JPS6235068A - Internal combustion engine ignition timing control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 1 five lights 1 The present invention relates to an ignition timing control device for an internal combustion engine.

9. A configuration in which a through hole communicating with the combustion chamber is drilled in a member constituting the combustion chamber such as the cylinder head of an internal combustion engine, and a focus sensor using a piezoelectric element is inserted into the hole to detect changes in the cylinder internal pressure as a so-called finger pressure signal. It can be obtained as It is also conceivable to provide a pressure gauge in the joint between the cylinder head and the cylinder block to obtain a finger pressure signal.

It can be seen that the engine cylinder internal pressure change during the operating state of the internal combustion engine is as shown in curve A in Fig. 1. When the ignition system is triggered at the ignition angle θrG, the ignition delay θd
The air-fuel mixture is then ignited, and the cylinder internal pressure then follows a process of rapidly rising, reaching a maximum pressure peak P (hereinafter referred to as the shiatsu peak), and then dropping.

It is known that the crank rotation angular position of this shiatsu peak is related to the state in which the engine exerts its maximum output, and the crank rotation angular position of the shiatsu peak that can provide this maximum output is as shown in the figure above. After dead center (hereinafter referred to as AT)
It was experimentally confirmed that the angle is between 12° and 13° (referred to as DC). Therefore, the acupressure peak is set as the ideal crank rotation angle position between 2° and 13° of ATDC.
The applicant has already proposed an ignition timing control device using a finger pressure detection method that controls the ignition timing θ!G to an ideal crank rotation angle position of 12° to 13″.

Such an ignition timing control device directly detects the cylinder internal pressure, obtains acupressure peak position data for each engine cycle using a shiatsu signal representing the cylinder internal pressure, and advances or advances the ignition timing for each engine cycle by comparing the data with crank reference position data. It is designed to retard the angle. Incidentally, in such a finger pressure detection type ignition timing control device, the top dead center (hereinafter referred to as TDC) position is normally used as the crank reference position, and in order to detect the crank reference position, a reference position signal is output at the TDC position. A reference position signal generation circuit is provided to generate a reference position signal.

On the other hand, a clock generation circuit is provided that generates clock pulses synchronized with the rotation of the crank, and the acupressure peak position is detected by counting the clock pulses from the generation time of the reference position signal to the acupressure peak time every time the reference position signal is generated.

Both the reference position signal generation circuit and the clock generation circuit require a detection section such as a pulser to be provided in the engine in order to obtain signals synchronized with crank rotation. However, the detection section requires relatively space, and when two detection sections are provided, the layout in the engine becomes difficult and the cost increases.

SUMMARY OF THE INVENTION Therefore, the present invention provides an ignition timing control device using a finger pressure detection method, which can control the ignition timing by generating a reference position signal and a clock pulse at low cost and without complicating the layout of the engine. The purpose is to

In the ignition timing control device according to the present invention, since it has been confirmed that the shiatsu peak position is equal to the reference position (TDC position) when the engine is started, the crank rotation angular position reaches the predetermined position from the reference angular position to the reference angular position again. A clock pulse generating means generates a number of zero pulses in synchronization with the crank rotation, generates a peak signal when the finger pressure signal reaches its maximum peak immediately after the start of the engine starting operation, and returns to the reference position at the point of generation of the peak signal. A signal is generated, and thereafter, a reference position signal is generated every time a predetermined number of clock pulses are counted.

Figure 2 shows an ignition timing control device for a two-stroke engine according to the present invention. An acupressure signal generating circuit 1 is included, which is obtained by drilling a through hole and closely inserting a pressure sensor such as a piezoelectric element into the through hole so that its detection head is exposed inside the combustion chamber. At the output end of the acupressure signal generation circuit 1, there is a waveform shaping circuit 2 that outputs a high level when the acupressure signal level is above a predetermined level.
is connected. Clock generation circuit 3 generates clock pulses synchronized with engine rotation.

The means for obtaining clock pulses is a disk that rotates in response to the rotation of the crankshaft, and is arranged at equal intervals of 64
A pulser is known in which a photocoupler is combined with a slit disk having slits of 1, and a clock pulse is obtained from the output signal of the photocoupler. The one-shot pulse generating circuit 4 generates a high-level pulse having a predetermined time width when the engine start switch 5 is turned on. The AND circuit 6 calculates the AND of the output levels of the waveform shaping circuit 2, clock generation circuit 3, and one-shot pulse generation circuit 4. The ring counter 7 for measuring the crank angle position is a 64-base counter that receives clock pulses and is reset to a count value of 0 by a high level signal output from the AND circuit 6. The reference position signal generation circuit 8 consists of a NOR circuit 9 and an AND circuit 10.
The ring counter 7 is at zero and generates a reference position signal when a clock pulse is generated. The peak hold circuit 11 holds the maximum value of the acupressure signal after being cleared by the reference position signal, and the comparator circuit 12 generates a peak detection signal when the acupressure signal itself falls below the maximum value. The latch circuit 13 latches the count value of the ring counter 7 every time the peak detection signal from the comparison circuit 12 is supplied to its gate terminal g. on the other hand,
The decoder 14 sends a reading command signal to the ignition angle setting circuit 15 when the count value of the ring counter 7 reaches 12, for example.
supply to. The count value 12 corresponds to a crank angle that is larger than the crank angle at which the acupressure peak value is predicted to occur, and the reading timing is such that it is not affected even if the valve seating noise of the exhaust valve mixes into the acupressure signal. It has gained.

