Patent Abstract:
A method for introducing recesses in workpiece surfaces to be machined, with the aid of at least one tool. The invention is characterized in that two workpiece surfaces that face each other are simultaneously machined using the tool in order to introduce recesses into said workpiece surfaces.

Full Description:
BACKGROUND 
     The invention relates to a method and a system for introducing recesses in work piece surfaces to be machined, with the aid of at least one tool. 
     A method is known from the German patent publication DE 10 2010 025 403 A1 for the production of a friction coating for a friction clutch with a coating material compressed on a carrier sheet. 
     SUMMARY 
     The objective of the invention is to simplify the introduction of recesses in work piece surfaces to be machined with the aid of at least one tool. 
     The objective is attained in a method for introducing recesses in work piece surfaces to be machined with the aid of at least one tool such that two work piece surfaces facing each other are simultaneously processed with the tool, in order to introduce recesses in work piece surfaces. These recesses represent, grooves, for example. It is particularly advantageous for these grooves or longitudinal grooves to extend parallel and to intersect other, parallel extending grooves or longitudinal grooves such that a waffle shape develops. The work piece surfaces represent preferably surfaces and/or friction areas of friction coatings, particularly wet-running lamellae. The method according to the invention may also be used in other fields, such as the semiconductor industry, particularly for chip separation. According to an essential aspect of the invention the two work piece surfaces facing each other, are processed simultaneously, particularly machined. The machining comprises for example a cutting and/or polishing. 
     A preferred exemplary embodiment of the invention is characterized in that the two tool surfaces of the tool, facing away from each other, simultaneously processing two work piece surfaces facing each other. This provides the advantage that the work piece surfaces facing each other can simultaneously be processed with a single tool, particularly comprising a cutting and/or polishing set. Here, the tool contacts the work piece at two different points of its periphery, arranged at an angle of 180 degrees in reference to each other. 
     The above-stated objective is attained in a device for inserting recesses in work piece surfaces to be machined with the help of at least one tool, particularly according to an above-described method, alternatively or additionally such that the device comprises two changeable supports with at least two work piece receivers, facing each other, and a machine bed, which extends in a x-y plane through and between the changeable supports. The changeable supports serve to receive the work pieces and for this purpose they are provided with clamping plates, for example. By the combination of work piece receivers facing each other with the machine bed the tool can be easily moved between and through the changeable supports for the simultaneous processing of two work piece surfaces facing away from each other. 
     A preferred exemplary embodiment of the system is implemented such that the changeable supports have two work piece receivers, facing away from each other. This way a loading and unloading of the system is implemented in a simple fashion. The work piece receivers can be loaded or unloaded, particularly advantageously during the processing of the work pieces at the work piece receivers facing each other. 
     Another preferred exemplary embodiment of the system is attained such that the work piece receivers are rotational by c1 and c2-axes of rotation, which are arranged perpendicular in reference to an x-direction and parallel in reference to in a y-direction. The c1 and the c2-axes of rotation may define a common axis of rotation. By rotating the work piece receivers about a defined angle of rotation a plurality of patterns of longitudinal grooves can be generated in the work piece surfaces. 
     Another preferred exemplary embodiment of the system is implemented such that the tool can be moved in a translational fashion in a positive and negative x-direction between the changeable supports. In order to implement the translational movement between and through the changeable supports, the tool comprises a spindle sled for example, which can be moved back and forth in the x-direction. The x-direction represents the primary feeding direction of the tool. To this regards, the processing of the work piece surfaces facing each other can be called a planar-circumferential lateral-processing method. This preferably represents a planar-circumferential lateral cutting process. 
     Another preferred exemplary embodiment of the system is attained such that the tool can be moved back and forth in a positive and negative y1-direction in a translational fashion between the changeable supports. In order to illustrate the translational movement between the changeable supports the tool preferably comprises a second spindle sled. Using the second spindle sled the tool can be positioned in a simple fashion between the changeable supports. 
     Another preferred exemplary embodiment of the system is implemented such that the tool is rotational about an axis of rotation, which is arranged perpendicular in reference to the x-y plane. The tool is preferably embodied as a spindle unit. The spindle unit can either comprise a compact spindle motor or a spindle with a spindle drive engine and a transmission. The spindle advantageously drives a tool via a spindle, which comprises several cutting or polishing disks. The cutting or polishing disks are advantageously designed on a spindle shaft of the spindle unit with spacers arranged therebetween. By the geometry and the arrangement of the tool disks, particularly the cutting or polishing disks, the dimensions and the number of the recesses to be generated, particularly the grooves, can be varied. 
