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
  • F02P7/06—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices of circuit-makers or -breakers, or pick-up devices adapted to sense particular points of the timing cycle
  • F02P7/067—Electromagnetic pick-up devices, e.g. providing induced current in a coil
  • F02P7/0677—Mechanical arrangements

Definitions

• This invention relates to a distributor construction including a signal generator ' for use in an internal, combustion engine.
• Known distributors have signal generating .apparatus including a fixed magnet with turning vanes which change the intensity of the magnetic field adjacent the magnet.
• An inductive sensor adjacent the magnet can sense these field fluctuations.
• U.S. Patent 4,235,213 to Jellissen teaches an ignition system having a Hall effect sensor with a magnetic circuit positioned to provide magnetic flux through the Hall effect sensor.
• the magnetic flux through the Hall effect sensor is interruptable by a high permeability vane
• a housing in an automotive ignition distributor system is mounted on a swing arm pivotal about the axis of a distributor shaft.
• the housing contains a magnetic circuit and a circuit board having a Hall effect sensor affixed thereto.
• U.S. Patent 4,223,249 issued to Eschelman teaches a bistable magnetic wire having ..an electrically conductive wire coil thereabout to form a magnetic wire assembly adjacent the magnet.
• the ends of the conductive wire are electrically connected to a sensing apparatus.
• a shield or shutter arrangement operated between the magnetic wire assembly and the magnet serves to cause the magnetic wire to be at times placed under the influence of the magnetic field of the magnet thereby resulting in the magnetic wire changing from one stable state to another state. In so changing states, a voltage is induced into the inductive wire to produce a pulse across the ends of the wire.
• crankshaft Also known are various geared couplings between the engine crankshaft and the shaft of the distributor. Typically, a pinion gear is used to transmit crankshaft • rotation to the distributor shaft causing it to rotate.
• a multiple pole magnet adapted to be charged in place has a generally ring-like configuration and is mounted on the distributor.
• the magnet is formed of a plastic material to reduce rotating weight and cost.
• a bipolar Hall sensor positioned adjacent the rotating magnetic ring provides a signal indicative of crankshaft position information.
• the bipolar feature results in a sensor that switches on and off by being subjected to a positive magnetic flux (associated with a north magnetic pull) and a negative magnetic flux (associated with a south magnetic pull) after experiencing a zero flux condition at the positive and negative transition.
• Such a signal can be utilized in an electronic engine control.
• the distributor includes an intermediate shaft mounted and oriented directly on the engine camshaft thereby eliminating the need for bearings.
• the rotating portion of the distributor is mounted to and supported by the camshaft.
• the stationary part of the distributor is mounted to and supported by the engine block. There is no. portion of the stationary part of the distributor which supports a rotating portion of the distributor.
• a spring is attached to the rotor body by a positive locking feature to the electrode, thus insuring a positive, electrically conductive path between the two pieces.
• Fig. 1 is a cross-section of a distributor mounted on " an engine camshaft in accordance with an embodiment of this invention
• O-MPI Fig. 2 is an end view of an intermediate shaft which is coupled to the engine camshaft;
• Fig. 3 is an end view of a magnet to be mounted on the intermediate shaft in accordance with an embodiment of this invention
• Fig. 4 is an elevation view of a magnetic charging tool for a distributor in accordance with an embodiment of this invention.
• Fig. 5 is a section view taken generally along section line 5-5 of Fig. 4 and includes a portion of the distributor of Fig. 1 to show how the magnetic charging tool mates with the distributor;
• Fig. 6 is. a top view of the rotor of a distributor in ' accordance with an embodiment of this invention
• Fig. 7 is a side view of an engine and a distributor mounted thereon in accordance with an embodiment of this invention.
• distributor 10 is directly mounted on a camshaft 20 of an engine 22.
• An . intermediate shaft 12 is mounted and oriented directly on camshaft 20 eliminating the need for any bearings.
• a ring-like magnet 14 is positioned on intermediate shaft 12 to provide an indication of the rotational position of intermediate shaft 12, of camshaft 20 and therefore of the engine crankshaft. Magnetic poles are induced in magnet 14 after magnet 14 is positioned on intermediate shaft 12.
• Such in place charging of magnet 14 (Fig. 5) permits accurate correlation between the rotational position of the magnetic poles on magnet 14 and the rotational position of the crankshaft in engine 22. As a result, it is possible to compensate for manufacturing tolerances which may otherwise contribute to inaccuracies.
• Intermediate shaft 12 is a generally hollow cylinder with decreasing diameter toward the end mounted on the outer diameter of camshaft 20.
• a screw 34 in combina ⁇ tion with a washer 36 is attached to a mounting stud 30 and engages an insert 38 coupled to intermediate shaft 12 thereby securing intermediate shaft 12 to mounting stud 30.
• Mounting stud 30 has a threaded portion 31 which screws into the central opening of camshaft 20.
• Intermediate shaft 12 has a plurality of radial, circumferentially spaced openings at the end adjacent camshaft 20.
• Insert 38 is a web that extends through the radial openings in intermediate shaft 12 and has integral circumferential ring-like portions both inside and outside intermediate shaft 12.
