Abstract:
A clutch having a pressure plate ( 1 ) and a counter plate ( 16 ) is provided, with the pressure plate being displaceable by a clutch actuating mechanism such that a clutch disk can be clamped between the pressure plate and counter plate. The pressure plate is a multi-piece pressure plate having a central body ( 1 ) which includes a friction surface and on which at least one connecting element ( 5 ) is located, which protrudes beyond the friction surface and is connected to the clutch actuating mechanism for burst optimization and cost savings purposes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of PCT/DE2010/000393, filed Apr. 1, 2010, which claims the benefit of German Patent Application No. 10 2009 019 074.0, filed Apr. 27, 2009, both of which are incorporated herein by reference as if fully set forth. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to a clutch with a pressure plate and counter plate, wherein the pressure plate can be displaced by a clutch actuation mechanism, so that a clutch disk can be clamped between the pressure plate and counter plate. The present invention relates, in addition, to a double clutch with a drive-side sub-clutch K 1  and a transmission-side sub-clutch K 2 . 
         [0003]    According to prior art, the pressure plate of a clutch is cast from one piece and has a central ring body and links that extend outward in the radial direction and by which the pressure plate is connected to the actuation system. Thus, for example, the pressure plate of the drive-side sub-clutch K 1  of a double clutch has links that are connected (e.g., riveted) to a tie rod that can be displaced in the axial direction by a plate spring/lever spring. 
         [0004]    Therefore, because the links reach out in the radial direction for the riveting of the tie rod by the friction face, during operation, flexural or tensile stresses occur in the base area of the links that lead to the result that the pressure plate could burst. The occurring flexural or tensile stresses are here dependent on rotational speed, wherein, due to manufacturing tolerances and influences in operation, the bursting rotational speed of the pressure plate could vary significantly. 
         [0005]    In addition, the geometry of the pressure plate K 1  is difficult to manufacture with the links in terms of casting. Pores and cavities that lead to high defect rates appear especially in the transition region of the links into the ring body of the pressure plate due to the differences in the diameters between the links and central ring body. 
       SUMMARY 
       [0006]    Therefore, one objective of the present invention is to provide a pressure plate with higher bursting strength. 
         [0007]    This objective is met according to the invention by a clutch with a pressure plate and counter plate, wherein the pressure plate can be displaced by a clutch actuation mechanism, so that a clutch disk can be clamped between the pressure plate and counter plate, wherein the pressure plate has a multiple-part construction and has a central body that comprises a friction face and on which at least one connection element is arranged (in particular: affixed) that projects over the friction face and connects to the clutch actuation mechanism. 
         [0008]    The central body is advantageously rotationally symmetric, in particular, constructed as a ring body and could be produced using casting technology. 
         [0009]    Furthermore, several connection elements are advantageously provided. 
         [0010]    According to one especially preferred embodiment, the connection element/elements is/are constructed as angle/angles that is/are affixed, in particular, riveted or screwed, on the central body or that is/are assembled with the central body with a positive-fit and/or material-fit connection. Here, the angle/angles can contact a side of the pressure plate facing away from the clutch disk. Furthermore, the angle/angles can be made from sheet metal. In addition, the angle/angles can have one or more reinforcing sections. 
         [0011]    According to one especially preferred embodiment, several connection elements are provided that are constructed as angles and are arranged distributed along the periphery (for example, in an installation situation of a double clutch, in a 50°/70° distribution) on a central body with a rotationally symmetric construction. 
         [0012]    With this multiple-part construction of the pressure plate including the central body and at least one connection element assembled with this central body for the clutch actuation mechanism, the central body can be produced as an economical cast-iron body, wherein the at least one/several connection element/elements possibly made from different materials can then be affixed on this central cast-iron body. Due to this configuration, the bursting rotational speed of the pressure plate K 1  built according to the invention is significantly increased and an economical, simple, and low-defect casting compound is produced. 
