JP2850621B2 - Ignition device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine having a reverse rotation preventing function.

[0002]

2. Description of the Related Art Since a two-cycle internal combustion engine tends to reverse, an ignition device for igniting the internal combustion engine is provided with a reverse rotation preventing function. Conventional ignition devices of this type include those disclosed in Japanese Utility Model Publication No. 3-11421 and those disclosed in Japanese Patent Publication No. 3-27759. Real fair 3-
In the ignition device disclosed in Japanese Patent No. 11421, an electronic device that determines forward rotation and reverse rotation of the engine from the phase relationship between the output of an exciter coil that gives ignition energy and the output of a signal coil that outputs a signal for determining ignition timing. Provide a circuit,
When the reverse rotation of the engine is detected, the ignition operation of the engine is stopped. In the ignition device disclosed in Japanese Patent Publication No. 3-27759, a signal generator is provided with two signal coils, and the phase relationship between the outputs of the two signal coils is determined by an electronic circuit. The normal rotation and the reverse rotation are detected, and the ignition operation is stopped when the reverse rotation is detected.

[0003]

[Problems to be solved by the invention] Japanese Patent Publication No. 3-27759
In the igniter shown in the above publication, it is necessary to provide two signal coils in the signal generator, so that the structure of the signal generator was inevitably complicated. In addition, all of the conventional ignition devices need to be provided with an electronic circuit for detecting the normal rotation and the reverse rotation of the engine, so that there is a problem that the configuration of the ignition device is complicated and the device becomes large.

Since a recent ignition device for an internal combustion engine uses a microcomputer to calculate the ignition timing, it is not advisable to provide an electronic circuit for detecting the forward rotation and the reverse rotation of the engine. It is preferable that the detection of the rotation direction can be performed by a microcomputer.

[0005] It is an object of the present invention to detect the rotational direction of an internal combustion engine using a signal obtained from one signal coil and to detect the rotational direction using a microcomputer. It is an object of the present invention to provide an ignition device for an internal combustion engine which can have a reverse rotation preventing function without increasing the size of the ignition device.

[0006]

According to the present invention, as shown in FIG. 1, a rotor driven by an internal combustion engine 1 having a reluctant comprising a projection or a recess and a magnetic pole opposed to the reluctor of the rotor are provided. A pulse signal having a first polarity and a pulse signal having a second polarity when the reluctor starts facing the magnetic pole portion and when the reluctor finishes facing the magnetic pole portion, respectively. Signal generator 2 with electronics
An ignition circuit 3 for outputting a high voltage for ignition when an ignition signal is given; a rotation speed calculating means 4 for calculating a rotation speed from a pulse signal output by the signal generator; And an ignition timing control device 7 having an ignition signal generation means 6 for generating the ignition signal at an ignition timing corresponding to the calculated advance angle. It relates to an ignition device.

In the present invention, the rotor of the signal generator has n (n is an integer of 2 or more) reluctors.
The circumferential length of one of the reactors is set to be longer than the circumferential length of the other reactor,
The angular interval between the n reluctors is set such that the pulse signals of the first polarity are generated at substantially equal intervals when the internal combustion engine is rotating forward.

Further, the ignition timing control device 7 generates a first polarity pulse signal generated this time and a first polarity pulse signal generated last time each time a signal emission generates a first polarity pulse signal. Pulse generation interval detecting means 8 for detecting the generation interval, and N · θx-1 <θx (where N is the distance between the pulse generation interval θx detected this time by the pulse generation interval detection means and the pulse generation interval θx-1 previously detected (Constant), it is detected that the internal combustion engine is rotating forward, and N · θ
When the relationship of x-1 <θx is not established, the rotation direction detecting means 9 for detecting that the internal combustion engine is rotating in reverse, and when the rotation direction detecting means has detected that the internal combustion engine is rotating forward. And a reverse rotation preventing means 10 for prohibiting the generation of an ignition signal when it is detected that the internal combustion engine is rotating in the reverse direction.

[0009]

With the above arrangement, it is possible to detect whether the internal combustion engine is rotating forward or backward without providing two signal coils in the signal generator, thereby simplifying the configuration of the signal generator. Can be. When the ignition timing is controlled by using a microcomputer, the microcomputer can detect the rotation direction of the engine by using the microcomputer.
There is no need to provide an extra electronic circuit, and the configuration of the ignition device can be simplified.

