Abstract:
An operation lever assembly of a vehicle transmission operator includes a lever base mounted on a vehicle body and having a top face formed with a hole. The assembly includes an engagement member mounted to the lever base from below and protruding through the hole. The assembly includes a tubular lever body joined to a protruding portion of the engagement member and mounted to an upper portion of the lever base. The assembly includes a rod accommodated in the lever body and extending vertically. The assembly includes a resilient member located between a lower end of the rod and a top face of the engagement member for biasing the rod upwardly. The lever body has a slit cut from a lower end of the lever body to a height position in an axial direction of the lever body. The rod is mounted with a lock-pin extending in a transverse direction of the lever body. The lock-pin protrudes outwardly through the slit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2003-044102 filed on Feb. 21, 2003; the entire contents of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to an operation lever assembly of a vehicle transmission operator for changing positions of a transmission by sliding an operation lever.  
           [0003]    Such an operation lever assembly is used in an automatic vehicle transmission operator of an automobile and the like. The operation lever includes a lever body which is a control lever (select lever). The operation lever includes a rod which is inserted into the lever body and which moves vertically. The operation lever includes a shift-knob mounted on a distal end of the rod and a lock-pin which is press-fitted into a proximal end of the rod. The operation lever includes a spring which normally biases the rod upward. The operation lever includes a lever base having a rotation shaft as the rotation center of the operation lever.  
           [0004]    The lever body and the lever base are integrally formed or welded to each other. Thus, during assembling of the operation lever, the spring and the rod are inserted, in this order, into a through hole formed in the center of the operation lever from the distal end of the lever body on which the shift-knob is mounted. The lever body is then fixed by chucking means. A notch (lock-pin-movable hole) is formed in the lever body. The lock-pin is press-fitted, from the notch, into a hole formed in the proximal end of the rod (see Japanese Patent Application Laid-Open No. H11 (2001) -286225 for example).  
         SUMMARY OF THE INVENTION  
         [0005]    When the lock-pin is press-fitted into the hole, it is necessary to strongly fix and retain the lever body. By strongly fixing and holding the lever body, the lever body adversely bears a mark of the chucking means which fixes the lever body. Therefore, the lever body can not be used as a design surface as it is, and it is necessary to cover the lever body with another member.  
           [0006]    When the lock-pin is press-fitted into the hole, the rod can not be fixed directly. The spring pushes the rod, and fixing of the press-fitting position is difficult. For this reason, the lock-pin and the notch of the lever body is required to have a great clearance threrebetween. When the lock-pin is press-fitted into the hole, a special positioning jig is required.  
           [0007]    It is an object of the present invention to provide an operation lever assembly of a vehicle transmission operator which can be assembled easily and precisely without scratching the lever body nor using a special jig.  
           [0008]    The invention provides a first aspect directed to the following operation lever assembly of a vehicle transmission operator. The assembly includes a lever base mounted on a vehicle body and having a top face formed with a hole. The assembly includes an engagement member mounted to the lever base from below and protruding through the hole. The assembly includes a tubular lever body joined to a protruding portion of the engagement member and mounted to an upper portion of the lever base. The assembly includes a rod accommodated in the lever body and extending vertically. The assembly includes a resilient member located between a lower end of the rod and a top face of the engagement member for biasing the rod upwardly. The lever body has a slit cut from a lower end of the lever body to a height position in an axial direction of the lever body. The rod is mounted with a lock-pin extending in a transverse direction of the lever body. The lock-pin protrudes outwardly through the slit.  
           [0009]    The lever base may be mounted with a rotation stopper. The rotation stopper may engage with an engagement portion formed at the lower end of the lever body for preventing the lever body from rotating.  
           [0010]    The lower end of the rod may include a guide for positioning and retaining the resilient member.  
           [0011]    The engagement member may have an upper end including a guide for positioning and retaining the resilient member.  
           [0012]    The engagement member and the lever body may be joined to each other by bolt fastening.  
