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AssigneesAutomobiles Peugeot, Automobiles Citroen
InventorJean Dupin
Estimating the term…
The present invention concerns essentially a method for moulding a rocker arm for an internal combustion engine and the mould structure for carrying out this method, which mould structure comprises a device for maintainiing a ceramic reinforcing element of the arm of the rocker arm co-operating with the cam of a camshaft and comprising a spindle-forming part disposed on the end of the reinforcing element and a pusher-forming assembly located above the spindle-forminig part to forcibly urge the latter against the reinforcing element.
A method for casting a rocker arm made of a light metal alloy for an internal combustion engine, said rocker arm including a lever body an arm of which, intended to co-operate with a cam of an engine camshaft, has a ceramic reinforcing element having an external convex friction surface intended to contact said cam;
The method of claim wherein said rocker arm includes opposite the reinforcing element and having a plane surface perpendicular to a longitudinal axis of the reinforcing element.
A mold structure having two half-molds, one top half-mold and one bottom half-mold for casting a rocker arm made of a light metal alloy for an internal combustion engine, said rocker arm including a lever body an arm of which, intended to co-operate with a cam of an engine camshaft, has a ceramic reinforcing element having an external convex friction surface intend to contact said cam;
A mold structure including two half-molds, one top half mold and one bottom half mold for casting a rocker arm made of a light metal alloy for an internal combustion engine, said rocker arm including a lever body an arm of which, intended to co-operate with a cam of a camshaft, has a ceramic reinforcing element having an external convex friction surface intended to contact said cam;
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
No references of this kind are recorded.
Materials for constructing engines or their parts: ceramic materials
Dies ; Die plates; Die supports; Cooling equipment for dies; Accessories for loosening and ejecting castings from dies: accessories for locating…
Casting in, on, or around objects which form part of the product
Rocking arms or levers: centre pivot rocking arms
Term ended 6 Apr 2008 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention concerns a method for moulding a rocker arm for an internal combustion engine, a mould structure for carrying out such a method as well as a rocker arm obtained according to the moulding method.
The invention concerns also a method for machining the rocker arm obtained from the moulding method as well as a rocker arm obtained according to the machining method.
There are known rocker arms of the type comprising a lever body with a first arm co-operating with a cam of a camshaft of the engine and with a second arm co-operating with a valve spindle, the lever body, made of a light metal alloy, being obtained by a chilled diecasting method. The arm which co-operates with the cam comprises an extremely hard reinforcing element which withstands the wear caused by friction with the cam which is inserted during the moulding inside the rocker arm made of light metal alloy. To this end, the reinforcing element is made of sintered material. carbide or special cast iron.
For a fuller understanding of the invention, reference is made to the following description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a longitudinal cross-sectional view showing in particular the device for maintaining the ceramic reinforcing element inside the mould structure according to the invention;
FIG. 2 is a cross-sectional view of the end of the arm of the rocker arm provided with the ceramic reinforcing element; and
Referring to FIG. 1, the mould structure 1 for the pressure diecasting of the light metal alloy forming the rocker arm comprises two boxes, one top box and one bottom box, the bottom box 2 only being shown in the Figure.
The numeral 3 designates a ceramic reinforcing element which is to be rendered solid, after moulding, with the arm of the lever body of the rocker arm co-operating with a cam of a camshaft of an internal combustion engine. This reinforcing element comprises a friction surface 3a intended to co-operate with the cam and previously polished according to a known method. This friction surface presents a bellied or convex shape which fits into a corresponding recess 2a of the bottom box 2. The reinforcing element 3 comprises further an anchoring end-forming part 3b of the element at the end of the arm of the rocker arm co-operating with the cam and located opposite the friction surface 3a.
According to the invention, a pusher-forming device 4 exerts a thrust on a spindle-forming part 5 so as to forcibly urge the latter against the anchoring end-forming part 3b of the reinforcing element 3. The spindle-forming part 5 located along the longitudinal axis of the reinforcing element 3 is preferably circular in cross-section, any other cross-sectional shape (oval, rectangular and so on) being also appropriate.