Abstract:
A dry multiple-disk clutch for transmitting power from the crankshaft of a motorcycle to a transmission input shaft and cutting off power transmission includes an outer clutch member interlocked with the crankshaft so as to be driven for rotation, a plurality of driving friction disks interlocked with the outer clutch member, a plurality of driven friction disks alternated with the driving friction disks and interlocked with the transmission input shaft, and a pressure member disposed opposite to the outer clutch member with the driving and the driven friction disks arranged alternately between the outer clutch member and the pressure member, and capable of moving in opposite axial direction to compress the driving and the driven friction disks together and to disengage the driven friction disks from the driving friction disks. Additionally, strap plates are disposed between a peripheral part of the outer clutch member and a peripheral part of the driving friction disks so as to be substantially tangent to the circumferences of the driving friction disks, and connect the respective peripheral parts of the outer clutch member and the driving friction disks to transmit the rotation of the outer clutch member to the driving friction disks.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a dry multiple-disk clutch for, for example, a motorcycle and, more particularly, to a low-noise or silent dry multiple-disk clutch.  
           [0003]    2. Description of the Related Art  
           [0004]    A generally known dry multiple-disk clutch includes driving friction disks provided on their outside circumferences with external teeth, driven friction disks provided on their inside circumferences with internal teeth, an outer clutch member having the shape of a bottomed cylinder and provided with slots in its side wall, an inner clutch member provided with splines, and pressure mechanism. The driving friction disks and the driven friction disks are arranged alternately with the external teeth of the driving friction disks engaged in the slots of the outer clutch member and the internal teeth of the driven clutch disks engaged with the splines of the inner clutch member. The driving clutch disks are axially movable relative to the outer clutch member, and the driven friction disks are axially movable relative to the inner clutch member. The pressure mechanism applies pressure to the superposed driving and driven clutch disks to transmit power from the outer clutch member to the inner clutch member by the agency of friction between the driving and the driven clutch disks. When the pressure applied to the driving and the driven clutch disks by the pressure mechanism is removed, the driving and the driven clutch disks are spaced apart to stop power transmission. Such a dry multiple-disk clutch is disclosed FIG. 1 of JP 2-570 B.  
           [0005]    While engaging or disengaging such a dry multiple-disk clutch or while the rotational speed of the outer clutch member is unstable, the outer clutch member is able to move in a rotating direction relative to the driving friction disks by a circumferential displacement corresponding to gaps between each of the external teeth of the driving friction disks and edges of parts of the sidewall of the outer clutch member defining the slots of the outer clutch member. Consequently, the edges of the parts of the side wall of the outer clutch member strike against the edges of the external teeth of the driving friction disks to generate hitting sounds.  
           [0006]    It is an object of the present invention to provide a dry multiple-disk clutch capable of controlling the generation of hitting sounds.  
         SUMMARY OF THE INVENTION  
         [0007]    To achieve the object, the present invention provides a dry multiple-disk clutch for transmitting power from a drive shaft to a transmission input shaft, including an outer clutch member interlocked with the drive shaft so as to be driven for rotation by the drive shaft; a plurality of driving friction disks interlocked with the outer clutch member; a plurality of driven friction disks alternated with the driving friction disks and interlocked with the transmission input shaft; and a pressure member disposed opposite to the outer clutch member with the driving and the driven friction disks arranged alternately between the outer clutch member and the pressure member, for moving in opposite axial direction to compress the driving and the driven friction disks together and to disengage the driven friction disks from the driving friction disks; the dry multiple-disk clutch comprising strap plates disposed between a peripheral part of the outer clutch member and a peripheral part of the driving friction disks, and connecting the respective peripheral parts of the outer clutch member and the driving friction disks.  
           [0008]    Since there are not any gaps with respect to a rotating direction between the outer clutch member and the driving friction disks, edges, facing a rotating direction, of the outer clutch member do not strike edges, facing the edges of the outer clutch member, of the driving friction disks and hence the dry multiple-disk clutch operates silently.  
           [0009]    Since the dry multiple-disk clutch of the present invention does not need any member corresponding to the inevitably large outer clutch member having the shape of a bottomed cylinder and included in the conventional dry multiple-disk clutch, the dry multiple-disk clutch of the present invention can be formed in compact construction.  
           [0010]    Preferably, each of the driving friction disks is provided with a plurality of external projections, the outer clutch member is provided with a plurality of external projections, studs are attached to the external projections of the outer clutch member, respectively, and each of the strap plates has one end attached to the external projection of each of the driving friction disks and the other end fitted on the stud.  
