GB2024322A - Apparatus for detecting angular position of engine crankshaft - Google Patents

Apparatus for detecting angular position of engine crankshaft Download PDF

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Publication number
GB2024322A
GB2024322A GB7921448A GB7921448A GB2024322A GB 2024322 A GB2024322 A GB 2024322A GB 7921448 A GB7921448 A GB 7921448A GB 7921448 A GB7921448 A GB 7921448A GB 2024322 A GB2024322 A GB 2024322A
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GB
United Kingdom
Prior art keywords
rotor
engine
rotor core
core
arcuate
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.)
Granted
Application number
GB7921448A
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GB2024322B (en
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Hitachi Ltd
Original Assignee
Hitachi Ltd
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Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Publication of GB2024322A publication Critical patent/GB2024322A/en
Application granted granted Critical
Publication of GB2024322B publication Critical patent/GB2024322B/en
Expired legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
    • G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
    • G01D5/2013—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by a movable ferromagnetic element, e.g. a core
    • 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
    • F02P1/00—Installations having electric ignition energy generated by magneto- or dynamo- electric generators without subsequent storage
    • F02P1/08—Layout of circuits
    • F02P1/086—Layout of circuits for generating sparks by discharging a capacitor into a coil circuit
    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K39/00—Generators specially adapted for producing a desired non-sinusoidal waveform
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D2205/00—Indexing scheme relating to details of means for transferring or converting the output of a sensing member
    • G01D2205/70—Position sensors comprising a moving target with particular shapes, e.g. of soft magnetic targets
    • G01D2205/77—Specific profiles
    • G01D2205/774—Profiles with a discontinuity, e.g. edge or stepped profile

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Abstract

A magnetic flux varying region 2 is provided on the outer periphery of a rotor 1 disposed opposite to and spaced from a core 5a, 5b of a pulse generator coil 6. The magnetic flux varying region 2 is arcuate and extends over a center angle theta of the rotor corresponding to a predetermined rotary angle of the engine so that output signals P1, P2 having opposite polarities may be generated by the pulse generator when the leading edge 2a and the trailing edge 2b of the magnetic flux varying region pass the core 5a, 5b. Two angular positions of the engine crankshaft can thus be detected in accordance with the output signals. <IMAGE>

