EP0096353A2 - Dispositif d'antiparasitage H.F. pour moteur de véhicule automobile - Google Patents

Dispositif d'antiparasitage H.F. pour moteur de véhicule automobile Download PDF

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Publication number
EP0096353A2
EP0096353A2 EP83105401A EP83105401A EP0096353A2 EP 0096353 A2 EP0096353 A2 EP 0096353A2 EP 83105401 A EP83105401 A EP 83105401A EP 83105401 A EP83105401 A EP 83105401A EP 0096353 A2 EP0096353 A2 EP 0096353A2
Authority
EP
European Patent Office
Prior art keywords
noise
suppressive
rotor
ignition system
electrode member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP83105401A
Other languages
German (de)
English (en)
Other versions
EP0096353A3 (fr
Inventor
Masazumi Sone
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Motor Co Ltd
Original Assignee
Nissan Motor Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Publication of EP0096353A2 publication Critical patent/EP0096353A2/fr
Publication of EP0096353A3 publication Critical patent/EP0096353A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P7/00—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices
    • F02P7/02—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices of distributors
    • F02P7/021—Mechanical distributors
    • F02P7/025—Mechanical distributors with noise suppression means specially adapted for the distributor

Definitions

  • the present invention relates generally to an ignition system for an internal combustion engine of an automotive vehicle, and more specifically to an ignition system of a radio-frequency-noise-suppressive type, wherein each of spark plugs installed within a corresponding engine cylinder has an elongated monolithic resistor between a central electrode and discharge electrode equal to or more than eight millimeters of resistance length.
  • the ignition system uses noise-suppressive-type high tension cables including a resistance and distributor having a rotor wherein a resistance material is interposed at an intermediate portion of a rotor electrode and a dielectric material is secured to either the upper end or lower end surfaces of the rotor electrode.
  • An engine ignition system mounted in an automotive vehicle mainly comprises, as is well known, a distributor, spark plugs, and high-tension cables.
  • a large current having a steep rise time flows through the distributor and spark plug to ignite an air-fuel mixture supplied within an engine combustion chamber.
  • the large current generates electromagnetic wave noise which disturbs communication from a radio equipment, etc.
  • Such noise generation has become a social problem due to the rapid increase in numbers of automotive vehicles.
  • Some countries have passed laws which prescribe maximum allowable electromagnetic wave noise electric field strength for automotive vehicles, e.g. under the recommendation of International Special Committee on Radio Interference (CISPR).
  • CISPR International Special Committee on Radio Interference
  • a distributor for distributing a high surge voltage generated at an ignition coil into each spark plug must be included in measures for suppressing electromagnetic wave generation.
  • a distributor e.g., having a construction of a type wherein a gap between a rotor electrode and each fixed electrode is made wider than the conventional one or having a construction of a type wherein a metal oxide coating is formed at a part of rotor electrode discharge surface.
  • the' applicant has developed a radio-frequency noise suppressive ignition system wherein parts having a large noise suppressive effect, i.e., a distributor having a rotor to which a dielectric material is added, resistor-equipped spark plugs having a considerably longer resistance path than the conventional resistance path, and resistive high-tension cables are combined so that an inexpensive noise suppressive ignition system can be achieved having a large noise suppressive effect without affecting engine performance.
  • Fig. 1 shows a noise suppressive type ignition system for which a patent application has been filed in Japan by the* Fig. 1
  • numeral 1 denotes a spark plug with a long resistance path provided in each cylinder of an internal combustion engine
  • numeral 24 denotes a distributor having a plurality of fixed electrodes 17 which correspond to each spark plug 1
  • one rotor electrode 21 which revolves in * applicant.
  • numeral 13 denotes noise suppressive type high tension cables each connected between the fixed electrode 17 and corresponding spark plug
  • numeral 28 denotes noise-suppressive type high tension cables connected between a center electrode 16 of the distributor 24 and ignition coil 27.
  • the spark plug 1 with the long resistance path t made of a monolithic resistor equal to or more than 8 mm of resistance length is installed within each engine cylinder of the internal combustion engine. It should be noted that the other spark plugs have the same construction as the spark plug shown in Fig. 1.
  • the spark plug 1 with the long resistance path includes a plug screw portion 2 provided at a lower part thereof for screwing the spark plug 1 to the corresponding portion. in each cylinder, a discharge electrode 4 located at the lower edge of the screw portion 2, and central electrode 8.
  • a conventional plug has a monolithic resistor of length 1 ranging from 5 to 6 mm
  • the spark plug 1 has a resistor with a length exceeding 8 mm and preferably about 15 mm.
  • numeral 3 denotes a grounded side electrode
  • numeral 5 denotes a seal ring
  • numeral 6 denotes a sealing material made of a conductive material
  • numeral 9 denotes a shell.
  • a noise-suppressive effect of the resistor-equipped spark plug 1 may be caused by a filter formed by an electrostatic capacitance between the monolthic resistor 7 and plug screwing portion 2 and resistance of the monolithic resistor 7 itself.
  • a parallel capacitance is inserted between both ends of the monolithic resistor 1.
  • the distributor 24 comprises an axle 14, rubber cap 15, central electrode 16, fixed electrodes 17, spring 18, contactor 19, rotor electrode 21 made of a conductive metal, rotor 22, cap 23, dielectric material 25, and caulking portion 26.
  • Numeral 20 denotes a discharge gap formed between the rotor electrode 21 and fixed electrode 17 while the rotor electrode 21 approaches one of the fixed electrodes 17.
  • the axle 14 is engaged with a camshaft of the engine through a wheel to synchronize with the engine speed. Therefore, the rotor electrode 21 rotates in synchronization with the engine, and is located to approach and pass sequencially in front of each fixed electrode 17.
  • a rotor wherein the dielectric material 25 is attached at either upper end or lower end of the rotor electrode 21 is called a dielectric material attached rotor.
  • the dielectric material 25 is attached between the rotor electrode 21 and rotor 22 (i.e., at the lower end of the rotor electrode 21).
  • the discharge voltage across the gap 20 between the rotor electrode 21 and fixed electrode 17 is reduced so that the generation of noise waves can remarkably be suppressed.
  • the rotor electrode 21 is made of a stainless steel or brass and the dielectric material 25 used thereat is made of a silicone material.
  • a silicone glass is most preferable in terms of noise suppressive effect, heat resistance effect, workability, arc resistance effect, and corona resistance effect.
