Abstract:
A method including: placing a first insert and a second insert in a casting mold and wherein the first insert and second insert including a plurality of connecting posts extending in between so that the first insert and second insert are in spaced-apart relationship in the mold, each of the first insert and the second insert including a first material; casting a molten second material into the casting mold so that the second material flows between the first insert the second insert and solidifying the second material.

Description:
TECHNICAL FIELD 
     The field to which the disclosure generally relates includes methods of joining different materials and products made therefrom. 
     BACKGROUND 
     Vehicles that include wheels such as, but not limited to, automobiles, trucks, buses, airplanes and the like typically include braking systems. Such braking systems commonly include drum or disc brake rotors. 
     SUMMARY OF EXEMPLARY EMBODIMENTS 
     One embodiment of the invention includes a method comprising: placing a first insert and a second insert in a casting mold and wherein the first insert and second insert comprising a plurality of connecting posts extending in between so that the first insert and second insert are in spaced-apart relationship in the mold, each of the first insert and the second insert comprising a first material; casting a molten second material into the casting mold so that the second material flows between the first insert and the second insert and solidifying the second material to provide a product comprising a cast over body portion with the first insert and second insert and so that the second material is mechanically locked or metallurgically bonded to the first material and so that one or both of the first insert and the second insert provides working surface for the product. 
     Other exemplary embodiments of the invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while disclosing exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  illustrates a braking wheel useful in a method according to one embodiment of the invention. 
         FIG. 2  illustrates a vented disc brake rotor including a braking wheel and a cast over body portion including a hub according to one embodiment of the invention. 
         FIG. 3  illustrates an insert with projections having a trapezoidal shape useful in making an brake rotor according to one embodiment of the invention. 
         FIG. 4  illustrates a non-vented disc brake rotor including a braking wheel and a cast over body portion including a hub according to one embodiment of the invention. 
         FIG. 5  illustrates a braking wheel for a drum rotor useful in a method according to one embodiment of the invention. 
         FIG. 6  illustrates a drum rotor including a braking wheel and cast over body portion including a hub according to one embodiment of the invention. 
         FIG. 7  illustrates a sectioned core insert useful in making a disc brake rotor according to one embodiment of the invention. 
         FIG. 8  illustrates a sectional plan view of a sectioned casting core overlying a portion of a braking wheel including an annular disc and post extending therefrom and wherein the post received in slots formed in the casting core according to one embodiment of the invention. 
         FIG. 9  illustrates a method of making a disc brake rotor according to one embodiment of the invention. 
         FIG. 10  illustrates placing a first annular disc insert in a casting mold in a method of making a brake rotor according to one embodiment of the invention. 
         FIG. 11  illustrates a casting core including a plurality of channels formed therein for use in a method according to one embodiment of the invention. 
         FIG. 12  illustrates a method of placing the casting core of  FIG. 10  in a casting mold according to one embodiment of the invention. 
         FIG. 13  illustrates an annular disc insert including locating features useful in a method according to one embodiment of the invention. 
         FIG. 14  illustrates a method of closing the casting mold and pouring molten material into the mold according to one embodiment of the invention. 
         FIG. 15  illustrates a vertical casting method including placing the first and second annular disc insert with locating feature in first and second mold halves respectively, and pouring molten material into the casting mold according to one embodiment of the invention. 
         FIG. 16  is a sectional, side view of an annular disc insert including a plurality of projections which may have a trapezoid-shape, L-shape or T-shape that is useful according to one embodiment of the invention. 
         FIG. 17A  is a perspective view with portions broken away of a brake rotor with straight vanes according to one embodiment of the invention. 
         FIG. 17B  is a perspective view with portions broken away of a brake rotor with pillar-type vanes according to another embodiment of the invention. 
         FIG. 17C  is a perspective view with portions broken away of a brake rotor with straight, tangential vanes according to another embodiment of the invention. 
         FIG. 17D  is a perspective view with portions broken away of a brake rotor with curved, tangential vanes according to another embodiment of the invention. 
         FIG. 18  is a sectional, side view of an annular insert including downwardly extending legs stamped out of the insert and useful in a method according to one embodiment of the invention. 
         FIG. 19  illustrates a sectional, side view of an annular insert including a tab stamped out of the insert including a downwardly extending leg portion and a foot useful in one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following description of the embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     Referring now to  FIG. 1 , one embodiment of the invention includes providing a braking wheel  10  which may include a first insert  12  and a second insert  14  which are maintained in spaced-apart relationship to each other by a plurality of posts  16  extending between the first insert  12  and the second insert  14 . In one embodiment, the first insert  12 , the second insert  14  and the posts  16  extending therebetween are cast from a single first material and are a continuous casting. The braking wheel  10  may be manufactured by casting, welding or other similar methods. 
