JP2543294Y2 - Diesel engine stop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a diesel engine stopping device that forcibly shuts off fuel supply or the like when the engine stops.

[Problems to be Solved by Conventional Technology and Invention] Conventionally, in a diesel engine driven by self-ignition of fuel by compression heat, when stopping the engine, a stop lever or the like is operated to forcibly restrict fuel supply. Alternatively, a means for forcibly restricting the supply of intake air by closing an opening / closing valve provided in the intake system is employed.

For example, in Japanese Utility Model Application Laid-Open No. 61-167436 and Japanese Utility Model Application Laid-Open No. 61-171843, when the engine is to be stopped, the stop solenoid is turned on by first connecting the key switch to the accessory terminal, There is disclosed a technique for forcibly moving a control rack of a fuel injection pump to a stop position.

However, in the above prior art, the key switch is connected to the accessory terminal until the engine stops,
If the key switch is kept connected to the accessory terminal even after the engine is stopped due to forgetting to return, the battery consumes more power than necessary, and it is difficult to restart the battery.

To cope with this, as disclosed in Japanese Patent Publication No. 56-1464, there is an apparatus that employs a timer device to stop the engine.

That is, when the key switch is turned off when the engine is stopped, the timer device starts operating at the same time, and the solenoid control device operates only while the timer device is operating to supply power from the power supply to the solenoid. Thus, the solenoid drives the fuel cut lever to forcibly shut off the fuel supply and stop the engine.

However, in this conventional example, the operation time of the timer device must be set to the longest time necessary for stopping the diesel engine after shutting off the fuel system and further considering engine variations. During the middle, even after the engine is stopped, the solenoid continues to be turned on, and wasteful power is consumed.

Therefore, although the solenoid is rated for a short time, it not only causes a problem such as heat generation but also increases a load on a battery.

Also, if the engine is not completely stopped after the key switch is turned off, and the key switch is turned on due to an erroneous operation, the operation of the timer device is preferentially reset by turning on the key switch. Then, since the solenoid is de-energized, the engine does not stop and the engine rotates again.

[Purpose of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a diesel engine stopping device that consumes a very small amount of current when the engine is stopped and that can reliably stop the engine. The purpose is.

Means and Action for Solving the Problems The diesel engine stop device according to the present invention detects the state of a key switch by turning on and off a switch element, and outputs an engine stop signal when the key switch is turned off. A key switch detection unit, a rotation detection unit that receives an engine stop signal from the key switch detection unit, detects rotation of the engine, and outputs a drive signal during engine rotation; and receives a drive signal from the rotation detection unit. An actuator drive unit that drives an engine stop actuator, and while a drive signal is being output from the rotation detection unit,
An operation holding unit for holding an output of an engine stop signal from the key switch detection unit even when the key switch is turned on.

That is, when the key switch is turned off, an engine stop signal is output from the key switch detection unit to the rotation detection unit, and the rotation detection unit detects rotation of the engine and outputs a drive signal to the actuator driving unit.

Then, an engine stop actuator is driven by the actuator drive unit, and a drive signal is output from the rotation detection unit until the engine is completely stopped, and the operation of the key switch detection unit is invalidated by the operation holding unit.

[Embodiment of the present invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention.
The figure is a circuit diagram of the stopping device, and FIG. 2 is a schematic diagram of the governor device.

(Configuration) Reference numeral 1 in the figure denotes a key switch.
Has an OFF terminal, an ON terminal, and an ST (starter) terminal, and a B terminal having a movable contact 1a selectively connectable to each of these terminals is connected to the battery 2 and via a rectifier 3a. Connected to the charge coil 4a of the magneto 4.

Reference numeral 5 denotes an engine stop circuit, which includes a key switch detecting unit 6, a rotation detecting unit 7, an actuator driving unit 8, and an operation holding unit 9.

The key switch detection unit 6 detects the key switch 1
The ON terminal and the ST terminal are connected via diodes D1 and D2, respectively, and a resistor R1 is connected to this connection point.
A capacitor C1 is connected to the resistor R1 via a diode D3.

A resistor R2 is connected to a connection point between the capacitor C1 and the diode D3, and the base of the NPN transistor TR1 and a bias resistor R3 are connected to the resistor R2.

The rotation detecting unit 7 has a resistor R4 connected to a smoothing capacitor C2 from a rectifier 3b connected to the magneto 4, and a transistor TR of the key switch detecting unit 6 connected to the resistor R4.
The collector of the transistor R1 is connected to the collector of the transistor TR1.The resistor R5 is connected to a connection point between the resistor R4 and the collector of the transistor TR1, and the base of the NPN transistor TR2 and the bias resistor R6 are connected to the resistor R5. I have.

