PISTON COMPRESSION RINGS OF COPPER ALLOYS
A piston ring is made from a copper-nickel-silicon-chromium alloy. This material permits the top compression ring of a piston to be moved closer to the piston crown, reducing crevice volume and reducing the tendency for pre-ignition. Ignition timing advance can be realized by installing the rings and letting the ECU advance the timing as the sensors allow, increasing efficiency. Also, shorter pistons and longer connecting rods are possible. The shorter pistons reduces the reciprocated mass in the engine and the longer connecting rods reduce the frictional loss caused by radial forces pushing the piston against the liner. Both reducing volume and tendency for pre-ignition increase engine efficiency.
1 . A piston ring formed from a copper-containing alloy that comprises copper, nickel, silicon, and chromium.
2 . The piston ring of claim 1 , wherein the copper-containing alloy is a copper-nickel-silicon-chromium alloy that contains:
about 5 wt % to about 9 wt % nickel;
about 1 wt % to about 3 wt % silicon;
about 0.2 wt % to about 2.0 wt % chromium; and
balance copper.
3 . The piston ring of claim 1 , wherein the copper-containing alloy is a copper-nickel-silicon-chromium alloy that contains:
about 6 wt % to about 8 wt % nickel;
about 1.5 wt % to about 2.5 wt % silicon;
about 0.3 wt % to about 1.5 wt % chromium; and
balance copper.
4 . The piston ring of claim 1 , wherein the copper-containing alloy is a copper-nickel-silicon-chromium alloy that contains:
about 6.4 wt % to about 7.6 wt % nickel;
about 1.5 wt % to about 2.5 wt % silicon;
about 0.6 wt % to about 1.2 wt % chromium; and
balance copper.
5 . The piston ring of claim 1 , wherein the piston ring consists essentially of the copper-containing alloy.
6 . The piston ring of claim 1 , wherein the piston ring is uncoated.
7 . The piston ring of claim 1 , having a rectangular or trapezoidal cross-section.
8 . The piston ring of claim 1 , having a butt cut, an angle cut, an overlapped cut, or a hook cut.
9 . The piston ring of claim 1 , wherein the piston ring weighs up to about 0.25 pounds to about 0.25 pounds.
10 . The piston ring of claim 1 , wherein the piston ring weighs from about 0.25 pounds to about 1.0 pound.
11 . A piston assembly, comprising:
a piston body comprising a top ring groove; and
a piston ring in the top ring groove, the piston ring being formed from a copper-containing alloy that comprises copper, nickel, silicon, and chromium.
12 . The piston assembly of claim 11 , wherein the copper-containing alloy is a copper-nickel-silicon-chromium alloy that contains:
about 5 wt % to about 9 wt % nickel;
about 1 wt % to about 3 wt % silicon;
about 0.2 wt % to about 2.0 wt % chromium; and
balance copper.
13 . The piston assembly of claim 11 , wherein the copper-containing alloy is a copper-nickel-silicon-chromium alloy that contains:
about 6 wt % to about 8 wt % nickel;
about 1.5 wt % to about 2.5 wt % silicon;
about 0.3 wt % to about 1.5 wt % chromium; and
balance copper.
14 . The piston assembly of claim 11 , wherein the copper-containing alloy is a copper-nickel-silicon-chromium alloy that contains:
about 6.4 wt % to about 7.6 wt % nickel;
about 1.5 wt % to about 2.5 wt % silicon;
about 0.6 wt % to about 1.2 wt % chromium; and
balance copper.
15 . The piston assembly of claim 11 , wherein the piston ring has a rectangular or trapezoidal cross-section.
16 . The piston assembly of claim 11 , wherein the piston ring weighs up to about 0.25 pounds to about 0.25 pounds.
17 . The piston assembly of claim 11 , wherein the piston ring weighs from about 0.25 pounds to about 1.0 pound.
18 . A method of improving engine efficiency, comprising using a piston assembly in an engine, the piston assembly comprising:
a piston body comprising a top ring groove; and
a piston ring in the top ring groove, the piston ring being formed from a copper-containing alloy that comprises copper, nickel, silicon, and chromium.
19 . The method of claim 18 , wherein the copper-containing alloy is a copper-nickel-silicon-chromium alloy that contains:
about 5 wt % to about 9 wt % nickel;
about 1 wt % to about 3 wt % silicon;
about 0.2 wt % to about 2.0 wt % chromium; and
balance copper.
20 . A method of making a piston ring, comprising:
forming the piston ring from a copper-containing alloy that comprises copper, nickel, silicon, and chromium.