JP3190383B2 - Afterburn prevention mechanism when the engine starts and stops - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for preventing an engine mounted on a running vehicle from generating afterburn when starting after stopping.

[0002]

2. Description of the Related Art In an autonomous vehicle or the like in which the engine may be stopped in an overloaded state, the inertia from the traveling vehicle side is maintained even after the stop because the mounted engine is overloaded. The engine rotates due to the running force, and the fuel oil flows into the cylinder due to the inertial running rotation, and when the engine is started again, it burns in the muffler, and a state called afterburn occurs.
Conventionally, as a technique relating to an afterburn prevention mechanism at the time of starting and stopping the engine, a technique as disclosed in Japanese Patent Publication No. 63-54890 is known.

[0003]

According to the present invention, the key switch of the engine is turned off, the ignition plug is not ignited, and the throttle valve is substantially fully closed so that the afterburn does not occur. It prevents unburned gas from flowing into the engine and eliminates afterburn.

[0004]

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described. In a traveling vehicle equipped with the engine E, an automatic transmission power transmission mechanism K, whose reduction ratio changes automatically when the state of the ground changes, is interposed between the engine E and the transmission case 9 to load the engine E with a load factor. And a vehicle speed sensor 2 for detecting a vehicle speed outputted from a transmission case 9, and an accelerator actuator 8 driven based on a signal from the vehicle speed sensor 2.
The throttle valve in the carburetor 15 is mechanically operated by the accelerator actuator 8, and the running speed is also automatically controlled at a constant value. At the same time, the throttle valve is almost fully closed by the accelerator actuator 8, and at the same time, power is supplied to the ignition plug.
The engine E is stopped by shorting the next line to ground .

[0005]

Next, the operation will be described. By starting the starter switch K, the engine E is started via the starter starter motor M. At the same time as the start of the engine E, the engine speed is detected by the engine speed sensor C.
The predetermined number of rotations is constantly monitored by the electronic control controllers 13 and 14 with the rotation as a target. Then, in a state of exceeding about 1000 rotations, normal operation is continued.
The control circuit of the present invention for detecting the low rotation state and fully closing the throttle valve is not operated until the starter switch K is operated to about 1000 rotations. Then, in the operation continuation state, the rotation speed is 4600
It detects both an over-rotation state of rotation or more and a low-rotation state of rotation number of 1000 or less. When an overspeed state of 4600 or more rotations is detected, the primary line is short-circuited and the engine is stopped immediately. In addition, the rotation speed is about 100
When a low rotation state of 0 rotation or less is detected, the throttle valve is fully closed by the accelerator actuator 8, and the primary line is short-circuited to stop the engine E. As described above, the throttle valve is fully closed via the accelerator actuator 8, the interlocking link 29, and the throttle valve opening / closing arm 28 at the same time as the detection of the low rotation state of about 1000 rotations or less. If the engine is stopped and the engine E continues the inertial rotation, afterburn may occur at the next restart even if fuel oil is sucked and unburned fuel remains in the cylinder or the muffler 7. It is gone.

[0006]

Next, an embodiment will be described. 1 is an overall side view of the traveling vehicle of the present invention, FIG. 2 is an overall plan view of the same, FIG. 3 is an enlarged plan view of an engine E showing a main part of the present invention, FIG.
FIG. 5 is an enlarged plan view of the accelerator actuator 8 and the carburetor 15; FIG. 5 is a control block diagram of an afterburn prevention mechanism when the engine is stopped according to the present invention; It is.

Referring to FIGS. 1 and 2, the overall configuration of a traveling vehicle equipped with an engine E will be described. In FIG. 1, the traveling vehicle of the present invention constitutes a four-wheel traveling vehicle supported by front wheels 25, 25 and rear wheels 26, 26. The front wheels 25 are supported by front axles 24,
The rear wheels 26 are driven wheels that are operated by the steering handle 20, and the rear axles 23 are driven by the engine E via the transmission case 9. A steering handle 20 is disposed at a position in front of the seat S, and an engine E is disposed inside a hood B below the seat S. The present invention relates to a technology related to an afterburn prevention mechanism mounted on a traveling vehicle when starting and stopping an engine.

