JP2003227396A - Control signal detection device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control signal detection device for an engine suitable for a snowmobile capable of exactly carrying out distinguishing of cylinders and an engine control even if a detection delay of a reluctor signal or a crank angle signal and a lack of output are generated. <P>SOLUTION: The recoil starter type multi-cylinder engine has a cylinder judgment part for preparing a cylinder distinguishing signal based on a predetermined rotation position of a crank shaft; a crank rotation angle detection part for detecting a rotation angle signal of the crank shaft; a memory part for memorizing the cylinder distinguishing signal and the crank shaft rotation angle signal at the time of stopping of the engine; and an engine control part for operating the engine control signal based on the memorized cylinder distinguishing signal and the crank rotation angle signal at the time of starting of the engine. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control signal detecting device suitable for controlling a snowmobile, an outboard motor, a general-purpose engine, a lawn mower, or a watercraft engine.

[0002]

2. Description of the Related Art Snowmobiles are mainly equipped with a two-cycle engine, which has a relatively simple engine structure, is lightweight, compact and has high power characteristics because of its commercial characteristics for leisure sports.

As an engine of a snowmobile, there is a engine using this two-cycle engine, which employs a fuel injection device to appropriately control the fuel injected from the injector according to the driving condition or the traveling condition (for example, the fuel injection device). JP 200
1-289134, JP-A-2001-289135). This type of snow vehicle is usually equipped with a recoil starter for pulling the recoil rope to start the vehicle, as described in the above publication. On the other hand, some snow vehicles have a starter motor for starting the engine,
Since there is a possibility of self-discharge of the battery when starting at low temperatures, a recoil starter that can manually start the engine with the starter motor is also equipped.

In order to detect signals necessary for engine control such as fuel injection control and ignition timing control, a crank angle detection gear as a striker for detecting with a crank angle sensor is installed on the outer circumference of the flywheel to rotate the flywheel. The sensor is installed and fixed to the crankcase so that the detection end faces the outer surface passing trajectory at the time of.

In the control signal detecting device having the above structure, the cylinder discrimination / crank position for each cylinder is detected and communicated to the electronic control module (ECM). Therefore, it is important in the starting control how to speed up the cylinder discrimination and perform the optimum ignition and injection control.

[0006]

However, the conventional engine control based on cylinder discrimination has the following problems. (1) At present, the cylinder discrimination signal is detected by the rotation of the engine to discriminate the cylinder. However, since the cylinder discrimination signal is output once every one revolution of the engine, the cylinder discrimination is performed by the crank rotation before the engine rotation. There are variations in the speed, and there is a maximum delay of one rotation.

(2) Also, the cylinder discrimination signal is related to the output level of the cylinder discrimination signal according to the recoil rotation speed at the time of starting. That is, since the cylinder discrimination signal is output due to the change in the magnetic flux between the striker and the sensor detection coil, the detection signal output rises as the rotation speed increases, and the voltage level becomes cylinder discriminable. Therefore, if the starting rotation speed is low, such as when the product is started at a low temperature, or if the reluctor is detected before the rotation speed rises, the output level cannot be judged below the specified value, and the 1-rotation cylinder judgment is slower. It is possible that Regarding this point, the cylinder can be discriminated from a low rotation region by lowering the voltage level at which the sensor signal can be discriminated.
It is easy to cause erroneous detection due to the influence of noise on the high speed side.

(3) As for the gear signal which is the engine crank position (crank angle) signal, if the gear signal is not reliably detected after the cylinder discrimination as in the above reference signals, an inaccurate crank signal is generated. There is a problem in that the quality is deteriorated, such as recognizing the position and failing to start due to abnormal injection / ignition, increasing the frequency of illegal combustion, and the like.

In the four-cycle engine, one of the reference angle signals used as a reference of the injection timing is for cylinder discrimination, the cylinder discriminated immediately before the engine is stopped is stored, and the crank angle detected at engine start is stored. The technology for detecting the piston crank angle from the stored cylinder discrimination result (Japanese Patent Laid-Open No. 11-159390), and the operating state together with the cylinder discrimination result are stored immediately before the ignition switch is turned off, and the crankshaft is stopped from those stored values. There is a technique for estimating the position (Japanese Patent Laid-Open No. 11-107823).

