Spark plug with built-in precombustion chamber

Claim 2

A spark plug comprising: an electrically conductive shell member (15); a precombustion chamber (13) formed within said shell member (15), said shell member having a gas passage (16) leading out from said precombustion chamber (13); an elongated electrically insulating sleeve (8) extending in a direction away from said gas passage (16) and precombustion chamber (13); electrode means (12,14) at least partially located within said precombustion chamber (13); means for feeding fuel into said precombustion chamber (13) for ignition by said electrode means, said fuel feeding means including means (5) defining an elongated fuel passage passing substantially axially through said elongated insulating sleeve (8) and terminating at said precombustion chamber (13); and means (2) for feeding fuel to the end of said fuel passage defining means (5) remote from said precombustion chamber (13); and metering means at the end portion of said fuel passage defining means (5) which is remote from said precombustion chamber (13) for adjustably metering the feeding of fuel to said precombustion chamber (13), said metering means including a variable diameter rod means (3) selectively communicating with the interior of the defined fuel passage, said rod means (3) being movably mounted relative to said fuel passage defining means (5) for movement in the axial direction of said fuel passage, said rod means having at least two portions (3b,3c) of different diameters and being movable responsive to vacuum in said precombustion chamber (13) for selectively communicating said different diameter portions with said fuel passage defining means (5) for varying the size of the fuel feeding passage in the vicinity of said rod means between a minimum fuel flow position at which a predetermined minimum amount of fuel is permitted to flow through said fuel passage and a maximum fuel flow position at which a predetermined maximum amount of fuel is permitted to flow through said fuel passage, and biasing means (4) biasing said rod means (3) relative to said fuel passage defining means (5) such that said metering means is in said maximum fuel flow position under low vacuum conditions in said precombustion chamber and is in said minimum fuel flow position under high vacuum conditions in said precombustion chamber.

Claim 3

A spark plug according to claim 1 wherein said electrode means includes two electrodes (12,14), at least one (14) of which is coupled to said electrically conductive shell (15).

Claim 4

A spark plug according to claim 2 wherein said insulating sleeve (8) carries the other (12) of said electrodes.

Claim 5

A spark plug according to claim 3 wherein said means for feeding fuel to said precombustion chamber includes valve means at the remote end of said tubular member (5) for selectively blocking the supply of fuel to said precombustion chamber (13).

Claim 6

A spark plug according to claim 4 wherein said valve means is located to selectively block the supply of fuel to said tubular member (5).

Claim 7

A spark plug according to claim 4 wherein said valve means is coupled to said metering means and blocks the supply of fuel when vacuum in said precombustion chamber falls below a predetermined value.

Claim 8

A spark plug according to claim 6 wherein said valve means includes a seat member in said fuel passage upstream of said metering means; and a valve member (3a) located in the fuel passage and biased under the influence of said metering means biasing means (4) toward said seat member.

Claim 9

A spark plug according to claim 7 wherein said valve member (3a) is connected to an end of said rod means.

Claim 10

A spark plug according to claim 8 wherein said rod means includes a first portion (3c) having a first diameter and a second portion (3b) having a second diameter larger than said first diameter, said first and second rod portions being connected end-to-end in axial alignment with each other and with said fuel passage, said first rod portion (3c) being oriented closer to said precombustion chamber (13) than said second rod portion and communicating with said fuel passage during increase of said vacuum before said second rod portion, and said valve member (3a) is connected to the free end of said second rod portion (3b).

Claim 11

A spark plug according to claim 9 wherein said first and second portions (3c,3b) and said valve member (3a) are integrally formed as a one-piece member (3).

Claim 12

A spark plug according to claim 1 wherein said insulating sleeve (8) defines a portion of said precombustion chamber (13).

Claim 13

A spark plug according to claim 1 wherein said fuel passage defining means includes an electrically conducting tubular member (5) passing through and carried by said elongated insulating sleeve (8).

Claim 14

A spark plug according to claim 12 wherein said electrode means includes two electrodes (12,14), one electrode (14) being connected to said shell (15); and the other electrode (12) being electrically connected to said tubular member (5).

Claim 15

A spark plug according to claim 12 further comprising a further check valve (9,10) at the end of said tubular member 5 closest to said precombustion chamber (13) for preventing back flow of the fuel-air mixture and combustion gas into the fuel passage, said check valve including means (10) in the fuel flow path for at least partially atomizing fuel at least just prior to its entry into said precombustion chamber (13).

Claim 16

A spark plug according to claim 12 including thermal expansion compensation means (7) coupled to said tubular member (5) and to said electrically insulating sleeve (8) for compensation of differential longitudinal expension and contraction between said tubular member (5) and said insulating sleeve (8).

Claim 17

A spark plug according to claim 13 comprising means (5,6) for coupling high voltage to said other electrode (12), said high voltage coupling means including said elecrically conducting tubular member (5).

Claim 18

A spark plug according to claim 13 wherein said tubular member (5) has an opening substantially in the center of the upper wall of said precombustion chamber, which upper wall is remote from said gas passage (16), and comprising an electrically conductive cross-member (17) connected to a portion of said tubular member defining said opening and spanning a portion of said opening, said other electrode (12) being coupled to and carried by said electrically conductive and cross-member (17).