     Another preferred exemplary embodiment of the system is implemented such that the changeable supports are rotational about c3 and c4-axes of rotation, which are arranged perpendicular in reference to the x-y plane. This way, the tool receivers can easily be rotated between a processing position and a loading and/or unloading position. In the processing position respectively two tool receivers are facing each other. In the loading and/or unloading position respectively two tool receivers are pointing away from each other. It is particularly advantageous for two tool receivers to respectively face each other simultaneously and two tool receivers to point away from each other. 
     Another preferred exemplary embodiment of the system is implemented such that the changeable supports are mobile towards and away from each other in the y2 and y3-directions. By the motions of the changeable supports towards and away from each other the depth of the recesses, particularly the grooves, can be adjusted in a simple fashion. 
     According to other exemplary embodiments the tool system and/or the changeable supports can be additionally mobile perpendicular in reference to the x-y plane. This way, the system according to the invention is provided with even more flexibility. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional advantages, features, and details of the invention are discernible from the following description, in which various exemplary embodiments are described in detail with reference to the drawing. Shown are: 
         FIG. 1  a simplified illustration of a system according to the invention, and 
         FIG. 2  a simplified illustration of a waffle pattern, which can be inserted in work piece surfaces using the system shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows in a simplified fashion a system  1  for inserting recesses in work piece surfaces to be machined. The system  1  comprises a machine bed  5 , which essentially has the form of a cube extending in the x-y plane. A tool  10  is arranged in a mobile fashion on the machine bed  5 . 
     The tool  10  comprises a spindle unit  12  and a tool set  14 . The tool set  14  comprises several tool disks, particularly cutting or polishing disks, which are located on a spindle shaft of the spindle unit  12  with spacers located therebetween. 
     The tool  10  can move back and forth in a translational fashion in an x-direction with the help of a first spindle sled  15 , as indicated by a double-arrow  16 . With the aid of a second spindle sled  18  the tool  10  can be moved back and forth in a y1-direction, as indicated by a double-arrow  19 . Furthermore, the tool  10  is rotational about an axis of rotation  20 , as indicated by an arrow  21 . The axis of rotation  20  is arranged perpendicular in reference to the x-y plane. 
     The reference character  25  marks either another tool or a second position of the tool  10 . The tool  10  can be moved on the machine bed  5  along the x-direction  16  between and through two changeable supports  30 ,  50 . Here, the x-direction represents the primary feed direction of the tool  10  and/or  25 . 
     The changeable supports  30 ,  50 , as indicated by the double-arrows  31 ,  51 , can be moved towards each other or away from each other in a translational fashion along a y2-axis and/or a y3-axis or a y2-direction and/or a y3-direction. The motion of the changeable supports  30 ,  50  in the direction of the double-arrows  31 ,  51  is illustrated by the tool sled  35 ,  55 , by which the changeable supports  30 ,  50  are guided on a machine bed  5 . 
     It is indicated by other arrows  32 ,  52  that the changeable supports  30 ,  50  are rotational about axes of rotation  33 ,  53 . The axes of rotation  33  and  53  are arranged parallel in reference to each other and perpendicular in reference to the x-y plane. The axes of rotation  33 ,  53  are also called c4 and/or c3-axes. 
     The changeable support  30  comprises a tool receiver  36  with a total of four work pieces  37 . A second work piece receiver  38  of the changeable support  30  also comprises four work pieces. It is indicated by an arrow  39  that the two work piece receivers  36  and  38  are rotational about an axis of rotation  40 , which is also called c1-axis. The axis of rotation or the c1-axis is arranged parallel in reference to the y1-direction  19 . 
     The changeable support  50  comprises a work piece receiver  56  with a total of four work pieces  57 . A second tool receiver  58  of the changeable support  50  also comprises four work pieces. An arrow  59  indicates that the two work piece receivers  56  and  58  are rotational about an axis of rotation  60 , which is also called c2-axis. Similarly, the axes of rotation  33  and  53  are called c4 and c3-axes. The axis of rotation or the c2-axis  60  preferably coincide with the axis of rotation or the c1-axis  40 . 
     The tool receivers  38  and  56  extend parallel in reference to each other and face each other such that they can be processed simultaneously with the tool  10  and/or the tool  25 . The work piece receivers  36  and  58  are also arranged parallel, but pointing away from each other. This way, the work piece receivers  36  and  58  preferably embodied as clamping plates, can easily be loaded and/or unloaded with work pieces, while the work pieces of the work piece receivers  38  and  56  facing each other are simultaneously processed. 
