JPH0742872B2 - Throttle detection device for outboard engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle detection device for an outboard engine.

[0002]

2. Description of the Related Art Conventionally, an outboard engine has been installed vertically.
To the rear of the crank chamber that houses the crankshaft
While a pair of right cylinder banks are erected in a V shape,
The left and right sides that guide intake air to each cylinder bank in front of the
A pair of intake passages are connected to each other, and the pair of left and right intake passages and a crankshaft are connected.
When viewed from the direction, the bisector of the pair of left and right cylinder banks (see FIG.
Approximately left-right symmetry with respect to XX line)
Is a line that extends orthogonally to the bisector and extends horizontally.
Throttle valve that rotates around the Lottole axis and the slot
Is located downstream of the valve and only intake air flows into the crank chamber.
There is one that is provided with a reed valve that allows. And this ship
In the engine for external machines in order to perform the operation control, when the attempts to detect the amount of intake air to the respective cylinder banks, by using the throttle detecting device, each
The opening of the throttle valve provided in the intake passage is detected.

At this time, the throttle detection device is constructed by a potentiometer system or the like, and a detection shaft is directly connected to a throttle shaft having a throttle valve or indirectly connected through a link or the like to detect a contact fixed to the detection shaft. The throttle opening is detected by the contact position with the board (resistive board, etc.).

[0004]

However, since the throttle detection device is designed to bring the contact fixed to the detection shaft into contact with the detection board and detect the throttle opening based on the contact position, vibration resistance is weak. .

However, in the prior art, since the throttle detection device is arranged at an arbitrary position around the engine, the engine vibration is transmitted to the detection shaft, and the contact between the contact fixed to the detection shaft and the detection board. Contact condition deteriorates,
It is difficult to ensure stable detection performance.

According to the present invention, in a throttle detection device for an outboard engine, deterioration of the detection function due to engine vibration is prevented, the detection function is easily and stably secured , and the intake function is improved.
The purpose of the present invention is to reduce the size of the diesel engine and the engine .

[0007]

The present invention is arranged vertically.
Left and right pair on the rear side of the crank chamber that houses the crankshaft
Cylinder bank is installed upright in V shape, while crank chamber
On the front side of the cylinder
The air passages are connected, and the pair of left and right intake passages are in the crankshaft direction.
Visually, the bisector of a pair of left and right cylinder banks (Fig. 1X-
X-rays) are arranged substantially symmetrically, and each intake passage is
A slot that extends perpendicularly to the bisector and extends horizontally.
A throttle valve that rotates around a tor axis and the throttle valve
Located downstream of the engine and allows only intake air to flow into the crank chamber
Throttle detection of an outboard engine equipped with a reed valve
In the discharge device, one of the pair of left and right intake passages is sucked.
Of the shaft ends of the throttle shaft provided in the air passage, the other intake passage
Connect the detection axis of the throttle detector to the shaft end far from the
However, the axial direction of the detection axis is the main direction of vibration that occurs in the engine.
And the one intake path above the reed valve.
Inclined so as to get closer to the bisector as the flow goes
The outer wall of the intake passage to the outer wall of the crank chamber.
Closer to the bisecting line than the bisector and the outer wall of the intake passage
A recess is formed with the front wall of the rank room, and the slot is formed in the recess.
It has a turtle detector .

[0008]

[Operation] A slot orthogonal to the bisector of the cylinder bank
Connect the detection shaft of the throttle detector to the shaft end of the torque shaft,
The axial direction of the detection shaft is almost straight to the main direction of the vibration generated in the engine.
Since they are arranged so that a large vibration acts in the axial direction of the detection shaft.
To prevent the deterioration of the detection function,
It is possible to easily and stably secure the output performance. Connect the detection shaft of the throttle detector to the end of the throttle shaft.
When connecting, one of the left and right intake passages
Of the other end of the throttle shaft provided on the
Since the detection shaft is connected to the shaft end on the far side, both intake paths are connected to each other.
The intake device can be made smaller and the size can be reduced.

Going upstream from the reed valve through one intake passage
Tilt it so that it approaches the bisector of the cylinder bank.
By inclining the outer wall of the intake passage to the outside of the crank chamber
The outer wall of the intake passage should be closer to the bisector than the side wall.
And a front wall of the crank chamber to form a recess in the recess.
Since the throttle detector is arranged, the throttle detector
It is possible to prevent the engine from protruding to the side,
The size of the gin can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially cutaway plan view showing an example of a V-type 6-cylinder two-cycle engine for outboard motors, to which the present invention is applied, at 60-degree equidistant ignition, and FIG. 2 is a front view of the engine. FIG. 3 is an ignition control system diagram of the engine.