However, these techniques only store the cylinder discrimination result or the operating state, and cannot solve the problems (1) to (3) at the time of restart.

Moreover, the techniques of the above-mentioned JP-A-11-159390 and JP-A-11-107823 are mainly aimed at controlling a four-cycle engine having a cam shaft for opening and closing an intake / exhaust valve for automobiles. It is difficult to apply to an engine such as a snow vehicle that has a slow start-up speed and cannot obtain a required sensor output, such as a two-cycle engine that starts recoil.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an engine control signal detecting device suitable for a snow vehicle which can accurately perform cylinder discrimination and engine control even if a detection delay of a reluctor signal or a crank angle signal or an output shortage occurs. And

[0013]

SUMMARY OF THE INVENTION In a recoil starter type multi-cylinder engine, the present invention provides a cylinder discriminating section for producing a cylinder discriminating signal based on a predetermined rotational position of a crankshaft, and a crank for detecting a rotational angle signal of the crankshaft. A rotation angle detection unit, a storage unit that stores the cylinder determination signal and the crankshaft rotation angle signal when the engine is stopped, and performs engine control based on the stored cylinder determination signal and the crank rotation angle signal when the engine is started. It is a control signal detecting device for an engine, which enables the following. In the present invention, the projecting reluctor and the multi-projecting gear that rotate with the rotation of the crankshaft are detected by the detection coils respectively provided in the crankcase, the cylinder is discriminated by the detection of the reluctor, and each of the teeth of the gear is detected. It is preferable that the crank rotation angle is detected. Further, in the present invention, the storage unit has a delay circuit for turning off the power supply at a timing later than when the key switch for turning on / off the power supply to the engine ignition device and other auxiliary equipment is turned off. Is preferred. Further, in the present invention, the magneto has a flywheel and a stator winding, and the reluctor and the gear are
Suitably, it is provided on the outer peripheral surface of the magneto flywheel, and those detection coils are provided around the flywheel. Further, in the present invention, it is preferable that the reluctor detection coil and the gear detection coil are provided on opposite sides of the crankshaft.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall side view of a snowmobile equipped with a two-cycle engine, and FIG. 2 is an overall plan view of the snowmobile. 3 is a side view of the vicinity of the recoil starter of the engine 10 mounted on the snowmobile, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, FIG. 5 is a control flowchart when the engine is stopped, and FIG. 6 is an engine. The control flowchart at the time of control is shown.

As shown in FIGS. 1 and 2, the snowmobile has a vehicle body length longer than the vehicle body width.
The front portion 8a of the vehicle body 8 is formed wider than the rear portion 8b. The engine 10 is housed and mounted in the engine room 12 of the vehicle body front portion 8a, and a pair of left and right steering skis 14a are provided at the lower portion of the vehicle body front portion 8a.
It is provided so that it can be swung left and right by steering. A seat 16 for seating an occupant is provided on the upper portion of the vehicle body rear portion 8b, and a crawler 18 for traveling drive is provided on the lower portion. In the central part of the vehicle body, in the upper part on the front side of the seat 16,
A windshield 20 is erected to cover the handle 14. A key switch, which is a main power supply switch, is provided inside the windshield 20, and a battery, which is a power supply, is housed in the engine room.

The engine 10 mounted in the engine room 12 is a two-cylinder two-cycle engine,
An air cleaner 22a and an intake system 22 of an air supply passage 22b provided with an injection (not shown) are connected to a rear portion of a crankcase 10a of the engine 10 via a reed valve, and an exhaust gas is provided at a front portion of a cylinder 10b of the engine 10. The exhaust system of the manifold 24a, the expansion chamber 24b, and the muffler 24c (which has an arc shape that curves from the front to the right rear of the vehicle body) is connected.

The engine 10 has a crankshaft 28 installed along the vehicle width direction of a snowmobile. The recoil starter 26 is provided on the right side of the engine 10.
(With start-up recoil rope 26a) is provided.