           [0013]    The invention provides a second aspect directed to a method of assembling an operation lever. The method includes the step of mounting a locking member transversely to an operation rod of an operation lever. The method includes the step of inserting the operation rod longitudinally in a tubular member of the operation lever, inserting the locking member longitudinally in an opening of the tubular member. The method includes the step of screwing the tubular member having the operation rod and the locking member and a base of the operation lever to each other. 
       
    
    
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS  
       [0014]    [0014]FIG. 1 is an exploded perspective view of an automatic vehicle transmission operator of an embodiment;  
         [0015]    [0015]FIG. 2 is a side view of the transmission operator shown in FIG. 1;  
         [0016]    [0016]FIG. 3 is a sectional view of the transmission operator as taken along III-III in FIG. 2;  
         [0017]    [0017]FIG. 4 is an exploded perspective view of the transmission operator shown in FIG. 1 in which a torque sensor is assembled to the lower end of a select lever;  
         [0018]    [0018]FIG. 5 illustrates a fixing portion of the torque sensor in the transmission operator shown in FIG. 1;  
         [0019]    [0019]FIGS. 6A and 6B illustrate an operation lever assembly of the transmission operator shown in FIG. 1, wherein FIG. 6A is a front view thereof and FIG. 6B is a side view thereof;  
         [0020]    [0020]FIG. 7 is a sectional view of the operation lever assembly in the transmission operator taken along VII-VII in FIG. 6B; and  
         [0021]    [0021]FIG. 8 is an exploded sectional view of the operation lever assembly of the transmission operator shown in FIG. 7. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    Embodiments of the present invention will be specifically explained with reference to the drawings.  
         [0023]    The embodiments are applied to an operation lever assembly of an automatic vehicle transmission operator. The operation lever adds assisting power to operating power generated in an input operator to change positions of an automatic transmission. This reduces a burden of a driver&#39;s shifting operation.  
         [0024]    As shown in FIG. 1, the transmission operator includes an input operator  1  which changes positions (range positions) of the automatic transmission. The transmission operator includes a power assistor  2  which adds the assisting power to the operating power generated in input operator  1  and outputs the resultant to the automatic transmission. The transmission operator includes a transmitting mechanism (not shown) for transmitting the output to the automatic transmission.  
         [0025]    As shown in FIG. 1, the power assistor  2  includes an electric motor  31  for adding the assisting power to the operating power generated in input operator  1 . The power assistor  2  includes a case  32  for fixing electric motor  31 . The power assistor  2  includes a gear mechanism (a combination of worm gear and worm wheel gear) accommodated in case  32 . According to this power assistor  2 , as the operating power of select lever  3  increases, a torque detected by a torque sensor  5  also increases. This is used to increase voltage to be applied to electric motor  31  in accordance with the torque. The rotation power of electric motor  31  is added to the operating power as the assisting power, and this is output to an output shaft  8  of torque sensor  5 .  
         [0026]    As shown in FIGS.  1  to  3 , the input operator  1  includes select lever (control lever)  3  as the operation lever. The input operator  1  includes a lever case  4  with first case  4   a  and a second case  4   b  which support select lever  3 . The input operator  1  includes torque sensor  5  as torque detecting means for detecting operating power (rotation torque) generated during operation of select lever  3 . The operation of select lever  3  changes the range positions (such as P range, R range, N range, D range, and L range) of the automatic transmission.  
         [0027]    The select lever  3  has a shift-knob  6  mounted on the distal end. The shift-knob  6  is grasped by a driver to slide select lever  3 . The select lever  3  is provided at the lower end with assembling structure for assembling torque sensor  5 .  
         [0028]    As shown in FIGS. 3 and 4, the assembling structure is vertically divided into an upper member and a lower member, with respect to an input shaft  7  and output shaft  8  of torque sensor  5 .  
         [0029]    The upper member includes a lever base  9  formed as a housing having a substantially U-shaped cross section. The lever base  9  is fixed to the lower end of select lever  3 . The lever base  9  is provided at the end with a first bearing member  10  which constitutes a bearing mechanism. The first bearing member  10  rotatably supports output shaft  8  of torque sensor  5 . The first bearing member  10  is joined to a second bearing member  19  which is a later-described lower member, forming a bearing for rotatably supporting output shaft  8 . The first bearing member  10 ,  19  is formed at the periphery with a ring fitting groove  11  for fitting later-described ring member  23  around the first groove  11 .  