  • the silicone glass is manufactured by impregnating or applying a silicone resin such as a silicone wanish to glass fabrics.
  • the noise-suppressive high tension cable 13 is used to connect each fixed electrode 17 to the corresponding resistor-equipped spark plug 1.
  • the other noise-suppressive high tension 28 is used to connect the central electrode 16 of the distributor 24 and secondary winding (not shown electrically) of the ignition coil 27.
  • Such noise-suppressive high tension cables comprise carbon-impregnated wires 10 covered with a braided wire 12, insulating sheath 11, and tube 13 made of silicone rubber.
  • the carbon-impregnated wires 10 has a uniform resistance per length of 8 through 20 kiloohms per meter.
  • 0 dB represents 1 uV/m.
  • Fig. 3 The measurement results shown in Fig. 3 are results measured actually when various ignition systems in combination of the elements listed in the Table are installed within an internal combustion engine having a displacement of 1,500 cc mounted in a bonnet-type automotive vehicle.
  • symbol E denotes a law- regulated maximum allowable noise level under a corresponding law (e.g., CISPR recommendation No. 18/2).
  • the entire noise level can be determined at' the most significant noise component generated from the element in which no noise suppression measure is carried out, thereby the entire noise suppressive effect being reduced.
  • a large noise suppressive effect can be obtained by 10 through 30 dB only in a case where all elements have taken noise suppression measures, as shown by D of Fig. 3.
  • the line D in which all elements have taken noise suppressive measures remarkably lower than the line E.
  • the line D comes near the line E in a region of 20 through 100 MHz.
  • Figs. 4(a) and 4(b) show the measurement results in the case of trucks, wherein Fig. 4(b) shows a cab-over engine.
  • 0 dB represents 1 ⁇ V/m.
  • Figs. 4(a) and 4(b) in more detail show the measurement results when the ignition system comprising the elements in the combination of D is applied to a truck.
  • the line D in Fig. 4(a) denotes the elements in combination of D which are applied to a cab-over engine truck in which a four-cycle 2,000 cc internal combustion engine is mounted
  • the line D in Fig. 4(b) denotes the elements in combination of D which are applied to a two-box cab behind-engine truck in which is mounted a four-cycle 1,500 cc internal combustion engine.
  • the hoise-suppressive high tension cable 28 generally has a length of about 30 centimeter and one end thereof is connected to the low-resistance ignition coil 27.
  • a lead wire (not shown in the drawings) is connected between a primary winding of the ignition coil and vehicle battery to supply a DC voltage to the primary winding thereof.
  • the noise current which does not attenuate through such a short noise-suppressive high tension cable 28 flows from a secondary winding of the low-resistance ignition coil 27 to the lead wire at the primary winding thereof so that the noise electromagnetic wave is radiated from the ignition coil and lead wire as an antenna. Therefore, it is necessary to further improve the noise suppressive effect.
  • the shape of vehicle or height of their internal combustion engines with respect to the earth surface may contribute to such indications of higher noise level.
  • each noise-suppressive high-tension cable 13 generally has a length of about 60 through 70 centimeters and one end of the high-tension cable 13 is finally grounded through the resistor-equipped spark plug 1, the noise current described above is greatly attenuated and thereby the generation of noise wave is remarkably reduced because of short length of an effective antenna.
  • the present invention is based on the above-described matter.
  • the present invention is directed to provide a resistance material at an intemediate portion of the rotor electrode 21, in more detail, between a contact at which the contactor 19 comes in touch with the rotor electrode 21 and two layers in which the dielectric material 25 is placed above or below the rotor electrode 21.
  • Fig. 5 shows one preferred embodiment of the present invention.
  • numeral 29 denotes a resistance material inserted at the intermediate portion described hereinabove:
  • the resistance material 29 is, preferably, of a wire-wound resistor type or carbon film resistor type.
  • the resistance value of the resistance material 29 ranges from 5 to 20 kiloohms.
  • the ignition energy is sent from the ignition coil 27 through the contactor 19 to a discharge end of the rotor electrode 21.
  • the discharge end is a tip of the rotor electrode 21 which faces toward one of the fixed electrodes 17 through the discharge gap 20 when the rotor 22 is revolved.
  • a kind of resistor-and-capacitor type filter is formed with the resistance material 29 and stray capacitance of the distributor and internal combustion engine with respect to the earth.
  • This resistor-and-capacitor type filter serves to attenuate the high-frequency noise current, thus reducing the noise current flowing through the ignition coil 27 and lead wire connected to the primary winding of the ignition coil.
  • Figs. 6(a) and 6(b) show measurement results of noise wave electric field strength in the case when the ignition system according to the present invention is used.
  • the measurement requirements are the same as those in the case of Figs. 4(a) and 4(b).
  • the charcteristic graphs shown in Figs. 6(a) and 6(b) are measurement results in the case when the wire-wound resistor having a resistance value of 12 kiloohms is used as the resistance material. It is preferable to use a high-resistance material, e.g., made of ceramics as the contactor 19. Consequently, the noise suppressive effect is furthermore increased.
  • the noise level is reduced in a frequency region from 20 to 100 MHz, i.e., the line of F being lower than the line of E.
  • the noise electromagnetic wave is radiated from each of the distributor, spark plugs, and high-tension cables constituting the ignition system. Furthermore, the maximum electric field strength of noise wave formed totally from the individual elements of the ignition system is dominated by the maximum noise electric field strength among the noise waves radiated from the individual elements.
  • the experiment indicates that it is less effective in preventing noise wave radiation to take the noise suppressive measures for the individual elements, separately. Since the experiment ensures that it is necessary to carry out the noise suppressive measure on the entire ignition system, the present invention is directed to suppresss the noise wave radiation by taking the noise suppressive measures for all the elements constituting the ignition system. Therefore, according to the present invention, the ignition system can suppress the noise wave generation over an entire frequency range from a low- frequency region of about 20 MHz to a high-frequency region of about 250 MHz.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
  • Spark Plugs (AREA)
EP83105401A 1982-06-03 1983-05-31 Dispositif d'antiparasitage H.F. pour moteur de véhicule automobile Withdrawn EP0096353A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP94058/82 1982-06-03
JP9405882A JPS58211573A (ja) 1982-06-03 1982-06-03 雑音防止型点火装置