The actuator drive section 8 is provided with the key switch 1
To the B terminal of PNP transistor TR3 via diode D4.
The resistors R7 and R8 connected in series to the diode D4 are connected to the collector of the transistor TR2 of the rotation detecting unit 7.

In the transistor TR3, an emitter and a base are biased via the resistor R7, and an exciting coil 10a of a relay switch 10 in which a surge absorbing diode D5 is connected in parallel is connected to a collector of the transistor TR3. .

A power supply Vcc is connected to one terminal of a relay contact 10b of the relay switch 10, and an exciting coil 11a of a solenoid 11, which is an example of an engine stop actuator, is connected to the other terminal.

The operation holding unit 9 includes an NPN transistor T at a connection point between the resistor R1 of the key switch detection unit 6 and the diode D3.
The collector of R4 is connected, and the base of the transistor TR4 is connected to the bias resistor R9 and the collector of the transistor TR3 of the actuator driving section 8 via the resistor R10.

As shown in FIG. 2, the plunger of the solenoid 11
Reference numeral 11b is connected to a stop lever 14 forcibly turning a governor lever 13 connected to a control rack 12a for setting the injection amount of the fuel injection pump 12 to a stop position (a position shown by a solid line in the drawing).

During normal operation, the plunger 11b of the solenoid 11 is in a protruding state, and the stop lever 14 is at a position separated from the governor lever 13 as shown by a dashed line in the drawing.

The governor shaft that pivots the governor lever 13
15 Governor shaft with centrifugal force accompanying engine rotation
A governor weight (not shown) for urging the motor 15 in the low-speed direction (clockwise direction in FIG. 2) is provided in opposition. Further, a control link 16 connected to the governor lever 13 is connected to the control lever 17 via a governor spring 18.

(Operation) Next, the operation of the embodiment having the above configuration will be described.

(Starting) First, when the contact 1a of the B terminal connected to the battery 2 of the key switch 1 is connected from the OFF terminal to the ON terminal, the transistor TR4 of the operation holding unit 9 is turned off. A charging current flows from D1 to the capacitor C1 via the resistor R1 and the diode D3.
Is applied to the base of the transistor TR1.

As a result, the transistor TR1 is turned on, the base voltage of the transistor TR2 of the rotation detecting unit 7 is substantially at the ground level, and the transistor TR2 of the rotation detecting unit 7 is turned off.
Accordingly, the transistor TR3 of the actuator drive unit 8 at the next stage is also turned off, and both the relay switch 10 and the solenoid 11 are kept off.

Next, the contact 1a is connected to the ST terminal to operate a starter (not shown) and start the engine.
1a is returned to ON terminal connection. When the engine is started, an AC voltage is generated in the charge coil 4a of the magneto 4, and the AC voltage is full-wave rectified by the rectifier 3a and the battery 2 is charged.

At this time, the output of the charge coil 4a of the magneto 4 is rectified by the rectifier 3b, smoothed by the capacitor C2, and input to the rotation detection unit 7. The key switch detection unit 6 includes the diode D1 and the resistor R1. Similarly, since the base current is supplied to the transistor TR1 via the diode D3, when the transistor TR1 is turned on, the current from the capacitor C2 is grounded via the resistor R4 and the transistor TR1, and the rotation detection unit is turned on. 7 transistors TR2
Remains OFF.

(Normal operation) During normal operation, the control rack of the fuel injection pump 12 is balanced with a flyweight (not shown) that urges the governor shaft 15 by centrifugal force according to the engine speed and a governor spring 18. Move 12a to keep the engine speed constant.

Next, when the contact 1a of the key switch 1 is connected from the ON terminal to the OFF terminal to stop the engine, the base current of the transistor TR1 of the key switch detecting unit 6 is cut off, and the transistor TR1 is turned off. I do.

Then, the output of the charge coil 4a of the magneto 4 flows through the resistors R4, R5, R6 of the rotation detecting unit 7, and
The transistor TR2 is biased by R6, a base current flows, and the transistor TR2 is turned on.

As a result, the transistor TR3 of the actuator drive unit 8 is turned on, the current is supplied from the battery 2 to the exciting coil 10a of the relay switch 10, and the relay contact 10b is turned on, and the current of the battery 2 is turned on by the exciting coil of the solenoid 11. 11
Supplied to a.

As a result, the plunger 11b of the solenoid 11 pulls the stop lever 14 in the clockwise direction in FIG. 2 to forcibly rotate the governor lever 13 in the same direction, that is, the stop direction, and the fuel connected to the governor lever 13 Operate the control rack 12a of the injection pump 12 to cut off the fuel supply,
Stop the engine.