A detailed description will be given with reference to a plan view around the engine shown in FIG. Electronic control controllers 13 and 14 are arranged below the steering handle 20 of the traveling vehicle and at the positions of the feet of the operator. The engine E is arranged at a position below the seat S behind the electronic control controllers 13 and 14. The engine E includes a cylinder block 5, a pre-cleaner 6, an air cleaner 27, a carburetor 15, a muffler 7, a cylinder head 16, and the like. And, between the crankshaft 30 which is the output shaft of the engine E and the input shaft of the transmission case 9,
An automatic transmission power transmission mechanism constituted by opening and closing pulleys 11 and 12 and an urging spring mechanism 10 is interposed. The automatic transmission power transmission mechanism includes an output-side open / close pulley 11 attached to a crankshaft 30 and an input shaft 33 of a transmission case 9.
, And an urging spring mechanism 10 attached to the output-side open / close pulley 11.

With this configuration, the rear axle 2 of the rear wheels 26
When a load for traveling on rough terrain is applied to 3/23, the rotation of the input-side open / close pulley 12 becomes heavy, and a load is applied to the rotation of the belt wound between the input-side open / close pulley 11 and
The output-side open / close pulley 11 provided with the biasing spring mechanism 10 opens first and changes to a small-diameter pulley. In accordance with this, the input side opening / closing pulley 12 changes to the large diameter side, the rotation speed of the rear axles 23, 23 decreases, and the speed decreases. Conversely, like a downhill road, the rear axle 23.2
3, the output side opening / closing pulley 11 changes to the large diameter side, and the rear axle 23
The number of rotations of the 23 is increased.

However, if only the automatic transmission power transmission mechanism is interposed between the engine E and the transmission case 9 as described above, the traveling speed becomes faster or slower depending on the condition of the ground, and the traveling speed is not constant. In, the vehicle speed sensor 2 and the vehicle speed rotator 1 are provided to constantly detect the vehicle speed,
When the vehicle speed changes due to a change in the state of the ground, in order to keep the vehicle speed constant, the electronic control controllers 13 and 14 are operated to electronically operate the accelerator actuator 8 and the carburetor 15 receives the change. Is changed in such a direction that the speed becomes constant.

Further, a tail pipe 17 is provided at the exhaust outlet of the muffler 7 to reduce noise coming out of the muffler 7. 8 is a shift control actuator,
In response to instructions from the electronic control controllers 13 and 14, the accelerator actuator 8 is controlled, and the opening and closing of the carburetor 15 is automatically controlled to control the rotation speed. As shown in FIG. 3, the accelerator actuator 8 is disposed at a position above the cylinder block 5 and at the rear of the carburetor 15. The accelerator actuator 8 is constituted by a forward / reverse drive motor. When the motor of the accelerator actuator 8 rotates, the arm of the accelerator actuator 8 rotates and the link 29
, The throttle valve opening / closing arm 28 is operated. By operating the throttle valve opening / closing arm 28, the throttle valve in the carburetor 15 is opened / closed.

The electronic actuators 13 and 14 receive the rotation of the vehicle speed sensor 2 to operate the accelerator actuator 8 in the forward and reverse directions. It rotates. Reference numeral 27 denotes an air cleaner, and reference numeral 3 denotes an upper end cover provided at the upper end of the oil supply hole flexible tube 4. Oil inspection can be performed with an oil inspection rod. The vehicle speed rotator 1 is a rotating plate fixedly mounted on a shaft protruding from the transmission case 9. The vehicle speed sensor 2 detects a notch concave portion at the tip of the vehicle speed rotator 1 so that the rotation speed of the rear axles 23. A signal is obtained and used as a vehicle speed signal.

Referring now to FIG. 5, a control block diagram of the afterburn prevention mechanism at the time of starting and stopping the engine according to the present invention will be described. The starting starter motor M is driven and rotated by the turning operation of the starter switch K of the traveling vehicle. The rotation of the starter motor M causes the engine E to start rotating. An engine rotation sensor C for detecting the rotation speed of the engine E is provided in the engine E, and a detection signal from the engine rotation sensor C is input to the electronic control controllers 13 and 14. The electronic controller 13
The signal from the throttle lever sensor R operated by the operator is also input to 14.