     The braking wheel  10  may be utilized to make a disc brake rotor  18  shown in  FIG. 2 . The disc brake rotor  18  includes a cast over body  20  including a hub portion  22  and a second portion  24  extending between the first insert  12  and the second insert  14 . The second portion  24  of the cast over body  20  may cover the insert annular inner surface and the outer circumferential surfaces of the inserts  12 ,  14 . A plurality of vanes  26  or fins extending between the first insert  12  and the second insert  14  may define a plurality of vents  28  or channels therebetween to provide a vented brake rotor as shown in  FIG. 2 . The vanes  26  may be straight-shaped vanes, curved vanes, pillar-type vanes or any other type vane known to those skilled in the art. In one embodiment, each of the posts  16  of the brake wheel  10  may be surrounded by an associated vane  26  so that the cast over body  20  is mechanically locked to the brake wheel  10  or metallurgically bonded thereto at the post  16 . 
     The braking wheel  10  may be made from a first material, such as cast iron to provide a first braking surface  34  on an outer face of the first insert  12  and a second braking surface  36  on an outer surface of the second insert  14 . The cast over body  20  may be made of a second material that has a density and melting point less than that of the first material. In one embodiment of the invention the second material may include aluminum or alloy thereof. In one embodiment, all the exposed surfaces of the rotor comprise the second material except the two annular braking surfaces  34 ,  36  which comprise the first material. This arrangement prevents corrosion of the first material except at the exposed braking surfaces  34 ,  36 . However, any corrosion at the exposed braking surfaces  34 ,  36  may be removed by the brake pads rubbing against the braking surfaces  34 ,  36 . 
     Referring again to  FIG. 1 , in one embodiment, the post  16  and/or an inner surface  30  of the first insert  12  and/or an inner surface  32  of the second insert  14  may be treated, for example by applying a coating of graphite so that the inner surfaces  30 ,  32  and/or the posts  16  is wet by the molten second material and a metallurgical bond is formed between the cast over body portion and the inserts  12 ,  14  or post  16 . 
     Referring now to  FIG. 3 , in one embodiment the first insert  12  (or the second insert  14 ) includes a plurality of trapezoid-shaped projections  16 ′ extending from an inner surface  30  of the first insert  12  (or an inner surface  32  of the second insert  14 ) thereof and wherein the second material is mechanically locked to the first material at the projections during a casting process. At least one of the outer surface  34  of the first insert  12  (or the outer surface  36  of the second insert  14 ) provides a first braking surface. Still other embodiment of annular disc inserts with projections  16 ′ are illustrates in FIGS.  16 , 18  and  19 . 
     Referring now to  FIG. 4 , alternatively, the second portion  24  of the cast over body  20  may completely fill the space between the first insert  12  and the second insert  14  to provide a solid non-vented disc brake rotor  18 . 
     Referring now to  FIG. 5 , in another embodiment of the invention, the brake wheel  10  may be constructed and arranged to form a cylindrical inner wall  14  with projections  16 ′ extending from an outer surface  36 . In one embodiment the projection  16 ′ may have a trapezoid-shape, T-shape, L-shape, rectangular-shape and the like. Some examples of the designs for the projections  16 ′ are shown in  FIG. 16 . An inner face  32  of the cylindrical wall provides a braking surface. 
     Referring now to  FIG. 6 , the brake wheel  10  of  FIG. 5  may be utilized to provide a cast over body  20  defining a hub portion  22  and a second portion  24  to completely cover all the projections  16 ′ on the braking wheel  10  to provide a drum brake rotor  18 . 
     Referring now to  FIG. 7 , a casting core  42  may be utilized to make a vented disc brake rotor shown in  FIG. 2 . The casting core  42  may be a permanent metal core. In one embodiment the core  42  may be sectioned  45  into many pieces each of which may be slid between the first insert  12  and second insert  14  from a position associated with the outer diameter of the brake wheel  10  towards the center thereof. Each portion  44  of the core  42  may include at least one slot  46  formed therein having an open end  48  to receive the posts  16  extending between the first insert  12  and the second insert  14 . 
       FIG. 8  is a sectional, planer view of a braking wheel  10  including a first insert  12  and a plurality of posts  16  extending upwardly therefrom and portions  44  of a core  42  overlying the first insert  12 . During the casting operations, the slots  46  formed in each portion  44  of the core  42  will be filled with the second material to form vanes  26  extending between the first insert  12  and the second insert  14 . The vane  26  may capture the posts  16  or projections  16 ′ and be mechanically locked thereto or the posts or projections may be treated so that the second material used to form the vane  26  is metallurgically bonded to the posts  16  or projections  16 ′. The core  42  may then be removed to leave vents  28  or channels between vanes  26 . 
     Referring now to  FIG. 9 , one embodiment of the invention includes placing a braking wheel  10  and including a core  42  into at least one of a first portion  50  of a casting mold  49  or second portion  52  of a casting mold wherein the second portion  52  includes a projection  54  constructed and arranged to extend into the first portion  50  of a casting mold  49  to define the hub  22  of the brake rotor. The casting mold  49  may be a permanent metal mold. The material utilized for the braking wheel may be a first material such as cast iron and a second molten material  56  may be poured into the casting mold through a charge line  58 . The second molten material  56  may be of a second material such as aluminum which has a lower melting point and is lighter than the first material. The casting mold  49  may include a vent  60  and other features known to those skilled in the art. 
