Abstract:
A shift device in a manual transmission of a motor vehicle having a central selector shaft ( 6 ) with two rocker arms ( 7, 8 ) to which a spindle ( 9 ) is supported. The spindle ( 9 ) supports a roller ( 10 ), which communicates with a pivotally mounted, spring-loaded contour element ( 2 ). The contour element ( 2 ) has a gate guide which extends in a circular arc (k) concentric with the selector shaft ( 6 ). The rocker arms ( 7, 8 ) have guide pins ( 19 ) which extend parallel to the selector shaft ( 6 ) on a radius (R) of the circular arc (k). The guide pins ( 19 ) are moveable through axially directed movement of the selector shaft ( 6 ) to engage the gate guide.

Description:
[0001]    This application is a national stage completion of PCT/EP2005/012712 filed Nov. 29, 2005 which claims priority from German Application Serial No. 10 2004 060 056.2 filed Dec. 14, 2004. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention pertains to a shift device with a central selector shaft in a manual transmission of a motor vehicle. 
       BACKGROUND OF THE INVENTION 
       [0003]    Drivers operate manual transmissions of motor vehicles by means of a shift lever, which from its resting position is moved in a so-called cross track and in several shift tracks (perpendicular to the cross track). The shifting procedure therefore consists, on the one hand, of a transverse movement of the shift lever, the selection and the shifting movements are perpendicular to each other. With the selection movement, a gear change sleeve is selected in the transmission, and with the shift movement, the respective gear is positioned in the power flow. In order to assist the driver in his shift movement and to provide him with a sense of the current shift lever position, selection- or shift forces are generated within the transmission, which counteract the driver&#39;s shift movements to a greater or lesser degree. 
         [0004]    According to DE 102 29 320 A1, upon which the invention is based, a shift device for the generation of a power selection process by a contour element has become known. The contour element is rotatable inside a gearbox, which is in mesh with a roller, which is fastened to a central selector shaft by rocker arms. During the rotation of the selector shaft, which corresponds to the selection movement, a selection force process is thus generated, which can be influenced by the contour of the contour element. 
         [0005]    According to DE 100 16 364 A1 a selection and shift module for a manual transmission has become known, in which due to the interaction of various springs, a coil spring and a leg spring, various selection forces are generated. The driver is thus assisted in his shift movement and has a sense of the shift track in which the shift lever is positioned, especially when selecting the reverse gear. 
         [0006]    According to the applicant&#39;s DE 40 20 160 A1 another shift device with a central selector shaft with a selector rocker has become known, through which selector forces in interaction with spring elements are generated, whereby through the selector rocker, during a selection move, various compression springs and a leg spring are adjusted. 
         [0007]    The above state of the art demonstrates that for the generation of selection force, special devices are always provided for manual transmissions. Additionally, shift devices may also have gate guides for selector shafts, which present the typical H-pattern for manual transmissions. 
       SUMMARY OF THE INVENTION 
       [0008]    It is the purpose of the present invention to improve a shift device of the previously mentioned type with respect to its function and at the same time reducing the number of components as well as the production costs for the entire transmission. 
         [0009]    According to the invention, it is intended that the contour element, for the generation of a power selection process, also assume the function of a gate guide during the selection and shift movement. For this, guide pins are additionally provided on the rocker arms, which interact with the gate guide that is positioned in the contour element and thus engage in positions relative to the individual shift tracks. This provides the advantage that the contour element in connection with the rocker arms at the central selector shaft in addition to the selection force generation also creates a gate guide, for which, according to the prior art, a separate device is required, which is connected to additional components. The invention-related combination of both functions results with regard to the complete transmission in a building space improvement, a lower number of components and lower production costs. 
         [0010]    According to a beneficial arrangement of the invention, the gate-type guide is formed by recesses assigned to the shift tracks, into which the guide pins engage and are thus fixed for the respective shift track. It is preferred that between the recesses angular faces are positioned, which perform a track deflection function. Thus achieving the benefit that the guide pins in the selection movement are always guided into a recess. The shift lever&#39;s classic H-pattern can therewith be reproduced with the gate guide of the invention. The guide pins are beveled and conically shaped at their end surfaces in order to improve the deflection function. 
         [0011]    In another beneficial arrangement of the invention, the contour element is designed as a stamped and embossed component, i.e. the outer contours and the recesses are stamped from a tin card while the beveled edges between the recesses are shaped, which can be done in one operation. With this, the advantage of lower production costs is achieved. 