           [0011]    Preferably, the strap plats are substantially tangent to the circumferences of the driving friction disks.  
           [0012]    The dry multiple-disk clutch may further include strap plates disposed between the respective peripheral parts of the outer clutch member and the pressure member, and connecting the outer clutch member and the pressure member.  
           [0013]    Preferably, the strap plates connected to the pressure member extend substantially along the circumference of the pressure member. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a longitudinal sectional view of a dry multiple-disk clutch in a first embodiment according of the present invention and parts associated with the former;  
         [0015]    [0015]FIG. 2 is a partly cut away end view of the dry multiple-disk clutch shown in FIG. 1;  
         [0016]    [0016]FIG. 3 is an end view of an outer clutch member;  
         [0017]    [0017]FIG. 4 is a sectional view taken on the line IV-IV in FIG. 3;  
         [0018]    [0018]FIG. 5 is an end view of a driving friction disk;  
         [0019]    [0019]FIG. 6 is a sectional view taken on the line VI-VI in FIG. 5;  
         [0020]    [0020]FIG. 7 is an end view of a pressure member;  
         [0021]    [0021]FIG. 8 is a sectional view taken on the line VIII-VIII in FIG. 7;  
         [0022]    [0022]FIG. 9 is an end view of a driven friction disk;  
         [0023]    [0023]FIG. 10 is a sectional view taken on the line X-X in FIG. 9;  
         [0024]    [0024]FIG. 11 is a sectional view taken on the line XI-XI in FIG. 2;  
         [0025]    [0025]FIG. 12 is a sectional view taken on the line XII-XII in FIG. 2;  
         [0026]    [0026]FIG. 13 is a longitudinal sectional view of a dry multiple-disk clutch in a second embodiment of the present invention and parts associated with the former;  
         [0027]    [0027]FIG. 14 is a front elevation of a driven friction disk with a vibration control function;  
         [0028]    [0028]FIG. 15 is a sectional view taken on the line XV-XV in FIG. 14;  
         [0029]    [0029]FIG. 16 is an enlarged front elevation of a plate spring; and  
         [0030]    [0030]FIG. 17 is a sectional view taken on the line XVII-XVII in FIG. 16. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]    [0031]FIG. 1 is a longitudinal sectional view of a dry multiple-disk clutch  1  in a first embodiment of the present invention intended to be applied to a motorcycle, and parts associated with the dry multiple-disk clutch  1 . The dry multiple-disk clutch  1  is mounted on one end of a transmission input shaft  4  included in a transmission. The transmission input shaft  4  is extended parallel to the crankshaft of an engine, not shown, i.e., a drive shaft, and supported for rotation in a ball bearing  3  on a crankcase  2 . A driven gear  7  is supported for rotation by a needle bearing  6  on the transmission input shaft  4  and engaged with a drive gear  5 . A side cover  8  is disposed near the driven gear  7 .  
         [0032]    The dry multiple-disk clutch  1  includes the following members as principal components. An outer clutch member  10  disposed on the outer side of the side cover  8  and the driven gear  7  are united with bolts  9 . Two driving friction disks  13  and one annular pressure member  14  are connected to the outer clutch member  10  by strap plates  26 , first collar studs  11  (FIGS. 1 and 11) and second collar studs  12  (FIG. 12). Three driven friction disks  15  and the two driving friction disks  13  are arranged axially alternately. The pressure member  14  is adjacent to the outermost driven friction disk  15 . The inside circumferences of the driven friction disks  15  are engaged with splines formed on the transmission input shaft  4 . The driven friction disks  15  are axially movable on the transmission input shaft  4 . A coned disk spring  19  for applying pressure to the friction disks is supported by a first disk spring holder  16 , a ball bearing  17  and a second disk spring holder  18  on the outer end of the transmission input shaft  4 . The coned disk spring  19  presses the pressure member  14  toward the outer clutch member  10 . An annular release plate  21  is held in place on the pressure member  14  with a snap ring  20 . A release pin  23  is fitted in the inner ring of a ball bearing  22  fitted in a central hole of the release plate  21 . The release pin  23  is provided with a flange  23   a.  The inner ring of the ball bearing  22  is pressed against the flange  23   a  of the release pin  23 . A release rod  24  is extended in an axial bore formed in the transmission input shaft  4 . The release rod  24  is pushed axially outward to push the release pin  23  axially outward. The dry multiple disk clutch  1  is covered with a clutch cover  25 .  
