Method for producing a leaf spring as a fiber composite component, and a leaf spring

Abstract

A leaf spring for a motor vehicle is made from a fiber composite component including individual fibers in form of at least two textile layers stacked on top of each other and a matrix made of a duroplastic or thermoplastic resin surrounding the fibers. The resin is hardened in a mold tool by applying pressure and heat. The stacked textile layers are formed inside a mold tool and fixed by a dry binder applied to at least one of the textile layers to form a dry preform. A fiber composite blank is stamped from the preform and subsequently infiltrated with the resin in a RTM cavity and hardened. The binder applied in dry form may only be arranged in certain areas of the textile layers.

What is claimed is: 
     
         1 . A leaf spring for a motor vehicle, comprising:
 at least two textile layers made of fibers and disposed on top of one another,   a dry binder arranged at least partially between the at least two textile layers and applied on at least one of the textile layers, and   a matrix formed of a hardened resin surrounding the fibers.   
     
     
         2 . The leaf spring of  claim 1 , wherein the ends of the individual fibers are completely embedded in the resin. 
     
     
         3 . The leaf spring of  claim 1 , wherein at least 90% of the fibers are oriented in a longitudinal direction of the leaf spring. 
     
     
         4 . The leaf spring of  claim 1 , wherein at least 95% of the fibers are oriented in a longitudinal direction of the leaf spring. 
     
     
         5 . The leaf spring of  claim 1 , wherein at least 99% of the fibers are oriented in a longitudinal direction of the leaf spring. 
     
     
         6 . The leaf spring of  claim 1 , comprising in cross-section a fiber fraction from 50% to 70%. 
     
     
         7 . The leaf spring of  claim 1 , comprising in cross-section a fiber fraction from 55% to 65%. 
     
     
         8 . The leaf spring of  claim 1 , comprising in cross-section a fiber fraction from 59% to 63%. 
     
     
         9 . The leaf spring of  claim 1 , wherein at least one of the fibers is formed from a material different from a material of other fibers. 
     
     
         10 . A leaf spring for a motor vehicle, comprising:
 at least two textile layers made of fibers and disposed on top of one another,   a dry binder arranged at least partially between the least two textile layers, and   a matrix formed of a hardened resin surrounding the fibers, wherein
 the textile layers are shaped inside a mold tool, 
 the dry binder is applied on at least one of the textile layers and the textile layers are fixed so as to form a dry preform, 
 the preform is infiltrated with the resin in an RTM (Resin Transfer Molding) cavity, and 
 the resin is hardened to produce the matrix formed of the hardened resin surrounding the fibers. 
   
     
     
         11 . A leaf spring for a motor vehicle produced by a method which comprises the steps of applying a binder on a textile web, cutting individual textile layers with the binder from the textile web, layering fibers in form of at least two of the textile layers with the binder on top of one another, shaping the textile layers with the binder inside a mold tool and melting the binder, fixing the textile layers by cooling the melted binder so as to form a dry preform, separating a fiber composite blank from the preform by stamping, infiltrating the fiber composite blank with resin in an RTM (Resin Transfer Molding) cavity, and hardening the resin to produce the leaf spring of individual fibers and a matrix formed of the hardened resin surrounding the fibers.