Abstract: The invention relates to a piston for an internal combustion engine, having shaft wall sections on the pressure and counter-pressure side, and connecting walls between the shaft wall sections. The connecting walls are arched on the counter-pressure side, and the connecting walls are largely straight on the pressure side, such that the counter-pressure side is more elastic that the pressure side.

Abstract: A piston assembly and method of making the same are disclosed. An exemplary piston assembly may include a multi-piece skirt secured to a piston crown having a ring belt portion defining a cooling gallery. The crown may include one or more a struts extending away from the ring belt portion to define a wrist pin bore(s). The piston skirt assembly may include two separate portions that each have at least one skirt support securing the respective skirt portion to the strut. A cover plate may be provided that is secured between a radially inner surface of the ring belt portion of the crown and a radially outer surface of the strut, such that the cover plate defines in part the cooling gallery.

Abstract: Disclosed is a piston for internal-combustion engines, which includes a low thermal-conductive member disposed at the top portion thereof, the low thermal-conductive member including an alloy containing Fe and Mn. The low thermal-conductive member includes a sintered body having 10˜60 mass % of Mn, 2 mass % or less of C, and the balance of Fe and inevitable impurities. Since the piston has the low thermal-conductive member having low thermal conductivity and thermal expansion properties similar to those of the aluminum alloy, which is the base metal of the piston, an increase in the temperature of a combustion chamber and vaporization of fuel are effectively promoted. Furthermore, thermal fatigue failure and separation of the low thermal-conductive member are prevented.

Abstract: By casting a preformed member composed of a fiber reinforced material into a base material of a piston, a pair of crown reinforcing portions corresponding to respective pin boss portions are formed on a crown portion, and the pair of crown reinforcing portions are connected to each other along the piston pin axis by a connecting portion. Thus, the strength of the piston is increased by the crown reinforcing portions, and also, heat distortion of the crown portion is inhibited since the crown reinforcing portions integrally connected to each other by the connecting portion are formed so as to serve as a rigid member extending along the piston pin axis.

Abstract: The aim is to improve the strength of an intermetallic bond between engine component made from an aluminium alloy and a reinforcing element made from austenitic cast iron. For that purpose, the reinforcing element is annealed in a decarbonising atmosphere before the known prior art alfin process is carried out, in order to obtain an alfin layer largely free of graphite scales.

Abstract: A cast piston having a metal insert that includes a cooling gallery and defines a piston ring groove. The piston insert includes an annular base having an annular cavity formed therein and an annular ring which extends radially outward from the base. A cast piston is fabricated by positioning the piston insert in a piston mold and casting a piston. After the piston is cast, the piston groove ring is machined in a portion of the annular ring and at least one channel is formed between the annular cavity and a bottom portion of the piston. In use, a cooling fluid is directed through the at least one channel and into the annular cavity.

Abstract: A piston, e.g. for an internal combustion engine, comprises a crown (16) and a skirt (12). The skirt (12) has an aperture (22) in which an insert (14) of a different material from the remainder of the skirt is secured. The insert (14) may be of plastics material injection moulded into a metal skirt. The insert (14) provides a plurality of pads (34) which extend from a thrust surface of the skirt so that the pads can transmit lateral forces and cause lubricant to be forced over the pads by hydrodynamic action during reciprocation of the piston.

Abstract: A piston having a head with ring grooves, a skirt having hub bores, and a pin, with the following dimensions:L/D=0.45-0.8H/D=0.25-0.5A/D=0.3-0.5T/D=0.45-0.8whereL=maxium length of the pistonD=maximum diameter of the pistonH=compression heightA=maximum skirt height below the bottom ring groove in a peripheral area having the approximate same skirt height of at least 45 degrees on the major thrust face of the piston with approximately symmetrical division of this area on both sides of a plane extending perpendicular to the pin axis and passing through the longitudinal axis of the piston,T=diametrically opposite distance between the hub bore ends located radially on the outside.The skirt bulges along the axis of the piston and has an oval cross-section. An axis of the hub bores is offset slightly towards the major thrust face. The piston includes a horizontal slit, which separates the head from the skirt. In a polar plane perpendicular to the piston axis the skirt has a greater ovality on the minor thrust face.

Abstract: The technical problem is to reduce the operating noise of such a piston. It is solved by means of a piston having the following dimensions: a) A=(0.45-0.65) D; b) H=(0.25-0.4) D; c) A=(0.3-0.4) D; d) A greater than or equal to B; e) T=(0.45-0.8) D; f) the piston ribs between the annular grooves (2, 3, 4) and the rod region with a very narrow operating clearance have, in the case of a hot operating piston, approximately the same clearance in relation to the cylinder operating path. An additional improvement consists in inserting an annular jacket in the piston head in the radial region behind the annular grooves, said jacket consisting of a material having a thermal expension factor less than that of the basic piston material. In a hot operating internal combustion engine, the piston has, in the region of the ribs, a clearance which, in the direction pressure/counter-pressure reaches approximately only 3-5 times the clearance in the very narrow clearance region of the piston rod.

