Abstract:
The preset invention provides a ceramic adjusting shim capable of minimizing the abrasion of parts contacting the adjusting shim, for example, a cam and a tappet. The ceramic adjusting shim is produced from a ceramic material and has a surface roughness of 0.05 to 0.2 .mu.m in ten-point average roughness Rz.
Abstract:
The present invention provides an improved adjusting shim used in a valve train for an internal combustion engine for an automobile. The adjusting shim produced from a base material consisting of a ceramic material containing 80 to 98 wt. % of silicon nitride and/or sialon and has a porosity of not more than 3%, a bending strength of not less than 1.0 GPa and an impact compressive elastic limit (Hugoniot elastic limit) of not less than 15 GPa, wherein the base material is provided on the surface thereof which contacts a cam with a ceramic surface layer having a composition different from that of the base material and a hardness lower than that of the base material. The adjusting shim of the present invention enables a power loss of a valve train to be minimized; the abrasion resistance thereof to be improved; and the fuel economy, the performance and durability of an internal combustion engine to be improved.
Abstract:
A valve mechanism for an internal combustion engine with a four-valve, double-overhead camshaft (DOHC) valve train in which the axes of valves for each cylinder diverge outwardly from and are non-parallel with respect to the axis of the cylinder, the valve mechanism having a finger follower for each camshaft lobe and valve and with a contact pad between the cam and the finger follower to permit rocking movement so that the orientation of the finger follower and the axis of the valve remains at a fixed relationship.
Abstract:
To make a sintered member having a molybdenum-containing wear-resisting layer it is known to compact a low-alloy iron powder for forming the body of said member and a non-alloyed iron-base metal powder, which contains molybdenum and is intended to form the wear-resisting layer, so as to form a shaped member, which is subsequently sintered. In order to reduce the manufacturing costs, it is proposed that in such process the metal powder for forming the wear-resisting layer contains a low-alloy iron powder and 10 to 30% by weight molybdenum and contains a total of 1.5 to 3.0% by weight carbon and phosphorus, carbon and phosphorus are optionally contained as alloying constituents in the iron powder of said metal powder in a total amount of 0.3 to 0.7% by weight, and the shaped member consisting of the body and the wear-resisting layer is subjected to liquid-phase sintering at temperatures from 1070.degree. to 1130.degree. C.
Abstract:
A shank of the valve reciprocates within a hydraulic fluid-receiving chamber, and a cap, detachedly confined with the chamber cooperates with the shank to define a dashpot. The dashpot serves to decelerate the final closing of the valve to minimize wear of the valve head and the seat against which it closes.
Abstract:
The specification describes a camshaft arrangement which opens a load-change valve of an internal combustion engine includes a camshaft having a projection which extends beyond what is otherwise a circular cross-section. The camshaft projection limits the relative angular motion between the camshaft and the cam element and includes a buffer which may comprise elastic material or a piston which interacts with a hydraulic medium. The buffer acts to cushion the approach motion of the camshaft projection and the inner wall, or stop, of the cam element, to prevent undesirable noise produced by, or wear of, the camshaft arrangement.
Abstract:
In a tappet structure in which a rotary movement is transformed into an axial movement by way of a cam, the tappet structure has a metallic tappet body, an inside of which has a hollow portion in a manner to have an opening at one end of the tappet body. A friction-resistant ceramic plate is integrally fixed to the open end of the tappet body by means of brazing, so that the cam can frictionally slide on the ceramic plate to move the tappet body axially.
Abstract:
A fuel injector controlled by electro-rheological valving is disclosed. The present invention comprises a cylindrical casing having a compression chamber for holding a metered quantity of fuel and a nozzle for injecting said fuel into an engine; a fuel inlet for supplying a metered quantity of fuel to said compression chamber; an outlet coupled to said compression chamber for permitting fuel to exit said chamber to be recirculated back to said inlet; reciprocating plunger means for driving compression fluid into said nozzle and outlet; and electro-rheological valve means for controlling the flow of fuel through said outlet whereby the amount of fuel injected into said nozzle is precisely metered.
Abstract:
In the embodiments disclosed in the specification, a valve mechanism, preferably for an internal combustion engine, includes a valve spring guide sleeve which receives a cup plunger and has a supply passage for a hydraulic pressure medium in one wall. The guide sleeve at least partially encloses the valve spring and the supply passage is disposed unilaterally in the guide sleeve which has a smaller wall thickness on the side away from the supply passage.
Abstract:
A method for forming extremely strong ceramic-to-metal joints is provided which is particularly applicable to the formation of components for internal combustion engines. The present method simultaneously brazes a ceramic to a metal and creates a normallized microstructure and desired mechanical in the metal in a single heating step. The ceramic is metallized, a suitable alloy is applied, and the ceramic-alloy-metal composite is first heated to about 160.degree. F. to 1750.degree. F. for about one hour and then gas quenched in nitrogen or argon, or a gas with similar heat transfer capabilities.