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
  • F02P7/061—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 pick-up devices without mechanical contacts

Definitions

• This invention relates to ignition distributors for internal combustion engines.
• a primary object of this invention is therefore to provide a breakerless distributor which is simple and cheap to manufacture and service.
• an ignition distributor including a base, a shaft adapted to be driven by an engine and extending within the base, a transmitter and a sensor positioned within the base, and a rotary member rotatable by the shaft between the transmitter and the sensor and foraed with discontinuities modifying the passage of radiation between the transmitter and the sensor, and in which the transmitter and the sensor are formed as a unit and the base is formed with an aperture positioned and dimensioned such that said unit can be secured in and removed from the base without removing the shaft or the rotary member from the base.
• the present invention also provides an ignition distributor including a base, a distributor cap closing the base and having a central h.t. input and spaced peripheral h.t.
• a rotor assembly for sequentially providing an h.t. path between said input and said outputs, a shaft rotatable by an engine and extending within the base, a rotary member arranged to be rotated by the shaft, electronic means cooperating with the rotary member to provide timing pulses, centrifugal means interposed between the shaft and the rotary member to advance the rotary member relative to the shaft as the shaft speed increases, and. in which the centrifugal means is mounted on top of the rotary member and the rotor assembly is secured to rotate with the rotary member.
• Figure 1 is an exploded perspective view of a distributor embodying the invention
• Figure 2 is an assembled view of certain parts of Figure 1, shown in longitudinal cross-section;
• Figure 3 is a plan view of a shaft assembly of Figure 1; and Figure 4 is a scrap sectional view on the line 4-4 of
• the distributor includes a base 10, a shaft assembly 16, a rotor assembly 18 a distributor cap 20, a vacuum actuator 22, a sensor unit 24, and an electronics module 26.
• the distributor operates in conjunction with a conventional ignition coil (not shown).
• the low tension side of the coil is controlled by the electronics module 26 which derives its timing information from the sensor unit 24.
• the sensor unit 24 as will be described in more detail, is a magnetic sensor cooperating with a rotating slotted vane 28.
• the shaft assembly comprises a shaft 30 journalled in the body 10 by a bearing 32.
• a drive pinion 34 is secured to the lower end of the shaft 30 by a pin 36.
• the lower end of the housing 10 is secured to an engine in known manner, and the drive pinion 34 is driven from the engine in the usual way.
• the slotted vane 28 is rotatably mounted on the shaft 30 by means of a bearing 38.
• Centrifugal weights 40 are mounted on pivots 42 secured by peening to a plate 44 which is also carried by the bearing 38.
• the weights 40 have cam surfaces 40a which bear on an arm 45 secured to the shaft 30.
• Outward movement of the weights 40 is restrained by a primary and a secondary return spring 46, 48 respectively each exerting tension between a post on the arm 45 and an upturned tab on the plate 44.
• the distributor cap 20 is of conventional form, having a central high tension input and equiscaped peripheral h.t. outputs.
• the rotor assembly 18 comprises a plastics rotor 70 carrying a metallic strip 72 for conducting h.t. current from the cap input to its outputs sequentially.
• the rotor assembly is arranged for movement with the vane 28, and for this purpose is secured thereto by means of screws 74 passing through the assembly 18 to engage in screw threads formed in the weight pivots 42.
• the use of the pivots to receive the screws 74 eaves space on the top of the shaft assembly 16, and this allow larger centrifugal weights to be used for a given overall size of distributor and consequently a better control of advance and- retard characteristics.
• the sensor unit ( Figure 4) comprises a permanent magnet 50 and a Hall effect drvice sensor positioned radially outwardly of the magnet 50. Pole pieces 54 are provided to form a magnetic return path.
• the vane 28 rotates between the magnet 50 and the sensor 52. As each slot of the vane 28 passes between them, the magnetic flux passing through the sensor 52 increases sharply, producing an output pulse which is processed by amplifying and switching circuits in the electronics module 26 to control the l.t. supply to the coil.
• Such processing circuitry is well known in the art and will not be described.
• the sensor unit 24 is mounted to the underside of a mounting plate 56 in the position indicated in broken lines in Figure 1.
• the mounting plate 56 is journalled for movement through an arc on the outer peripheral surface of the bearing 32 and is secured thereon by a washer 58 and circlip 60.
• the mounting plate 56, and thus the sensor unit 24, is moved in advance and retard directions around the shaft 30 by the vacuum actuator 22.
• the base 10 has a mlat transverse portion 12 adjacent the bearing 32, which portion is apertured at 62.
• the aperture 62 is aligned with the rest position of the sensor unit 24 and has a shape commensurate with but slightly larger than the underneath plan view of the sensor unit 24. The latter may therefore be inserted into and removed from the base in a direction parallel to the shaft 28 without removing any of the other parts, and secured in position for example by screws (not shown) driven into tapped bores 64 in the mounting plate, or by means of a snap fit.
• the electronics module 26 is suitably fastened to the base portion 12 to cover the aperture 62.
• the sensor unit 24 and module 26 are interconnected by cables 64 passing through the aperture 62.
• the invention may, of course, equally be applied to a distributor in which the sensor unit and vane or other rotary member take different forms.
• the essential feature is that an engine-driven member rotates between a transmitter and a sensor of radiation, said member having discontinuities for identifying engine timing.
• the transmitter may be a light source and the receiver a light-sensitive device, the rotary member being slotted or formed with opaque and transparent portions.

Landscapes

• 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)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26236563

Family Applications (1)

Country Status (5)

Families Citing this family (2)

Family Cites Families (3)

• 1979
  • 1979-01-10 JP JP50021779A patent/JPS55500056A/ja active Pending
  • 1979-01-10 WO PCT/GB1979/000003 patent/WO1979000495A1/en unknown
  • 1979-01-12 CA CA000319548A patent/CA1157907A/en not_active Expired
  • 1979-08-13 EP EP19790900046 patent/EP0009039A1/en not_active Withdrawn
• 1980
  • 1980-04-24 FR FR8009590A patent/FR2454536A1/fr active Granted

Non-Patent Citations (1)

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