         [0030]    The lever base  9  has another end having a first fixing member  12  as a fixing mechanism for fixing input shaft  7 . The first fixing member  12  includes a substantially semi-circular input shaft guide  13  which covers the upper half of input shaft  7 . The first fixing member  12  includes a rotation shaft  15  which is fitted into a bush  14  which is press-fitted into second case  4   b . The first fixing member  12  includes screw holes  17  through which a second fixing member  18  (later-described lower member) is fixed to first fixing member  12  by means of screws  16 .  
         [0031]    The lower member includes second fixing member  18  as the fixing mechanism which is fixed to first fixing member  12  for non-rotatably fixing input shaft  7 . The lower member includes a second bearing member  19  as a bearing mechanism. Second bearing member  19  and first bearing member  10  form a bearing for rotatably supporting output shaft  8 .  
         [0032]    The second fixing member  18  is formed with a flat surface portion  21  which comes into close contact with a flat surface portion  20 , serving as rotation-detent member, formed on the lower side of input shaft  7 , thereby fixing input shaft  7  to first fixing member  12 . The flat surface portion  21  is groove having a substantially U-shaped section formed in the fixing surface  18   a  of second fixing member  18 . The second fixing member  18  includes screw holes  22  through which second fixing member  18  is fixed to first fixing member  12  by screws  16 .  
         [0033]    The flat surface portion  20  formed on input shaft  7  and the flat surface portion  21  formed in second fixing member  18  are brought into close contact with each other in this manner, and second fixing member  18  is fixed to first fixing member  12  by the screws. By fixing these members  18  and  12 , rattles of input shaft  7  in its both rotation and axial directions are eliminated. Therefore, the embodiment prevents detection error of a torque detecting value caused by the rattle of input shaft  7 .  
         [0034]    The second bearing member  19  includes a semi-circular receiver  19   a  which rotatably supports output shaft  8 . The second bearing member  19  is joined to first bearing member  10 , forming a bearing. The second bearing member  19  is formed with a ring fitting groove  24  around which C-shaped ring member  23  having spring properties is fitted. The second bearing member  19  is brought into abutment against first bearing member  10 . The ring member  23  is fitted into respective ring fitting grooves  11  and  24 . This forms the bearing for rotatably supporting output shaft  8 .  
         [0035]    The first bearing member  10  and second bearing member  19 , fixed to each other by ring member  23 , is inserted into a bush  25  which is press-fitted into first case  4   a  and is fixed to first case  4   a.    
         [0036]    As shown in FIGS. 3 and 4, torque sensor  5  includes a sensor body  26  which is provided at the opposite ends with input shaft  7  and output shaft  8 . As described above, the input shaft  7  includes flat surface portion  20  serving as a detent member which can be fixed to select lever  3  without rattle. The output shaft  8  is coaxial with input shaft  7  and is rotatably supported by the bearing. The distal end of output shaft  8  is connected to later-described power assistor  2  through a circular hole  27  formed in first case  4   a.    
         [0037]    The sensor body  26  is provided at the opposite sides with flat portions  28  for preventing torque sensor  5  from rotating around the axis. As shown in FIG. 5, the flat portions  28  are interposed between inner wall surfaces  29  formed inside first case  4   a.    
         [0038]    The interposition of flat portions  28  formed on sensor body  26  between the inner wall surfaces  29  of first case  4   a  prevents a rotation rattle of torque sensor  5 . The inner wall surfaces  29  of first case  4   a  are provided with elastic rubber members  30  so that a rattle is not caused due to poor working precision. The interposition of sensor body  26  between rubber members  30  prevents a value detected by torque sensor  5  from being varied.  
         [0039]    As shown in FIG. 3, select lever  3  holding torque sensor  5  at the lower end is accommodated in lever case  4 . The rotation shaft  15  is inserted into bush  14  formed in first case  4   a  so that select lever  3  can rotate. The first bearing member  10  and second bearing member  19  are coupled to each other to form the bearing which is inserted into bush  25  formed in second case  4   a  so that select lever  3  can rotate. The select lever  3  faces a slide groove  33  formed in lever case  4 . The slide groove  33  is formed in the upper end of lever case  4  over a sliding range of select lever  3 .  
