JPH0642375A - Throttle valve opening adjustment device at engine start - Google Patents

Abstract

(57) [Summary] [Purpose] To solve the problem that the engine cannot be started because the throttle valve cannot be returned to the origin position A due to the biting of the carbon deposited and deposited on it. [Structure] The origin position A is set to a valve fully open position C in a valve opening adjustment swing region B of the throttle lever 3. The limit switch 5 is provided so as to be located at the valve fully open position C, and operates to detect the position when the throttle lever 3 returns to the valve fully open position C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a device that adjusts and operates a throttle valve to a valve opening degree according to a body temperature.

[0002]

[Prerequisite Configuration] FIG. 2 shows an example of a graph of a valve opening setting value G of a throttle valve with respect to a body temperature T at engine start. According to the starting valve opening degree setting value G, the valve opening degree θ of the throttle valve is adjusted, and then the engine is started. Thus, by supplying the air-fuel mixture according to the aircraft temperature T without excess or deficiency, it is possible to eliminate the start-up error due to lack of fuel at low temperature, and to prevent abnormal occurrence of unburned harmful components in exhaust gas due to excess fuel at high temperature. It can be lost.

In order to do so, the throttle valve opening adjusting device for starting the engine of the present invention is intended for those having the following presupposed structure, as shown in FIGS. 1 to 3, for example.

That is, the engine air / fuel mixer 1
The throttle lever 3 of the throttle valve 2 is configured so that the opening can be adjusted by the actuator 4, and when the throttle lever 3 returns to the origin position A of the valve opening / closing swing end, the limit switch 5 detects this. The temperature sensor 6 can detect the body temperature of the engine, and the body temperature T detected by the temperature sensor 6 allows the microcomputer 7 to operate.
The internal valve opening calculation means 8 is configured to calculate the starting valve opening set value G of the throttle valve 2 at the time of engine startup, and the CPU 9 in the microcomputer 7 is operated by the start operation of the engine start switch 10. Based on the operation, first, the actuator 4 is operated in the forward direction to return the throttle lever 3 to the origin position A. When the throttle lever 3 returns to the origin position A, the limit switch 5 Detected by the throttle lever 3
Is stopped at the origin position A, and then the actuator 4 is set in accordance with the starting valve opening set value G calculated by the valve opening calculating means 8.
Is operated in the reverse direction to advance the throttle lever 3 to the starting valve opening position corresponding to the starting valve opening setting value G and stop it, and then the engine starting device 11 is operated to operate the engine. Is configured to start.

The air / fuel mixer 1 means a carburetor in the case of a gasoline engine and a fuel gas mixer in the case of a gas engine. The actuator 4 includes a stepping motor, a stepping linear motor,
Servo motors or solenoids with operating position detectors are available.

[0006]

2. Description of the Related Art In the above-described premise structure, the structure of the limit switch 5 is shown in FIG. 4 in the prior art.

That is, the origin position A is set to the valve fully closed position D in the valve opening adjustment swing region B of the throttle lever 3. The limit switch 5 is provided at the valve fully closed position D so that when the throttle lever 3 returns to the valve fully closed position D, position detection operation is performed.

[0008]

In the above prior art, when carbon is deposited on the throttle valve 2, the throttle valve 3 cannot return to the origin position A (= valve fully closed position D) and the engine cannot be started. .

The fuel exhaust gas in the fuel chamber flows back to the intake port during the overlap period of the intake and exhaust valves, and the carbon in the backflowing fuel exhaust gas adheres to the throttle valve 2 and the inner peripheral surface 12 of the mixer around the throttle valve 2. And deposit.

When the deposition and deposition of carbon progresses, the throttle valve 2 catches on the deposited carbon and the origin position A
(= Valve fully closed position D) cannot be returned. Then, the detection operation of the limit switch 5 is stopped and the engine cannot be started.

In order to avoid such inability to start the engine, it is necessary to remove the carbon deposited on the throttle valve 2 and the like from time to time, which increases maintenance costs.