Claim 19

A spark plug according to claim 17 wherein said opening is substantially round and said electrically conductive cross-member (17) comprises a generally bar-shaped member spanning said opening substantially along a diameter thereof.

Claim 20

A spark plug according to claim 1 wherein said rod means includes a first portion (3c) having a first diameter and a second portion (3b) having a second diameter larger than said first diameter said first and second rod portions being connected end-to-end in axial alignment with each other and with said fuel passage, said first rod portion (3c) being oriented closer to said precombustion chamber (13) than said second rod portion and communicating with said fuel passage during increase of said vacuum before said second rod portion.

Claim 21

A spark plug according to claim 1 wherein said gas passage (16) is substantially larger than said fuel feeding passage defined by said fuel feeding means (5).

Claim 22

A spark plug according to claim 20 wherein said fuel feeding passage has a substantially circular cross-section, and wherein said gas passage (16) has a substantially circular cross-section, the diameter of said gas passage (16) being substantially larger than the diameter of said fuel feeding passage.

Claim 23

A spark plug according to claim 1 wherein said electrode means (12,14) defines A spark gap substantially centrally of said precombustion chamber (13).

Claim 24

A spark plug comprising: an electrically conducting shell member (15); an electrically insulating sleeve (8) coupled with said shell member (15); a precombustion chamber (13) formed within said electrically conducting shell member (15); a first electrode (14) connected to said shell member (15); an electrically conducting tubular member (5) extending substantially axially through said electrically insulating sleeve (8) and having a lower end terminating at said precombustion chamber (13); a second electrode (12) coupled to said lower end of said electrically conducting tubular member (5) and spaced from said first conductor (14) to form a gap therebetween, said gap being inside said precombustion chamber (13); means (6) for coupling high voltage to said electrically conducting tubular member (5); means (2,3) coupled to said electrically conducting tubular member (5) for feeding fuel through said electrically conducting tubular member (5); a gas passage (16) leading from said precombustion chamber (13) through said electrically conducting shell member (15); and metering means at the end portion of said electrically conducting tubular member (5) which is remote from said precombustion chamber (13) for adjustably metering the feeding of fuel to said precombustion chamber (13), said metering means including a variable diameter rod means (3) selectively communicating with the interior of said tubular member (5), said rod means (3) being movably mounted relative to said tubular member (5) for movement in the axial direction thereof, said rod means (3) having at least two portions (3b,3c) of different diameters and being movable responsive to vacuum in said precombustion chamber (13) for selectively communicating said different diameter portions with the interior of said tubular member (5) for varying the size of the fuel feeding passage therethrough between a minimum fuel flow position at which a predetermined minimum amount of fuel is permitted to flow through said fuel passage and a maximum fuel flow position at which a predetermined maximum amount of fuel is permitted to flow through said fuel passage, and biasing means (4) biasing said rod means (3) relative to said tubular member (5) such that said metering means is in said maximum fuel flow position under low vacuum conditions in said precombustion chamber and is in said minimum fuel flow position under high vacuum conditions in said precombustion chamber.

Claim 25

A spark plug comprising: an electrically conducting shell member (15); an electrically insulating sleeve (8) coupled with said shell member (15); a precombustion chamber (13) formed within said electrically conducting shell member (15); a first electrode (14) connected to said shell member (15); an electrically conducting tubular member (5) extending substantially axially through said electrically insulating sleeve (8) and having a lower end terminating at said precombustion chamber (13); a second electrode (12) coupled to said lower end of said electrically conducting tubular member (5) and spaced from said first conductor (14) to form a gap therebetween, said gap being inside said precombustion chamber (13); means (6) for coupling high voltage to said electrically conducting tubular member (5); means (2,3) coupled to said electrically conducting tubular member (5) for feeding fuel through said electrically conducting tubular member (5); a gas passage (16) leading from said precombustion chamber (13) through said electrically conducting shell member (15); and metering means at the end portion of said electrically conducting tubular member (5) which is remote from said precombustion chamber (13) for adjustably metering the feeding of fuel to said precombustion chamber (13), said metering means including a variable diameter rod means (3) selectively communicating with the interior of said tubular member (5), said rod means (3) being movably mounted relative to said tubular member (5) for movement in the axial direction thereof, said rod means (3) having at least two portions (3b,3c) of different diameters and being movable responsive to vacuum in said precombustion chamber (13) for selectively communicating said different diameter portions with the interior of said tubular member (5) for varying the size of the fuel feeding passage therethrough between a minimum fuel flow position at which a predetermined minimum amount of fuel is permitted to flow through said fuel passage and a maximum fuel flow position at which a predetermined maximum amount of fuel is permitted to flow through said fuel passage, and biasing means (4) biasing said rod means (3) relative to said tubular member (5) such that said metering means is in said maximum fuel flow position under low vacuum conditions in said precombustion chamber and is in said minimum fuel flow position under high vacuum conditions in said precombustion chamber.

