JPS62168962A - Engine starting device - Google Patents

Abstract

PURPOSE:To prevent a support equipment connected with a PTO shaft from being damaged at the time of engine start by providing a means which checks the drive of a starter motor when the PTO shaft is connected with an engine, and when a governor is inoperative. CONSTITUTION:A governor mechanism which keeps constant the rotary speed of both a PTO shaft for an external support equipment and an engine, is included. Regardless of the PTO shaft being in operation, when the governor is in an inoperative condition by mistake, a switch 21 is closed and a switch 20 is opened. And a transistor 19 is turned 'on', and a transistor 18 is turned 'off'. As a result, a contact 26b is kept open, furthermore, a contact 27b is also kept open for driving no starter motor 28. Therefore, this constitution prevents the support equipment connected with the PTO shaft from being damaged at the time of engine start.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a PTO (Power
The present invention relates to an engine starting device for a vehicle having a Take Off) shaft.

[Conventional technology]

For example, three-wheeled or four-wheeled rough terrain vehicles equipped with wide, low-pressure tires, so-called balloon tires, are often equipped with a PTO shaft for driving external work equipment. P
The TO shaft is a shaft that is rotated by the output of the vehicle drive engine, and various external working devices such as grass cutting blades and sprayers can be attached to this PTO shaft as necessary.

That is, a vehicle having a PTO shaft can function as a multi-purpose vehicle by appropriately replacing external work equipment.

On the other hand, a vehicle having such a PTO shaft is provided with a governor mechanism for controlling the engine rotation speed to a constant value. When performing desired work by attaching external work equipment to the PTO shaft, the governor mechanism is activated to keep the rotational speed of the PTO shaft constant and enable travel at a constant speed, thereby stabilizing the PTO work. is planned.

[Problem that the invention seeks to solve]

However, when starting the engine to perform PTO work, it is not uncommon to neglect to check the operating state of the governor mechanism and drive the starter motor to start the engine with the governor mechanism in an inactive state. If such a situation is left unaddressed, the PTO shaft may be rotated at a high speed and the work equipment attached to the PTO shaft may be damaged.

[Means for solving problems]

The engine starting device of the present invention has been made in pursuit of the above-mentioned problem, and is equipped with means for preventing the starter motor from being driven when the PTO shaft is connected to the engine and the governor mechanism is inactive.

[Effect]

If the governor mechanism is accidentally turned off when starting the engine during PTO work, the starter motor will not drive.

〔Example〕

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

FIG. 2 is a power transmission system diagram of a vehicle to which the present invention is applied, that is, a vehicle having a PTO shaft. The rotational force of the crankshaft l of the engine is transmitted to the clutch 3 that engages and engages the engine, and the rotational force output from the clutch 3 is transmitted to the submission 4 and P
It is transmitted to the TO axis 8. In submission 4, high speed (
A gear selection is made between low speed ("High"), low speed ("Low") or reverse ("Reverse"); if "Reverse" is selected, the rotational force in the opposite direction is applied directly to the differential at low speed. The signal is transmitted to gear 6. submission 4
When "high" or "low" is selected, forward high-speed or low-speed rotational force is transmitted to the differential gear 6 via the forward 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. For the differential gear 6, when the vehicle is traveling straight, "lock" is normally selected to stabilize travel, and when the vehicle is making a U-turn, "activation" is appropriately selected. On the other hand, "on" and "off" are also selected for the PTO shaft 8, and when "on" is selected, the rotational force output from the clutch 3 is transmitted to the work equipment 9, and "off" is selected. In this case, the rotation of the PTO shaft 8 is stopped regardless of the rotation of the output shaft of the clutch 3. Note that 2 is a starter motor, which is electrically driven to forcibly rotate the crankshaft to 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.

At the connection point between the charge coil 14 and the CDI unit 13, a thyristor 15, a resistor 16. ．． A discharge circuit consisting of 17 is connected, and the gate of thyristor 15 is connected to a resistor 1.
G and 17 connection points. The collector of a switching pnp transistor 18 whose emitter is grounded is a diode 3 at the connection point between the resistors 16 and 17.
By controlling the on/off of this transistor 18, the thyristor 15 is turned on or off.
OFF” state. In addition, the diode 30
has its cathode side connected to the collector of the transistor 18. The base of the transistor 18 is connected to the collector of a pnp (pnp) run risk 19, and the emitter of the transistor 19 is grounded via a switch 21 that is interlocked with the PTO shaft drive selection lever. In addition, switch 2
1 is switched to close when the PTO shaft drive selection lever is selected to the "drive" side. A power supply connection terminal 23 is connected to a connection point between the collector of the transistor 19 and the base of the transistor 18 via a resistor 22. This resistor 22, transistor 19 and switch 2
A series circuit consisting of a resistor 24 and a switch 20 interlocked with the governor mechanism selection lever is connected in parallel to the series circuit consisting of the transistor 19, and the base of the transistor 19 is connected to the connection point between the switch 20 and the resistor 24. There is. It should be noted that the switch 20 is operated to close when the governor mechanism selection lever is selected to "actuate".