An object of the present invention is to solve the problem that the throttle valve cannot be returned to the origin position A due to the biting of the carbon deposited and deposited on the throttle valve and the engine cannot be started.

[0013]

According to the present invention, in order to achieve the above-mentioned object in the above-mentioned premise structure, for example, as shown in FIG. 1, the limit switch 5 is constructed as the following characteristic structure. It is characterized by

That is, the origin position A is set at the valve fully open position C in the valve opening adjustment swing region B of the throttle lever 3, and the limit switch 5 is provided at the valve fully open position C. When the throttle lever 3 returns to the valve fully opened position C, the position detection operation is performed.

[0015]

The present invention operates as follows. When the start switch 10 is started, the CPU 9 operates to move the throttle lever 3 with the actuator 4 to the origin position A.
(= Valve fully open position C) When the throttle lever 3 reaches the origin position A (= valve fully open position C), the limit switch 5 detects this.

At this time, even if carbon is adhering to and depositing on the throttle valve 2 and the inner peripheral surface 12 of the mixer,
Since the throttle valve 2 opens, it does not become stuck due to the adhered and deposited carbon, and the origin position A (=
Smoothly returns to the valve fully open position C). This allows
The detection operation of the limit switch 5 proceeds without any problems, and the engine can be reliably started.

[0017]

The present invention has the following effects because it is configured and operates as described above.

Since the throttle valve 2 opens toward the valve fully open position C when returning to the origin position A,
Even if carbon adheres and accumulates on the throttle valve 2 etc., this accumulation does not get stuck on the carbon and the throttle valve 2 returns smoothly to the origin position A (= valve fully open position C). , Surely advance to the detection operation of the limit switch 5.

As a result, the throttle lever 3 in the next step
After advancing to the opening position of the starting valve, the engine can be reliably started by advancing to the operation of the starting device 11, and the failure to start is eliminated.

Therefore, it is possible to omit the work of removing the adhered / accumulated carbon such as the throttle lever for avoiding the inability to start the engine, which is required in the above-mentioned prior art, and the maintenance cost for this carbon removal work is unnecessary.

[0021]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a throttle valve opening adjustment device when starting a gas engine.

In FIG. 1, reference numeral 1 is a fuel gas mixer for a gas engine. The throttle lever 3 of the throttle valve 2 of the mixer 1 is elastically pressed toward the valve closing side by the return spring 21 and pressed toward the valve opening side by the output rod 4a of the stepping motor 4. When the throttle lever 3 returns to the origin position A of the valve opening / closing swing end, the limit switch 5 detects this.

The temperature sensor 6 detects the body temperature T of the engine. Based on the airframe temperature T detected by the temperature sensor 6, the valve opening calculation means 8 in the microcomputer 7 calculates the starting valve opening set value of the throttle valve 2 at the engine start.

FIG. 2 shows a graph of the starting valve opening set value G. In this graph, the starting valve opening setting value G
Is 90 ° in a low temperature region where the machine body temperature T is −15 ° C. or lower, and is 20 ° in a high temperature region of 60 ° C. or higher, −15
As the temperature approaches 60 ° C from 90 ° C, the temperature gradually changes from 90 ° to 20 °.

FIG. 3 is a flow chart of the throttle valve opening adjusting device of FIG. 1, and the following steps <S1> to <S1
The control operates in the order of 0><S1> When the engine start switch 10 is turned on, the CPU 9 in the microcomputer 7 operates, and the control operation is as follows.

<S2> First, the stepping motor 4 is rotated in the forward direction via the motor drive circuit 22,
The output rod 4a is operated in the forward direction to return the throttle lever 3 to the origin position A. <S3> When the throttle lever 3 is returned to the origin position A,
When the limit switch 5 detects this, <S
4> The stepping motor 4 is temporarily stopped and the throttle lever 3 is stopped at the origin position A.

