Claims
- 1. A contact-breaking ignition plug wherein an electrical ignition pulse traverses a short-circuit path and an electromagnet such that a magnetic field builds up in the electromagnet and causes an interruption of the short-circuit path for inducing an ignition spark, comprising:
- a housing defining a longitudinal axis;
- an electromagnet including a magnet coil arranged in said housing;
- said electromagnet further including a magnet core arranged within said magnet coil;
- an elastic rod arranged within said magnet core along said longitudinal axis;
- an armature fixed to said elastic rod and located within a magnetic field of the electromagnet;
- first and second electrodes arranged outside said magnet core and forming a portion of the short-circuit path;
- said magnet core at a location outside said magnet coil having an enlargement containing a cavity accommodating said armature;
- said first electrode in conjunction with said armature being magnetically deflected in substantially transverse direction relative to said longitudinal axis of said housing in response to the electrical ignition pulse for interrupting said portion of said short-circuit path; and
- said elastic rod being connected with said armature carrying said first electrode at a location outside of said magnet core.
- 2. The contact-breaking ignition plug as defined in claim 1, wherein:
- said magnet core has a head end; and
- said elastic rod having an end fixed in said head end of said magnet core.
- 3. The contact-breaking ignition plug as defined in claim 2, wherein:
- said elastic rod has a free end opposite said fixed end;
- said cavity of said enlargement of said magnet core having a longitudinal center plane; and
- said armature being arranged at said free end of said elastic rod in asymmetrical relation to said longitudinal center plane of said cavity.
- 4. The contact-breaking ignition plug as defined in claim 2, wherein :
- said armature has a free end opposite said fixed end of said elastic rod;
- said armature having a recess; and
- said recess and said first electrode being arranged at said free end of said armature.
- 5. The contact-breaking ignition plug as defined in claim 1, wherein:
- said armature, said first electrode and said second electrode are structured as replaceable parts.
- 6. The contact-breaking ignition plug as defined in claim 1, wherein:
- said magnet core has a bore for receiving said elastic rod; and
- said bore having a stepped configuration.
- 7. The contact-breaking ignition plug as defined in claim 1, wherein:
- said housing contains a cavity;
- said armature is capable of performing a motion for effecting interruption of the short-circuit; and
- a seal for limiting said motion of said armature and for insulating said magnet core and for sealing said cavity.
- 8. The contact-breaking ignition plug as defined in claim 1, wherein:
- said housing contains a cavity providing a clearance space between said housing and said magnet coil; and
- said housing being provided with vent openings for venting said clearance space and said cavity.
- 9. A break ignition plug for installation in an electrically conductive machine member, comprising:
- a magnet core of magnetic material containing a cavity and defining a longitudinal axis of the break ignition plug;
- an elastic support rod having a first end and a second end;
- said elastic support rod being formed of resilient and electrically conductive material and being anchored at said first end in said magnet core and extending substantially along said longitudinal axis in said cavity;
- an armature piece of magnetic material attached to said second end of said elastic support rod and extending externally of said magnet core;
- a magnet coil surrounding said magnet core;
- said magnet coil having an input side and an output side;
- first electrical conductor means connected to said input side of said magnet coil for supplying an electrical ignition pulse to said magnet coil;
- second electrical conductor means connecting said output side of said magnet coil to said elastic support rod;
- a mobile contact electrode carried by said armature piece;
- said armature piece, in response to said electrical ignition pulse, conjointly with said mobile contact electrode carried by said armature piece, being magnetically deflected in a direction substantially transverse to said longitudinal axis of the break ignition plug;
- electrical insulation means;
- support means for supporting said electrical insulation means relative to the electrically conductive machine member and for establishing electrical ground contact with the electrically conductive machine member;
- a stationary contact electrode carried by said support means; and
- said armature piece having an idle position in which said mobile contact electrode completes an electrical circuit with said stationary contact electrode and a magnetically deflected position in which said electrical circuit is interrupted when said electrical ignition pulse is supplied to said magnet coil.
- 10. The break ignition plug as defined in claim 9, wherein:
- said armature piece is attached to said second end of said support rod in asymmetrical relationship to said support rod.