The engine 11 is a crank arranged vertically.
A pair of left and right shafts are provided on the rear side of the crank chamber 19 that houses the shaft 12.
While the Linda banks 11A and 11B are erected in a V shape,
In front of the crank chamber 19, each cylinder bank 11A, 1
Connect a pair of left and right intake passages 17 that guide intake air to 1B,
The pair of right intake passages 17 is a pair of right and left when viewed in the crankshaft direction.
Bisectors of the cylinder banks 11A and 11B (see FIG. 1X-
X-rays) are arranged substantially symmetrically to each intake passage 17
Is a line that extends orthogonally to the bisector and extends horizontally.
A throttle valve 23 that rotates around the rottle shaft 23A,
Located in the crank chamber 19 downstream of the throttle valve 23
And a reed valve 18 that allows only the inflow of intake air to the
Degree bank V-type 6 cylinder engine, 1st cylinder 11A
And the second cylinder 11B, the third cylinder 11C and the fourth cylinder 11D,
The fifth cylinder 11E and the sixth cylinder 11F each form a V-shape. The crankshaft 12 of the engine 11 is arranged vertically, and a piston 14 housed in each cylinder arranged horizontally is connected to the crankshaft 12 via a connecting rod 13. A cylinder head 16 defining a combustion chamber 15 for each cylinder is fixed to the rear of the engine 11. A carburetor 20 and an intake box 21 for supplying air-fuel mixture to a crank chamber 19 of each cylinder are connected to a front portion of the engine 11 via a reed valve 18 provided in an intake passage 17 corresponding to each cylinder. ing. Reference numeral 22 (22A to 22F) indicates a spark plug, and 23 indicates a throttle valve.

In the engine 11, the starter switch 26 and the starter relay 27 are closed under the condition that the power switch 25 connected to the battery 24 shown in FIG. 28 is drivable.

Further, the engine 11 is provided with a controller 29 composed of a microcomputer so that the ignition timing can be electronically controlled. That is, the controller 29 has an ignition timing setting device 30 (CPU) and an ignition signal generator 31, as will be described later in detail, and includes a pulsar coil 32, a crank angle signal (timing signal) generator 33, and a throttle detector 3.
4. Based on the output signals of the temperature detector 35, the overheat detector 36, and the knock detector 37, the optimum ignition timing is set for each operating state of the engine 11, and the ignition of each cylinder is performed via the CDI unit 38. The ignition states of the plugs 22A to 22F can be controlled. In FIG. 3, 3
Reference numeral 9 is an electric circuit that can drive each circuit of the controller 29, and reference numeral 30A is a sampling cycle generation circuit for the ignition timing setting device 30.

By the way, as shown in FIG. 4, the controller 29 accommodates a large number of constituent elements 40 of electronic parts in a case 42 in a state of being arranged on a substrate 41, and is filled in the case 42. Resin filling part 43 formed by resin
It is held in the case 42 in a state of being encapsulated by.
Further, the controller 29 is arranged such that the surface including the substrate 41 is substantially orthogonal to the direction in which the vibration generated in the engine 11 is large, that is, the main direction, as shown by the line XX in FIG. That is,
A mounting base 45 is fixed to a central portion 44 of both cylinder groups forming the V-shape of the engine 11, and a box-shaped mounting bracket 47 is fixed to the mounting base 45 via a rubber damper 46 by a mounting screw 48. A controller 29 is fixed to a controller 47 by a mounting screw 49 in a state in which a substrate 41 of the controller 29 is arranged orthogonal to the central axis of the engine 11.

Here, as shown in FIG. 5, the boss portion 51 of the rotor 50 forming the magneto is fixed to the upper end portion of the crankshaft 12 of the engine 11 by the half-moon key 52 and the nut 53. A permanent magnet 54 is fixed to the inner surface of the rotor 50. Reference numeral 55 is a coil for power generation, and a plurality of coils are arranged annularly so as to correspond to the inner surface of the permanent magnet 54. These power generation coils 55 are fixed to a plurality of legs 56 provided in the engine 11.

Reference numeral 57 is a permanent magnet, and its N pole and S pole are located at two diametrical positions on the boss portion 51 of the rotor 50.
It is fixed so that it is located at 80 degree intervals. Further, 32 (32A, 32B, 32C) are three pulsar coils, which are support bases 58 supported by the engine 11.
It is fixed to the inner surface of the annular holder 59 which is integrated with the main body at intervals of 120 degrees. That is, in the pulsar coil 32, every time the crankshaft 12 rotates by 60 degrees, one of the pulsar coils 32A, 32B, 32C faces the N pole or S pole of the permanent magnet 57 once, and as shown in FIG. Pulses P ₁ and P ₄ for the first cylinder 11A and the fourth cylinder 11D are induced in the pulsar coil 32A, and a pulse P for the second cylinder 11B and the fifth cylinder 11E is generated in the pulsar coil 32B.
₂ and P ₅ are induced, and the pulses P ₃ and P ₆ for the third cylinder 11C and the sixth cylinder 11F are induced in the pulsar coil 32C. Note that, as shown in FIG. 7, when the pulses P _{1 to} P ₆ are generated, the crank angle position is relative to the top dead center (TDC) of each cylinder, and the ignition timing for start (θ ₀ ), for example, the top dead center. It is fixed at a time point on the advance side by the front (BTDC) θ ₀ degree.

A ring gear 6 which receives the rotational force of the starting motor 28 when the engine is started is provided on the outer periphery of the rotor 50.
0 is fixed, and the crank angle signal generator 33 fixedly arranged on the engine 11 is provided on the outer peripheral portion of the ring gear 60.
Are opposed to each other. This crank angle signal generator 3
3 includes a ring gear 6 as the crankshaft 12 rotates.
A pulse is induced opposite each meshing tooth of zero.