       FIGS. 10-14  illustrate another embodiment of making a brake rotor. The first insert  12  may be a separate annular disc  12  with trapezoidal projections  16 ′ as shown in  FIG. 16  and placed in the first portion of a casting mold  50 . Thereafter, a casting core  42  may be placed over the first insert  12  (as shown in  FIG. 12 ). The core  42  as shown in  FIG. 11  may be a single intact piece including a plurality of channels  46  formed therein and constructed and arranged to produce vanes  26  during the casting process.  FIG. 13  illustrates one embodiment of the invention in which the first insert  12  or the second insert  14  may include an annular disc portion  59  with locating features  106  on the braking surfaces  34 ,  36 . As shown in  FIG. 14 , in one embodiment each of the first portion  50  and second portion  52  of the casting mold  49  may include the locating features  64  working together with the locating features  106  on the inserts to hold the inserts in place in the mold for casting. For example a plurality of recesses  64  formed therein to receive the locating features  106  so that each of the first insert  12  and second insert  14  may be held in a designed position. In another embodiment the second portion  52  of the casting mold  49  may include a magnet  104  to hold the second insert  14  and then be placed over the first portion  50  to close the mold  49 , and the molten second material  56  may then be poured in through a charge line  58  to form a brake rotor having a cast over body  20  including a hub  22  and a second portion  24  (not shown) extending between the first insert  12  and the second insert  14 . The locating features  106  on the first insert  12  and the second insert  14  may be machined off later. The locating features  106  may also be constructed to rest on the shoulder of a specially designed mold and may be clamped onto by the mold halves. To make a non-vented disc brake rotor the core  42  is not used. 
     Referring now to  FIG. 15 , in another embodiment each of the first insert  12  and second insert  14  may be held in a vertical position. Molten material  56  may be poured into the casting mold  49  to provide a rotor including a cast over body portion  20  including a hub portion  22  and a second portion  24  extending between the first insert  12  and the second insert  14 , for example as shown in  FIG. 4 . 
       FIG. 16  illustrates one embodiment of a first insert  12  (or second insert  14 ) including a plurality of projections  16 ′ extending outwardly from a inner surface  30  of the first insert  12 . The first insert  12  may include an outer first braking surface  34 . The projections  16 ′ may be constructed and arranged so that a mechanical lock is provided when the second material is cast into the casting mold. The projections  16 ′ may have any of a variety of shapes. For example, the projection  16 ′ may be trapezoid-shaped, L-shaped, T-shaped or may have any shape providing a shoulder or surface against which the second material may be trapped and thereby preventing the first insert  12  (or second insert  14 ) from being pulled away from the second portion  24  of the cast over body  20 . 
       FIG. 17A  is a perspective view with portions broken away of a brake rotor according to one embodiment of the invention which includes straight vanes  26  with individual posts  16  trapped therein.  FIG. 17B  is a perspective view with portions broken away of a brake rotor according to another embodiment of the invention of a pillar-type design.  FIG. 17C  is a perspective view with portions broken away of a brake rotor according to another embodiment of the invention including tangential, straight aluminum vanes  26  with vane-shaped cast iron posts  16  trapped inside the aluminum vanes  26 .  FIG. 17D  is a perspective view with portions broken away of a brake rotor according to another embodiment of the invention including tangential, curved aluminum vanes  26  with individual cast iron post  16  trapped inside the vanes  26 . 
       FIG. 18  illustrates another embodiment of the invention including an insert  14  which includes a plurality of projections  16 ′ which may be formed by stamping a downwardly extending leg portion  68  out of the insert such as stainless steel or other material suitable for stamping. 
     As shown in  FIG. 19 , the projection  16 ′ may include a first bend  70  and second bend  72  therein to define a leg portion  68  and a foot portion  72  which may be substantially parallel to the main body portion  76  of the insert  14 . In one embodiment, the projection  16 ′ may be stamped out of the main body portion  76  of the insert  14  at a location that is not in use. 
     Various embodiments of the invention may include any design features as that in traditional brake rotor designs, e.g., cross drilled holes or other machined features on the rotor surface, as well as coatings or heat treatment of rotor surfaces and the like. Various surface treatments may be performed on the first insert  12 , second insert  14  and projections  16 ′ or posts  16  to improve the brake and/or rotor performance. 
     According to various illustrative embodiments of the invention, frictional damping may be achieved by the movement of the interfacing surfaces of the first material and the second material against each other. 
     One embodiment of the invention includes a product which may have a frictional damping means. In embodiments wherein at least a portion of at least one of inner faces  30 ,  32  of the inserts  12 ,  14  respectively, or the posts  16  may be coated with a material to product frictional damping. The coating may include fibers or particles that resist flowing when exposed to the temperature of a molten material such as in casting. 
     The above description of embodiments of the invention is merely exemplary in nature and, thus, variations thereof are not to be regarded as a departure from the spirit and scope of the invention.