In response, the ignition angle setting circuit 15 reads the contents of the latch circuit 13 and determines the latch contents as peak position data θpx on the crank angle. Note that the decoder 14
A configuration is also conceivable in which the latch contents are supplied to the ignition angle setting circuit 15 via a gate circuit that opens the gate in response to a read command signal from the ignition angle setting circuit 15. The ignition angle setting circuit 15 is configured by a microprocessor, etc., and receives peak position data θ.
Based on px, desired ignition angle θIC data is supplied to the ignition command circuit 16 according to a program described later.

The ignition command circuit 16 counts clock pulses based on the reference position signal to know the current crank angle value θig, and when this current value θig and the input θTG match, opens the ignition switch SW, thereby opening the ignition transformer T. Ignition current flows through the primary coil of the spark plug (not shown) to ignite the spark plug. Note that the ignition angle setting circuit 15 and the ignition command circuit 16 form an ignition command means. Further, the ignition angle setting circuit 15 receives various engine parameters from the engine parameter sensor 17, namely, engine rotation speed Ne1 suction negative pressure P B N throttle distance θth,
A mode that operates based on the engine cooling water 21TW or the like may also be provided.

Such ignition timing according to the present invention! In the 17611 device, when the starter switch 5 is turned on when starting the engine, the one-shot pulse generating circuit 4 generates a high-level pulse with a predetermined time width representing the starting state of the engine, as shown in FIG. 3(A). When the crankshaft is rotated by a starter motor (not shown) and the combustion chamber pressure rises, and the acupressure signal level output from the acupressure signal generating circuit 1 exceeds a predetermined level as shown in FIG. 3(B), the waveform is shaped. The output level of the circuit 2 becomes high as shown in FIG. 3(C), and this high level is taken as the peak signal.

On the other hand, as the crankshaft rotates, a clock pulse is generated from the clock generation circuit 3 as shown in FIG. 3(D). When the output level of the waveform shaping circuit 2 becomes high level and a clock pulse is generated while a high level pulse is being generated from the one shot pulse generation circuit 4, A
As shown in FIG. 3(E), the ND circuit 6 supplies the ring counter 7 with a reset pulse having the same buff width of 12 as the clock pulse. The reset pulse resets the count value of ring counter 7 to O, so ring counter 7
is counted up from 0. When the count value of the ring counter 7 reaches O, a reference position signal is generated from the reference position signal generation circuit 8 as shown in FIG. 3(F) simultaneously with the clock pulse generated at that time. That is, when the engine speed is low, the peak of the acupressure signal coincides with the TDC position, so the time when the reset pulse is generated becomes the reference position for the crank rotation angle. Therefore, a reference position signal is generated at the reference position every time 64 clock pulses are counted starting from the time when the reset pulse is generated.

After the engine is started, when the reference position signal and the clock pulse are generated as shown in FIGS. 4(A) and 4(B), the acupressure signal changes as shown by the solid line in FIG. 4(C). , the output of the peak hold circuit 11 is as shown by the dotted line 41i1(C). The comparison circuit 12 generates a peak detection signal as shown in FIG. 4(D) at each maximum point of the acupressure signal. FIG. 4(E) shows numerically how the count value of the ring counter 7 changes.

FIG. 4(F) shows numerically how the latched contents of the latch circuit 13 change. Figure 4 (G) shows the decoder 14
In this case, the high level is the read command signal.

FIG. 5 shows an example of a program related to ignition control of the ignition angle setting circuit 15 of the device shown in FIG. That is,
The ignition angle setting circuit 15 performs the ignition control operation by:
First, the ignition angle θIG is set to the initial value θIGO and waits for a reading command signal from the decoder 11. When the reading command signal is received, the latched contents of the latch circuit 10 are taken in as peak position data θp× (step Sr.
, S2). Next, this peak position data θpx is equal to the top dead center angle θTDC (here, θTDC=O'), for example, 1
Determine whether it is greater or less than the sum of the angle α of 2° (step $3); if it is, advance the ignition angle θIG by Δθ (step S4); if it is smaller, increase the ignition angle θIC, △ The angle is retarded by θ (step Ss). One cycle of operations from steps S1 to S5 from the above-mentioned start to end are sequentially executed in response to clock pulses, and the cycle operations are repeated. The following programs are also similar in this regard.