         [0040]    The select lever  3  includes an intermediate portion. As shown in FIG. 3, the intermediate portion is mounted to a slide member  35  which comes into contact with the opening inner peripheral edge  34  of slide groove  33 . The slide member  35  is formed as a slide sleeve including two cylindrical portions, i.e., a small-diameter portion  35   a  and a large-diameter portion  35   b  having different diameters vertically. The slide member  35  is inserted into select lever  3  from the distal end on which shift-knob  6  is mounted, and is fixed at the intermediate portion of the lever  3 . The slide member  35  is mounted at a position closer to shift-knob  6  than rotation shaft  15  of select lever  3 . According to this arrangement, a rattle of select lever  3  is suppressed at a position close to shift-knob  6 .  
         [0041]    The slide member  35  is fixed by a supporting portion  36  formed on select lever  3 . That is, the slide member  35  is fixed to select lever  3  by fitting large-diameter portion  35   b  of slide member  35  into supporting portion  36 . The fitting of large-diameter portion  35   b  into supporting portion  36  prevents slide member  35  from falling out from select lever  3  downward (toward torque sensor  5 ).  
         [0042]    The slide groove  33  has opening inner peripheral edge  34  which has a guide  37  for guiding the sliding motion of slide member  35 . The guide  37  is formed into a stepped shape in coincidence with the shape of slide member  35 . The guide  37  is formed over the entire length of slide groove  33 . The slide member  35  has flexibility to some extent in the vertical direction.  
         [0043]    By mounting slide member  35  on select lever  3 , the slide member  35  comes into contact with opening inner peripheral edge  34  and slides thereon, and slides together with select lever  3 . This prevents select lever  3  from rattling. That is, a rattle produced between slide groove  33  and select lever  3  is absorbed by slide member  35  mounted on select lever  3 . Therefore, if slide member  35  is added, the cost of the assembly is less increased and the assembly is more inexpensive as compared with a case in which working precision of rotation shaft  15  or bush  14  of select lever  3  is enhanced.  
         [0044]    As shown in FIG. 3, the input operator  1  includes a side surface  38  of the lower end of select lever  3  closer to the proximal end of rotation shaft  15 . The input operator  1  includes an inner surface  39  of the lever case in the vicinity of bush  14  which rotatably supports rotation shaft  15 . The side surface  38  and inner surface  39  has threrebetween a spring member  40  as an elastic member for pushing select lever  3  against lever case  4 . The spring member  40  employs a wave washer. The elastic spring member  40  can push select lever  3  against an inner surface  41  of first case  4   a  in lever case  4 . The spring member  40  has a compression margin which absorbs size variations of lever case  4  and select lever  3 . This eliminates a rattle even if the working precision is the same level as the conventional technique.  
         [0045]    In the conventional configuration, a case cover is mounted on the case for preventing a torque sensor from falling out. However, size variations caused by assembling of the case and the case cover allow the torque sensor to be axially moved using the spline. The movable torque sensor produces a lateral rattle on the select lever. On the other hand, this embodiment has the configuration where spring member  40  provided between side surface  38  and inner surface  39  biases select lever  3  against one inner surface  41  of the lever case  4  under a constant biasing force. This configuration prevents a rattle produced in select lever  3  in the lateral direction (axial direction of rotation shaft  15 ).  
         [0046]    Therefore, the spring member  40  prevents the rattle of the lower end of select lever  3 . The slide member  35 , which comes into contact with opening inner peripheral edge  34  and slides thereon, is provided in the vicinity of shift-knob  6 . This configuration further reduces the rattle of select lever  3 . As a result, even if the transmission operator of the automatic vehicle is applied to an input operator having a short stroke, a rattle caused by stroke is suppressed, thus giving the driver comfortable shifting operation.  