Abstract: A linear hydraulic actuator of small size having limited clearance between the inside of the cylindrical housing and the outside of the piston rod is provided with a deformable or frangible piston of an engineered plastic material which is sufficiently strong to survive normal operation of the actuator but which will break or deform if the cylinder is punched through or "petalled" causing inward projections tending to block movement of the piston. Another embodiment discloses a plastic end gland which is frangible, or deformable in the event of an impact deforming the rod such that it would not pass through the end gland except for such deformation. Because of the relative weakness of the plastic material, the width of the land on the piston acting against the inside of the cylinder is maximized by placing the dynamic seals at or near its outside circumferential edges.

Abstract: The external profile of a piston rod employed in the engines of passenger cars ensures smoother piston travel on start-up and during partial loading. In these operating ranges, piston ring parts may impact on the sliding surface of the cylinder on the counter-pressure side and give rise, amongst other things, to undesirable noise. To obviate such impacts, the piston rod tapers at the end facing the crankshaft space on the counter-pressure side, and has a transversal slit (3) at its junction with the piston head and an adjustment strip (4) in the vicinity of the said slit. An additional adjustable strip (5) may also be provided in the lower part of the rod, on the pressure side. As a result of the position of the adjustment strips, the special design of the piston and the special shape of the rod casing, the piston head aligns itself at a slight angle to the counter-pressure side, with increasing play between the piston head and the sliding surface of the cylinder in the said operating ranges.

Abstract: A light metal piston for internal combustion engines has a pair of inserts on the inside of upper piston skirt made of a material of lower thermal expansion coefficient than that of the light metal, such as steel. Each insert has a pair of bands which are joined by a connecting portion of the insert in the region of the gudgeon pin boss. Each band extends circumferentially away from the gudgeon pin boss, so as to control thermal expansion of the piston skirt. A free end of each band are bent inwardly, so that the insert can be set firmly on the mold core of the piston during casting operation by snapping the bent portions of the insert into the grooves on the mold core.

Abstract: In expansion-controlled light alloy pistons for internal combustion engines, expansion control elements made of steel are bonded to the carrying portions of the cast skirt on the inside peripheral surface thereof and are embedded in the hubs of the piston pin bosses. To provide for an optimum expansion control action throughout the height of the piston skirt, the expansion control elements are provided on both sides of the plane of oscillation of the connecting rod with an aperture, which is open toward the end of the skirt and has a height amounting to at least 30% of the height of the expansion control elements. Said aperture has a peripheral dimension amounting to more than 10% of the piston diameter. Projections for supporting the expansion control element at its edges defining the aperture protrude into the latter.

Abstract: A piston for internal combustion engines made of a light alloy and comprising a skirt portion and a head portion, having a ceramic insert adapted on the head portion and connected to same by mechanical locking. The ceramic insert is provided with pores at least on the portion engaging the piston head. The pores have a size which enable them to be filled with the light alloy during the manufacture of the piston by the squeeze casting method.

Abstract: A piston made of cast aluminum base alloy is provided with gudgeon pin bosses which are connected to the piston skirt by means of a frusto-conical strut which has recesses in the skirt and are specially dimensioned to leave large unsupported skirt areas to minimize risk of seizure in an engine cylinder; in particular the distance between the outer surfaces of the bosses is from 0.6 to 0.8 of the outer diameter of the piston and the distance between the inner surfaces of the bosses is 25 to 35 percent of the outer diameter of the piston, and the cone angle of the struts is from 60.degree. to 110.degree..

Abstract: A piston carries on its skirt surface a number of separate strips of a plastics material, such as a polyetheretherketone alloy, so that the strips are hydrodynamically lubricated and transmit lateral thrust from the piston to an associated cylinder or liner. The strips are just proud of the skirt surface and may be contained in recesses formed in the skirt surface.

Abstract: In a plunger piston for internal combustion engines, having a regulating strip in the piston body, the regulating strip is arranged in the axial middle third of the height of the piston body and the regulating effect is designed so that the piston body possesses its narrowest installation play uniformly at the level of the regulating strip equally in the cold installation state and in the engine operation. Above and below this region with minimum installation play the piston body possesses spherically retracted end regions at its upper and lower ends for the generation of hydrodynamic lubricant oil wedges.

Abstract: An integral strut and groove protector assembly is provided for incorporation within a light metal piston. The assembly includes a ring groove protector, an expansion control strut, and a connecting member connecting the groove protector and strut. All are stamped as one piece from a sheet metal substrate. The piston is cast about two such assemblies arranged in opposing relation within a mold. Each ring groove protector traverses an arc of somewhat less than one hundred eighty degrees to facilitate the manufacturing process.

Abstract: A piston mainly composed of an aluminium alloy for use in a cylinder of aluminium alloy. The piston is provided with one or more inserts of ferritic steel. The insert or inserts extend across opposed thrust faces of the piston and form part of the running surface of the piston skirt.

Abstract: A cast light metal piston has a plurality of longitudinally extending reinforcing members. These reinforcing members may be disposed at predetermined positions in the piston as cast and are designed to impart a compressive stress to the material of the piston in the regions where the reinforcing members are located. Conveniently, the reinforcing members may be located adjacent the opposite sides of each of a pair of gudgeon pin holes provided in the skirt of the piston.

Abstract: A light metal piston for an engine or compressor has two sheet steel inserts. Each insert has two pairs of elongated bands extending circumferentially away from a gudgeon pin boss. The bands nearer the crown end of the piston skirt are longer than those nearer the open end of the skirt, and preferably are also wider, so as to exert greater thermal expansion control nearer the crown end of the skirt than nearer the open end.