On the other hand, a starter button 25, a starting safety relay 26, a starter relay 27, and a starter motor 28 constitute a starting circuit. The fixed contact of the starter button 25 is connected to the power supply connection terminal 23, and the movable contact is connected to one terminal of a contact drive coil 261 of the starting safety relay 26.

The other end of the contact drive coil 26a is connected to a connection point between the cathode of the diode 30 and the collector of the transistor 18. One end of the contact 26b of the starting safety relay 26 is connected to the movable contact of the starter button 25, and the other end is grounded via a contact drive coil 27a of the starter relay 27. One end of the contact 27b of the starter relay 27 is connected to the power supply connection terminal 23, and the other end is connected to the input terminal of the starter motor 28, and the other input terminal of the starter motor 28 is grounded.

Next, the operation of this embodiment configured as described above will be explained. When the PTO axis is selected to the drive side, switch 2
1 is closed. When the PTO shaft is driven, the governor mechanism is normally operated, so the switch 20 is also closed. Therefore, transistor 19 becomes "off" and transistor 18 becomes "on". Therefore, when the starter button 25 is operated and closed in this state, "power supply connection terminal 23 - starter button 25 -
A current flows between the coil 26a and the run lister 18, and the contact 26b is closed. Then, a closed circuit of "power supply connection terminal 23 - starter button 25 - contact 26b - coil 27a" is formed, current flows through the coil 27a, and the contact 27
b is closed.

When the contact 27b is closed, current flows from the power supply connection terminal 23 to the starter motor 28, which rotates the starter motor 28 and starts the engine.

Next, a case will be described in which the governor mechanism is erroneously placed in a non-operating state even though the PTO shaft is in a driving state. At this time, switch 21 is closed and switch 20 is open. In this case, the transistor 19 is turned on, the base potential of the transistor 18 is lowered, and the transistor 18 is turned off. Therefore, even if the starter button 25 is operated and closed, no current flows through the coil 26a. As a result, the contact 26b is kept open, and the contact 27b is also kept open, so that the starter motor 28 is not driven.

Note that when the PTO shaft drive selection lever is selected to the "non-drive" side, the switch 21 is opened from the beginning, so the transistor 18 is "on" regardless of the state of the switch 20, and the starter button is turned on. 25, a current flows through the coil 26a, and the starter motor 28
drives normally.

Further, in this embodiment, when the transistor 18 is "on", the thyristor 15 is "off", and conversely, when the transistor 18 is "on", the thyristor 15 is "off";
8 is "off", the thyristor 15 is "on", so the transistor 18 is "off", such as when the PTO shaft is in the driving state and the governor mechanism is in the inactive state.
If so, the thyristor 15 is turned on, and the electromotive force generated in the charge coil 14 is grounded via the thyristor 15. Therefore, the electromotive force of the charge coil 14 is not supplied to the CDI unit 13, resulting in a misfire state.

〔Effect of the invention〕

As explained above, according to the engine starting device of the present invention, if the governor mechanism is in the "off" state when starting the engine during PTO work, the starter motor will not drive, so the governor mechanism will be in the inactive state. Even if you accidentally press the starter button while the engine is still on, you will not be able to start the engine. Therefore, there is no problem of causing the PTO shaft to rotate at a high speed when starting the engine and damaging the working machine attached to the PTO shaft.

[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. 18.19...Transistor, 20.21...Switch, 25...Starter button, 26...Starting safety relay, 27...Starter relay, 28...Starter motor. Patent applicant: Yamaha Motor Co., Ltd. Representative: President Yamakawa (and 2 others) Figure 2: Mr. Commissioner of the Japan Patent Office 61.3,101.
Display of the case 1986 Patent Application No. 9000 2, Name of the invention Engine starting device 3, Person making the amendment Relationship to the case Patent Applicant name (name) (AO7) Yama/Motor Co., Ltd. 5, Target of correction 2 (・1・) (1) “Diode 25” on page 5, line 20 of the specification is corrected to “diode 30.” (2) r pnp J on page 5, line 19 and page 6, line 6 of the same book
are corrected to rnpnJ, respectively. that's all

Claims (1)

[Claims] In a vehicle that has a PTO shaft for driving external work equipment and a governor mechanism that keeps the engine rotational speed constant, the PTO shaft is connected to the engine and an electrically driven starter motor that forcibly rotates the engine to start the engine. An engine starting device comprising means for preventing the starter motor from being driven when the governor mechanism is in an inoperative state.