Each output pulse P _{1 of the} pulsar coil 32
As shown in FIG. 3, P ₆ to P ₆ are encoded by the encoder 62 via the waveform shaping circuit 61 of the controller 29, and are sequentially transmitted to the preset counter 63 via the ignition timing setting device 30 in a mutually distinguishable state. It The output pulse of the crank angle signal generator 33 is transmitted to the preset counter 63 as a subdivided pulse indicated by P _C in FIG. 7 in the double cycle circuit 64 of the controller 29 as shown in FIG. It

The pulsar coil 32, the crank angle signal generator 33, and the preset counter 63 constitute the crank angle detector of the present invention. That is, the pulsar coil 32 generates the pulses for the number of cylinders corresponding to the constant angle position of the crankshaft 12, that is, the reference angle signal of the crankshaft 12, in one revolution of the crankshaft 12.
Therefore, the pulsar coil 32 functions as a reference angle signal generator of the crankshaft 12, and the preset counter 63 counts the number of pulses generated by the crank angle signal generator 33 after the pulse generation of the pulsar coil 32. The angular position can be detected. As shown in FIG. 7, in detecting the angular position of the crankshaft 12, N cylinders (for example, the second cylinder 11B) are detected.
Of the pulse angle P ₁ of the pulser coil 32A corresponding to the N−1 cylinder (for example, the first cylinder 11A) is used as a reference angle signal related to the crank angle position of, for example, the advance angle θ with respect to the TDC, and after the P ₁ generation time If the number of pulse generations ΣP _C of the crank angle signal generator 33 is counted in the case where the pulse generated by the pulsar coil 32B corresponding to the N cylinder is used as the reference angle signal,
In contrast to the need to count the number of pulses for 60 ° -θ, in the case of 6 cylinders, it is sufficient to count ΣP _C for 60 ° -θ, and the pulse generation of the pulser coil 32B corresponding to the N cylinder is required. The angle θ before the time point can be indexed with high accuracy by counting a smaller number of pulses.

The pulsar coil 32 also functions as an engine speed detector. That is, since the pulsar coil 32 generates pulses corresponding to the number of cylinders for each revolution of the crankshaft 12, the ignition timing setter 30 counts the number of pulses generated by the pulsar coil 32 within a unit time to determine the crankshaft. It is possible to detect 12 rotation angles, that is, the engine speed.

The throttle detector 34 is shown in FIG.
And as shown in FIG. 9, the base portion 65 and the cap portion 6 thereof.
The housing 67 composed of 6 is fixed to the mounting bracket 69 by the mounting screw 68, and the mounting bracket 69 is fixed to the main body of the carburetor 20 by the mounting screw 70. Further, a contact 72 is fixed to the detection shaft 71 of the throttle detector 34, and the throttle opening of the carburetor 20 is determined by the sliding contact position of the contact 72 rotating with the detection shaft 71 with respect to the resistance board 73, that is, by the potentiometer method. That is, the intake air amount to each cylinder can be detected. In the throttle detector 34, the detection shaft 71 is the carburetor 20.
It is directly connected to the throttle shaft 23A. That is,
In the throttle detector 34, its housing 67
And the detection shaft 71 are both connected to the carburetor 20, no matter what vibration occurs in the engine 11,
The vibration modes of the housing 67 and the detection shaft 71 are the same. That is, the relative movement of the housing 67 and the detection shaft 71 due to the vibration is prevented from occurring, and the malfunction of the detector 34 due to the vibration can be prevented from occurring. The main direction of vibration of the engine 11 is set in the engine central axis direction indicated by the line XX in FIG. 1 as described above. Therefore, in this throttle detector 34,
The vibration resistance is particularly weak, and the axial direction of the detection shaft 71, that is, the contact direction of the contact 72 with the resistance board 73 is arranged substantially orthogonal to the main direction of vibration generated in the engine 11.
It is also possible to reasonably protect the detector 34 from vibrations. At this time, the throttle detector 34 is
The slot provided in one of the paired intake passages 17
Of the shaft ends of the torque shaft 23A, it is far from the other intake passage 17
The detection shaft 71 of the throttle detector 34 is connected to the shaft end on the side.
Then, the axial direction of the detection shaft 71 is set to the engine 11 as described above.
Intake air on one side while arranging them almost orthogonal to the main direction of generated vibration
As the route 17 goes upstream from the reed valve 18, the above 2 etc.
Inclination so that it is close to the dividing line (Fig. 1X-X line)
The outer wall 17A of the intake passage 17 to the crank chamber 19
The intake passage should be closer to the bisector than the outer wall 19A.
The outer wall 17A of 17 and the front wall 19B of the crank chamber 19,
To form a recess 110, and detect the throttle in the recess 110.
The vessel 34 is arranged.

Further, the temperature detector 35 is composed of, for example, a thermistor, is attached to the cylinder head 16 between the third cylinder 11C and the fifth cylinder 11E, and detects the temperature of the engine 11 through the detection of the cooling water temperature. It is possible.
The detection results of the throttle detector 34 and the temperature detector 35 are alternately transmitted to the A / D converter 75 via the buffer 74, and the ignition timing setting device 30 is digitized in the A / D converter 75. Have been transmitted to.

Further, the overheat detector 36 is
For example, each cylinder head 16 of the first cylinder 11A and the second cylinder 11B is composed of a bimetal contact type temperature sensitive switch.
Mounted on the ignition timing setter 30 for detecting the temperature of the cooling water in the cylinder head 16 and detecting the detection result of, for example, t ₁ ° C or more.
It is possible to communicate to.

The knock detector 37 is of a vibration detecting type such as a piezoelectric element type or a magnetostrictive type.
It is attached to the cylinder head 16 between the 1D and the sixth cylinder 11F. The knock detector 37 detects vibration of a certain level or higher generated in the engine 11, detects abnormal combustion (knock) such as harmful knocking or premature ignition, and transmits the detection result to the ignition timing setter 30. It is possible.