[0010]

FIG. 2 shows a hardware configuration of an embodiment of the present invention. In FIG. 2, 2 is a signal generator, 3 is an ignition circuit, 11 is a microcomputer CPU, and 12 is a microcomputer.
And 13 are RAMs (random access memories)
And ROM (read only memory). Reference numeral 14 denotes a waveform shaping circuit that receives a pulse signal Vp obtained from the signal generator 2 and outputs a rectangular wave signal Vq.

The signal generator 2 comprises a rotor 2A having four reluctors Ro to R3 projecting from the outer periphery of a cylindrical rotating body 200, and a signal generator 2B. The signal generator 2B includes a core 201 having a magnetic pole portion facing the reluctor of the rotor 2A, and a signal coil 2 wound around the core.
02, and a permanent magnet (not shown) for flowing a magnetic flux through the iron core.
Output a pulse signal of the first polarity when each of them starts facing the magnetic pole portion of the iron core 201, and outputs a pulse signal of the second polarity when the reactors Ro to R3 finish facing the magnetic pole portion of the iron core 201. Output. Rotating body 2 constituting rotor 2A
As 00, a flywheel attached to an internal combustion engine can be used. In this embodiment, the rotation in the clockwise direction CW in FIG. In the present embodiment, one end of each of the reactors Ro to R3 numbered 0 to 3 (the end which is located on the front side in the rotation direction during the forward rotation and is opposed to the magnetic pole portion of the signal emission first). The angle interval between them is set to 90 degrees.

FIG. 4A shows the waveform of the pulse signal Vp output from the signal coil 202 when the internal combustion engine is rotating forward. In this example, the pulse signal of the first polarity is a positive pulse signal. The pulse signal of the second polarity is a pulse signal of a negative polarity. Numerals 0 to 3 respectively attached to the positive pulse signals in FIG. 4A are located at one end of each of the reluctors Ro to R3 in FIG. (Ends). That is, the positive pulse signals numbered 0 to 3 are generated when the reactors Ro to R3 respectively start to face the magnetic pole portion of the signal emission. Also 0
A series of negative pulse signals generated following the positive pulse signals of .about.3 are generated when each of the reactors Ro.about.R3 finishes facing the magnetic pole portion of the signal emission.

FIG. 4C shows the waveform of the pulse signal Vp induced in the signal coil 202 when the internal combustion engine rotates in the reverse direction. When the engine rotates in the reverse direction, one end 0 to 3 of the reluctors R0 to R3 of the rotor 2A emits a signal. When facing the magnetic pole portion of the electron, that is, when the reluctor of the rotor 2A finishes facing the magnetic pole portion of the signal-emitting electron, negative pulse signals numbered 0 to 3 are induced.

The waveform shaping circuit 14 outputs a positive-polarity pulse signal (a first-polarity pulse signal) output from the signal coil 202.
Rises when a negative pulse signal (second
, A rectangular signal Vq which falls when a pulse signal having the same polarity is generated. The waveform of the rectangular wave signal Vq output by the waveform shaping circuit 14 when the engine is rotating forward is as shown in FIG. 4B, and the rectangular wave signal Vq output by the waveform shaping circuit 14 when the engine is rotating in reverse is shown in FIG. )become that way. The rectangular wave signal Vq is given to the CPU of the microcomputer.

As is apparent from FIG. 4, when the engine is rotating forward, the intervals of generation of the positive polarity pulse signals (intervals between the rising edges of the rectangular wave signals) θo to θ3 are all substantially equal. The interval θo between the positive pulse signal and the next positive pulse signal is shorter than the intervals θ1 to θ3 of the other positive pulse signals. Therefore, the forward rotation and the reverse rotation of the engine can be detected by sequentially comparing the generation intervals of the positive pulse signal (intervals between the rising edges of the rectangular wave signal).

The ignition circuit 3 includes an ignition coil 300 and a primary current control circuit 301 for controlling the primary current of the ignition coil to rapidly change when an ignition signal Vi is given.
And an ignition plug 302 attached to the cylinder of the internal combustion engine and connected to the secondary coil of the ignition coil, and generates a high voltage for ignition on the secondary side of the ignition coil when an ignition signal Vi is given. I do. As the primary current control circuit 301, a capacitor discharge type circuit or a current cutoff type circuit is known, but in the present invention, any of these types of circuits may be used.

Each means of the ignition timing control device 7 shown in FIG. 1 is realized by a microcomputer. 6 and 7 are flowcharts showing an algorithm of a program for realizing each means. FIG. 6 shows an algorithm of a main routine for realizing the rotational speed calculating means 4 and the advance angle calculating means 5, and FIG. 9 shows an algorithm of an interrupt routine executed each time a rising of the wave signal Vq is detected.