         [0033]    Referring to FIG. 2 showing the dry multiple disk clutch  1  in a partly cutaway end view, there are shown the release plate  21 , the snap ring  20  and the pressure member  14 . The first collar studs  11  and the second collar studs  12  are arranged circumferentially alternately.  
         [0034]    [0034]FIG. 3 shows the outer clutch member  10  in an end view and FIG. 4 is a sectional view taken on the line IV-IV in FIG. 3. External projections  10   a  and  10   b  are arranged alternately on the outside circumference of the outer clutch member  10 . The external projections  10   a  and  10   b  are provided with threaded holes  10   c  and  10   d,  respectively. The collar studs  11  and  12  are engaged in the threaded holes  10   c  and  10   d,  respectively. The external projections  10   a  and  10   b  have slightly different axial lengths, respectively, as shown in FIGS. 11 and 12. The outer clutch member  10  is provided with holes  10   e.  The bolts  9  are passed through the holes  10   e  to fasten the outer clutch member  10  to the driven gear  7 .  
         [0035]    [0035]FIG. 5 shows the driving friction disk  13  in an end view and FIG. 6 is a sectional view taken on the line VI-VI in FIG. 5. The driving friction disk  13  is provided with three external projections  13   a  on its outside circumference. Each of strap plates  26  has one end fastened to the external projection  13   a  with a rivet  27  such that the strap plate  26  is substantially tangent to the outside circumference of the driving friction disk  13 , and the other end provided with a hole  26   a.  The two driving friction disks  13  of the dry multiple-disk clutch have the same shape. The first collar studs  11  are passed through the holes  26   a  of one of the driving friction disks  13 , and the second collar studs  12  are passed through the holes  26   a  of the other driving friction disk  13 .  
         [0036]    [0036]FIG. 7 shows the pressure member  14  in an end view and FIG. 8 is a sectional view taken on the line VIII-VIII in FIG. 7. The pressure member  14  is provided with three external projections  14   a  on its outside circumference. Each of the strap plates  26  has one end fastened to the external projection  14   a  with a rivet  27  such that the strap plate  26  is substantially tangent to the outside circumference of the pressure member  14 , and the other end provided with a hole  26   a.  The first collar studs  11  are passed trough the holes  26   a  of the strap plates  26 . The pressure member  14  has an inner friction surface  14   b  as shown in FIG. 8.  
         [0037]    [0037]FIG. 9 shows the driven friction plate  15  in an end view and FIG. 10 is a sectional view taken on the line X-X in FIG. 9. The driven friction disk  15  has a shape resembling a wheel. The driven friction disk  15  has a hub  28 , an annular plate  29  and rims  30 . The annular plate  29  is fastened to the hub  28  with rivets  31 . Splines  28   a  are formed in the side surface of the bore of the hub  28 . The splines  28   a  engage with the splines  4   a  (FIG. 1) of the transmission input shaft  4 . The annular plate  29  and the rims  30  are formed of the same material. The rims  30  are bonded adhesively to the outer and inner surfaces of a peripheral part of the annular plate  29 .  
         [0038]    [0038]FIG. 11 is a sectional view taken on the line XI-XI in FIG. 2. FIG. 11 shows the engaged dry multiple-disk clutch  1 . The driven friction disk  15 , the driving friction disk  13 , the driven friction disk  15 , the driving friction disk  13 , the driven friction disk  15  and the pressure member  14  are arranged in that order from the side of the outer clutch member  10  outward. The external projection  13   a  of the driving friction disk  13 , the external projection  14   a  of the pressure member  14 , and the strap plates  26  fastened to those external projections with the rivets  27  are seen in FIG. 11. An externally threaded inner part of the first collar stud  11  extending inward from a collar  11   a  formed on the first collar stud  11  is screwed in the threaded hole  10   c  of the external projection  10   a  of the outer clutch member  10 . The strap plate  26  fastened to the driving friction disk  13 , a collar  32 , the strap plate  26  fastened to the pressure member  14 , and an outer clutch plate  33  are mounted in that order on an outer part of the first collar stud  11  extending outward from the collar  11   a,  and are fastened to the outer part of the first collar stud  11  with a nut  34  screwed on an externally threaded outer end of the outer part of the first collar stud  11 . The first collar stud  11  is passed through the hole  26   a  of the strap plate  26 . The outer clutch plate  33  is an annular member for holding the free ends of the six collar studs  11  and  12  at equal angular intervals.  