The specific ignition control procedure of the controller 29 will be described below. First, the control of the controller 29 during normal operation will be described. Ignition timing setting device 3 of controller 29
At 0, the optimum ignition timing for each combination of the engine speed and the throttle opening as the intake air amount is predetermined in the form of a map (or a functional expression). (The applicant has already clarified an example of the map set in the ignition timing setting device 30 in the specification and drawings attached to Japanese Patent Application No. 57-146268.) During operation, the ignition timing setter 30 determines the engine speed obtained by counting the output pulses of the pulser coil 32 as described above, the throttle opening detected by the throttle detector 34, that is, the intake air amount, and the map described above. Based on the above, the optimum ignition timing corresponding to the operating state at that time is set. In this way, the ignition timing setting device 30 transmits the optimum ignition timing of each cylinder to the preset counter 63 of the ignition signal generator 31.

On the other hand, the preset counter 63 is also a part of the crank angle detector in the present invention as described above, and the pulsar coil 3 as the reference angle signal generator.
The number of pulses generated by the crank angle signal generator 33 after the second pulse generation time is counted to detect the angular position of the crankshaft 12.

Therefore, the ignition signal generator 3 according to the present invention is used.
In the preset counter 63 as a part of 1, the crank angle counted as described above is calculated by the ignition timing setter 30.
The ignition signal is transmitted to the selection circuit 76 at the time point when the optimum ignition timing transmitted from is reached. The selection circuit 76 includes
At the same time as the ignition signal from the preset counter 63, the cylinder identification signal is directly transmitted from the ignition timing setting device 30,
It is possible to identify to which cylinder the ignition signal transmitted from the preset counter 63 is a signal.
The ignition signal thus transmitted to the selection circuit 76 is
It is transmitted to the CDI ignition device corresponding to each cylinder of the CDI unit 38 via the waveform shaping circuit 77. Each of the CDI units 38 of the CDI unit 38 starts charging the ignition capacitor with the voltage generated in the magneto power generation coil 55, and then the SCR of the SCR is generated by the ignition signal current generated in the ignition signal generator 31. At the same time that the gate is made conductive, the electric charge stored in the ignition capacitor is rapidly applied to the primary side of the ignition coil to generate a high voltage on the secondary side of the ignition coil, and the spark plugs 22A to
A discharge can be generated at 22F. That is, according to the advance angle control by the controller 29, the optimum ignition that does not cause abnormal combustion in the normal operating state of the engine can be performed by selecting the ignition timing which is preset in the ignition timing setting device 30 in the form of a map. It becomes possible to ignite at the time.

Next, the starting control by the controller 29 will be described. This starting control is executed by the starting program written in the controller 29 and shown in FIG. That is, when the power switch 25 is closed (step (1)) and the start switch 26 is closed (step (2)), the controller 29 determines whether the closed state of the start switch 26 continues. Judge (step (3)). If the determination result of step (3) is YES, the switching circuit 78 causes the selection circuit 7
6 is stopped, the buffer 79 is operated, the output of the waveform shaping circuit 61, that is, the starting ignition timing (θ
₀ ), for example, an output signal fixed at BTDCθ ₀ degrees is transmitted to the waveform shaping circuit 77, and the CDI unit 38 is ignition-controlled at the BTDCθ ₀ degrees via the waveform shaping circuit 77 (step (4)), and again. Return to step (3). If the determination result of step (3) is NO, the switching circuit 78 stops the operation of the buffer 79 and activates the selection circuit 76, and the ignition timing setting device 30 causes the temperature detector 3 to operate as described later.
The ignition timing determined based on the detection result of No. 5 is set as the optimum ignition timing, and the CDI unit 38 is ignition-controlled (step
(6)).

Therefore, according to the starting control by the controller 29, it is possible to ignite at the optimum timing for starting when the engine 11 is started, to automatically and easily start the engine 11, and to secure a stable startability. Is possible.

Next, the warm-up control by the controller 29 will be described. This warm-up control is written in the controller 29 after the engine 11 is started by the above-mentioned start control.
It is executed by the warm-up program shown in. Here, the ignition timing setter 30, an engine temperature t on the horizontal axis, the warm-up ignition timing as shown in FIG. 12 taken on the vertical axis advance angle θ are set in advance, the engine temperature, for example, t ₂ When the engine is warmed up after starting, the optimum ignition timing is, for example, BTDCθ
And _once, at the time of warm-up after start-up is less than t ₃ ° C. over the engine temperature, for example, t ₂ ° C. optimum ignition timing, for example, BT
It is set to DC θ ₂ degrees.

