Parent bore cylinder block of an opposed-piston engine
A parent bore cylinder block of an internal combustion, opposed-piston engine includes cooling passages that are formed using a 3-D printed casting core. The casting core can include portions that are ceramic. The parent bore cylinder block can include multiple cylinders, each cylinder with cooling passages and turbulence inducing features in those cooling passages, particularly surrounding the central portions of the cylinders.
1. A parent bore cylinder block of an opposed-piston internal combustion engine, comprising:
a cylinder in the parent bore cylinder block including a cylinder bore with a bore surface and a longitudinal axis;
a combustion zone in an intermediate portion of the cylinder along the longitudinal axis of the cylinder bore; and
a cooling jacket wall of the parent bore cylinder block surrounding the combustion zone on an outside portion of the cylinder, the cooling jacket wall enclosing cooling features;
wherein the parent bore cylinder block is cast from a single type of metal or metal alloy.
2. The parent bore cylinder block of claim 1 , further comprising longitudinally separated intake and exhaust ports of the cylinder each port comprising:
an array of adjacent port openings in the parent bore cylinder block arranged along a respective circumference of the cylinder in a respective plenum of the engine; and
a port bridge between each pair of adjacent port openings.
3. The parent bore cylinder block of claim 2 , further comprising a cooling passage for conducting coolant through at least one port bridge of the exhaust port.
4. The parent bore cylinder block of any one of claims 1 - 3 , wherein the parent bore cylinder block is made of a single metal casting.
5. The parent bore cylinder block of claim 4 , wherein the port openings are cast features in the parent bore cylinder block.
6. The parent bore cylinder block of claim 1 , wherein the cooling features comprise any of pegs, walls, ridges, ribs, and other protrusions from an outer wall of the cylinder that are configured to create a coolant flow path for cooling fluid.
7. The parent bore cylinder block of claim 6 , wherein the cooling features include a spacing of about 5 mm.
8. The parent bore cylinder block of claim 1 , wherein the cylinder bore comprises one or more machined features.
9. The parent bore cylinder block of claim 2 , wherein the exhaust plenum is an exhaust gas plenum chamber into which all of the exhaust port openings open from the interior of the cylinder.
10. An opposed-piston engine, comprising:
a parent bore cylinder block;
the parent bore cylinder block comprising:
at least one cylinder with a cylinder bore, a bore surface, and a longitudinal axis;
a combustion zone in an intermediate portion of the at least one cylinder, along the longitudinal axis of the cylinder bore;
a cooling jacket wall of the parent bore cylinder block surrounding the combustion zone on an outside portion of the cylinder, the cooling jacket wall enclosing a coolant flow path; and
longitudinally separated intake and exhaust ports of the at least one cylinder, each port comprising an array of circumferentially-spaced adjacent port openings in the parent bore cylinder block from the cylinder bore to an intake plenum and to an exhaust plenum, respectively, and a port bridge between each pair of adjacent port openings;
wherein the parent bore cylinder block is cast from a single type of metal or metal alloy.
11. The opposed-piston engine of claim 10 , wherein each pair of opposed-pistons is configured to move across and open and close the ports, further wherein a combustion chamber is defined in the combustion zone between end surfaces of the pistons as the pistons approach respective top center locations.