JPS62170780A - Engine ignition device - Google Patents

Abstract

PURPOSE:To prevent nonconformity such as constant speed traveling at high speed from occurring by providing a means which has an engine stalled when a governor mechanism action is selected as well as high speed traveling is selected with a sub-gearbox. CONSTITUTION:When HI is selected with a submission as a governor mechanism is left operated, transistors 18 and 19 are turned off, because switches 20 and 21 are closed, and in this condition a thyristor 15 is conducted when electromotive force generates in a charge coil 14. Accordingly, the electromotive force generated in the charge coil 14 is not supplied to a CDI unit 13 and earthed through the thyristor 15, so an electric charge is not charged in a capacitor 13a within CDI unit, and an ignition plug 11 is stalled without firing. Therefore, constant speed traveling by means of a governor mechanism is limited to low speed, and nonconformity such as constant speed traveling at high speed does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine ignition system for a multi-purpose vehicle with an auxiliary transmission.

[Conventional technology]

In general, multi-purpose vehicles are equipped with a sub-transmission for switching between high-speed running (normal running) and low-speed running, in addition to a main transmission that switches speeds between multiple speeds. When the vehicle is traveling on a normal road, high-speed travel is selected in the sub-transmission, and low-speed travel is selected when performing desired work while driving external work equipment in a farmland or the like. Note that external work equipment is normally driven using PTO (Power Take 0).
ff) Utilizes the rotational force of the shaft. Here, the PTO shaft is a shaft that rotates by the output of the vehicle drive engine, and this PTO shaft
Various external work equipment such as grass cutting blades and sprayers can be attached to the TO shaft as needed.

On the other hand, such multi-purpose vehicles are provided with a governor mechanism for controlling the engine rotation speed at a constant level. Then, when attaching external work equipment to the PTO shaft and selecting low-speed travel using the auxiliary transmission to perform the desired work,
By operating this governor mechanism, the rotational speed of the PTO shaft is kept constant, and the vehicle can travel at a constant speed, thereby stabilizing the PTO operation.

[Problem that the invention seeks to solve]

In this way, it has conventionally been possible to drive at a constant speed by activating the governor mechanism during PTO work while driving at low speeds, but conversely, it has been possible to operate the governor mechanism when high speed driving is selected with the auxiliary transmission. If this occurs, a problem will occur in which the vehicle will run at a constant high speed.

[Means for solving problems]

The engine ignition device of the present invention has been developed in view of the above-mentioned problems, and is equipped with means for misfiring the engine when high-speed running is selected by the auxiliary transmission and governor mechanism operation is selected.

[Effect]

If the governor mechanism is turned on when high-speed driving is selected in the sub-transmission, the engine will misfire and the vehicle will stop running.

〔Example〕

Hereinafter, the present invention will be described in detail along with examples.

FIG. 2 is a power transmission system diagram of an example of a multi-purpose vehicle to which the present invention is applied, that is, a vehicle having an auxiliary transmission inserted in series with a main transmission in a rotary drive system. The rotational force of the crankshaft 1 of the engine is transmitted to the clutch 3 which engages and engages the engine, and the rotational force output from the clutch 3 reaches the sub-transmission (sub-transmission i) 4 and PTOTaO2. In submission 4, a gear selection is made between high speed ("High"), low speed ("Low"), or reverse ("Reverse"), and if "Reverse" is selected, rotational force in the opposite direction is performed. is directly transmitted to the differential gear 6 at a low rotational speed. When "high" or "low" is selected in the submission 4, high-speed or low-speed rotational force in the forward direction is transmitted to the differential gear 6 via the forward transmission (main transmission) 5. In forward mission 5, one of the first to fifth gears or neutral is selected. In the differential gear 6, either differential operation or lock is selected and transmitted to the wheels 7. In addition, in differential gear 6,
When the vehicle is traveling straight, "lock" is usually selected to stabilize travel, and when the vehicle is making a U-turn, "activation" is selected as appropriate.

On the other hand, if PTOTaO2 is 1 ON or OFF is selected, if ON is selected, the rotational force output from clutch 3 is transmitted to work equipment 9, and if OFF is selected , the PTOTaO2 rotation stops regardless of the rotation of the output shaft of the clutch 3. Note that 2 is a starter motor, which is driven to rotate a crankshaft and start the engine.