         [0013]    Double clutches are often constructed with a wear stop for the individual sub-clutches K 1  and K 2 . The function of the wear stop is to no longer allow the pressure force at the end of the clutch service life to flow via the clutch disk, but instead to form a mechanical stop, wherein slippage of the clutch disk is achieved. With the present multiple-part pressure plate consisting of the central body and at least one connection element, a wear stop can be realized economically just for the drive-side sub-clutch K 1 . Here, at an axially oriented area of the connection element, at least one projection is arranged as a wear stop that contacts the counter plate of the clutch in the maximum wear state. 
         [0014]    The clutch can further have a tie rod that has an attachment area that is connected to the connection element and is connected to the clutch actuation mechanism, in particular, with a plate spring of the clutch actuation mechanism. 
         [0015]    The present invention further provides a double clutch with a drive-side sub-clutch K 1  and a transmission-side sub-clutch K 2 , wherein the drive-side sub-clutch comprises a multiple-part pressure plate with the features according to at least one of the preceding embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The present invention will be explained in detail below with reference to preferred embodiments in connection with the associated figures. 
           [0017]    Shown in these figures are: 
           [0018]      FIG. 1  is a top view of a pressure plate of a drive-side sub-clutch K 1  of a double clutch from the viewing direction of the drive, 
           [0019]      FIG. 2  is a view of an angle that is used as a connection element between the pressure plate of the sub-clutch K 1  and the tie rod of the sub-clutch K 1 , 
           [0020]      FIG. 3  is a top view of a pressure plate of the drive-side sub-clutch from the viewing direction of the drive with ring body according to  FIG. 1  and several angles according to  FIG. 2  arranged distributed along the periphery of the ring body as a function of the respective installation situation, and 
           [0021]      FIG. 4  is a perspective view of the double clutch in the area of the connection between the tie rod and pressure plate of sub-clutch K 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]      FIG. 1  shows the ring body  1  of the multiple-part pressure plate. 
         [0023]    As can be inferred from  FIG. 1 , this ring body  1  has no links, wherein the casting geometry is very simple and the possibility of a defect is greatly reduced accordingly. In addition, additional freedoms are gained for attaching the casting spout or the possibility for subsequently grinding or turning the outer diameter of the ring body  1 , wherein a very small unbalanced mass can be achieved. 
         [0024]    After production of the ring body as a cast-iron body, this is subsequently turned or ground in the area of the later friction face (not visible in  FIG. 1 ). In addition, the contact faces  2  for the angles  5  used as connection elements and shown in  FIG. 2  are milled in the ring body  1  or formed in this body in a different way. These contact faces  2  are arranged on the side of the cast-iron body  1  opposite the friction face (i.e., “the back side”). 
         [0025]    In the area of these contact faces  2 , according to the present embodiment, at least one rivet hole  3  is formed, so that the angles  5  could be connected to the ring body  1  to form a multiple-part pressure plate. 
         [0026]    As can be inferred from  FIG. 1 , a recess  4  is also formed on the contact face  2 , wherein this recess is used as a holder for a reinforcing area  8  that is formed in the angles  5  and will be described in more detail below. 
         [0027]    The number and construction of the rivet holes  3  and also the number and shape of the recesses  4 , as well as the number and shape of the reinforcing areas  8  can be adapted freely to the respective use case. The type and means of connection between the angles  5  and ring body  1  itself can also be adapted freely to the respective conditions. 
         [0028]    In addition, the ring body  1  can be indeed produced preferably as a cast-iron body, but the use of other materials than cast iron is alternatively also possible. 
         [0029]    The angles  5  shown in  FIG. 2  are assembled to the contact faces  2  of the ring body  1 . For this purpose, the angles  5  comprise a first area  5 A that is arranged in the radial direction and includes a contact face  6  that contacts the contact face  2 . This first area  5   a  oriented in the radial direction also comprises a rivet hole  11  through which the connection rivet extends. 