That is, the controller 29 inputs the detection result of the temperature detector 35 to the ignition timing setting device 30 as described above (step (6)), and judges whether the detection result is t ₂ ° C or less. Yes (step (7)). The judgment result of step (7) is Y
In the case of ES, it is judged whether the advance angle based on the map under the operating condition is BTDC θ ₁ degree or more (step (8)). When the determination result of step (8) is NO, the ignition timing setting device 30 sets BTDC θ ₁ degree as the optimum ignition timing, and the ignition signal generator 31 outputs the C
The ignition of the DI unit 38 is controlled (step (9)), and the process returns to step (6). YES in step (8)
In this case, the ignition timing setting device 30 preferentially sets the advance angle based on the map as the optimum ignition timing, and controls the ignition of the CDI unit 38 via the ignition signal generator 31 (step (10)). If the determination result of step (7) is NO, it is determined whether the detection result of the temperature detector 35 is more than t ₂ ° C and less than t ₃ ° C (step (11)). Step (11)
If the result of the determination is YES, it is determined whether the advance angle based on the map under that operating condition is BTDC θ ₂ degrees or more (step (12)). If the determination result in step (12) is NO, the ignition timing setting device 30 determines that the BT
DC θ ₂ degrees is set as the optimum ignition timing, the ignition of the CDI unit 38 is controlled via the ignition signal generator 31 (step (13)), and the process returns to step (6) again. If the determination result of step (12) is YES, the ignition timing setting device 30
The advance angle based on the map is preferentially set as the optimum ignition timing, and the ignition of the CDI unit 38 is controlled via the ignition signal generator 31 (step (14)). When the determination result of step (11) is NO, the ignition timing setting device 30 sets the advance angle based on the map as the optimum ignition timing, and controls the ignition of the CDI unit 38 via the ignition signal generator 31 ( Step (15)). The controller 29 performs steps (14) and (15).
After ignition control by, the process returns to step (6) again, and the same control program as above is repeatedly executed.

When the advance angle based on the map is larger than the advance angle based on the warm-up characteristics in steps (8) and (12) of the warm-up control, the reason why the advance angle based on the map is prioritized is as follows. There are two points. That is, the first is that a larger advance angle is appropriate for the purpose of warm-up control. Secondly, the control procedure by the controller 29 is, after the start control, the normal control by the map to reach the warm-up control, and the preset advance angle by the map after the start control is the advance angle based on the warm-up control. Therefore, it is necessary to avoid a sudden decrease in the engine rotation speed due to the sudden decrease in the excessive preset advance angle and the accompanying shock.

Therefore, according to the warm-up control by the controller 29, during the warm-up after the start, the automatic warm-up is automatically performed at the optimum time for warm-up without causing an inappropriate warm-up operation time and deterioration of fuel consumption. Ignition can be controlled, warm-up operation can be facilitated and ensured, and engine rotation during warm-up can be stabilized.

Next, during idling by the controller 29,
The low speed rotation control during trolling will be described. This low speed rotation control is executed by the low speed rotation program shown in FIG. here,
The ignition timing setting device 30 has a predetermined engine speed,
For example, when the engine is rotating at a low speed of N ₁ rpm or less, the optimum ignition timing, for example, BTDCθ ₃ degrees is set, and the setting state of the BTDCθ ₃ degree is maintained while the crankshaft 12 makes, for example, n rotations. That is, the controller 29 processes the output pulse frequency of the pulsar coil 32 by the F / V converter 80 and outputs the output voltage corresponding to the engine rotation speed (step (16)).
It is determined whether the output voltage of the V converter 80 is equal to or lower than the reference voltage V ₀₁ corresponding to N ₁ rpm set in the setter 82 (step (17)). YES in step (17)
If the ignition timing setting device 30 is
While n is rotating 2 times, BTDCθ ₃ degrees is set as the optimum ignition timing, the CDI unit 38 is ignition-controlled through the ignition signal generator 31 (step (18)), and the step (16) is performed again.
Return to. When the determination result of step (17) is NO, the ignition timing setting device 30 sets the advance angle based on the map as the optimum ignition timing, and controls the ignition of the CDI unit 38 via the ignition signal generator 31. (Step (19)).
After the ignition control in step (19), the controller 29 returns to step (16) again and repeatedly executes the same control program as above.

In the above low speed rotation control, BTDC
The reason why n ₃ rotations are held at θ ₃ degrees is that smooth rotation control is performed without increasing the rotation speed more than necessary.

Therefore, according to the low speed rotation control by the controller 29, when the engine 11 reaches the set low speed, the ignition timing is automatically advanced to raise the engine speed and stop the engine. By repeating the prevention operation many times, a stable low speed rotation state can be obtained. That is, even when the engine 11 for the outboard motor is attached to the hulls of different sizes to perform idling or trolling operation, or forward / reverse switching operation, without increasing the fuel supplied to the engine 11,
The desired low-speed rotation can be stably obtained with low fuel consumption and noise, and the hull can be parked at a fixed position under the action of tidal current.

Next, the overheat suppressing control by the controller 29 will be described. This overheat suppression control is executed by the overheat suppression program shown in FIG. Here, in the ignition timing setting device 30, the engine temperature is a predetermined temperature, for example, t ₄ ° C or more, the throttle opening is a predetermined opening, for example, α ₁ degree or more, and the engine rotation speed is a predetermined speed, for example N ₂ rp.
When it is m or more, the ignition timing setting signal for the misfired cylinders is transmitted to the ignition signal generator 31 so as to sequentially misfire the plurality of cylinders other than some of the cylinders at predetermined time intervals. It's supposed to happen. Figure 15
Is a diagram showing a control state by overheat suppression control, in which the horizontal axis represents time H and the vertical axis represents engine rotation speed N. In the engine 11 including six cylinders 11A to 11F, the sixth cylinder 11F, the fifth cylinder Cylinder 11E, third cylinder 1
1C, the second cylinder 11B sequentially example at a time H ₁ of h ₁ to h ₂ seconds to misfire, continues finally operation of the engine 11 by only two cylinders of the first cylinder 11A and the fourth cylinder 11D state Is shown.