         [0039]    [0039]FIG. 12 is a sectional view taken on the line XII-XII in FIG. 2. FIG. 12 shows the engaged dry multiple-disk clutch  1 . The driven friction disk  15 , the driving friction disk  13 , the driven friction disk  15 , the driving friction disk  13 , the driven friction disk  15  and the pressure member  14  are arranged in that order from the side of the outer clutch member  10  outward. The external projection  13   a  of another driving friction disk  13 , namely, the driving friction disk  13  not shown in FIG. 11, and the strap plate  26  fastened to the external projection  13   a  with the rivets  27  are seen in FIG. 121. An externally threaded inner part of the second collar stud  12  extending inward from a collar  12   a  formed on the second collar stud  12  is screwed in the threaded hole  10   d  of the external projection  10   b  of the outer clutch member  10 . The externally threaded part of the second collar stud  12  screwed in the threaded hole  10   d  has a length longer than that of the externally threaded inner part of the first collar stud  11  screwed in the threaded hole  10 . The strap plate  26  fastened to the driving friction disk  13 , and the outer clutch plate  33  are mounted in that order on an outer part of the second collar stud  12  extending outward from the collar  12   a,  and are fastened to the outer part of the second collar stud  12  with a nut  34  screwed on an externally threaded outer end of the outer part of the second collar stud  12 . Any collar is not put on the second collar stud  12 . The second collar stud  12  is passed through the hole  26   a  of the strap plate  26 . When the outer clutch member  10  turns, i.e., when the outer clutch member  10  moves to the left as viewed in FIGS. 11 and 12, the driving friction disks  13  and the pressure member  14  are pulled by the strap plates  26  and rotate together with the outer clutch member  10 .  
         [0040]    Referring to FIG. 1, a coned disk spring  35  for vibration control is fitted in a groove formed in a surface, facing the driven friction disk  15 , of the outer clutch member  10 . An annular vibration control plate  36  is held between the coned disk spring  35  and a friction surface of the driven friction disk  15  nearest to the outer clutch member  10 . The coned disk spring  35  presses the vibration control plate  36  against the driven friction disk  15 . The coned disk spring  35  absorbs axial vibrations of the friction disks  13  and  15  to prevent the dry multiple-disk clutch  1  from generating vibrational noise.  
         [0041]    The coned disk spring  19  for applying pressure to the friction disks  13  and  15  is supported at the outer end of the dry multiple-disk clutch  1  by the first disk spring holder  16  fastened to the outer end of the transmission input shaft  4 , the ball bearing  17 , and the second disk spring holder  18 . The coned disk spring  19  apply pressure through the pressure member  14  to the friction disks  13  and  15  toward the outer clutch member  10  to engage the dry multiple-disk clutch  1 .  
         [0042]    The annular release plate  21  is held in place on the pressure member  14  with the snap ring  20 . the release pin  23  is fitted in the inner ring of the ball bearing  22  fitted in the central hole of the release plate  21 . The outer end of the release rod  24  extended through the transmission input shaft  4  is in contact with the inner end of the release pin  23 . The release rod  24  is pushed axially outward by hydraulic or mechanical force to disengage the dry multiple-disk clutch  1 . Then, the release plate  21  is moved outward through the release pin  23 , and the ball bearing  22  in contact with the flange  23   a  of the release pin  23  to push the pressure member  14  outward, i.e., in a direction away from the outer clutch member  10 , against the resilience of the coned disk spring  19  through the snap ring  20  by the release plate  21 . Consequently, the contact surfaces of the outer clutch member  10 , the vibration control plate  36 , the driving friction disks  13 , the driven friction disks  15  and the pressure member  14  are separated to disengage the dry multiple-disk clutch  1 . Thus, power transmission from the outer clutch member  10  to the transmission input shaft  4 , namely, power transmission from the crankshaft of the engine to the transmission, is cut off.  
         [0043]    Strap plates  26  are formed of an elastic metal. As shown in FIGS. 11 and 12, the strap plates  26  warp elastically while the dry multiple-disk clutch  1  is engaged. When the pressure member  14  is pushed away from the outer clutch member  10  by the release rod  24  and pressure acting between the adjacent friction surfaces is removed, the driving friction disks  13  and the pressure member  14  are moved by the resilience of the strap plate  26  so that the friction surfaces are separated. Thus, the dry multiple-disk clutch  1  can be satisfactorily sharply disengaged. When the pressure applied to the release rod  24  is removed, the dry multiple-disk clutch  1  is engaged by the pressure exerted by the coned disk spring  19 .  