       FIG. 2  shows a waffle pattern  63 , which can be produced in a simple fashion with the system  1  shown in  FIG. 1 . The waffle pattern  63  comprises several oblong recesses  64  to  67  intersecting each other, which are also called grooves, longitudinal grooves, or riffles. 
     Such waffle patterns are used for example as wet-running lamellae of motor vehicle clutches, in order to allow a cooling oil flow through the friction coatings. The cooling oil flow improves the heat dissipation during the operation of the friction coatings. Such waffle patterns are also used in the semiconductor industry in order to produce individual components and/or circuits by cutting a semiconductor disk. 
     The system  1  shown in  FIG. 1  serves in a particularly advantageous fashion for the industrial production of wet-running coatings for the use of wet-running double-clutches, hydraulic brakes, as well as clutches in the two-wheeler field. The system  1  preferably produces waffle patterns as shown in  FIG. 2 , in paper friction pads. 
     The system  1  according to the invention allows in a particularly advantageous fashion the processing of eight work pieces simultaneously using a single tool. Furthermore, the changeable supports  30 ,  50  can be loaded and unloaded during the processing of the eight work pieces by said tool  10 . This way the clock time during the production of the waffle patterns can be considerably reduced. 
     The tool receivers  36 ,  38 , and  56 ,  58  are embodied as clamping plates, for example. The respectively four work pieces can be clamped on the clamping plates magnetically or pneumatically. 
     The work piece receivers  36 ,  38 , and  56 ,  58  are rotational about the axes of rotation  40 ,  60 , independent from each other. By the rotation of the tool receivers and/or the clamping plates between two certain angular positions intersecting grooves can be inserted in the work pieces with an arbitrary angle of intersection. 
     When processing new work pieces, the tool  10  initially moves in the positive x-direction, thus in  FIG. 1  towards the right, simultaneously cutting and/or polishing a first group of parallel grooves into all eight work pieces which are clamped on the clamping plates  38 ,  58  facing each other. After a complete travel of the tool  10 , the clamping plates and/or the work piece receivers  38 ,  56  with the work pieces are rotated by a certain angle about the axes of rotation  40 ,  60 . During the return travel of the tool in the negative x-direction, thus in  FIG. 1  from the right towards the left, the waffle patterns are simultaneously finished in all eight work pieces. 
     Parallel to the polishing or cutting, respectively eight new work pieces can be clamped on the work piece receivers  36 ,  58  pointing away from each other. This way, the time for changing the work pieces can be partially or entirely eliminated. After the tool  10  has completed its return travel, the two exchange columns  30 ,  50  are rotated by 180 degrees about their axes of rotation  33 ,  53 . This way, the finished work pieces are brought into their unloading position and the newly clamped work pieces are brought into their processing position. 
     By using two different tools  10  and  25 , in a simple fashion different distribution patterns can be generated in two directions. The waffle pattern illustrated in  FIG. 2  shows horizontal longitudinal grooves  64 ,  65 , distanced from each other to a slightly wider extent than the vertical longitudinal grooves  66 ,  67 . Accordingly, this waffle pattern cannot be generated with a single tool device  10 . The horizontal longitudinal grooves  64 ,  65  are generated with the tool  10 , for example. The vertical longitudinal grooves  66 ,  67  are generated with the tool  25 , for example. 
     LIST OF REFERENCE CHARACTERS 
     
         
           1  system 
           5  machine bed 
           10  tool 
           12  spindle unit 
           14  tool set 
           15  first spindle sled 
           16  double arrow 
           18  second spindle sled 
           19  double arrow 
           20  axis of rotation 
           21  arrow 
           25  tool 
           30  changeable support 
           31  double arrow 
           32  arrow 
           33  axis of rotation 
           35  work piece sled 
           36  work piece receiver 
           37  work pieces 
           38  work piece receiver 
           39  arrow 
           40  axis of rotation 
           50  changeable support 
           51  double arrow 
           52  arrow 
           53  axis of rotation 
           55  work piece sled 
           56  work piece receiver 
           57  work pieces 
           58  work piece receiver 
           59  arrow 
           60  axis of rotation 
           63  waffle pattern 
           64  recesses 
           65  recesses 
           66  recesses 
           67  recesses

Technology Classification (CPC): 8