         [0047]    The select lever  3  has a configuration shown in FIGS.  6  to  8  so that select lever  3  can easily and precisely be assembled without a special jig or the like. The select lever  3  includes a lever body  50  and a rod  51  inserted into a guide hole  53  formed in the lever body  50 . The select lever  3  includes a spring  52  as an elastic member for biasing rod  51  upwardly, and lever base  9 . The select lever  3  includes fixing means for fixing lever body  50  to lever base  9 .  
         [0048]    In FIG. 8, the lever body  50  includes a cylindrical small-diameter portion  50   a . The lever body  50  also includes a cylindrical large-diameter portion  50   b  having larger diameter than that of small-diameter portion  50   a . The lever body  50  has at the center a guide hole  53  which extends vertically through lever body  50 . The rod  51  inserted into guide hole  53  is vertically movably guided in guide hole  53 . The guide hole  53  includes a guide hole  53   a  formed in small-diameter portion  50   a . The guide hole  53  also includes a guide hole  53   b  formed in large-diameter portion  50   b . The guide hole  53   a  with smaller diameter has rod  51  to be inserted thereinto. The guide hole  53   b  with larger diameter has rod  51  with a proximal end  51   a  to be inserted thereinto. The rod  51  has lock-pin  54  to be inserted therethrough. The large-diameter portion  50   b  of lever body  50  has a proximal end which has a retaining portion  61  for preventing lever body  50  from rotating with respect to lever base  9 . The retaining portion  61  is not formed into a cylindrical shape for preventing its rotation but is formed into a square shape for positioning it. The retaining portion  61  engages with a rotation stopper  60  which is formed on later-described lever base  9 . The retaining portion  61  may be formed into a polygonal shape other than a square shape.  
         [0049]    The lever body  50  includes a slit  55  formed from the proximal end of large-diameter portion  50   b  to a predetermined height position. The slit  55  has lock-pin  54  inserted and protruding therefrom. When pushing of a button PN (FIG. 3) provided on shift-knob  6  permits rod  51  to be pushed down, the slit  55  guides lock-pin  54  to be vertically moved. The slit  55  has a width which is set to such a value that a minimum clearance is ensured to slide lock-pin  54 . Therefore, no rattle is produced between lock-pin  54  and slit  55 , which enhances the operating feeling of select lever  3 . The lever body  50  includes a thread  56 , as a portion to be fixed, on the inner peripheral surface of the proximal end of guide hole  53   b  formed in large-diameter portion  50   b . The thread  56  is a female thread which is threadedly engaged with a later-described fixing screw  62 .  
         [0050]    The rod  51  is inserted into guide hole  53 , with a distal end  51   b  projecting upward from lever body  50  to engage with button PN in shift-knob  6 . The proximal end  51   a  of rod  51  is formed with a lock-pin insertion hole  57  into which lock-pin  54  is press-fitted in a lateral direction normal to the axial direction. The proximal end  51   a  of rod  51  includes a lower end which has a guide  58  for positioning and retaining spring  52 . The guide  58  is formed into a circular projection and comes into the distal end of spring  52  to be guided.  
         [0051]    The spring  52  has a coil spring having such a size that spring  52  can be inserted into guide hole  53   b  formed in large-diameter portion  50   b . The spring  52  is inserted into guide hole  53   b  and comes into contact with proximal end  51   a  of rod  51  to normally bias rod  51  upward.  
         [0052]    The lever base  9  includes a hole  59  for fixing lever body  50  to a surface  9   a  of lever base  9  using the later-described fixing means. The lever body  50  includes guide hole  53  through which rod  51  and spring  52  are inserted. The hole  59  includes a periphery having rotation stopper  60  for preventing lever body  50  from rotating with respect to lever base  9 . The rotation stopper  60  projects, as low guide walls, from opposite sides relative to square retaining portion  61 . The rotation stopper  60  comes into contact with opposed side surfaces of retaining portion  61 . This configuration prevents lever body  50  from rotating with respect to lever base  9 .  