• Intermediate shaft 12 is formed of a combination of powdered metal and plastic.
• insert 38 is also formed of a plastic and powdered metal combination and formed in place by injection around intermediate shaft 12.
• a lip seal 42 between insert 38 and engine head 24 acts as a seal to keep oil in passages 26 around camshaft 20 from leaking from engine 22.
• a shoulder portion 64 of intermediate shaft 12 supports magnet 14 as shown in Fig. 2. Shoulder portion 64 has circumferential, outwardly facing teeth 66. Magnet 14 (Fig. 3) has circumferential, inwardly facing teeth 68 for engaging teeth 66.
• the end of intermediate shaft 12 projecting away from engine 22 supports a rotor 46 (see Fig. 6).
• Rotor 46 carries a staple-like electrode 48 and spring 50.
• the mounting of spring 50 on rotor 46 is accomplished by a compression fit and uses no secondary mounting process such as a rivet or a heat stake.
• Rotor 46 includes a clamp-like ledge 47 to hold down spring 50.
• a back stop 49 acts in cooperation with ledge 47 to positively hold spring 50 to rotor 46.
• Such a construction for attaching spring 50 provides a positive locking feature to electrode 48 thus insuring a positive, electrically conductive path between the two pieces.
• Staple-like electrode 48 reduces cost of manufacturing.
• the wire drawn material minimizes material costs and weight.
• the staple form can be obtained by relatively low cost tooling.
• the sharp pointed electrode design also reduces the generation of high levels of radio frequency interference.
• Sensor 54 (Figs. 1 and 5) is coupled to an electronic engine control and provides crankshaft position information.
• Sensor 54 is a bipolar Hall-type device. The bipolar feature results in a sensor that switches on and off by being subjected to a positive magnetic flux and a negative magnetic flux after- experiencing a zero flux condition at transitions between positive and negative magnetic flux.
• a positive magnetic flux is associated with the passage of a north magnetic pole on magnet 14 and a negative magnetic flux is associated with the passage of a south magnetic pole on magnet 14.
• a sensor holder 52 (Figs. 1, 5 and 7) is mounted on head 24 and supports bipolar Hall-type sensor 54 in proximity to magnet 14.
• Sensor holder 52 includes ' charging tool locating holes 56 for receiving pins 72 positioning a charging tool 70 to charge magnet 14 (see Fig. 5). Accordingly, after magnet 14 is positioned on intermediate shaft 12, sensor holder 52 is mounted on head 24, and the engine position is determined to be in a known position (such as top dead center of cylinder one).
• Sensor holder 52 also supports distributor cap 58 in proximity to spring 50 and electrode 48 so that a firing voltage can be supplied through a central electrode 60 to spring 50 and distributed through electrode 48 to a plurality of spark plug associated electrodes 62 (Fig. 1).
• O PI Charging tool 70 (Figs. 4 and 5) is generally circular with a protruding handle 74.
• a circular pilot 76 extends along the axis of charging tool 70 for engaging the central opening of intermediate shaft 12.
• a pair of pins 72 extend parallel to pilot 76 for engaging locating holes 56.
• a partially hollow cylindrical portion 78 extends around pilot 76 along the outside of intermediate shaft 12 to magnet 14.
• An undulating conductor bus bar 80 is supported by cylindrical portion 78 adjacent magnet 14. The undulations are, in sequence, axially upward, circumferential, axially downward, circumferential, axially upward, and so on.
• the axial portions of bus bar 80 are spaced about 45° apart so that- current flowing in bus bar 80 induces eight magnet poles in magnet 14.
• Magnet 14 is mounted on intermediate shaft 12 as an uncharged injection molded plastic magnet containing oriented magnetic dipoles.
• the engine crankshaft is positioned to a known positon
• magnetizing fixture is located relative to sensor 54 and magnet 14. At this point, torque can be applied to camshaft 20 to take up any timing belt looseness and the magnet 14 is magnetized.
• Ring-like magnet 14 is magnetized relative to a known engine position so that the 45° north and south poles are generated alternately over the outer diameter of the magnetic in a location such that the sensor switches at a prescribed point relative to the known engine position.
• bipolar Hall-type sensor 54 is potted in the plastic base which is mounted directly to the engine head to assure a positive known location in relation to the rotation of the magnet.
• the crankshaft can be located at 35° after top dead center (ATDC) so that charg ⁇ ing conductors can be equally spaced around sensor. This will result in a signal being generated at 10° before top dead center (BTDC) by the sensor during engine operation.
• ⁇ -_MPI Sensor 54 is triggered by a low magnetic flux level, such as plus and minus 50 gauss around a zero flux transition point, and its sensitivity to air gap size, temperature and run-out variation is minimal.
• the maximum amplitude of magnetic flux at the pole face is approximately 900 gauss.
• Sensor holder 52 also contains a pole piece 55 (Fig. 1) adjacent sensor 54 to focus the magnetic flux from magnet 14 thereby concentrating the flux to improve the accuracy of sensor 54 ' .

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Ignition Installations For Internal Combustion Engines (AREA)

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• 1982
  • 1982-08-27 JP JP57503067A patent/JPS59501469A/ja active Pending
  • 1982-08-27 WO PCT/US1982/001167 patent/WO1984000999A1/en not_active Ceased
  • 1982-08-27 DE DE8282903091T patent/DE3277633D1/de not_active Expired
  • 1982-08-27 EP EP19820903091 patent/EP0116542B1/de not_active Expired

Non-Patent Citations (1)

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