         [0030]    The angle  5  further comprises an area  5 B that is oriented in the axial direction and on which wear stops  13  and  14  are arranged that will be described in more detail below and are also called “wings.” 
         [0031]    For reinforcing the transition area of the first radial area  5 A and axial area  5 B, the reinforcing area  8  is provided that engages in the recess  4  of the ring body  1  in the mounted state. 
         [0032]    The angle  5  also comprises a second area  5 C that is oriented in the radial direction and comprises the contact face  7 , wherein the contact faces  7  are provided for contact on corresponding contact faces of a tie rod of the drive-side sub-clutch K 1 . 
         [0033]    Furthermore, in each contact face  7  of the second area  5 C oriented in the radial direction, there is at least one rivet hole  12  to connect the angle  5  to the tie rod. 
         [0034]    The transition area of the axial area  5 B and second radial area  5 C is reinforced by the reinforcing areas  9  and  10 . 
         [0035]    These angles  5  affixed to the ring body  1  of the built pressure plate are produced from sheet metal according to the present embodiment and are riveted on the ring body. These angles produced from sheet metal have significantly tougher material properties than the cast-iron material (in particular, gray cast iron) of the ring body  1 . Due to the better toughness, bursting of the angles can be prevented. In addition, the angles are very stiff in the axial direction due to the geometry shown in  FIG. 2 . 
         [0036]    In  FIG. 3 , the built pressure plate is shown as an assembly consisting of ring body  1  and a total of six angles  5  as one possible embodiment. A distribution of the angles  5  along the periphery of the ring body  1  and a number of angles  5  can be adapted freely to the respective use case. 
         [0037]    In  FIG. 4 , a perspective diagram of a partial area of the double clutch is shown in the area of the connection between the multiple-part pressure plate (i.e., the built pressure plate) with ring body  1  and angles  5  on one side, as well as tie rod  15  and central counter plate  16 , as well as the leaf springs  17  between the central counter plate and multiple-part pressure plate. 
         [0038]    As mentioned in connection with  FIG. 2 , the angles  5  also comprise a mechanical wear stop for the drive-side sub-clutch K 1  via the wings  13  and  14  that can be inferred, in particular, from  FIG. 2  in the axial area  5 B of the angles  5 . These wings  13 ,  14  run in the maximum wear state against the friction face of the central counter plate  16 , as can be inferred from  FIG. 4 . Just from this figure it is clear that these wings  13 ,  14  can run against the links  18  of the central counter plate. 
         [0039]    Due to the presently very short tolerance chain between the friction face of the central counter plate  16 , the clutch disk, the built pressure plate of the sub-clutch K 1 , and the wings  13 ,  14 , a very precise wear stop can be realized. Because the links  18  of the central counter plate  16  take over the function of the wear stop in this case, a cost-intensive and tolerance-loaded milling process can be eliminated. 
         [0040]    Advantages of the present pressure plate with multiple-part construction are also the ring body of the pressure plate K 1  that can be produced using casting technology in a very simple and economical way, as well as the tough and axially stiff attachment of the ring body to the tie rod by the angles and also the wear stop that can be produced very economically and acts with precision. 
         [0041]    Accordingly, this arrangement produces an optimization of the bursting rotational speed of the clutch, an economical and precise wear stop for the sub-clutch K 1 , and a simple geometry of the pressure plate K 1  for minimizing rejects. 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
         
           
               1  Ring body 
               2  Contact face 
               3  Drilled rivet hole 
               4  Recess 
               5  Angle 
               5 A Radial arranged area 
               5 B Axial area 
               5 C Axial area 
               6  Contact face 
               7  Contact face 
               8  Reinforcement 
               9  Reinforcement 
               10  Reinforcement 
               11  Drilled rivet hole 
               12  Drilled rivet hole 
               13  Wear stop 
               14  Wear stop