More specifically, as shown in FIG. 4, the engine 10
On the crankshaft 28 shaft end (right side of the first cylinder) of
A flywheel 30a of a rotor of a magneto 30 that generates electric power required for the engine 10 and the vehicle, and a recoil pulley 26b of the recoil starter 26 located outside the flywheel 30a are installed. In the magneto 30, a stator winding 30b which is a stator is installed at an inner peripheral portion of a bowl-shaped flywheel 30a which is the rotor. Further, the recoil starter 26 is installed around a recoil starter pulley 26b arranged ahead of the flywheel 30a (on the right side in the vehicle body width direction). In the starting mechanism of the recoil starter 26, when the user pulls the rope 26a by hand, a ratchet (not shown) in the rotating part of the recoil starter pops out, and a hole 26c in the peripheral part of the recoil starter pulley 26b.
And the crankshaft 28 of the engine 10 rotates to start the operation of the engine 10.

The engine 10 shown in FIGS. 1 to 4 is of a fuel injection type, and is provided with a high-pressure fuel pump indicated by reference numeral 32. The pump 32 has a pulley (driven pulley) 32a and a crankshaft end. A timing belt 36 is wound around a portion (provided between the magneto 30 and the recoil pulley 26b) and a high-pressure fuel pump driving pulley (drive pulley) 34 so as to be driven.

Here, as a structure / means for detecting a signal necessary for engine control from the start, the outer circumference of the flywheel 30a is fried in a plate shape with a certain thickness in the circumferential direction by the plate thickness. A reluctor 38 protruding from the wheel peripheral surface and a gear 40 having a plurality of teeth are installed, and the pulsar coil 42 for cylinder discrimination is arranged so that the detection end faces the outer surface passing locus of the reluctor 38 and the gear 40 when the flywheel 30a rotates. And the crankshaft rotation angle detecting unit 44 are installed and fixed to the crankcase 10a. The pulsar coils 42 and 44 are arranged on the opposite sides of the crankshaft 28 so as to facilitate installation and inspection work. The output signals of the pulser coils 42 and 44 are input to an electronic control module (ECM) for engine control.

Flywheel 30a of the coumagneto 30
Rotates once for each revolution of the crankshaft 28, and the pulser coil 42 causes the reluctor 38 to rotate once for each revolution of the crankshaft 28.
Is detected once. Since the reluctor 38 is installed in correspondence with the predetermined rotation angle position of the crankshaft 28, the ECU determines the crank angle position, that is, the cycle operation position of each cylinder with reference to it. Further, another pulsar coil 44 can detect the teeth of the gear 40 formed for each predetermined angle of the crankshaft and can know the rotation angle of the crankshaft based on the number of detected teeth. Although not shown, the engine control unit receives various detection signals such as engine cooling water temperature and intake pipe negative pressure in addition to the signals of the pulsar coils 42 and 44, and further, an ignition control unit (CDI unit) and a fuel injection unit. It has a well-known configuration such as outputting a drive signal to other auxiliary machines. Power for each control unit and actuator is supplied from a battery via a key switch.

The flow of the control signal detecting apparatus according to the embodiment is shown in FIGS. 5 and 6, in which each step is represented by S.
... and so on. As shown in FIG. 5, when the engine is stopped,
The key switch is turned off (S1), and the ECU and other parts / equipment (CDI ignition power source, injector injection power source, pump, low-pressure side pump power source, variable Preg fuel pressure control power source) are supplied from the battery. Is stopped (S2). Then, the crank angle position based on the reluctor signal and the gear signal immediately before the engine is stopped is written in the memory of the ECM (S3). The reluctor signal / gear signal at this time is 170 r. p. Since it cannot be detected by m, the crank angle amount that rotates by inertia includes a correction value according to operating conditions. Next, delay control is performed to delay and stop the power supply to the ECU (S4).

On the other hand, as shown in FIG. 6, when the engine is started, the key switch is turned on (S11), and power is supplied from the battery to each component / equipment, that is, the ECU and other components / equipment (S12). ). The stored crank angle is read (S13).

Next, when the engine is started by the recoil starter and stopped by cranking several times (S1
4: No), the reluctor signal and the gear signal immediately before the stop are stored again (S15). On the other hand, if it is started by the recoil starter (S14: Yes), the magneto 30 rotates by the rotation of the crankshaft 28 to generate electric power, so the battery is charged with the generated electric power (S16). Next, the detection signal of the reluctor (once for one rotation of the crankshaft) is input, and cylinder discrimination is performed (S17). In this case, the reluctor signal written in S13 is used together with the output from the pulser coil 42 after the start.

The gear signal is detected to detect the crank angle for each cylinder (S18). In this case, the gear signal written in S15 is used together with the output from the pulser coil 42 after starting.