That is, in this overheat suppressing control, the controller 29 inputs the engine temperature detected by the overheat detector 36, that is, the temperature sensitive switch to the ignition timing setting device 30 (step (20)), and the detection result is obtained. t
It is judged whether the temperature is ₄ ° C or higher (step (21)). If the determination result in step (21) is NO, the process returns to step (20), and if the determination result is YES, it is determined whether the throttle opening detected by the throttle detector 34 is α ₁ degree or more. (Step (22)). If the decision result in the step (22) is NO, the process returns to the step (20) and the decision result is YE.
If S, it is determined whether the engine speed detected by counting the output pulses of the pulsar coil 32 is N ₂ rpm or more (step (23)). If the decision result in the step (23) is NO, the process returns to the step (20), and if the decision result is YES, the ignition timing setter 30 executes the misfire control shown in FIG. 15 (step (24a) ), The engine speed is kept at N ₂ rpm (step (24b)), and then it is determined whether the throttle opening detected by the throttle detector 34 is α ₁ degree or less (step (24c)). If the decision result in the step (24c) is NO, the step (24c)
Return to b). If the result of the determination is YES, the misfire is released (step (24d)) and the process returns to step (20). Also,
When the determination result of step (21) is YES, the controller 29 sounds a buzzer to give a warning to the driver (step (25)), and the engine temperature detected by the temperature detector 35 is t ₅ Determine whether it is below ℃ (Step (2
6)). If the determination result of step (26) is NO, the process returns to step (25) and the buzzer continues to ring, and the determination result is Y.
If it is ES, stop the buzzer (step (2
7)) and returns to step (20).

In step (24c) of the overheat control program, the throttle opening is set to α ₁ degree.
The reason for determining the following is step (24a),
When the engine temperature is lowered after the operation of the misfire control by (24b), the engine temperature is lowered in order to prevent the ignition state of the engine from returning to the normal operating state and impairing safety without any notice to the driver. Therefore, it is to ensure the manual release of the misfire control state accompanied by the throttle opening operation by the driver's intention without automatically releasing the misfire control state. Further, in step (23) of the overheat suppression program, the engine speed is N ₂ r
The reason for determining whether it is pm or more is that the engine 11 is N
_This is because it is difficult to continue the operation of the engine 11 with only some of the cylinders 11A and 11D under the condition of ₂ rpm or less.

Therefore, according to the overheat suppressing control by the controller 29, when the engine temperature rises abnormally,
A buzzer sounds to alert the driver, and the engine speed is gradually reduced without shock,
The occurrence of overheat can be reliably suppressed. That is,
A plurality of cylinders other than some of the three or more cylinders are sequentially extinguished at predetermined time intervals, and finally some of the cylinders continue to operate. It is possible to reliably suppress the occurrence of overheat by decelerating the engine while avoiding the stop of water cooling or air cooling of the engine due to the stop.

Next, knock suppression control by the controller 29 will be described. This knock suppression control is executed by the knock suppression program shown in FIG. Here, the ignition timing setting device 30 detects the abnormal combustion (knock) by the knock detector 37,
The ignition timing is set to be retarded in a stepwise manner, and the retarded state of each stage is maintained. FIG. 17
Is a diagram showing the ignition timing setting state by the ignition timing setting device 30 with the horizontal axis indicating time H and the vertical axis indicating the advance angle θ. For example, when knock is detected at point A, the angle is retarded by a degree. When the ignition timing of the B point is set, the retard setting state is held for a predetermined time H ₂ , for example, h ₃ minutes, and the knock is detected again after the holding time of the B point to the C point has elapsed, ,
For example, the ignition timing at the point D is retarded by b degrees and the new retard setting state is held for a predetermined time H ₂ . The ignition timing at point D is retarded a + b in total compared to the initial state at point A. After the holding time at points D to E has elapsed, the initial ignition timing is sequentially restored in the steps reverse to the above. At this time, if the knock is detected again between the points F and G, the retard angle is set again by b degrees at this point. The retard angle width of a + b degrees in FIG. 17 is set to a value that can sufficiently suppress knocking.

That is, in the knock suppression control, the controller 2
9 indicates the detection result of the knock detector 37 by the ignition timing setting device 3
It is input to 0 (step (28)), and it is determined whether there is knock (step (29)). If the decision result in the step (29) is NO, the process returns to the step (28), and if the decision result is YES, the engine speed detected by counting the output pulses of the pulsar coil 32 is N ₃ rpm or more. It is judged (step (30)). If the decision result in the step (30) is NO, the ignition timing setting device 30 sets the advance angle based on the map as the optimum ignition timing, and the ignition signal generator 31
Ignition control of the CDI unit 38 via the
(31)). If the decision result in the step (30) is YES, it is decided whether or not the throttle opening detected by the throttle detector 34 is α ₂ degrees or more (step (32)). If the determination result of step (32) is NO, the ignition timing setting device 30 sets the advance angle based on the map as the optimum ignition timing, and controls the ignition of the CDI unit 38 via the ignition signal generator 31 (step ( 33)). If the decision result in the step (32) is YES, the ignition timing setting device 30 sets the ignition timing already set at that time to the a-degree retard, and holds the retard setting state for h ₃ minutes (step (34)). Ignition timing setter 30 is set after the retard is maintained in step (34).
Determines again whether there is a knock (step (35)). If the determination result of step (35) is NO, the ignition timing setting device 30
Resets the ignition timing state before the a-degree retard setting in step (34) (step (36)), and returns to step (28). If the decision result in the step (35) is YES, the ignition timing setting device 30 further sets the b-degree retard angle in addition to the a-degree retard angle setting state in the step (34), and sets the width a to the initial state.
Hold the retard angle setting state of + b degrees for h ₃ minutes (step (3
7)). After the delay angle is maintained in step (37), the ignition timing setting device 30 determines again whether knock has occurred (step (3
8)). If the decision result in the step (38) is YES, the process returns to the step (37), and the retard angle setting state of the width a + b degrees with respect to the initial state set in the step (37) is held again for h ₃ minutes, and the step If the determination result in (38) is NO, the retard angle width of b degrees added in step (37) is restored, and the setting is returned to the a degree retarded state, and the a degree retarded state is further changed to h ₃
Hold for a minute (step (39)). After the retard angle is maintained in step (39), the ignition timing setting device 30 further determines whether there is knock (step (40)). If the decision result in the step (40) is NO, the ignition timing setting device 30 determines that the step (3)
The ignition timing state before the a-degree retardation setting in 9) is reset (step (36)), and the process returns to step (28). Step (40)
If the determination result of is YES, the ignition timing setting device 30
A step of adding a retard angle width of b degrees to the a angle retard setting state in step (39) and holding the retard angle setting state for h ₃ minutes
Return to (37). After the ignition control in steps (31) and (33), the controller 29 returns to step (28) again and repeatedly executes the same control program as above.