         [0012]    According to a beneficial improvement of the invention, the gate-type guide is configured as a continuous slotted contour, wherein circular extensions form the locking positions for the respective shift tracks, and between the extensions restrictions for the slotted contour are provided. This gate-type guide configuration has the benefit that the entire contour element can be produced as a complete stamped component. The restrictions formed as two-dimensional contours thus assume the track deflection function. 
         [0013]    In another beneficial arrangement of the invention, stops for the selection as well as for the shift movement are provided at the contour element and/or at the rocker arms. This results in additional benefits with respect to building space as well as the number of components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Exemplary embodiments of the invention are illustrated in the diagrams and will be further clarified below. The diagrams show: 
           [0015]      FIG. 1  a first exemplary embodiment of a shift device with contour element according to the invention; 
           [0016]      FIG. 2  a cross-section along line II-II; 
           [0017]      FIG. 3  a plan view of the shift device with a partial cross-section along line III-III; 
           [0018]      FIG. 4  a second exemplary embodiment of a shift device with a modified gate guide and 
           [0019]      FIG. 5  a plan view of the shift device as well as a partial cross-section along line V-V. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]      FIG. 1  shows a detail of a shift device  1  with a contour element  2 , which is pivotable around a case-fixed trunnion  3 , yet is positioned axially fixed in a gear case  4 , and with its end, which is opposite from the trunnion  3 , is supported against the case,  4  via a spring element  5 . On a central selector shaft  6  two rocker arms  7 ,  8  (see also  FIG. 3 ) are affixed, between which, parallel to the central selector shaft  6 , a spindle  9  with a rotatable roller  10  is positioned. The contour element  2  has a contour  11 , which is in contact with the roller  10  and is configured according to a selected power selection process, as is further described in the type-defining publication, the applicant&#39;s DE 102 29 320 A1. The contour  11  is limited on both sides by protrusions  11   a  and  11   b , which during the selection movement function as stops. One rotation of the selector shaft  6  around its longitudinal axis thus corresponds to the selection movement, illustrated by a double arrow W. During the selection movement—as previously mentioned—a shift lever (not illustrated) is moved in a cross track (not illustrated) for selection of a shift track. The described shift device  1  is part of a manual transmission for motor vehicles, not shown here, and thus is known. 
         [0021]    According to the invention, oblong formed recesses  12 ,  13 ,  14  and  15 , which are positioned intermittently to each other on an approximately circular arc k around the axis of the selector shaft  6 , as well as the not illustrated shift tracks, are positioned in the contour element  2 . Beveled areas  16 ,  17  and  18 , so-called diagonal shift bevels, with track-deflection function, are positioned between the recesses  12 ,  13 ,  14  and  15 . 
         [0022]      FIG. 2  shows a partial cross-section along section line II-II through the contour element  2  in the area of the recess  13 . On both sides of the recess  13  in the direction of selection and on both sides of the contour element  2 , beveled areas  16 ,  17  are positioned, which are preferably embossed into the contour element  2 . The contour element  2  can thus be produced as a stamped and embossed component. 
         [0023]      FIG. 3  shows a plan view of the selector shaft  6  with both rocker arms  7 ,  8  as well as a partial cross section along section line III-III in  FIG. 1 . The rocker arms  7 ,  8  are extend past the spindle  9  and have, at their ends, two guide pins  19 , which are directed toward the inside, i.e. in the direction of the contour element  2 . The guide pins  19  are formed conically and beveled on their end surfaces; they are positioned on the same axis a, which runs through the recess  13  of the contour element  2  and at a distance R parallel to the longitudinal axis of the selector shaft  6 , wherein R is equal to the radius of the circular arc k in  FIG. 1 . The shift movement of the selector shaft  6  in a longitudinal direction is illustrated by a double arrow S. The illustration shows that during a movement of the selector shaft  6  in the direction of arrow S, one of the two guide pins  19  can be moved to mesh with the recess  13 . The rocker arms  7 ,  8  during the shift movement form shift stops with their interior surfaces  7   a ,  8   a . In  FIG. 2  the shift movement is also illustrated by a double arrow S, wherein it is noticeable that the guide pins  19  come into sliding contact with the beveled areas  16 ,  17  during the selection movement. 