         [0044]    Thus, the two driving friction disks  13  and the single pressure member  14  of the dry multiple-disk clutch  1  in the first embodiment are connected to the outer clutch member  10  by the strap plates  26 . Therefore, the rotating outer clutch member  10  drags the driving friction disks  13  and the pressure member  14  through the strap plates  26  and, consequently, the driving friction disks  13  and the pressure member  14  rotates together with the outer clutch member  10 . Since there are not any gaps corresponding to the gaps between the external teeth of the driving friction disks and edges of the parts of the side wall of the outer clutch member defining the slots in the conventional dry multiple-disk clutch, the dry multiple-disk clutch  1  in the first embodiment does not generate any hitting sounds. Thus, the dry multiple-disk clutch  1  in the first embodiment operates silently.  
         [0045]    The conventional dry multiple-disk clutch mentioned above needs the outer clutch member provided in its side wall with the slots and having the shape of a large bottomed cylinder. The dry multiple-disk clutch  1  in the first embodiment can be formed in compact construction by fastening the strap plates  26  attached to the driving friction disks  13  and the pressure member  14  to the six collar studs  11  and  12  attached to the outer clutch member  10 .  
         [0046]    The splines  28   a  formed in the hubs  28  of the driven friction disks  15  are engaged directly with the splines  4   a  formed on the transmission input shaft  4  without using any member corresponding to the inner clutch member of the conventional dry multiple-disk clutch. Thus, the dry multiple-disk clutch  1  in the first embodiment needs fewer parts and is simpler in construction than the conventional dry multiple-disk clutch.  
         [0047]    [0047]FIG. 13 shows a dry multiple-disk clutch  40  in a second embodiment of the present invention and parts associated with the former. The dry multiple-disk clutch  40 , similarly to the dry multiple-disk clutch  1  in the first embodiment, is mounted on one end of a transmission input shaft  4  included in a transmission. The transmission input shaft  4  is extended parallel to the crankshaft of an engine, not shown, i.e., a drive shaft, and supported for rotation in a ball bearing  3  on a crankcase  2 . A driven gear  7  is supported for rotation by a needle bearing  6  on the transmission input shaft  4  and engaged with a drive gear  5 . A side cover  8  is disposed near the driven gear  7 .  
         [0048]    An outer clutch member  41  disposed on the outer side of the side cover  8  and the driven gear  7  are united with bolts  9 . Two driving friction disks  42  and an annular pressure member  43  are connected to the outer clutch member  41  by strap plates  45  put on collars  46  put on two kinds of collar studs  44 . When the outer clutch member  41  rotates, the driving friction disks  42  and the annular pressure member  43  are pulled by the strap plates  45  for rotation together with the outer clutch member  41 . The two driving friction disks  42  have the same shape as that of the driving friction disks  13  of the first embodiment. The shape and function of the pressure member  43  are different from those of the pressure member  14  of the first embodiment. The shape and function of the pressure member  43  are the same as those of the combination of the pressure member  14  and the release plate  21  of the first embodiment.  
         [0049]    One driven friction disk  47  having a vibration control function is interposed between the outer clutch member  41  and the driving friction disk  42 , and two driven friction disks  48 , which are the same as the driven friction disks  15  of the first embodiment, are interposed between the adjacent driving friction disks  42  and between the outermost driving friction disk  42  and the pressure member  43 , respectively. Splines formed in the bores of the hubs of the driven friction disks  47  and  48  are engaged with splines formed on the transmission input shaft  4 . The driven friction disks  47  and  48  are axially movable on the transmission input shaft  4 . The outer clutch member  41  of the second embodiment is not provided with any member corresponding to the coned disk spring  35  and the vibration control plate  36  put on the outer clutch member  10  of the first embodiment. The functions of the coned disk spring  35  and the vibration control plate  36  are replaced by the vibration control function of the driven friction disk  47 .  
         [0050]    A friction-disk-holding coned disk spring  51  is held between an outer clutch plate  50  put on and fastened with nuts  49  to studs  44 , and the pressure member  43  to press the pressure member  43  and the friction disks toward the outer clutch member  41 . FIG. 13 shows the engaged dry multiple-disk clutch  40 .  