         [0053]    The fixing means includes thread  56 , as a portion to be fixed, on the inner peripheral surface of the proximal end of guide hole  53 . The fixing means includes fixing screw  62  which threadedly engages with thread  56  to fix lever body  50  to lever base  9 . The thread  56  as female thread is formed in the inner peripheral surface of the proximal end of guide hole  53  at a position corresponding to retaining portion  61  formed on lever body  50 . The fixing screw  62  includes a male screw  63  which is threadedly engaged with thread  56 . The fixing screw  62  is provided at the distal end with a guide  64  for positioning and retaining spring  52 . The guide  64  is formed as a circular projection and comes into the distal end of spring  52  to guide spring  52 .  
         [0054]    Assembling procedure of the operation lever assembly will be explained next.  
         [0055]    Referring to FIG. 8, the lock-pin  54  is press-fitted into lock-pin insertion hole  57  formed in proximal end  51   a  of rod  51 . Next, the rod  51  into which lock-pin  54  is press-fitted is inserted into guide hole  53  of lever body  50 . When the rod  51  is inserted into guide hole  53 , the lock-pin  54  press-fitted into rod  51  is exposed from slit  55  formed in lever body  50 . Then, spring  52  is inserted into guide hole  53 .  
         [0056]    The lever body  50  having rod  51  and spring  52  inserted into guide hole  53  is mounted on lever base  9 . The lever body  50  is mounted on lever base  9  while positioning retaining portion  61  of lever body  50  with respect to rotation stopper  60  formed on lever base  9 . With this configuration, lever body  50  is retained by rotation stopper  60  such that lever body  50  can not rotate.  
         [0057]    Next, the fixing screw  62  is inserted into hole  59  formed in lever base  9  from a back surface  9   b  which is opposite from surface  9   a  of lever base  9  which fixes lever body  50 . The fixing screw  62  is threadedly engaged with thread  56  of lever body  50 . When the fixing screw  62  is threadedly engaged with thread  56 , rotation stopper  60  prevents lever body  50  from rotating even if lever body  50  is not fixed by a jig or the like. This facilitates the fastening operation of screw.  
         [0058]    The fastening fixing screw  62  applies a predetermined load to spring  52 , which normally biases rod  51  upward. Guide  58  of rod  51  and guide  64  of fixing screw  62  respectively enter upper end lower end of spring  52 . This positions spring  52  in guide hole  53  without rattling.  
         [0059]    According to this embodiment, the lock-pin  54  can easily be press-fitted into rod  51  before it is inserted into lever body  50  using a fixing jig. The rod  51 , fixed when lock-pin  54  is press-fitted, is covered with lever body  50  after press-fitting of lock-pin  54 . This prevents the surface of lever body  50  from being not damaged. The lever body  50  is fixed to lever base  9  by fixing screw  62 , thus facilitating assemble. This reduces the assembling steps, and needs no equipment such as special jig, thus reducing productive cost.  
         [0060]    Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the above teachings. The scope of the invention is defined with reference to the following claims.  
         [0061]    In accordance with the invention, before inserting of the rod in the lever body, the lock pin is inserted in the rod in advance. The rod, in which lock pin is inserted, is inserted in the lever body as another component. The lever body is fixed to the lever base, using the engagement member. This facilitates press-fitting of the lock pin in the rod, without a special jig and allows the lever body to be used as a design surface as it is, without damaging of the surface of the lever body.  
         [0062]    The previous press fitting of the lock pin in the rod permits small clearance between the slit formed to the lever body and the lock pin in the slit. This dimensional accuracy therebetween enhances operating feeling during shift operation and allows a smaller size.  
         [0063]    The lever base is formed with the rotation stopper which engages with engagement portion formed to the proximal end of the lever body for preventing the lever body from rotating. This facilitates assembling of the lever body to the lever base, and requires no special equipment such as a positioning jig.  
         [0064]    The rod is formed at the lower end with the guide for positioning and retaining the resilient member. This allows the upper end of the resilient member to be positioned by the guide without rattle. The resilient member may employ, for example, a spring.  
         [0065]    The engagement member is formed at the upper end with the guide for positioning and retaining the resilient member. This allows the lower end of the resilient member to be positioned by the guide without rattle, and prevents the resilient member from rattling during expanding or contracting.  
         [0066]    The joining of the engagement member and the lever body to each other by bolt fastening allows the lever body to be easily fixed to the lever base by screwing, without a lot of work such as welding.