- 11. A method of generating an ignition spark with a break ignition plug having a longitudinal axis, comprising the steps of:
- transmitting an electrical ignition pulse to the break ignition plug;
- conducting the electrical ignition pulse through an electromagnet of the break ignition plug for establishing a magnetic field for attracting a resiliently supported armature piece of magnetic material;
- conducting said electrical ignition pulse from said electromagnet through an electrically conductive resilient support member and through said armature piece and thereby magnetically deflecting said armature piece substantially transversely to the longitudinal axis of the break ignition plug and the direction of compression pressure acting upon the break ignition plug;
- conducting said electrical ignition pulse from a mobile contact electrode supported by said armature piece to an electrically grounded stationary contact electrode for completing an electrical circuit; and
- during said step of magnetically deflecting said armature piece, deflecting conjointly therewith said mobile contact electrode in a direction transverse to said longitudinal axis of the break ignition plug and said direction of compression pressure such that said mobile contact electrode is displaced away from said stationary contact electrode for interrupting said electrical circuit and thereby inducing the ignition spark.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 00639/86 |
Feb 1986 |
CHX |
|
CROSS REFERENCE TO RELATED CASES
This application is related to my commonly assigned U.S. Pat. No. 3,693,607, granted Sept. 26, 1972, U.S. Pat. No. 3,908,146, granted Sept. 23,1975, U.S. Pat. No. 4,172,439, granted Oct. 30, 1979, and U.S. Pat. No. 4,509,469, granted Apr. 9,1985.
The present invention broadly relates to ignition plugs and, more specifically, pertains to a new and improved construction of a break or contact-breaking ignition plug or spark plug and a method of generating an ignition spark therewith.
In its more specific apparatus aspects the present invention relates to a new and improved construction of a break or contact-breaking ignition plug or spark plug in which an electrical ignition pulse traverses a magnet coil of an electromagnet and a short-circuit path completed by a plurality of electrodes, for instance a pair of contact electrodes, such that a magnetic field arising around the electromagnet effects an opening of the electrodes and therefore an interruption of the short-circuit path as well as the formation of a spark. The contact-breaking ignition plug has an elastic or resilient rod arranged within a magnet core of the electromagnet and extending along a longitudinal axis of the contact-breaking ignition plug. An armature is fastened to the elastic rod within the magnetic field. The short-circuit path is completed by the contact electrodes in a region outside of the magnet core.
In other words, the break ignition plug of the present invention is for installation in an electrically conductive machine member and comprises a magnet core, a support rod and an armature piece. The magnet core is of magnetic material and contains a cavity or hollow space and defines a longitudinal axis of the break ignition plug. The support rod is a rod of elastically resilient and electrically conductive material anchored at a first end in the magnet core and extending substantially along the longitudinal axis of the cavity. The armature piece is of magnetic material and is attached to a second end of the support rod and preferably extends beyond the magnet core.
The method of the invention is for generating an ignition spark employing a break ignition plug and comprises the steps of transmitting an electrical ignition pulse to the break ignition plug and conducting the electrical ignition pulse through an electromagnet of the break ignition plug for establishing a magnetic field for attracting a resiliently supported armature piece of magnetic material.
Contact-breaking ignition plugs of the abovementioned type are known from German patent No. 204,545 dated Nov. 29, 1907 and the aforementioned U.S. Pat. No. 4,509,469, dated Apr. 4, 1985, in which two mutually insulated flat springs or lamellae are fixed in the gap or slot of an electromagnet. Armatures are fixed at the end of these flat springs or lamellae such that they are situated within the magnet core. The armatures possess members or legs projecting into the combustion chamber with electrode heads or contacts at their free ends. In the initially mentioned contact-breaking ignition plug, the magnet core and the mutually facing surfaces of the armatures are constructed such that when the armature strikes the magnet core, the armature members perform a rotary motion in order to effect an interruption of the electrode heads, and thus at every interruption movement the flat springs or lamellae carrying the armatures are flexed.
In the other type of contact-breaking ignition plug, the flat springs or lamellae are arranged in the magnet core such that during the interruption of the electrodes there occur at the flat springs or lamellae strong vibrations at the fixing point. The flat springs or lamellae are thus always highly stressed at the same position which leads to rapid metal fatigue and results in the metal quickly breaking.
In other known contact-breaking ignition plugs of this type, only one flat spring or lamella having an electrode is provided, but the problem is the same.
A further disadvantage consists in that, in a comparable embodiment, a friction effect occurs between the armatures and the magnet core with each interruption movement which leads to rapid wear and to an alteration of the armature throw and ignition timing point and leads to disadvantageous or undesired effects. In one such known embodiment, it is further disadvantageous that due to progressive wear of the two electrodes, the two armature plates on the flat springs touch and inhibit a separation or interruption of the electrodes. It is also disadvantageous in such contact-breaking ignition plugs that the hollow space or cavity in the lower portion of the housing is so constructed and the magnet coil together with the magnet core and the flat springs or lamellae are so arranged that overheating of the magnet coil and carbonization of the lower portion of the magnet core and of the armature can result, which is detrimental to operation.
