Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
  • G01P3/481—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals
  • G01P3/487—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals delivered by rotating magnets
• • 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
  • F02P7/0675—Electromagnetic pick-up devices, e.g. providing induced current in a coil with variable reluctance, e.g. depending on the shape of a tooth
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
  • G01P3/481—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals
  • G01P3/4815—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals using a pulse wire sensor, e.g. Wiegand wire

Definitions

• the invention relates to a sensor according to the type of the main claim.
• sensors which consist of a rotor with a magnet and a stator with a magnetic field-sensitive element, for detecting angles, reference marks, rotational speeds and the like. It is further known to design the rotor so that a permanent magnet is enclosed between two pole plates and the pole plates have claws on their circumference, the magnetic circuit being closed via the air space between the claws. The magnetic field generated in this way influences a magnetic field-sensitive element of a stator which is arranged in the vicinity of the circumference of the rotor.
• a sensor is described for example in DE-OS 26 49 321.
• the sensor according to the invention with the characterizing features of the main claim has the advantage that immediately successive fields of pronounced direction are generated with a steep zero crossing of the induction, so that defined bipolar signals can be generated with small jitter, which also have a particularly large duty cycle.
• This high duty cycle is of particular advantage when using such a sensor for ignition systems in internal combustion engines.
• FIG. 1a and b show a top view and a cross section through an embodiment of a sensor according to the invention
• Figure 2 is a timing diagram of the pulses generated by the sensor of Figure 1. Description of the embodiment
• FIG. 1a and b 1 denotes the axis of a rotor.
• the rotor consists of two pole plates 10, 11, which extend in the radial direction and are fastened to the axis 1 by means of a hub 12.
• a permanent magnet 13 is arranged between the pole plates 10, 11.
• Claws are integrally formed on the circumference of the pole sheets 10, 11 in the axial direction, the claws of the pole sheet 10 being denoted by 15a, 15b and the claws of the pole sheet 11 by 16.
• the number of claws 16 corresponds to the number of cylinders of the internal combustion engine and the claws 16 are distributed equidistantly over the circumference.
• the number of claws 15a, 15b is twice the number of claws 16, and a pair of claws 15a, 15b is arranged on both sides of a claw 16 of the pole plate 11.
• the magnetic circuit closes from the magnet 13 via the pole plate 11, the claws 16, the air gap to the claws 15a, 15b and via the pole plate 10 back to the magnet 13.
• the field lines which are produced in this way are designated by 20, 20a in FIG. 1a .
• a stator with a magnetic field sensitive element 1 4, for example a Hall, Wiegand or field plate element.
• the magnetic field-sensitive element 1 4 when the rotor rotates, successively comes into the influence of the field lines 20 and 20 a.
• conventional sensors of the type here only a pair of claws were directly opposite one another, for example claws 16 / 15a.
• each claw 16 of the pole plate 11 is enclosed by two claws 15a, 15b of the pole plate 10, so that a pronounced field 20, 20a results in both directions.
• the angle ⁇ between the claws 16 and 15a or 15b is dimensioned such that an optimal signal yield is obtained in the element 14.
• the angle Ot is small compared to the angle that the claws 16 form to one another.
• This last-mentioned condition is expressed in particular in the time diagram of the generated pulses 17, 18 or 17 ', 18' shown in FIG.
• the pulses 17, 17 ' are each generated by the field 20 and the pulses 18, 18' are each generated by the fields 20a, with an encoder according to the prior art and a field 20a ', the pulses 17, 17' are subject to high jitter.
• Pulses 17, 18, corresponding to the angle ⁇ are denoted by ta.
• the time between the spaced-apart pulses 18, 17 ' is one with t b
• Designated angle ⁇ As can be seen from FIG. 2, the relatively small angle ⁇ results in a relatively large duty cycle t b / t a .
• the speed of the rotor or the internal combustion engine can be determined from the length of one of the two time intervals ta or t b . Then, however, it is necessary that the times t a , t b differ significantly from one another, so that incorrect measurements due to confusion are not possible, as would be possible, for example, if t a and t b differed only slightly from one another.
• the bipolar signals 17, 18 are also used in ignition systems of combustion engines for the so-called closing time control, with known controls starting from a basic time which is reduced by means of control technology known per se depending on the operating parameters present. Then, however, it is necessary to base the closing time as high as possible in order to realize a wide control range. Due to the relatively long time t b , this requirement is met with the sensor according to the invention. Overall, the arrangement of the claws according to the invention thus results in a bipolar useful signal of large amplitude which is particularly sharply defined in terms of time and which can be used for a wide variety of control and regulation processes.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General 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)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6157877

Family Applications (1)

Country Status (5)

Families Citing this family (18)

Family Cites Families (15)

• 1982
  • 1982-03-11 DE DE19823208721 patent/DE3208721A1/de active Granted
  • 1982-10-14 US US06/434,180 patent/US4503391A/en not_active Expired - Fee Related
• 1983
  • 1983-02-26 EP EP83900777A patent/EP0102365A1/de not_active Withdrawn
  • 1983-02-26 WO PCT/DE1983/000034 patent/WO1983003283A1/en unknown
  • 1983-03-10 ES ES520481A patent/ES520481A0/es active Granted

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events