At this time, as the relay switch 10 is turned on, the collector of the transistor TR3 of the actuator driving section 8 becomes high level.
The transistor T of the operation holding unit 9 connected to the collector of No. 3
A base bias voltage is applied to the base of R4 via a resistor R9, and the transistor TR4 is turned on.

Therefore, even if the contact 1a of the key switch 1 is connected to the ON terminal due to an erroneous operation before the engine is completely stopped, the current flowing from the power supply VCC through the diode D1 is not changed by the resistance R1
Through the transistor TR4 of the operation holding unit 9 and the transistor TR1 of the key switch detecting unit 6.
Is turned off, the transistor TR2 of the rotation detecting section 7 and the transistor TR3 of the actuator driving section 8 are kept ON, and the engine is reliably stopped.

When the engine is completely stopped and the output from the charge coil 4a stops, the transistor TR2 of the rotation detecting section 7 is turned off and the transistor TR3 of the actuator driving section 8 is turned off, so that the exciting coil of the solenoid 11 is turned off. The supply of current to 11a stops, and solenoid 1
1 returns to the initial position.

That is, since the solenoid 11 is turned off immediately after the engine is completely stopped, power is not wasted and the load on the battery 2 is reduced.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 3 and FIG. 4 are front views of the main parts of the engine stop actuator provided in the intake system according to states, and the second embodiment is to stop the engine by restricting the intake air.

In this embodiment, the intake air is restricted to stop the engine. When a relay switch 10 provided in the actuator drive unit 8 of the engine stop circuit 5 is turned on, the intake pipe 19 is stopped.
An excitation coil 11a of a solenoid 11, which is an example of an engine stop actuator fixed to the outer wall of the solenoid, is energized, a plunger 11b of the solenoid 11 retreats, and an open / close valve disposed on the intake pipe 19 via a link 20. The valve 21 is closed to restrict the intake air and stop the engine (the state shown in FIG. 4).

When the relay switch 10 is turned off, the open / close valve 2
1 receives the urging force of the return spring 21a and opens again (the state of FIG. 3).

Note that the present invention is not limited to the above embodiments. For example, the engine employed may be a diesel engine mounted on a vehicle as well as a general-purpose engine, and the engine stop actuator is not limited to an electromagnetic solenoid. Alternatively, a hydraulic actuator may be used, and in the first embodiment, the engine stop actuator may directly bias the control rack 12a of the fuel injection pump 12 in the stop direction. Further, the engine stop actuator may be directly driven by the driving unit.

[Effects of the Invention] As described above, according to the present invention, a key switch detection unit that detects the state of a key switch by turning on and off a switch element and outputs an engine stop signal when the key switch is turned off. A rotation detection unit that receives the engine stop signal from the key switch detection unit, detects the rotation of the engine, and outputs a drive signal during engine rotation, and an engine stop actuator that receives the drive signal from the rotation detection unit. An actuator drive unit for driving; and an operation holding unit for holding an output of an engine stop signal from the key switch detection unit even when the key switch is turned on while a drive signal is output from the rotation detection unit. Therefore, when stopping the engine, the engine stop actuator is driven only while the engine is rotating. Even when the key switch is turned on due to an erroneous operation when the engine is not completely stopped, the engine does not rotate again without any unnecessary current consumption when the engine is stopped. Excellent effects such as stopping can be achieved.

[Brief description of the drawings]

1 and 2 show a first embodiment of the present invention. FIG. 1 is a circuit diagram of a stopping device, FIG. 2 is a schematic diagram of a governor device, and FIG. 3 and FIG. It is a principal part front view according to the state of the engine stop device provided in the intake system by 2 Example. 1 Key switch 6 Key switch detecting section 7 Rotation detecting section 8 Actuator driving section 9 Operation holding section 11 Engine stop actuator (solenoid) Tr1 Switch element (transistor)

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-125339 (JP, A) JP-A-3-18648 (JP, A) JP-A-3-33476 (JP, A) 19135 (JP, U) Japanese Utility Model Application No. Sho 53-101919 (JP, U) Japanese Utility Model Application No. 2-12071 (JP, U) Japanese Utility Model Application No. Sho 59-144138 (JP, U) Japanese Patent Publication No. 56-1464 (JP, B2)

Claims (1)

(57) [Scope of request for utility model registration] 1. A key switch detecting section for detecting a state of a key switch by turning on and off a switch element and outputting an engine stop signal when the key switch is turned off, and an engine stop signal from the key switch detecting section. A rotation detection unit that detects rotation of the engine in response to the rotation, and outputs a drive signal during rotation of the engine; an actuator drive unit that receives a drive signal from the rotation detection unit and drives an engine stop actuator; And an operation holding unit for holding an output of an engine stop signal from the key switch detection unit even when the key switch is turned on while the drive signal is output from the diesel engine. .