In the main routine shown in FIG. 6, when the engine is started, first, initial settings of each section are performed, and the rotation speed is calculated. The calculation of the number of rotations is performed, for example, from the time from when the reference rising of the rectangular wave signal Vq is detected to when the same reference rising is detected next (the time required for one rotation). In this example, the rising edge of a rectangular wave signal corresponding to the reference pulse signal is set as the reference rising edge, and the reference flag is set in the RAM when the reference rising edge is detected. . The reference rising of the rectangular wave signal corresponding to the 0th pulse signal is detected by sequentially comparing the high-level period TH and the low-level period TL of the rectangular wave signal Vq and detecting TH> TL. Do.

In the main routine, the advance angle of the ignition timing at the calculated rotation speed is calculated. This advance angle is calculated in the form of the number of clock pulses to be counted by the ignition timing determination timer from the time when the reference rise of the rectangular wave signal is detected to the ignition timing.

Each time a rising edge of the rectangular wave signal Vq is detected, an interrupt routine shown in FIG. 7 is executed. In addition to the timer for determining the ignition timing, the microcomputer includes, as shown in FIG. 5, a counter for measuring the time from one rise of the rectangular wave signal to the next rise as a pulse generation interval θx. The RAM is provided with an address Ax for storing the pulse generation interval measured at each rising edge of the rectangular wave signal as θx and an address Ax-1 for storing the pulse generating interval measured at the previous rising edge as θx-1. Keep it. In the interrupt routine of FIG. 7, first, θx measured at the previous rising of the square wave signal and stored at the address Ax is moved to the address Ax-1 as θx-1, and the measured value measured at the current rising is It is stored in the address Ax as θx.

Next, it is determined whether the rotation direction determination flag RVFLG is set and whether or not the flag is "1". If RVFLG is not 1, θx-1 and N
• Compare the magnitude with θx. Here, N is a constant, and the relationship of θx-1 <N · θx and N · θx-1> θx is always satisfied at the time of forward rotation even when there is a rotation fluctuation at the time of rapid acceleration / deceleration of the engine, Sometimes, when θx = θo is measured, the relationship of θx-1> N · θx is established, and when θx = θ3 is detected, the relationship of N · θx-1 <θx is established. Set the size of.

As a result of judging the magnitude relationship between θx-1 and N · θx, if θx-1> N · θx (when the engine is rotating in reverse), a rotation direction judgment flag is set. (RVFLG = 1) and returns to the main routine. When the rotation direction determination flag is set, RVFLG = RVFLG =
Since it is determined to be 1, it is subsequently determined whether or not the relationship of N · θx-1 <θx holds. At this time, θx-1
= Θo, θx = θ3, so that the relationship of N · θx-1 <θx holds. In this case, the process returns to the main routine without performing the ignition operation.

In the process of determining whether or not the rotation direction determination flag RVFLG is 1, if the flag has already been set to 1 and the relationship of N · θx-1 <θx is not established, the reference Reset the flag and return to the main routine.

The rotation direction judging flag RVFLG is not set, the engine is rotating forward, and θx-1> N · θ
If the relationship x is not established, the ignition operation is performed after setting the rotation direction determination flag to 0.

In this ignition operation, it is first determined whether or not a reference flag is set in the RAM. When the reference flag is set (the rising edge of the rectangular wave signal corresponds to the pulse signal of the 0th pulse signal). (When the reference rises), the ignition timing determination timer is immediately set to the already calculated advance angle and the timer is started.
When the measurement of the set count value is completed by the ignition timing determination timer, the ignition signal Vi is generated and the reference flag is reset. When the ignition signal Vi is generated,
The ignition circuit 3 generates a high voltage for ignition, causing a spark in a spark plug to ignite the engine.

In the above-described embodiment, in the interrupt routine shown in FIG. 7, the pulse generation interval detecting means 8 is realized by reading the pulse generation interval θx and storing the pulse generation interval in the address Ax. The process of determining the contents of RVFLG, θx-1 and N · θx
The rotation direction detecting means 9 is realized by the process of determining the magnitude of the rotation direction and the process of setting the rotation direction determination flag. Also, the magnitude of N · θx-1 and θx is determined, and N · θ
When the relationship of x-1 <θx holds, the process of returning to the main routine without generating an ignition signal implements reverse rotation prevention means. In the above embodiment, the rotor of the signal generator includes four reluctors, but the number of reluctors is arbitrary. For example, as shown in FIG. 3, six reluctors Ro to R5 may be provided. In this case,
The angular interval between the ends of the reluctors Ro to R5 numbered 0 to 5 is set to 60 degrees.