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved construction of a contact-breaking ignition plug which does not exhibit the aforementioned drawbacks and shortcomings of the prior art constructions.
A further important object of the invention is to provide a contact-breaking ignition plug in which the magnet core, the hollow space or cavity and the armature, which is movable in a direction transverse to the longitudinal axis of the ignition plug, are constructed in a manner more capable of functioning properly and in which the interruption or contact breaking movement is capable of being carried out in a manner which is free of wear and in which overheating and carbonizing effects are reduced.
It is also an object of the invention to provide a method of generating an ignition spark employing a break ignition plug and exploiting the advantages of the inventive break ignition plug.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the break or contact-breaking ignition plug of the present invention is manifested by the features that a region of increased wall thickness containing a recess is provided on the magnet core in the region of the armature and outside of the magnet coil. The armature having an electrode projects beyond the magnet core and is located at the end of the elastic rod.
In other words, the break ignition plug of the present invention is manifested by the features that it comprises a magnet coil surrounding the magnet core. First electrical conductor means are connected to the input side of the magnet coil for supplying an electrical or control pulse to the magnet coil. Second electrical means connect the output side of the magnet coil to the first end of the support rod. A mobile contact electrode is mounted in the armature piece. Electrical insulation means support the magnet core and support means support the electrical insulation means relative to the electrically conductive machine member for establishing electrical ground contact with the electrically conductive machine member. A stationary contact electrode is mounted on the support means. The armature piece has an idle position in which the mobile contact electrode completes an electrical circuit with the stationary contact electrode and a magnetically deflected position in which the electrical circuit is interrupted when the electrical ignition pulse is supplied to the magnet coil.
The method of the present invention is manifested by the features that it comprises the further steps of conducting the electrical ignition pulse from the electromagnet through an electrically conductive, elastically resilient support member and through the armature piece such that the electrical ignition pulse interacts with the magnetic field to deflect the electrically conductive armature piece relative to the magnetic field. A subsequent method step entails conducting the electrical ignition pulse from the mobile contact electrode to an electrically grounded stationary contact electrode for completing an electrical circuit and allowing the magnetic field to attract the resiliently supported armature piece and to deflect the electrically conductive, elastically resilient support member such that the mobile contact electrode is displaced away from the stationary contact electrode for interrupting the electrical circuit and thereby inducing the ignition spark.
A concentration of the magnetic effect in the region of the armature is assured due to the fact that the magnet core possesses in the region of the armature an enlargement or mushroom shaped region of increased wall thickness having conically extending lateral surfaces and containing a cavity or hollow space. Since the armature is arranged in the cavity of the magnet and asymmetrically in relation to the longitudinal plane of the cavity of the magnet core so as to be movable in a direction transverse to the direction of compression pressure propagation, the compression pressure supports or augments the contact-breaking or interruption motion. Due to the pattern of the magnetic field lines or lines of magnetic flux, a repulsion effect on the armature extending beyond the magnet core arises in supplement to the magnetic attraction effect. The interruption or contact-breaking sequence can thereby be accelerated and carried out in a more accurate manner, and furthermore, the long elastic rod substantially eliminates material deformation during the interruption or contact-breaking movement.
Because the armature is provided with a recess or pocket at the portion which projects into the combustion chamber, the movable contact electrode fixed thereto is biased or pre-loaded in the direction of interruption and the requisite magnetic force is reduced. Furthermore, with this arrangement, the armature and the contact electrodes can be easily replaced due to the fact that they protrude beyond the ignition plug housing. Due to the arrangement of the stepped or shouldered hollow space or cavity in the magnet core, carbonization or sooting of the armature is minimized and because the hollow space or cavity is provided with vents, overheating is reduced. This is especially advantageous when the contact-breaking ignition plug is not utilized in internal combustion piston prime movers but is used as an ignitor or detonator.
If there is direct supply of electrical current from the ignition cable to the magnet coil and to the elastic resilient rod, then the provision of a seal in the upper portion of the contact-breaking ignition plug can be dispensed with, permitting a more compact design. The elastic or resilient rod can also be welded to the upper portion of the magnet core, in which case no seal is required for the elastic rod.
US Referenced Citations (5)
Patent Grant
4850316