Then, various tables are looked up from the determined cylinder and crank angle position to determine the fuel injection timing suitable for each cylinder (S19), and the fuel is injected from the injector at that timing (S2).
0). Next, various tables are looked up from the determined cylinder and crank angle position to determine the ignition timing suitable for each cylinder (S21), and the mixture gas in the cylinder is ignited at that timing (S22).

According to the embodiment, even if the detection delay or the output shortage of the reluctor signal or the crank angle signal occurs, the reluctor signal and the crank angle signal at the time of the stop before that are stored and used. Position detection delay can be prevented and engine control can be performed accurately.
Note that the present invention is not limited to the engine for a snow vehicle, and may be used as a control signal detection device for an outboard engine, a general-purpose engine, a lawn mower engine, or a watercraft engine.

[0028]

As described above, according to the present invention, even if the detection delay of the reluctor signal or the crank angle signal or the output shortage occurs, the reluctor signal and the crank angle signal at the time of stopping before that are stored and used. Therefore, it is possible to prevent cylinder discrimination and crank angle position detection delay and detection variation depending on the crank angle position at the time of stop. Further, even when the rotation speed of the starting recoil is slow, it is possible to prevent a delay in cylinder discrimination. Therefore, the engine control at the time of starting can be accurately performed, and the startability can be improved. In addition, it is possible to prevent an inaccurate crank detection position from occurring due to insufficient output of a gear signal or detection delay, and it is possible to improve startability. Further, it is possible to prevent illegal combustion of the engine and improve the starting quality. Furthermore, since it is not necessary to raise the detection level of the sensor voltage,
It is not affected by the noise at the time of high rotation at the time of starting, and the startability is improved.

[Brief description of drawings]

FIG. 1 is an overall side view of a snowmobile equipped with a two-cycle engine according to an embodiment.

FIG. 2 shows an overall plan view of the snowmobile.

FIG. 3 is a side view showing the vicinity of a recoil starter of an engine mounted on a snowmobile.

4 is a cross-sectional view taken along the line IV-IV of the engine of FIG.

FIG. 5 is a control flowchart when the engine is stopped.

FIG. 6 shows a control flow chart during engine control.

[Explanation of symbols]

10 engine 24 Exhaust system 26 Recoil start 26a recoil rope 26b recoil pulley 28 crankshaft 30 Magneto 30a flywheel 30b stator winding 32 high pressure fuel pump 38-cylinder discriminator 40 Crankshaft rotation angle detection gear 42 Reluctor detection pulsar coil 44 Gear detection pulsar coil

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 35/00 F02D 35/00 362D F02N 3/02 F02N 3/02 Z F term (reference) 3G084 AA06 BA00 BA15 BA16 BA28 CA01 CA07 DA04 EA07 EB06 EC01 FA36 FA38 FA39

Claims (5)

[Claims] 1. A recoil starter type multi-cylinder engine, a cylinder discriminating section for producing a cylinder discriminating signal based on a predetermined rotational position of a crankshaft, a crank rotational angle detecting section for detecting a rotational angle signal of the crankshaft, and the cylinder. A storage unit that stores a determination signal and a crankshaft rotation angle signal when the engine is stopped, and enables engine control based on the stored cylinder determination signal and the crank rotation angle signal when the engine is started. Control signal detection device for engine. 2. A reluctor and a gear that rotate with the rotation of a crankshaft in an engine are detected by detection coils provided in a crankcase, a cylinder is discriminated by the detection of the reluctor, and each tooth of the gear is detected. The control signal detecting device for an engine according to claim 1, wherein a crank rotation angle is detected. 3. The storage unit has a delay circuit that turns off the power supply at a timing later than when the key switch that turns on and off the power supply to the engine ignition device and other auxiliary machinery is turned off. The control signal detecting device for an engine according to claim 1 or 2, wherein: 4. The magneto has a flywheel and a stator winding, the reluctor and the gear are provided on an outer peripheral surface of the magneto flywheel, and the detection coils thereof are provided around the flywheel. The engine control signal detecting device according to claim 1, wherein the control signal detecting device is an engine control signal detecting device. 5. The engine control signal according to claim 1, wherein the reluctor detection coil and the gear detection coil are provided on opposite sides of the crankshaft. Detection device.