Description

SPECIFICATION Apparatus for detecting angular position of engine crankshaft This invention relates to an apparatus for detecting the angular position of the crankshaft of an engine and especially one capable of detecting two angular positions of the crankshaft by a signal pulse generator (hereinafter referred to as a pulser).
It is well known that the ignition timing should be electrically advanced or retarded in accordance with the rotational speed of the engine.
For example, the specification of the US Patent No.
3,646,667 discloses an ignition circuit for electrically detecting two different angular positions of the crankshaft. According to this disclosure, a permanent magnet is embedded in a rotor having an annular disc shape and rotated in timing with the rotation of the crankshaft of the engine and two pulsers are fixed on the inner periphery of the annular-disc rotor, with an angular displacement O3 corresponding to an ignition lead angle between the radial axes of the two pulsers, whereby output signals are obtained by the use of the sudden change in magnetic flux density caused when the magnet passes the cores of the pulsers.According to this structure, however, since the two pulsers are rigidly mounted on the stator, angularly spaced from each other, the size of the stater must be large enough as compared with those of the pulsers and also not only the mounting but the maintenance of the pulsers requires much elaborate labor.
It is therefore an object of this invention to provide an apparatus for detecting the angular position of the crankshaft of an engine, which can detect two different angular positions of the crankshaft by means of a single pulser and accordingly, derive two output signals having opposite polarities.
According to this invention, there is provided an apparatus for detecting the angular positions of the crankshaft of an engine, comprising a rotor rotated in timing with the revolution of the engine and a pulser. The core of the rotor is provided with an arcuate magnetic flux varying region extending over a center angle of the rotor corresponding to a predetermined rotary angle of the engine. A single stationary pulser is disposed to face the periphery of the rotor core with an airgap therebetween.
Taking the facility in working into consideration, the rotor may preferably be formed of a magnetic material such as iron and shaped into a disc with an arcuate projection or groove integrally formed along a part of the outer periphery thereof.
To improve the output of the pulser, a piece of arcuate magnet may preferably be fitted in the arcuate groove.
Other objects, features and advantages of this invention will be apparent in connection with the following description, the appended claims and the accompanying drawings, in which: Fig. 1 shows in block diagram an electronic ignition timing advancing apparatus provided with an apparatus for detecting the angular positions of the crankshaft of an engine, as an embodiment of this invention; Fig. 2 is a cross section taken along the line ll-ll in Fig. 1; Fig. 3 shows the waveforms of the outputs of the pulser used in the apparatus shown in Fig. 1; Fig. 4 shows an ignition circuit used with the embodiment of this invention; Fig. 5 shows a second embodiment of this invention, in which the relative arrangements of the rotor and the pulser are manifested; Fig. 6 shows the waveforms of the outputs of the pulser shown in Fig. 5;; Fig. 7 shows a third embodiment of this invention, in which the relative arrangements of the rotor and the pulser are manifested; Fig. 8 shows a cross sectional view associated with Fig.7; Fig. 9 shows the waveforms of the outputs of the pulser shown in Fig. 7; and Fig. 10 shows a fourth embodiment of this invention, in which the relative arrangements of the rotor and the pulser are manifested.
Referring particularly to Fig. 1, there is illustrated an apparatus for detecting the angular positions of the crankshaft of an engine (hereafter referred to for brevity as crank angle detector). In Fig. 1, a discshaped rotor 1 is made of a magnetic material such as iron orthe like and rotated in timing with the crankshaft of the engine. The disc-shaped rotor 1 has a projection 2 provided on a part of its periphery, the projection 2 serving as a magnetic flux varying region (corresponding to an ignition lead angle of 0).
The radially outer periphery of the projection 2 is arcuate and concentric with the outer periphery of the rotor 1. The projection 2 may be formed integrally with the rotor 1 through, for example, shaping process using extruding deformation.
A pulser3, whose cross section is shown in Fig. 2 and which is disposed to face the rotor 1, comprises a magnet 4, core pieces 5a and 5b and a pulse generating coil 6. The magnet 4, the core pieces 5a and 5b and the coil 6 are assembled together as shown in Fig. 2 and the assembly is moulded with region.
With this structure, when the projection 2 of the rotor 1 is lying opposite to the core piece 5a, the airgap between the rotor 1 and the core pieces 5a and 5b is shortened so that the magnetic flux through the core piece 5a is more in this case than in another case where the projection 2 is out of the encounter with the core piece 5a. Namely, the output of the pulse generating coil 6 suddenly changes because of the steep change in magnetic flux when the core piece 5a encounters the leading edge 2a and the trailing edge 2b of the arcuate projection 2.As shown in Fig. 3, the coil 3 delivers, during every one rotation of the rotor 1, a positive pulse P, and a negative pulse P2 having a lag equal to the angle Owith respect to P1. The output pulses P1 and P2, having opposite polarities, can be easily separated from each other for individual use. Namely, the signals P, and P2 are led to an electronic ignition timing advancing circuit 7, as shown in Fig. 1, to control the ignition timing of an ignition circuit 8 in accordance with the rpm of the engine.
Fig. 4 shows a capacitor discharged ignition device of stepwise ignition timing advancing type to which a crank angle detector as an embodiment of this invention is applied. In Fig. 4, the positive output P1 of the pulse generating coil 6 is transmitted through a diode D1, a thyristor SCR and a diode D3 so that the thyristor SCR is controlled, and the negative output P2 is sent through a diode D4, a resistor R, the thyristor SCR and a diode D2 so that the thyristor SCR is controlled. A charging coil 9 to charge a capacitor C delivers an ac output when energized buy a main rotor 10 rotated in timing with the rotor 1. The ac output is rectified by the combination of diodes D5 and D6 and the capacitor C and charges the capacitor C.The charges stored in the capacitor Care released through the primary winding 1 la of an ignition coil 11 when the SCR is fired under the control of the pulse signals from the pulser 3. As a result, a high voltage is induced across the secondary winding 11 b of the ignition coil 11 so that an ignition plug 12 produces a spark. The sparking of the ignition plug 12 takes place in response only to the output pulse P, corresponding to the non-advanced ignition angle while the rpm of the engine is low. This is because while the rpm of the engine is low, the output P2 as well as the output P1 is so small that the output P2 cannot control the thyristor SCR against the resistance of the resistor R. As the rpm of the engine increases, the output P2 comes also to acquire control over the thyristor SCR.This means that the ignition timing is advanced stepwise by an angle Oat the high rpm performance of the engine. This, according to this embodiment, the different angular positions corresponding to the non-advanced and the advanced ignition timings can be detected by the use of the single pulser 3 and the ignition timing can be electronically advanced. It is also understood that instead of the stepwise advance as described above, some intermediate angular positions between the two extreem angular positions corresponding to the above mentioned non-advanced and the advanced ignition timings may be detected to select intermediate advances of ignition timing depending on the rpm of the engine.
Figs. 5 and 7 (with 8) show other embodiments of this invention, in which modified arrangements of the rotor and the pulser are illustrated.
In Fig. 5, an arcuate magnetic material 13, for example an iron plate, extending over a center angle of û is embedded in the periphery of a disc-shaped rotor 1 of a non-magnetic material such as die-cast aluminum. This rotor 1 can also give rise to a positive and a negative pulses P2 and P1, as shown in Fig.
6, corresponding to the angular positions indicated by the extreme ends 1 2a and 1 2b of the magnetic material 13.
In the embodiment shown in Figs. 7 and 8, a piece of magnet 14 is embedded in a rotor 1 so that magnetic flux is generated only within an angle of û.
Although the structure of this embodiment is more complex than that of the embodiments described above, the output waveforms obtained by this embodiment is improved. In Figs. 7 and 8, a pole piece 15 and an axial portion 16 are made of a magnetic material such as iron, while the main part 17 of the rotor 1 is formed of a non-magnetic material such as die-cast aluminum. A pulser 3 comprises a coil 6 and a core 5a which contains no magnet therein.
In the embodiment shown in Fig. 10, an arcuate recess 20 extending over a center angle û is substituted for the projection 2 in the embodiment shown in Figs. 1 and 2. Also, in this case, magnetic flux changes through the angle û and a negative and a positive pulses corresponding to the ends 20a and 20b can be generated.

