10 2006 059 688 A1 from the applicant which to this extent is to be a constituent part of the present application. 
       FIG. 2  shows the fundamental construction of a machine tool  10  according to the disclosure which differs from the machine tool  100  according to the prior art according to  FIG. 1 , in particular, in the region of the sliding mechanism  11  for transferring a tool  101  out of the tool magazine  12  into the tool receptacle  14 . 
     The sliding mechanism  11  has a sliding element  15  in the form of a slide  16 , which sliding element  15  is configured at least in regions in the form of a toothed rack with a toothing system  17 . Here, the toothing system  17  interacts with at least one, but in particular with at least two, gearwheels  18 ,  19  which can be seen in  FIG. 2  and form a gear mechanism  20 . One gearwheel  18  meshes with the toothing system  17  of the slide  16 , whereas the other gearwheel  19 , as can be seen best using a combination of  FIGS. 5 and 6 , interacts with a toothing system  21  of a manually actuable rotary switch  22 . The two gearwheels  18 ,  19  have a different diameter and are mounted in a rotationally fixed manner with respect to one another in a common rotational axis  23 . An axle which cannot be seen in  FIG. 6  and is mounted into two crossmembers  25 ,  26  which are arranged on the housing  24  of the machine tool  10  serves to mount the two gearwheels  18 ,  19 . 
     As can be seen, in particular, from a combination of  FIGS. 2 and 6 , the rotary switch  22  has a rotary knob  27  which can be grasped by the fingers of the operator and which is adjoined by a circular plate  28  on the side which faces the gearwheel  19 . The plate  28  closes an opening  29  of the housing  24 , the region between the plate  28  and the opening  29  being of sealed configuration on the housing  24 . 
     The method of operation of the sliding mechanism  11 , as can be seen, in particular, using  FIGS. 3 and 4 , is such that, in the case of a rotation of the rotary switch  22  in the clockwise or in the counterclockwise direction, the rotational movement of the rotary switch  22  or the rotation of the gearwheels  18 ,  19  which are arranged in a rotationally fixed manner with respect to one another is converted into a linear movement of the slide  16  in the direction of the double arrow  31 . As a result of a corresponding variation of the diameter of the two gearwheels  18 ,  19  or their number of teeth, a desired displacement transmission ratio is possible in such a way that a relatively small rotation of the rotary switch  22  results in a relatively large displacement travel of the slide  16 . 
       FIGS. 7 and 8  show a modified sliding mechanism  11   a . Here, the rotary switch  22  is replaced by a sliding switch  32  which is likewise preferably sealed with respect to the housing  24  and to the underside of which the gearwheel  19   a  is fastened together with the gearwheel  18   a  in an axle  33 . The axle  33  is guided on the housing  24  in a linear guide  34 , the gearwheel  19   a  interacting with the toothing system  17   a  of the slide  16   a  and the gearwheel  18   a  being supported on a toothing system  35 , arranged in a stationary manner, of the housing  24 . The method of operation of the sliding mechanism  11   a  is such that a linear movement of the sliding switch  32  in the direction of the double arrow  36  is converted into a rotation of the gearwheels  18   a ,  19   a , which rotation in return moves the slide  16  in the direction of the double arrow  36 . 
     In comparison with the sliding mechanism  11 , the sliding mechanism  11   a  has the advantage that a greater transmission ratio of the gearwheels  18   a ,  19   a  can be achieved than with the gearwheels  18 ,  19 , with the result that the diameter of the gearwheels  18   a ,  19   a  can be selected to be smaller than that of the gearwheels  18 ,  19 . 
       FIGS. 9 and 10  show a third sliding mechanism  11   b  which is based substantially on the sliding mechanism  11   a  of  FIGS. 7 and 8 . The sliding mechanism  11   b  has a sliding switch  32   b  which acts on the toothing system  17   b  of the slide  16   b  via two gearwheels  18   b  which are arranged on both sides of the slide  16   b . Furthermore, two guides  39 ,  40  which are fixed to the housing are provided with toothing systems  42 ,  43  which interact with the gearwheels  19   b . The sliding mechanism  11   b  is distinguished by relatively low friction and particularly satisfactory guidance of the slide  16   b.    
       FIGS. 11 to 13  show that part region of the tool receptacle  14  which faces the tool magazine  12  in more detail. Here, in particular on the side  44  which faces the tool magazine  12 , a region  46  is seen on the inner circumference  45  of the tool receptacle  14 , which region  46  acts as positioning region and makes angularly correct positioning of the tool  101  in the tool receptacle  14  possible during sliding of the tool  101  from the tool magazine  12  into the tool receptacle  14 . Here, the region  46  has a plurality of entry guides  47  which are of wedge-like configuration and the tips of which protrude toward the side  44 . During sliding of the tool  101  in the direction of the arrow  48 , the tool  101  which has, in particular, a hexagonal cross section passes with its outer contour  50  (see  FIGS. 3, 4 ) into an operative connection with the entry guides  47  and, during its linear movement or during sliding, is aligned with the inner contour  49  of the region  46  in such a way that, during sliding, jamming of the outer contour  50  of the tool  101  with the inner contour  49  of the region  46  of the tool receptacle  14  is avoided. 
       FIGS. 14 to 16  show a modified tool receptacle  54 . The tool receptacle  54  is distinguished by a plurality of longitudinal ribs  56  which are arranged parallel to the longitudinal axis  55  of the tool receptacle  54  at uniform angular intervals on the inner circumference of the tool receptacle  54 . As can be seen, in particular, using  FIG. 15 , the longitudinal ribs  56  have a triangular shape with straight side faces  57 ,  58  here. 
     In a modification, however, it can also be possible in accordance with  FIG. 16  that the longitudinal ribs  56  have a curved contour with a radius R in cross section. It is seen, furthermore, that the longitudinal ribs  56  have entry edges  60  at least on the side  59  which faces the tool magazine  12 , which entry edges  16  make an angularly correct alignment of the tool  101  or its outer contour  50  with the longitudinal ribs  56  possible. 
     The above-described machine tool  10  according to the disclosure can be altered or modified in a wide variety of ways, without deviating from the concept of the disclosure. It is thus possible, for example, to provide a motor-powered sliding mechanism instead of a manual operation of the sliding mechanism  11 ,  11   a ,  11   b . It is also conceivable to dispense with the specially adapted tool receptacle  14 ,  54  for the angularly correct alignment of the tool  101 .