         [0051]    A central part of the pressure member  43  has the function of a release. An outer end part of a release pin  23  is fitted in the inner ring of a ball bearing  52  fitted in a central bore of the pressure member  43 . A release rod  24  extended through the transmission input shaft  4  has an outer end in contact with the inner end of the release pin  23 . The release rod  24  is pushed axially outward by hydraulic or mechanical force to disengage the dry multiple-disk clutch  40 . Then, the pressure member  43  is moved outward through the release pin  23  and the ball bearing  52  against the resilience of the coned disk spring  51  to move the pressure member  43  away from the outer clutch member  41 . Consequently, the contact surfaces of the outer clutch member  41 , the driving friction disks  42 , the driven friction disk  47  having a vibration control function, the driven friction disks  48  and the pressure member  43  are separated to disengage the dry multiple-disk clutch  40 . Thus, power transmission from the outer clutch member  41  to the transmission input shaft  4 , namely, power transmission from the crankshaft of the engine to the transmission, is cut off.  
         [0052]    [0052]FIG. 14 shows the driven friction disk  47  with a vibration control function in an end view, and FIG. 15 is a sectional view take on the line XV-XV in FIG. 14. The driven friction disk  47  with a vibration control function has a hub  53 , an annular plate  54 , plate springs  55 , and two peripheral annular plates  56  facing each other. The annular plate  54  is fastened to the hub  53  with rivets  57 . The plate springs  55  are fastened to the annular plate  54  with rivets  58  of a comparatively small diameter. The peripheral annular plates  56  are fastened to the outer and the inner surface of each plate spring  55  with grommets  59 . Splines  53   a  are formed in the side surface of the bore of the hub  53 . The splines  53   a  are engaged with the splines  4   a  formed on the transmission input shaft  4 .  
         [0053]    [0053]FIG. 16 shows the plate spring  55  in an enlarged front elevation and FIG. 17 is a sectional view taken on the line XVII-XVII in FIG. 16. The plate spring  55  is formed of an elastic metal. Parts on the opposite sides of a central part of the plate spring  55  are warped in opposite directions, respectively, in a natural state as shown in FIG. 17. The plate spring  55  is provided with grommet receiving holes  55   a  and rivet receiving holes  55   b  through which the rivets  58  are passed. As shown in FIG. 15, the peripheral annular plates  56  are fastened to the opposite surfaces of the plate springs  55  with the grommets  59  inserted in the grommet receiving holes  55   a.  The two grommets  59  are inserted in the two grommet receiving holes  55   a  of each plate spring  55  in opposite directions, respectively. One of those two grommets  59  fastens one of the peripheral annular plates  56  to the plate spring  55 , and the other grommet  59  fastens the other peripheral annular plate  56  to the same plate spring  55 . The two peripheral annular plates  56  are spaced apart by the plate springs  55  warped in a natural state. When the dry multiple-disk clutch  40  is engaged, the peripheral annular plates  56  are urged in opposite directions, respectively, by the agency of the plate springs  55 . Thus, the driven friction disk  47  with a vibration control function absorbs axial vibrations of the friction disks  42  and  48  to prevent the dry multiple-disk clutch  40  from generating vibrational noise.  
         [0054]    As apparent from the foregoing description, the dry multiple-disk clutch  40  in the second embodiment, similar to the dry multiple-disk clutch  1  in the first embodiment, prevents the generation of hitting sounds that is caused by the collision of the external teeth of the driving friction disks against the edges of parts of the side wall of the outer clutch member defining the slots in the conventional dry multiple-disk clutch by the agency of the plate springs  55 . Since the dry multiple-disk clutch  40  in the second embodiment does not need an inevitably large outer clutch member having the shape of a bottomed cylinder, the dry multiple-disk clutch  40  can be formed in compact construction. Since the dry multiple-disk clutch  40  does not need any member corresponding to the inner clutch member of the conventional dry multiple-disk clutch, the dry multiple-disk clutch  40  in the second embodiment needs fewer parts. The driven friction disk  47  with a vibration control function effectively prevents the generation of by the friction surfaces of the friction disks. Since the pressure member  43  has a releasing function, the dry multiple-disk clutch  40  in the second embodiment does not need any member corresponding to the release plate  21  of the first embodiment, and needs fewer parts than the dry multiple-disk clutch  1  in the first embodiment. Since the coned disk spring  51  retained in place by the outer clutch plate  50  connected to the outer clutch member  41  presses the pressure member  43 , the dry multiple-disk clutch  40  in the second embodiment does not need any member corresponding to the first disk spring holder  16 , the ball bearing  17  and the second disk spring holder  18  of the dry multiple-disk clutch  1  in the first embodiment. Thus, the dry multiple-disk clutch  40  in the second embodiment needs a reduced number of parts and cal be formed in compact, lightweight construction.