Claims (8)

1. A crank angle detector for an engine comprising a rotor having a core and rotated in timing with the revolution of the engine and pulse generating means disposed to face said rotor and having core means and trigger coil means wound on said core means, the improvement wherein the core of said rotor is provided with an arcuate magnetic flux varying region extending over a center angle of said rotor corresponding to a predetermined rotary angle of the engine, and said rotor core is disposed opposite to a single stationary pulse generator provided as said pulse generating means with an airgap therebetween.
2. A crank angle detector as claimed in Claim 1, wherein said rotor core is provided with an arcuate projection along a part of the periphery thereof, said arcuate projection extending over a center angle of said rotor core corresponding to a predetermined rotary angle of the engine.
3. A crank angle detector as claimed in Claim 2, wherein said arcuate projection is formed by protruding radially outward both the opposite end surfaces of said rotor core.
4. A crank angle detector as claimed in Claim 1, wherein said rotor core has an arcuate groove cut along a part of the periphery thereof, said arcuate groove extending over a center angle of said rotor core corresponding to a predetermined rotary angle of the engine.
5. A crank angle detector as claimed in Claim 1, wherein said rotor core is made of a non-magnetic material and has an arcuate groove cut along a part of the periphery thereof, said groove extending over a center angle of said rotor core corresponding to a predetermined rotary angle of the engine, and a piece of magnetic material is fixedly fitted in said arcuate groove.
6. A crank angle detector as claimed in Claim 1, wherein said rotor core is made of a non-magnetic material and has an arcuate groove cut along a part of the periphery thereof, said arcuate groove extending over a center angle of said rotor core corresponding to a predetermined rotary angle of the engine, and a piece of magnet is fixedly fitted in said groove.
7. A crank angle detector as claimed in Claim 6, wherein said magnet has a pole piece fixedly attached to the outer surface thereof.
8. A crank angle detector substantially as hereinbefore described with reference to Figures 1 to 4or Figures 5 and 6, or Figures 7 to 9 or Figure 10 of the accompanying drawings.
GB7921448A 1978-06-26 1979-06-20 Apparatus for detecting angular position of engine crankshaft Expired GB2024322B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7654378A JPS554518A (en) 1978-06-26 1978-06-26 Crank angle detector of engines