In the above embodiment, the reluctor is constituted by the projection. However, the reluctor may be any as long as it causes a change in the magnetic flux linked to the signal coil when facing the magnetic pole of the signal emission. The concave portion formed on the outer periphery of can be used as a reluctor.

[0028]

As described above, according to the present invention, it is possible to detect whether the internal combustion engine is rotating forward or backward without providing two signal coils in the signal generator. There is an advantage that the configuration can be simplified.

According to the present invention, when the ignition timing is controlled using a microcomputer, the rotation direction of the engine can be detected using the microcomputer, so that there is no need to provide an extra electronic circuit. There is an advantage that the configuration of the ignition device can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of the present invention.

FIG. 2 is a configuration diagram schematically showing a configuration of hardware used in an embodiment of the present invention.

FIG. 3 is a front view schematically showing a configuration of a rotor of a signal generator used in another embodiment of the present invention.

FIGS. 4A and 4B are waveform diagrams respectively showing a waveform of a pulse signal and a waveform of a rectangular wave signal obtained at the time of normal rotation of the internal combustion engine in the embodiment of the present invention. (C)
And (D) are waveform diagrams respectively showing a waveform of a pulse signal and a waveform of a rectangular wave signal obtained when the internal combustion engine rotates in reverse.

FIG. 5 is a diagram illustrating a method of measuring a pulse generation interval.

FIG. 6 is a flowchart showing a main routine of a program when each means of the ignition timing control device is realized by a microcomputer in the embodiment of the present invention.

FIG. 7 is a flowchart showing an interrupt routine of the program.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Signal generator, 3 ... Ignition circuit, 4 ... Revolution speed calculating means, 5 ... Advance angle calculating means, 6 ... Ignition signal generating means, 7 ... Ignition timing control device, 8 ... Pulse generation interval detection Means 9: Rotation direction detecting means 10: Reverse rotation preventing means.

Continuation of the front page (56) References Japanese Utility Model Hei 2-3067 (JP, U) Japanese Utility Model Showa 53-92517 (JP, U) Japanese Utility Model Utility Model Hei 1-174543 (JP, U) Japanese Utility Model Utility Model 59-27159 (JP) (U, U) Jpn. 1-177460 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F02P 7/067 F02P 11/02 303 F02D 17/04

Claims (1)

(57) [Claims] 1. An ignition circuit for outputting a high voltage for ignition when an ignition signal is applied, a rotor driven by an internal combustion engine having a reluctor comprising a projection or a recess, and a reluctor of the rotor A pulse signal of the first polarity and a pulse signal of the second polarity when the reluctor starts facing the magnetic pole portion and when the reluctor finishes facing the magnetic pole portion, respectively. A signal generator having a signal generator for outputting the signal; a rotation speed calculating means for calculating a rotation speed from a pulse signal output from the signal generator; and a lead angle calculation for calculating a lead angle at each of the calculated rotation speeds. Means and an ignition timing control device having an ignition signal generation means for generating the ignition signal at an ignition timing corresponding to the calculated advance angle, wherein the rotor of the signal generator comprises: Previous N (n is an integer of 2 or more) of the above-mentioned reluctors, and the circumferential length of one of the n reluctors is set longer than the circumferential length of the other reluctors; When the internal combustion engine is rotating forward, the angular interval between the n reactors is set so that the generation intervals of the pulse signal of the first polarity are substantially equal, and the ignition timing control device includes: Pulse generation interval detection means for detecting the generation interval between the pulse signal of the first polarity generated this time and the pulse signal of the first polarity generated last time each time the signal emission generates a pulse signal of the first polarity. Between the pulse generation interval θx detected this time by the pulse generation interval detection means and the pulse generation interval θx-1 detected last time.
When the relationship of θx-1 <θx (N is a constant) is established, it is detected that the internal combustion engine is rotating forward, and N · θx-1 <
a rotation direction detecting means for detecting that the internal combustion engine is rotating reversely when the relationship of θx is not established; and the ignition signal when the rotation direction detecting means detects that the internal combustion engine is rotating forward. And a reverse rotation preventing means for prohibiting the generation of the ignition signal when it is detected that the internal combustion engine is rotating in the reverse direction.