FIG. 6 shows an example of an operating program when the ignition command circuit 16 is formed by a microprocessor. That is, when the ignition command circuit 16 detects the reference device signal (
Step S++), current crank angle value θ of built-in register
ig is set to θTDC (or a predetermined value) (step $12). Next, the ignition angle data θ■G from the ignition angle setting circuit 15 is taken in (step 12) and compared with the current crank angle value θig, and when the condition θig=θTG is established, an ignition command is immediately issued (step S14).
515), open the ignition switch SW. on the other hand,
If θig≠θrc, the unit crank angle δθ is added to θig in preparation for the next program cycle (step 516
). In step S14, instead of determining whether θIQ=θrG, it may be possible to determine whether the difference between 01g and θIG is smaller than δθ.

In the above example, peak position data θpx is obtained for each engine cycle, and θpx in each cycle determines the ignition angle θrG for the next cycle.

In the above-described embodiments of the present invention, the starting state of the engine is detected by turning on the starter switch, but the detection is not limited to this, for example, when the clock pulse generation interval is longer than a predetermined time, or when the engine rotation is detected. The engine starting start state may be set when the number of revolutions is equal to or less than a predetermined number of revolutions.

1. As is clear from the above, according to the ignition timing control device according to the present invention, it is confirmed that the finger pressure peak position coincides with the reference position (TDC position) at the time of engine starting, so the engine starting operation is performed. The reference position signal is generated immediately after the start when the shiatsu signal reaches its maximum peak, and thereafter, the reference position signal is generated every time the clock pulse is counted equivalent to one engine cycle, so the crank rotation angle It is possible to accurately control the ignition timing by detecting the reference position without using a dedicated balsa or the like. Therefore, since only one balsa is required, the balsa can be easily installed in the engine, and the cost of the entire device can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a graph illustrating internal pressure changes in an engine cylinder, FIG. 2 is a circuit diagram illustrating an embodiment of the present invention, and FIGS. 3 and 4 are signal waveform diagrams illustrating the operation of the device shown in FIG. FIGS. 5 and 6 are flowcharts showing operating programs of the portion constituted by the microprocessor of the apparatus shown in FIG. Explanation of symbols of main parts 7...Ring counter 8...Reference position signal generation circuit 13...Latch circuit 14...Decoder 15... - Ignition command circuit 16...Ignition command circuit SW...Ignition switch T...Ignition transformer Applicant Honda Motor Co., Ltd. Agent Patent attorney Motohiko Fujimura Figure 1 Figure 4 Diagram (cut)
- Fig. 5 End Start End Procedure Amendment Written spontaneously) October 24, 1985 1, Indication of the incident 1985 Patent Application No. 173904 2, Name of the invention Ignition timing control device for internal combustion engine 3, Person making the amendment Relationship to the incident Patent applicant address: 6-27-8 Jingumae, Shibuya-ku, Tokyo
Name (532) Honda Motor Co., Ltd. 4, Agent Address: 104 Address: 3-10-9 Ginza, Chuo-ku, Tokyo Procedural Notice (self-motivated) October 30, 1985 1, Incident Indication: 1985 Patent Application No. 173904 2, Title of Invention: Internal Combustion Engine Ignition Timing Control Device 3, Relationship with the Amendment Case Patent Applicant Address: 6-27-8 Jingumae, Shibuya-ku, Tokyo
Name (532) Honda Motor Co., Ltd. 4, Agent 104

Claims (1)

[Claims] a reference position signal generating means for generating a reference position signal each time the crank rotational angular position of the internal combustion engine reaches a reference angular position; a finger pressure signal generating means for generating a finger pressure signal representing the engine combustion chamber pressure; and a reference position signal. peak position detection means for generating an acupressure peak data signal representing the maximum peak position of the acupressure signal from generation to generation of the next reference position signal; and an ignition command for instructing engine ignition at an ignition angle according to the acupressure peak data signal. The reference position signal generating means generates a predetermined number of clock pulses in synchronization with the crank rotation until the crank rotation angular position reaches the reference angular position again from the reference angular position. a clock pulse generating means; a peak detecting means for generating a peak signal when the acupressure signal reaches a maximum peak immediately after the start of the engine starting operation; and a reference position signal for generating a reference position signal at the time of generation of the peak signal and thereafter for generating the clock pulse. 1. An ignition timing control device for an internal combustion engine, comprising: counting means for generating the reference position signal every time a predetermined number of .