Publications (2)

Publication Number Publication Date
EP0096353A2 true EP0096353A2 (fr) 1983-12-21
EP0096353A3 EP0096353A3 (fr) 1984-04-11

Family

ID=14099935

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83105401A Withdrawn EP0096353A3 (fr) 1982-06-03 1983-05-31 Dispositif d'antiparasitage H.F. pour moteur de véhicule automobile

Country Status (2)

Country Link
EP (1) EP0096353A3 (fr)
JP (1) JPS58211573A (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4039787A (en) * 1974-04-20 1977-08-02 Toyota Jidosha Kogyo Kabushiki Kaisha Distributor for internal combustion engine containing apparatus for suppressing noise
US4135066A (en) * 1974-04-20 1979-01-16 Toyota Jidosha Kogyo Kabushiki Kaisha Distributor for internal combustion engine containing apparatus for suppressing noise
US4217470A (en) * 1977-07-06 1980-08-12 Robert Bosch Gmbh Ignition distributor with noise suppression electrodes
US4332988A (en) * 1980-11-12 1982-06-01 General Motors Corporation Radio frequency interference suppressing ignition distributor
US4369343A (en) * 1979-11-26 1983-01-18 Nissan Motor Co., Ltd. Ignition distributor having electrodes with thermistor discharging portions

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4039787A (en) * 1974-04-20 1977-08-02 Toyota Jidosha Kogyo Kabushiki Kaisha Distributor for internal combustion engine containing apparatus for suppressing noise
US4135066A (en) * 1974-04-20 1979-01-16 Toyota Jidosha Kogyo Kabushiki Kaisha Distributor for internal combustion engine containing apparatus for suppressing noise
US4217470A (en) * 1977-07-06 1980-08-12 Robert Bosch Gmbh Ignition distributor with noise suppression electrodes
US4369343A (en) * 1979-11-26 1983-01-18 Nissan Motor Co., Ltd. Ignition distributor having electrodes with thermistor discharging portions
US4332988A (en) * 1980-11-12 1982-06-01 General Motors Corporation Radio frequency interference suppressing ignition distributor

Also Published As

Publication number Publication date
JPS58211573A (ja) 1983-12-09
EP0096353A3 (fr) 1984-04-11

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Inventor name: SONE, MASAZUMI