Claim 26

A stratified charge internal combustion engine having a plurality of combustion chambers, comprising: a plurality of spark plugs of the same number as the number of combustion chambers and coupled to said engine in communication with a respective combustion chamber, each of said spark plugs including: an electrically conductive shell member (15); a precombustion chamber (13) formed within said shell member (15), said shell member having an outlet (16) leading out from said precombustion chamber (13); an elongated electrically insulating sleeve (8) extending in a direction away from said gas passage (16) and precombustion chamber (13); electrode means (12,14) at least partially located within said precombustion chamber (13); means for feeding fuel into said precombustion chamber (13) for ignition by said electrode means (12,14), said fuel feeding means including means (5) defining an elongated fuel passage passing substantially axially through said elongated insulating sleeve (8) and terminating at said precombustion chamber (13); and means (2) for feeding fuel to the end of said fuel passage defining means (5) remote from said precombustion chamber (13); and metering means at the end portion of said fuel passage defining means (5) which is remote from said precombustion chamber (13) for adjustably metering the feeding of fuel to said precombustion chamber (13), said meteriNg means including a variable diameter rode means (3) selectively communicating with the interior of the defined fuel passage, said rod means (3) being movably mounted relative to said fuel passage defining means (5) for movement in the axial direction of said fuel passage, said rod means having at least two portions (3b,3c) of different diameters and being movable responsive to vacuum in said precombustion chamber (13) for selectively communicating said different diameter portions with said fuel passage defining means (5) for varying the size of the fuel feeding passage in the vicinity of said rod means between a minimum fuel flow position at which a predetermined minimum amount of fuel is permitted to flow through said fuel passage and a maximum fuel flow position at which a predetermined maximum amount of fuel is permitted to flow through said fuel passage, and biasing means (4) biasing said rod means (3) relative to said fuel passage defining means (5) such that said metering means is in said maximum fuel flow position under low vacuum conditions in said precombustion chamber and is in said minimum fuel flow position under high vacuum conditions in said precombustion chamber; said stratified charge internal combustion engine further comprising: high voltage distribution means (18,19) coupled to said spark plugs for selectively causing said electrode means to ignite said fuel-air mixture in said precombustion chamber in timed relationship to the operation of said engine; and fuel supply means (24,25) for supplying fuel at least to said fuel feeding means of each of said spark plugs.

Claim 27

A stratified charge internal combustion engine having a plurality of combustion chambers, comprising: a plurality of spark plugs of the same number as the number of combustion chambers and coupled to said engine in communication with a respective combustion chamber, each of said spark plugs including: an electrically conductive shell member (15); a precombustion chamber (13) formed within said shell member (15), said shell member having an outlet (16) leading out from said precombustion chamber (13); an elongated electrically insulating sleeve (8) extending in a direction away from said gas passage (16) and precombustion chamber (13); electrode means (12,14) at least partially located within said precombustion chamber (13); means for feeding fuel into said precombustion chamber (13) for ignition by said electrode means (12,14), said fuel feeding means including means (5) defining an elongated fuel passage passing substantially axially through said elongated insulating sleeve (8) and terminating at said precombustion chamber (13); and means (2) for feeding fuel to the end of said fuel passage defining means (5) remote from said precombustion chamber (13); and metering means at the end portion of said fuel passage defining means (5) which is remote from said precombustion chamber (13) for adjustably metering the feeding of fuel to said precombustion chamber (13), said meteriNg means including a variable diameter rode means (3) selectively communicating with the interior of the defined fuel passage, said rod means (3) being movably mounted relative to said fuel passage defining means (5) for movement in the axial direction of said fuel passage, said rod means having at least two portions (3b,3c) of different diameters and being movable responsive to vacuum in said precombustion chamber (13) for selectively communicating said different diameter portions with said fuel passage defining means (5) for varying the size of the fuel feeding passage in the vicinity of said rod means between a minimum fuel flow position at which a predetermined minimum amount of fuel is permitted to flow through said fuel passage and a maximum fuel flow position at which a predetermined maximum amount of fuel is permitted to flow through said fuel passage, and biasing means (4) biasing said rod means (3) relative to said fuel passage defining means (5) such that said metering means is in said maximum fuel flow position under low vacuum conditions in said precombustion chamber and is in said minimum fuel flow position under high vacuum conditions in said precombustion chamber; said stratified charge internal combustion engine further comprising: high voltage distribution means (18,19) coupled to said spark plugs for selectively causing said electrode means to ignite said fuel-air mixture in said precombustion chamber in timed relationship to the operation of said engine; and fuel supply means (24,25) for supplying fuel at least to said fuel feeding means of each of said spark plugs.

Claim 28

An engine according to claim 24 wherein said fuel supply means includes a pressure regulator (24) for feeding fuel to said spark plugs at a regulated pressure.

Claim 29

An engine according to claim 24 wherein said fuel supply means further comprises a carburetor (26) for supplying a fuel-air mixture to said combustion chambers.

Claim 30

An engine according to claim 24 including air supply means (28) for supplying only air to each of said engine combustion chambers, the fuel being supplied only to said spark plugs.