The signals from the throttle lever sensor R and the engine rotation sensor C are transmitted to the electronic controller 1
The control signal is supplied to the accelerator actuator 8 based on the comparison and judgment in 3.14. The forward / reverse rotation of the accelerator actuator 8 rotates the throttle valve opening / closing arm 28 provided on the carburetor 15 via the interlocking link 29. The throttle valve opening / closing arm 28
The rotation of the throttle valve opens and closes a throttle valve, which is a main part of the present invention, and the rotation speed of the engine E changes.

Next, a control flowchart will be described with reference to FIG. By starting the starter switch K, the engine E is started via the starter starter motor M. At the same time as the start of the engine E, the engine speed is detected by the engine speed sensor C, and the predetermined speed is constantly monitored by the electronic controller 13.
14 to monitor. Then, in a state of exceeding about 1000 rotations, normal operation is continued. And while driving,
An over-rotation state where the number of rotations is 4600 or more and the number of rotations is 1
Detect both low rotation state of less than 000 rotations.

If an overspeed condition of 4600 rpm or more is detected, the primary line is short-circuited and the engine is stopped immediately. When a low rotation state where the rotation speed is about 1000 rotations or less is detected, the throttle valve is fully closed by the accelerator actuator 8 and the primary line is short-circuited to stop the engine E. Thus, about 1
The throttle valve is fully closed via the accelerator actuator 8, the interlocking link 29, and the throttle valve opening / closing arm 28 at the same time as the detection of a low rotation state of 000 rotations or less, so that the engine is stopped in an overload state, and the engine is stopped. Even if the fuel oil is sucked and the unburned fuel stays in the cylinder or the muffler 7 when the engine E continues the inertial rotation, the after-burn does not occur in the next restart.

[0017]

As described above, the present invention has the following advantages. First, when the number of revolutions of the engine E falls below one point, this low revolution state is detected by the engine revolution sensor C, and the throttle valve is immediately fully closed by the accelerator actuator 8 , and at the same time, the primary To shut down engine E
Even if the rotation continues due to inertial rotation,
The fuel is sucked into the cylinder from the heater 15 and the muffler 7
And fuel oil stays near the muffler 7
Is gone. Therefore, at the time of restart,
Ignited fuel oil may cause afterburn.
Has disappeared.

Second, such an engine E is automatically driven.
Mounted on a control vehicle, the vehicle is suddenly stopped by automatic cruise control
When the vehicle is running inertia
Also, fully close the throttle valve, short-circuit the primary
By stopping the engine E, the automatic cruise control vehicle
The problem of the occurrence of afterburn in Japan
You can do it.

[Brief description of the drawings]

FIG. 1 is an overall side view of a traveling vehicle according to the present invention.

FIG. 2 is an overall plan view of the same.

FIG. 3 is an enlarged plan view of a part of an engine E showing a main part of a vehicle speed control mechanism of a traveling vehicle according to the present invention.

FIG. 4 shows an accelerator actuator 8 and a carburetor 15
It is an enlarged plan view of a part.

FIG. 5 is a control block diagram of an afterburn prevention mechanism at the time of starting and stopping the engine according to the present invention.

FIG. 6 is a control flowchart of an afterburn prevention mechanism when the engine is started and stopped.

[Explanation of symbols]

 K Starter switch C Engine rotation sensor E Engine 1 Speed rotating body 8 Accelerator actuator 13, 14 Electronic control controller 28 Throttle valve opening / closing arm

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ identification code FI F02D 43/00 301 F02D 43/00 301A 301K (58) Field surveyed (Int.Cl. ⁷ , DB name) F02D 9/00- 11/10 F02D 29/00-29/06 F02D 41/00-45/00 395

Claims (1)

(57) [Claims] 1. A traveling vehicle equipped with an engine E, interposed between an engine E and a transmission case 9 an automatic transmission power transmission mechanism K whose reduction ratio changes automatically when the condition of the ground changes. A vehicle speed sensor 2 for controlling a load ratio to the engine E to be constant and detecting a vehicle speed output from a transmission case 9 and an accelerator actuator 8 driven based on a signal from the vehicle speed sensor 2 are provided. The throttle actuator in the carburetor 15 is mechanically operated by the accelerator actuator 8, and the running speed is automatically controlled to be constant. When the throttle valve is almost fully closed by the accelerator actuator 8 , the electric power is supplied to the ignition plug.
An afterburn prevention mechanism at the time of engine start / stop, wherein a primary line to be supplied is short-circuited to ground to stop the engine E.