FIG. 1 is a circuit diagram showing an embodiment of the present invention used in a vehicle having a power transmission system as described above. 11
is the spark plug, 12 is the ignition coil, 13 is C
The DI unit 14 is a charge coil, and these constitute a capacitive discharge type ignition device. In addition, C
In the DI unit 13, 13a is a capacitor, 1
3b is a silice, and 13C and 13d are diodes.

A discharge circuit consisting of a thyristor 15 and resistors 16 and 17 is connected to the connection point between the charge coil 14 and the CDI unit 13, and the gate of the thyristor 15 is connected to the resistor 16.
and 17 connection points. Collectors of switching PNP transistors 18 and 19 whose emitters are grounded are connected to the connection point of the resistors 16 and 17. The base of the transistor 18 is connected to a connection point between the resistor 22 and the switch 21 in a series circuit consisting of a power supply connection terminal 23, a resistor 22, a switch 21 interlocked with the governor mechanism selection lever, and ground. Note that the switch 21 is operated to be closed when the governor mechanism selection lever is selected as "actuated". Further, the base of the transistor 19 is connected to a connection point between the resistor 24 and the switch 20 in a series circuit consisting of a power supply connection terminal 23, a resistor 24, a switch 20 interlocked with the selection lever of the submission 4, and ground. The switch 20 is closed when high-speed running is selected in the submission 4, and is opened in other cases.

Next, the operation of this embodiment configured as described above will be explained. When "low" is selected in submission 4 and "operate" is selected in the governor mechanism, switch 2
o is open and switch 21 is closed. Therefore,
Transistor 19 is in the "on" state and transistor 18 is in the "off" state. If either transistor 1B or I9 turns on, thyristor 1
Since the gate potential of the thyristor 5 becomes the ground potential, the thyristor 15 becomes non-conductive. Therefore, the electromotive force generated in the charge coil 14 is not grounded via the thyristor 15, but is supplied to the CDI unit 13, and the capacitor 13a is charged with electric charge. Then, this charge is discharged at the timing of the ignition timing signal applied to the gate of the thyristor 13b, and a current flows through the primary side of the ignition coil 12, causing the spark plug 11 to generate a spark. In this way, if the governor mechanism is operated with "low" selected in submission 4, the engine will drive normally.

However, if "high (high-speed running)" is selected in submission 4 while the governor mechanism is in the operating state, both switches 20 and 21 are closed. Then, both transistors 19 and 18 are turned off, and when charge coil 14 generates an electromotive force in this state, the gate potential of thyristor 15 rises and thyristor 15 becomes conductive. Therefore, the electromotive force generated in the charge coil 14 is not supplied to the CDI unit 13 but is grounded via the thyristor 15. Therefore, CDI unit 13
Since the capacitor 13a inside the spark plug 11 is not charged with electric charge, a spark cannot be generated in the spark plug 11.

In other words, the engine will misfire.

Note that at least one of transistors 19 and 18 is turned on unless the governor mechanism is turned on with "high (high speed running)" selected in submission 4, so thyristor 15 is in a non-conducting state. Therefore, the capacitive discharge type ignition system operates normally.

〔Effect of the invention〕

As explained above, according to the engine ignition system of the present invention, if the governor mechanism is turned on when high-speed driving is selected in the auxiliary transmission, the engine will misfire and the vehicle will stop running. Constant speed running is always limited to low speeds, and the problem of constant speed running at high speeds does not occur.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, and Fig. 2 is a circuit diagram showing an embodiment of the present invention.
FIG. 2 is a power transmission system diagram of a vehicle to which the illustrated embodiment is applied. 11...Spark plug, 12...Ignition coil, 13...CDI unit, 14...Charge coil, 15...Sirisk, 18.19...Transistor, 20.21...Switch.

Claims (1)

[Claims] In a vehicle that has an auxiliary transmission that is inserted in series with the main transmission in the rotary drive system and switches between high-speed and low-speed driving, and a governor mechanism that maintains the engine rotational speed at a constant speed, the auxiliary transmission is capable of high-speed driving. An engine ignition system having means for misfiring the engine when selected and governor mechanism operation is selected.