         [0024]    The function of the shift device  1  is as follows: During the selection movement according to double arrow W, the rocker arms  7 ,  8  are pivoted upward or downward out of the resting position (neutral position) illustrated in  FIG. 1 . The roller  10  thereby rolls onto the contour  11  of the contour element  2 , whereas due to the support of the spring element  5 , a selection force is generated. As mentioned, the selection movement W is equal to a transverse movement by the shift lever in the cross track of an H-shift pattern for the selection of a shift track. The recesses in the contour element  2  are always assigned to a shift track, namely the uppermost recess  12  to shift track  5 / 6 , the adjacent recess  13  to shift track  3 / 4  and the neutral position, the recess  14  to shift track  1 / 2  and the recess  15  to the shift track for the reverse gear. In the selection movement, i.e. the tilt-out of the rocker arms  7 ,  8 , the guide pins are no longer in mesh, i.e. in the position illustrated in  FIGS. 2 and 3  they are outside of the contour element  2 . Following the completion of the selection process, the shift movement is initiated by a longitudinal movement of the selector shaft  6  according to double arrow S, so that one of the two guide pins  19  engages in one of the recesses  12  through  15 . A not-illustrated selected gear change sleeve is thus moved axially and the affected gear wheel for the selected gear is shifted into the power flow. The selection stops  11   a ,  11   b  on the contour element  2  form a limitation for the swivel movement of rocker arms  7 ,  8  and/or the not-illustrated shift lever in the cross track during the selection movement. However the shift movement is limited by the shift stops  7   a ,  8   a.    
         [0025]      FIG. 4  shows a second exemplary embodiment of the invention in hand with a contour element  20 , which has a modified gate guide in the form of a continuous, closed slotted contour  21 . The contour element  20 , in the following referred to as gate element  20 , is here strictly formed as a gate and affixed to the case at two points, via trunnions  22 ,  23 . The slotted contour  21  has four roughly circular shaped extensions  24 ,  25 ,  26 ,  27  as well as constrictions  28 ,  29 ,  30 , which are aligned between them. The extensions  24  through  27  are assigned to the above-mentioned shift tracks; the constrictions  28  through  30  assume the track deflection function. In the drawing, to the right of the gate element  20 —analogous to the previous embodiment—a central selector shaft  31  is arranged with attached support rockers  32 ,  33  (cf.  FIG. 5 ). 
         [0026]      FIG. 5  shows a plan view of the support rockers  32 ,  33 , which are connected through a rod  34 , which is arranged parallel to the selector shaft  31 . At the ends of the support rockers  32 ,  33 , which are opposite from the selector shaft  31 , the guide pins  35 ,  36 —analogous to the previous exemplary embodiment—are arranged on both sides of the gate element  20 . The gate element  20  is sectioned according to the sectional plane V-V, i.e. in the area of extension  25 . The roughly circular extensions  24  through  27  are equal to the diameters of gate pins  35 ,  36  and positively receive them in a corresponding shift movement in the direction of the double arrow S. The constrictions  28  through  30  between the extensions  24  through  27  function as deflectors and prevent a shift movement in this area. Thus they assume in analogous form the function of the beveled areas  16  through  18  according to the first exemplary embodiment. The benefit of the continuous two-dimensional slotted contour  21  is found in a more advantageous production. The gate element  20  can be produced strictly as a stamped component, i.e. without an additional embossing process. 
       REFERENCE SYMBOLS 
       [0000]    
       
           1  shift device 
           2  contour element 
           3  trunnion 
           4  case 
           5  spring element 
           6  selector shaft 
           7  rocker arm 
           7   a  shift stop 
           8  rocker arm 
           8   a  shift stop 
           9  spindle 
           10  roller 
           11  contour 
           11   a  selector stop 
           11   b  selector stop 
           12  recess ( 5 / 6 ) 
           13  recess ( 3 / 4 ) 
           14  recess ( 1 / 2 ) 
           15  recess (R) 
           16  bevel pair 
           17  bevel pair 
           18  bevel pair 
           19  gate pin 
           20  contour element (gate element) 
           21  slotted contour 
           22  trunnion 
           23  trunnion 
           24  extension 
           25  extension 
           26  extension 
           27  extension 
           28  constriction 
           29  constriction 
           30  constriction 
           31  selector shaft 
           32  support rocker 
           33  support rocker 
           34  rod 
           35  guide pin 
           36  guide pin