Multi-disk clutch and method of manufacturing a core plate of a multi-disk clutch

Abstract

A multi-disk clutch 6 is provided with a reduced thickness so that the size of devices, such as a transmission employing the multi-disk clutch 6 can also be reduced. The multi-disk clutch 6 is configured to transmit and interrupt a torque between a radially outer wall 52 and a second cylindrical portion 69 of a spline hub. The multi-disk clutch 6 includes a plurality of first friction plates 50 and a plurality of second friction plates 51 . Radially outer portions of the first friction plates 50 are coupled in a circumferential direction to the radially outer wall 52 . Each second friction plate 51 has a core plate 90 and a friction facing 51 a . The core plate 90 has a friction mounting portion opposed to the first friction plate 50 , and tooth portions. The tooth portions are in mesh with the second cylindrical portion 69 of the spline hub. The friction facing 51 a is joined to the friction mounting portion. The friction mounting portion has a smaller thickness than the tooth portion.

What is claimed is:  
     
         1 . A multi-disk clutch for transmitting and interrupting a torque comprising: 
 first and second rotatable members;    a plurality of first plates circumferentially non-rotatably coupled to said first rotatable member, but axially movable relative to said first rotatable member; and    a plurality of second plates circumferentially non-rotatably coupled to said second rotatable member, but axially movable relative to said second rotatable member,    each of said second plates including a core plate with a coupling portion and a friction mounting portion that has a friction member, said friction mounting portion being opposed to an adjacent one of said first plates, each of said core plates said coupling portions being circumferentially coupled to the second member, said friction member being joined to said friction mounting portion,    each of said friction mounting portions of each of said core plates having a thickness smaller than a thickness of each of said coupling portions of each of said core plates.    
     
     
         2 . The multi-disk clutch according to  claim 1 , wherein 
 each of said coupling portions of each of said core plates has teeth that engage teeth of said second rotatable member such that said coupling portions of said core plates and the second rotatable member are coupled together by teeth meshing.    
     
     
         3 . The multi-disk clutch according to  claim 1 , wherein 
 each of said coupling portions of each of said core plates includes an internally-toothed wheel that engages teeth of said second rotatable member.    
     
     
         4 . The multi-disk clutch according to  claim 3 , wherein 
 each of said coupling portions of each of said core plates projects outwardly beyond one side surface of said friction mounting portions of said core plates such that cross sections of said core plates are L-shaped.    
     
     
         5 . The multi-disk clutch according to  claim 3 , wherein 
 said friction members are joined to opposite side surfaces of said friction mounting portions of said core plates; and    each of said coupling portions of each of said core plates projects outwardly beyond said opposite side surfaces of said friction mounting portions such that cross sections of said core plates are T-shaped.    
     
     
         6 . The multi-disk clutch according to  claim 2 , wherein 
 each of said coupling portions of each of said core plates projects outwardly beyond one side surface of said friction mounting portions of said core plates such that cross sections of said core plates are L-shaped.    
     
     
         7 . The multi-disk clutch according to  claim 2 , wherein 
 said friction members are joined to an opposite side surfaces of said friction mounting portions of said core plates; and    each of said coupling portions of each of said core plates projects outwardly beyond opposite side surfaces of said friction mounting portions such that cross sections of said core plates are T-shaped.    
     
     
         8 . The multi-disk clutch according to  claim 1 , wherein 
 each of said coupling portions of each of said core plates projects outwardly beyond one side surface of said friction mounting portions of said core plates such that cross sections of said core plates are L-shaped.    
     
     
         9 . The multi-disk clutch according to  claim 1 , wherein 
 said friction members are joined to an opposite side surfaces of said friction mounting portions of said core plates; and    each of said coupling portions of each of said core plates projects outwardly beyond opposite side surfaces of said friction mounting portions such that cross sections of said core plates are T-shaped.    
     
     
         10 . The multi-disk clutch according to  claim 1 , further comprising 
 a movably pressure plate arranged to press said first and second friction plates together; and    a return spring arranged to bias said pressure plate away from said first and second friction plates.    
     
     
         11 . The multi-disk clutch according to  claim 10 , wherein 
 each of said coupling portions of each of said core plates has teeth that engage teeth of said second rotatable member such that said coupling portions of said core plates and the second rotatable member are coupled together by teeth meshing.    
     
     
         12 . The multi-disk clutch according to  claim 11 , wherein 
 each of said coupling portions of each of said core plates projects outwardly beyond one side surface of said friction mounting portions of said core plates such that cross sections of said core plates are L-shaped.    
     
     
         13 . The multi-disk clutch according to  claim 11 , wherein 
 said friction members are joined to opposite side surfaces of said friction mounting portions of said core plates; and    each of said coupling portions of each of said core plates projects outwardly beyond said opposite side surfaces of said friction mounting portions such that cross sections of said core plates are T-shaped.    
     