Publications (2)

Publication Number Publication Date
GB2024322A true GB2024322A (en) 1980-01-09
GB2024322B GB2024322B (en) 1983-04-27

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB7921448A Expired GB2024322B (en) 1978-06-26 1979-06-20 Apparatus for detecting angular position of engine crankshaft

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JP (1) JPS554518A (en)
DE (1) DE2925561A1 (en)
GB (1) GB2024322B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1983003283A1 (en) * 1982-03-11 1983-09-29 Bosch Gmbh Robert Sensor

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JPS569077A (en) * 1979-06-30 1981-01-29 Toshiba Corp Deciding system for operating state of apparatus
EP0058498B1 (en) * 1981-02-18 1985-09-11 LUCAS INDUSTRIES public limited company Position transducer
EP0066975B2 (en) * 1981-06-05 1989-12-13 LUCAS INDUSTRIES public limited company Internal combustion engine function control system
JPS6040957B2 (en) * 1981-08-06 1985-09-13 宮地電子株式会社 How to control the quality of resistance welding
JPS6178580A (en) * 1984-09-21 1986-04-22 Dengensha Mfg Co Ltd Controlling method for resistance welding
JPS6213277A (en) * 1985-07-09 1987-01-22 Dengensha Mfg Co Ltd Monitoring method for abnormality in work plate thickness in spot welding
JPS63122773U (en) * 1987-01-30 1988-08-10
JPS6457989A (en) * 1987-08-28 1989-03-06 Kinzoku Gijutsu Kenkyusho Kk Method for controlling electric resistance welding of metal
DE3924843A1 (en) * 1989-07-27 1991-02-07 Prufrex Elektro App METHOD AND ARRANGEMENT WITH INDUCTIVE ENCODER FOR CONTROLLING, IN PARTICULAR, THE IGNITION TIMING POINT OF INTERNAL COMBUSTION ENGINES
US6298811B1 (en) 1998-09-29 2001-10-09 Komatsu Zenoah Co. Stratified scavenging two-cycle engine
JP3592237B2 (en) 1999-04-23 2004-11-24 小松ゼノア株式会社 Stratified scavenging two-cycle engine
DE60336678D1 (en) 2002-12-20 2011-05-19 Husqvarna Zenoah Co Ltd EITAKTSP LMOTORS
JP4286636B2 (en) 2003-11-12 2009-07-01 ハスクバーナ・ゼノア株式会社 Conductive coupling mechanism between angled valve stems
JP2005146915A (en) 2003-11-12 2005-06-09 Komatsu Zenoah Co Transmitting coupling mechanism
JP5922569B2 (en) 2012-12-28 2016-05-24 株式会社マキタ Stratified scavenging two-stroke engine
CN104234855A (en) * 2013-06-21 2014-12-24 浙江福爱电子有限公司 Corner marking device of electronic fuel injection engine
CN106152922B (en) 2016-06-15 2018-10-12 山东固特电气有限公司 Location of the core method applied to rotor of large turbo-type generator hub of a spool point location judgment means

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1983003283A1 (en) * 1982-03-11 1983-09-29 Bosch Gmbh Robert Sensor

Also Published As

Publication number Publication date
DE2925561A1 (en) 1980-01-10
JPS554518A (en) 1980-01-14
GB2024322B (en) 1983-04-27

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PCNP Patent ceased through non-payment of renewal fee