JPH0511562B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Technical Field) The present invention relates to detection of a reference position of a rotating body for detecting a crank angle position in an engine ignition control device.

(Prior Art) Conventionally, when detecting a crank angle position in an engine ignition control device, a first rotating body having a convex portion at each unit angle on the circumference of the crankshaft and a reference position of the crankshaft on the circumference are used. and a second rotating body having a convex portion indicating the angle, an angle signal is detected from the first rotating body via an electromagnetic pickup, and a reference position signal is detected from the second rotating body via another electromagnetic pickup. , the crank angle position was calculated using a microcomputer, and the energization timing and ignition timing were controlled by calculation processing (for example, the
Publication No. 19851).

Another method is to attach a rotary body with convex portions for each unit angle on the circumference and remove N convex portions to the crankshaft, and detect an angle signal from the rotary body via an electromagnetic pickup. Using a microcomputer, calculate the time required to rotate a unit angle and the time required to rotate (unit angle) x (N+1), and determine the reference position by taking the difference, and calculate the crank angular position, It controlled energization timing and ignition timing.

(Problems to be Solved by the Invention) However, in the former method, since the first rotating body and the second rotating body are provided on the same axis,
Each electromagnetic pickup mistakenly detects the protrusion of the rotating body corresponding to the other electromagnetic pickup due to interference, and in order to avoid interference, it is necessary to space the first and second rotating bodies sufficiently apart in the axial direction. However, there was a problem that the shape of the detection part became large.

In addition, in the latter method, it is necessary to calculate the time difference using a microcomputer, so when the rotational fluctuation is large like an engine, the program becomes enormous and the calculation takes a long time, making it impossible to follow the high speed rotation of the engine. There was a problem.

(Means for Solving the Problems) The present invention provides a rotating body in which a convex portion is provided for each unit angle on the circumference of a rotating body attached to a crankshaft of an engine, and at least one of the convex portions is missing. body and
two electromagnetic pickups arranged at regular intervals around the rotating body; first and second latch circuits that respectively latch the signals detected by the electromagnetic pickups and reset them using a reset signal; The reset signal is output based on the output of the latch circuit, and the first and second
and a microcomputer that detects the reference position of the rotating body based on the output of the latch circuit.

(Function) When the rotating body rotates due to rotation of the engine crankshaft, each electromagnetic pickup detects a crank angle signal every time a convex portion of the rotating body passes. The crank angle signals are latched by the first and second D-type flip-flops, respectively, and are reset by a reset signal output from the microcomputer after a certain period of time from the fall of the output signal of the first D-type flip-flop. Therefore, during one rotation of the rotating body, there are times when the output of the first D-type flip-flop becomes "L" and the output of the second D-type flip-flop becomes "L". The microcomputer detects this moment and sets it as the reference position of the rotating body, that is, the crankshaft.

(Embodiment) Fig. 1 is a block diagram of an embodiment of the present invention, in which numeral 1 is attached to the crankshaft of an engine (not shown), and convex portions are provided at 45 degree intervals on the circumference. A rotating body with one piece missing; 2 and 3 are electromagnetic pickups that detect a rotation angle signal (hereinafter referred to as a crank angle signal) when the convex portion passes; 4 and 5 are electromagnetic pickups that shape the waveform of the rotation angle signal. waveform shaping circuit,
Reference numerals 6 and 7 denote a D-type flip-flop 8 which latches the output signals from the waveform shaping circuits 4 and 5, and a microcomputer. The electromagnetic pickups 2 and 3 are arranged at an interval of 90 degrees from each other about the axis of the rotating body 1. Note that other parts of the engine ignition control device are omitted.

Next, the operation of this embodiment will be explained with reference to FIG. 1 and the timing chart of FIG. 2. In FIG. 1, the rotating body 1 is rotated due to the operation of the engine (not shown).
When rotates in the direction of the arrow, the electromagnetic pick-up 2
detects the crank angle signal shown in FIG. 2a every time the convex portion of the rotating body 1 passes, and the electromagnetic pickup 3 similarly detects the crank angle signal shown in FIG. 2b. The respective crank angle signals are waveform-shaped by waveform shaping circuits 4 and 5, respectively, and inputted to the CK terminals of D-type flip-flops 6 and 7. The D-type flip-flops 6 and 7 change their output terminals or Q at the rising edge of the input signal, and send their outputs to the input terminals INT or Q of the microcomputer 8.
Send to STATUS. microcomputer 8
immediately after the fall of the signal input to the input terminal INT, the F/FCLR signal shown in Figure 2e is input to the terminal F/
Output from FCLR, D type flip-flop 6, 7
Reset. The output waveforms of the D-type flip-flops 6 and 7 are shown in FIG. 2c and d, respectively. The microcomputer 8 is at a position where the input signal of the input terminal INT is "L" and the STATUS input signal is "L", that is, the signal shown in FIG. 2c is "L".
The position p where the signal d becomes "L" is detected, and this position is taken as the reference position of the rotating body 1, that is, the crankshaft. In addition, in the microcomputer 8, the program for outputting the F/FCLR signal shown in Figure 2e from the terminal F/FCLR after a certain period of time from the fall of the signal input to the input terminal INT can be realized with a simple program. is publicly known.

3 to 5 show other embodiments of the arrangement of electromagnetic pickups, and FIG.
This is the case where the angle is 60 degrees, as shown in Figure 4.
Figure 5 shows the case where the angles are 128° and 180°, respectively. Each crank angle signal detected by each of the electromagnetic pickups 2 and 3 is processed by the circuit shown in FIG.
8. The reference position p is detected in the same manner as in FIG. 2.

(Effects of the Invention) As explained above, since the present invention uses one rotating body to obtain the crank angle signal, it is more efficient than the method using two rotating bodies to obtain the angle signal and the reference position signal. The shape becomes smaller. In addition, each crank angle signal detected by the electromagnetic pickup is
and a second D-type flip-flop or latch circuit, and by resetting both latch circuits based on the output of the first latch circuit, the output of the first latch circuit is activated only at a predetermined position of the rotating body. Since the output of the second latch circuit is set to "L", the program for detecting a predetermined position of the rotating body using a microcomputer from the outputs of both of the above-mentioned latch circuits is very simple. Become. Therefore, even if the crank rotation fluctuates drastically,
Even during high rotation, it is possible to reliably detect the reference position in a short time. Furthermore, since the mutual spacing between the electromagnetic pickups can be set arbitrarily, the present invention is applicable to various chelicerae engines.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a timing chart of Fig. 1, Figs. 8 are timing charts corresponding to FIGS. 3 to 5. FIG. 1... Rotating body, 2, 3... Electromagnetic pickup, 4,
5... Waveform shaping circuit, 6, 7... D-type flip-flop, 8... Microcomputer.

Claims (1)

[Claims] 1. A rotary body attached to the crankshaft of an engine, with convex portions provided at every unit angle on the circumference of the rotary body, at least one of which is missing, and a convex portion arranged at regular intervals around the rotary body. two electromagnetic pickups installed, first and second latch circuits that respectively latch the signals detected by the electromagnetic pickups and reset them using a reset signal, and reset the output of the first latch circuit from the reset state. means for outputting the reset signal immediately after the reset state changes to a non-reset state; and means for detecting that the output of the first latch circuit is no longer in the reset state and the output of the second latch circuit is in the reset state. An engine ignition control device comprising: a microcomputer having a microcomputer;