     
         14 . The multi-disk clutch according to  claim 10 , wherein 
 each of said coupling portions of each of said core plates includes an internally-toothed wheel that engages teeth of said second rotatable member.    
     
     
         15 . The multi-disk clutch according to  claim 14 , wherein 
 each of said coupling portions of each of said core plates projects outwardly beyond one side surface of said friction mounting portions of said core plates such that cross sections of said core plates are L-shaped.    
     
     
         16 . The multi-disk clutch according to  claim 14 , wherein 
 said friction members are joined to opposite side surfaces of said friction mounting portions of said core plates; and    each of said coupling portions of each of said core plates projects outwardly beyond said opposite side surfaces of said friction mounting portions such that cross sections of said core plates are T-shaped.    
     
     
         17 . The multi-disk clutch according to  claim 2 , wherein 
 said coupling portions of said core plates have a larger thickness than said friction mounting portions at least at a tooth surface portion of said teeth of said coupling portions which are adapted to contact said teeth of one of said rotatable members.    
     
     
         18 . A friction plate for a multi-disk clutch that transmits and interrupts torque between first and second rotatable members, said friction plate comprising: 
 a pair of friction facing portions; and    a core plate including a coupling portion and a friction mounting portion with said friction facing portions being coupled to opposite sides of said friction mounting portion of said core plate,    said friction mounting portion of said core plate having a thickness smaller than a thickness of said coupling portion of said core plate that is adapted to engage one of said first and second rotatable members.    
     
     
         19 . The friction plate according to  claim 18 , wherein 
 said coupling portion of said core plate has teeth that are adapted to engage teeth of one of the rotatable members.    
     
     
         20 . The friction plate according to  claim 19 , wherein 
 said teeth of said coupling portion of said core plate form an internally-toothed wheel.    
     
     
         21 . The friction plate according to  claim 20 , wherein 
 said coupling portion of said core plate has a larger thickness than said friction mounting portion at least at a tooth surface portion of said teeth of said coupling portion which is adapted to contact a tooth of one of the rotatable members.    
     
     
         22 . The friction plate according to  claim 20 , wherein 
 said coupling portion of said core plate projects outwardly beyond one side surface of said friction mounting portion of said core plate such that a cross section of said core plate is L-shaped.    
     
     
         23 . The friction plate according to  claim 20 , wherein 
 said friction members are joined to opposite side surfaces of said friction mounting portion of said core plate; and    said coupling portion of said core plate projects outwardly beyond said opposite side surfaces of said friction mounting portion such that a cross section of said core plate is T-shaped.    
     
     
         24 . The friction plate according to  claim 19 , wherein 
 said coupling portion of said core plate has a larger thickness than said friction mounting portion at least at a tooth surface portion of said teeth of said coupling portion which is adapted to contact a tooth of one of the rotatable members.    
     
     
         25 . The friction plate according to  claim 19 , wherein 
 said coupling portion of said core plate projects outwardly beyond one side surface of said friction mounting portion of said core plate such that a cross section of said core plate is L-shaped.    
     
     
         26 . The friction plate according to  claim 19 , wherein 
 said friction members are joined to opposite side surfaces of said friction mounting portion of said core plate; and    said coupling portion of said core plate projects outwardly beyond said opposite side surfaces of said friction mounting portion such that a cross section of said core plate is T-shaped.    
     
     
         27 . The friction plate according to  claim 18 , wherein 
 said coupling portion of said core plate projects outwardly beyond one side surface of said friction mounting portion of said core plate, such that a cross section of said core plate is L-shaped.    
     
     
         28 . The friction plate according to  claim 18 , wherein 
 said coupling portion of said core plate projects outwardly beyond said opposite side surfaces of said friction mounting portion such that a cross section of said core plate is T-shaped.    
     
     
         29 . A method of manufacturing a core plate for a friction plate of a multi-disk clutch, said core plate having a final form with a coupling portion and a friction mounting portion, said method comprising the steps of: 
 preparing a sheet material having a uniform thickness equal to that of a final thickness of said friction mounting portion and a larger surface area than a surface area of said core plate of said final form;    removing a central portion of said sheet material to form an annular ring with a central opening; and    applying force to the sheet material in a direction transverse to the direction of its thickness to axially offset a part of said sheet material to be formed into said coupling portion.    
     
     
         30 . The method of manufacturing a core plate of a multi-disk clutch according to  claim 29 , wherein 
 said force is applied prior to said removing of said central portion.    
     
     
         31 . The method of manufacturing a core plate of a multi-disk clutch according to claim  30 , wherein 
 said central portion is removed prior to said force being applied to said sheet material.    
     
     
         32 . The method of manufacturing a core plate of a multi-disk clutch according to  claim 29 , wherein 
 said removing of said central portion forms a plurality of tooth portions.