<S5> Next, the temperature sensor 6 detects the body temperature of the engine. <S6> The valve opening calculation means 8 calculates the start valve opening set value G based on the detected temperature. <S7> The stepping motor 4 is rotated in the reverse direction according to the start valve opening setting value G to operate the output rod 4a in the reverse direction. <S8> The throttle lever 3 sets the start valve opening setting. When the start valve opening position corresponding to the value G is reached, <S9>, the stepping motor 4 and the throttle lever 3 are stopped.

<S10> Then, the starter drive circuit 23
The cell starter (starting device) 11 of the engine is operated via the to start the engine.

The origin position A is set to the valve fully open position C in the valve opening adjustment swing region B of the throttle lever 3. The limit switch 5 is provided so as to be located at the valve fully open position C, and is configured to perform position detection operation when the throttle lever 3 returns to the valve fully open position C.

In FIG. 1, reference numeral 31 is an adjustment bolt for restricting the valve fully closed position, 32 is an adjustment bolt for restricting the valve fully opened position, 33 is a fuel gas supply source, 34 is a pressure regulator, and 35 is a zero governor.

As another embodiment of the present invention, in the structure of the above embodiment, it is conceivable to use a stepping linear motor, a servo motor, or a solenoid with a current transformer for detecting an operating position in place of the stepping motor 4. To be

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a throttle valve opening adjustment device for starting an engine according to the present invention.

FIG. 2 is a graph of a valve opening set value of a throttle valve, which is set in the valve opening calculation means 8 of FIG.

FIG. 3 is a flowchart of the throttle valve opening adjustment device of FIG.

FIG. 4 is a block diagram showing a throttle valve opening adjustment device at the time of starting the engine of the related art, and is a diagram corresponding to the lower half portion of FIG. 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel gas mixer (air fuel mixer), 2 ... Throttle valve, 3 ... Throttle lever, 4 ... Stepping motor (actuator), 5 ... Limit switch, 6 ... Temperature sensor, 7 ... Microcomputer, 8 ... Valve opening calculation means , 9 ... CP
U, 10 ... Start switch, 11 ... Cell starter (starting device), A ... Origin position, B ... Valve opening adjustment swing region, C ... Valve fully open position, G ... Starting valve opening set value.

Claims (1)

[Claims] 1. A throttle lever (3) of a throttle valve (2) of an air / fuel mixer (1) of an engine is constructed so that an opening can be adjusted by an actuator (4), and this throttle lever (3) is a valve. When it returns to the origin position (A) of the open / close swing end, this is configured to be detected by the limit switch (5), and the temperature of the engine body can be detected by the temperature sensor (6). Airframe temperature (T) detected by the sensor (6)
According to the configuration, the valve opening calculation means (8) in the microcomputer (7) calculates the starting valve opening set value (G) of the throttle valve (2) at the engine start, and the engine start switch ( Based on the CPU (9) in the microcomputer (7) being activated by the starting operation of 10), first, the actuator (4) is activated in the forward direction,
The throttle lever (3) is returned to the origin position (A), and when the throttle lever (3) returns to the origin position (A), the limit switch (5) detects this and the throttle lever (3) 3) is stopped at the origin position (A), and then the actuator (4) is operated in the reverse direction according to the starting valve opening set value (G) calculated by the valve opening calculating means (8), The throttle lever (3) is advanced to the starting valve opening position corresponding to the starting valve opening set value (G) and stopped, and then the engine starting device (11) is operated,
In the throttle valve opening adjustment device for starting the engine, which is configured to start the engine, the origin position (A) is a valve fully opened position (C) of a valve opening adjustment swing region (B) of the throttle lever (3). ), The limit switch (5) is set to the valve fully open position (C).
The throttle valve opening degree adjusting device at the time of starting the engine, wherein the throttle valve opening degree adjusting device is configured to perform a position detection operation when the throttle lever (3) is returned to the valve fully open position (C).