The steps of the knock control program
The reason why the engine speed is judged to be N ₃ rpm or higher in (30) is that the engine is apt to stop and is not appropriate when the retard angle is set under the condition of N ₃ rpm or lower. Also, in step (32) of the knock suppression program, the reason for determining whether the throttle opening is α ₂ degrees or more is that when setting the retard angle under the condition of α ₂ degrees or less, This is because the shock due to the sudden decrease in speed is large and not appropriate.

Therefore, according to the knock suppression control by the controller 29, when the knock occurs during the steady operation of the engine 11, the ignition timing is intentionally delayed for a predetermined time, and the normal ignition is performed after the predetermined time has elapsed. It is possible to return to the time. That is, since the retarded state is maintained for a certain period of time, when knocking occurs frequently within the above-mentioned certain period of time, the engine is not repeatedly set to retard and return to the steady state from the steady state. It is possible to avoid sensitive changes in rotation speed and ship speed. Also,
Since the retarded state is set in stages, it is possible to obtain a retarded width that can sufficiently suppress knock without causing a sharp decrease in the engine rotation speed and the hull speed. It is possible to reasonably protect the engine from the occurrence of knock by avoiding the impact on the human body or the occurrence of mental anxiety. In other words, engines used for outboard motors, etc. have large differences in their applications and operating environments due to their properties.Therefore, carbon deposition on the combustion chamber, piston or mismatch of spark plugs, use of low octane gasoline, etc. In consideration of the occurrence of knocking due to the engine, it is usual to set the engine maximum ignition advance range to the retard side from the required advance angle, and it may not be possible to bring out the engine performance 100% by giving priority to safety. On the other hand, according to the knock suppression control, it is possible to protect the engine while avoiding a sharp decrease in the engine rotation speed when a knock occurs, and to sufficiently bring out the engine performance during normal operation in which no knock occurs.

Next, the over-rotation preventing control by the controller 29 will be described. This over-rotation preventing control is executed by the over-rotation preventing program written in the controller 29 and shown in FIG. That is, the controller 29 controls the first cylinder 11
A, the output pulse frequency of the pulsar coil 32 for the third cylinder 11C and the fifth cylinder 11E is processed by the F / V converter 83, and an output voltage corresponding to the engine speed is output (step (41)), and the overspeed comparison is performed. In the circuit 84, the output voltage of the F / V converter 83 is a reference voltage V corresponding to a predetermined speed set in the setter 85, for example, N ₄ rpm.
It is determined whether the value is ₀₂ or less (step (42)). Step
If the determination result in (42) is NO, the process returns to step (41), and if the determination result in step (42) is YES, the overspeed comparison circuit 84 intermittently turns on the transistor 86. Here, the emitter of the transistor 86 is the ignition signal generator 31.
Is connected to all the signal lines for transmitting the ignition signal for each cylinder to the CDI unit 38, and the collector of the transistor 86 is grounded. Therefore, step (42) as described above.
Is YES and the transistor 86 is intermittently turned on, the ignition signal for each cylinder of the ignition signal generator 31 is transmitted to the CDI unit 38 only intermittently, and each cylinder is ignited and misfired. The excessive rotation of the engine 11 is repeatedly prevented (step (43)), and the process returns to step (41).

Therefore, according to the over-rotation prevention control by the controller 29, when the engine 11 shifts to the neutral state,
Alternatively, the engine is prevented from over-rotating by preventing over-rotation at the time of no load such as when the hull is jumping while sailing, and abnormal increase in engine speed due to propeller wear of the outboard motor equipped with the engine 11. It will be possible.

Next, the reverse rotation prevention control by the controller 29 will be described. This reverse rotation prevention control is executed by the reverse rotation prevention program shown in FIG. That is, during the engine operation (step (44)), the ignition timing setting device 30 outputs the output pulses P _{1 to} P ₆ corresponding to the cylinders of the pulsar coil 32 in the normal order, that is, P ₁
→ P ₂ → P ₃ → P ₄ → P ₅ → P ₆ is judged (step (45)). NO in step (45)
If so, the ignition timing setting device 30 does not transmit the ignition timing setting for all cylinders to the ignition signal generator 31,
Misfire control of the DI unit 38 is performed (step (46)). If the decision result in the step (45) is YES, the ignition timing setting device 30 confirms that the rotation of the engine 11 is in the normal rotation direction (step (47)), and returns to the step (45) to return to the normal ignition. Continue timing control.

