摘要 |
<p>A piston for an internal combustion engine comprising a piston body (1) and a crown portion (3) that are connected by anchoring means comprising elongate members (7, 23, 26, 79, 80) that extend from the crown portion (3) into the piston body (1) so as to transmit tensile and compressive loads from the crown to a portion of the piston body in a region spaced axially away from the crown portion at a temperature which, at maximum operating temperatures, is low enough to prevent loosening of the anchoring means, characterized in that cooperating surfaces of said anchoring means (7, 9, 16) and piston body (1) are pre-loaded into contact with one another by virtue of strain energy stored in the anchoring means and piston body (1) and which acts axially to prevent parting of said cooperating surfaces by said tensile and compressive loads without being dependent on any reaction forces between the adjacent faces of the crown portion and piston body. Said anchoring means may comprise at least one member (7) that is inserted into a bore (12) in the piston body and is rigidly connected axially to the crown portion (3) at one end and rigidly axially connected to said portion of the piston body at its other end. Alternatively, said anchoring means may comprise at least one strut member (79) that extends from the crown portion (3) into a bore (82) in the piston body (1) so as to absorb compressive forces therebetween and thereby relieve compressive loading of the adjacent faces of the piston body (1) and crown portion (3), and at least one tie member (80) that is connected between the piston body (1) and crown portion (3) to restrain separation and that is pre-loaded in tension.</p> |