Spark ignition engine, pre-chamber, and method for cooling a pre-chamber
A spark ignition engine includes: a pre-chamber (PC); a main chamber (MC); and a cylinder head coupled with a water jacket. The PC includes: a spark plug; and a PC body. The spark plug is surrounded by a jacket with thermal-conductive substance. The thermal-conductive substance is solid at room temperature and liquid at working temperature of the PC. At working temperature of the PC, the liquid thermal-conductive substance conducts heat from the spark plug to the water jacket. The PC body is coated with a layer of non-thermal-conductive substance.
1. A spark ignition engine comprising: a pre-chamber (PC); a main chamber (MC); and a cylinder head coupled with a water jacket,
wherein the PC comprises: a spark plug; and a PC body,
wherein the spark plug is surrounded by a jacket with thermal-conductive substance,
wherein the thermal-conductive substance is solid at room temperature and liquid at working temperature of the PC,
wherein, at working temperature of the PC, the liquid thermal-conductive substance conducts heat from the spark plug to the water jacket,
wherein the PC body is coated with a layer of non-thermal-conductive substance,
wherein the spark plug comprises a thread extending in a direction along an axis of the PC body,
wherein the jacket surrounds the spark plug in the direction along the axis, and
wherein the jacket does not extend beyond a lowest level of the thread in the direction along the axis.
2. The spark ignition engine according to claim 1 ,
wherein the PC further comprises a PC cap disposed at an interface between the PC and the MC,
wherein the PC cap comprises a plurality of holes that connect an inner space of the PC to the MC.
3. The spark ignition engine according to claim 2 , wherein the PC cap is thermal-conductive and forms a thermal bridge with the PC body.
4. A pre-chamber (PC) of a spark ignition engine, the PC comprising: a spark plug; and a PC body,
wherein the spark plug is surrounded by a jacket with thermal-conductive substance,
wherein the thermal-conductive substance is solid at room temperature and liquid at working temperature of the PC,
wherein, at working temperature of the PC, the liquid thermal-conductive substance conducts heat from the spark plug to the water jacket,
wherein the PC body is coated with a layer of non-thermal-conductive substance,
wherein the spark plug comprises a thread extending in a direction along an axis of the PC body,
wherein the jacket surrounds the spark plug in the direction along the axis, and
wherein the jacket does not extend beyond a lowest level of the thread in the direction along the axis.
5. The PC according to claim 4 , further comprising a PC cap disposed at an interface between the PC and a main chamber (MC) of the spark ignition engine,
wherein the PC cap comprises a plurality of holes that connect an inner space of the PC to the MC.
6. The PC according to claim 5 , wherein the PC cap is thermal-conductive and forms a thermal bridge with the PC body.
7. A method for cooling a spark ignition engine, wherein the spark ignition engine comprises: a pre-chamber (PC); a main chamber (MC); and a cylinder head coupled with a water jacket, and wherein the PC comprises: a spark plug; and a PC body, the method comprising:
surrounding the spark plug with a jacket containing thermal-conductive substance; and
coating the PC body with a layer of non-thermal-conductive substance,
wherein the thermal-conductive substance is solid at room temperature and liquid at working temperature of the PC, and
wherein, at working temperature of the PC, the liquid thermal-conductive substance conducts heat from the spark plug to the water jacket,
wherein the spark plug comprises a thread extending in a direction along an axis of the PC body,
wherein the jacket surrounds the spark plug in the direction along the axis, and
wherein the jacket does not extend beyond a lowest level of the thread in the direction along the axis.
8. The method according to claim 7 ,
wherein the PC further comprises a PC cap disposed at an interface between the PC and the MC,
wherein the PC cap comprises a plurality of holes that connect an inner space of the PC to the MC.
9. The method according to claim 8 , wherein the PC cap is thermal-conductive and forms a thermal bridge with the PC body.