Therefore, according to the reverse rotation prevention control by the controller 29, it is possible to automatically detect the occurrence of the reverse rotation phenomenon peculiar to the two-cycle engine and prevent the dangerous continuous reverse rotation.

Further, in the engine 11, when the throttle detector 34 is provided in the carburetor 20, its vibration resistance is particularly weak, that is, the axial direction of the detection shaft 71, that is, the contact direction of the contact 72 to the resistance board 73. Are arranged substantially orthogonal to the circumferential direction of the vibration generated in the engine 11. Therefore, it is possible to avoid a large vibration acting in the axial direction of the detection shaft 71 as much as possible, and the contact 72 fixed to the detection shaft 71 and the resistance board 7 are fixed.
The detection performance can be easily and stably ensured, for example, by preventing the deterioration of the contact state with 3.

The operation and effect of this embodiment will be described below.
It It is orthogonal to the bisector of the cylinder banks 11A and 11B.
Check the throttle detector 34 at the shaft end of the throttle shaft 23A.
The output shaft 71 is connected, and the axial direction of the detection shaft 71 is set to the engine 1
Since it is arranged almost orthogonal to the main direction of the vibration generated in 1, the detection axis
As much vibration as possible should be applied in the axial direction of 71.
Avoiding deterioration of the detection function and easily stabilizing the detection performance
Can be secured. The throttle detector 34 is attached to the shaft end of the throttle shaft 23A.
When connecting the detection shafts 71, a pair of left and right intake passages 17
Of the throttle shaft 23A provided in the intake passage 17 on one side of the
Of the shaft ends, detected at the shaft end farther from the other intake passage 17
Since the shaft 71 is connected, both intake passages 17, 17 are brought close to each other.
They can be placed in contact with each other, and the size of the intake device can be reduced. As one intake passage 17 goes upstream from the reed valve 18,
Close to the bisector of cylinder banks 11A and 11B.
The outer wall 1 of the intake passage 17 by inclining
7A is divided into two parts from the outer wall 19A of the crank chamber 19
The outer wall 17A of the intake passage 17 and the crank
A recess 110 is formed with the front wall 19B of the chamber 19 and
Since the throttle detector 34 is arranged at 110,
The rottle detector 34 should project to the side of the engine 11.
Can be suppressed and the engine can be downsized.

[0051]

As described above, according to the present invention, in the throttle detection device for an outboard engine, deterioration of the detection function due to engine vibration is prevented, the detection performance is easily and stably ensured , and the intake device Miniaturization and small engine
It is possible to achieve the reduction.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing an embodiment of an outboard engine according to the present invention.

FIG. 2 is a plan view showing the engine.

FIG. 3 is an ignition control system diagram of the engine.

FIG. 4 is a partially cutaway plan view showing a controller attached to the engine.

FIG. 5 is a cross-sectional view showing a crankshaft upper structure of the engine.

FIG. 6 is an explanatory view showing an arrangement state of pulser coils of the engine.

FIG. 7 is a waveform diagram showing each output pulse of the pulsar coil and the crank angle signal generator of the engine.

FIG. 8 is a front view showing a mounted state of a throttle detector of the engine.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a flowchart showing a start program.

FIG. 11 is a flowchart showing a warm-up program.

FIG. 12 is a diagram showing a warm-up control state.

FIG. 13 is a flowchart showing a low speed rotation program.

FIG. 14 is a flowchart showing an overheat suppressing program.

FIG. 15 is a diagram showing an overheat suppression control state.

FIG. 16 is a flowchart showing a knock suppression program.

FIG. 17 is a diagram showing a knock suppression control state.

FIG. 18 is a flowchart showing an overspeed prevention program.

FIG. 19 is a flowchart showing a reverse rotation prevention program.

[Explanation of symbols]

11 Engines 11A, 11B Cylinder bank 17 Intake passage (intake pipe) 17A Outer side wall 18 Reed valve 19 Crank chamber 19A Outer side wall 19B Front wall 23 Throttle valve 23A Throttle shaft 34 Throttle detector 71 Detection shaft 72 Contact 73 Resistance plate (detection board )

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01B 7/30 C

Claims (1)

[Claims] 1. A vertically arranged crankshaft is accommodated.
A pair of left and right cylinder banks are V-shaped on the rear side of the crank chamber.
Stand on the other side of the cylinder chamber on the front side of the crank chamber.
The pair of left and right intake passages that guide intake air to the
The intake passage of is a pair of left and right cylinders when viewed in the crankshaft direction.
Approximately left-right symmetry with respect to the bank bisector (Figure 1X-X line)
Is arranged in each intake passage, and is orthogonal to the bisector.
Slots that rotate around a throttle axis that both extend horizontally
A throttle valve and a crank located downstream of the throttle valve.
Outboard with a reed valve that allows only intake air to flow into the room
In the engine engine throttle detection device, the left and right
Throttle shaft provided in one of the pair of intake passages
Of the shaft ends of, the shaft end farthest from the other intake passage is
The detector axis of the shuttle detector and connect the axis of the
While they are arranged substantially orthogonal to the main direction of vibration that occurs in the engine,
As the intake passage on one side goes upstream from the reed valve, the above 2 etc.
By inclining it so that it is close to the dividing line,
The outer wall is closer to the bisector than the outer wall of the crank chamber
The outer wall of the intake passage and the front wall of the crank chamber
And a throttle detector disposed in the recess, the throttle detector for an outboard engine.