JP3340862B2 - Check valve drive mechanism for sub-chamber gas engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas engine for mainly burning gaseous fuel, in which a sub-chamber is provided for improving ignitability, and a check valve for supplying fuel to the sub-chamber and a spark plug are provided. The present invention relates to a check valve drive mechanism of a sub-chamber gas engine.

[0002]

2. Description of the Related Art Conventionally, a technique of supplying a gas by providing a check valve in a sub chamber has been known. For example, as disclosed in Japanese Patent Application Laid-Open No. 2-81925. However, if the amount of gas supplied from the check valve to the sub-chamber is too large, or if propane gas is used, smoke is generated in the sub-chamber and combustion residues are caught in the check valve,
A misfire occurred due to a malfunction of the check valve. In this case, forcibly set the check valve to 2
In some cases, if the user makes a rotation of up to three times, the engine operates normally and the operation of the engine is continued. Further, the operation of the check valve changes with time, and there is a variation between cylinders, which causes a problem that NOx increases with time. It is also known that a check valve is formed by a mechanically driven valve.However, since the valve opening period is constant, combustion gas is blown under certain conditions, causing an increase in valve temperature and abnormal wear. Had occurred.

[0003]

SUMMARY OF THE INVENTION The present invention is intended to solve the problem that the check valve for supplying fuel gas into the sub-chamber bites carbon in fuel residue and causes misfire in the sub-chamber. is there. Further, the gas supply amount to the sub-chamber is stabilized, the engine speed is stabilized, the variation of the gas supply amount to the sub-chamber is eliminated, and the NOx is reduced. Further, the combustion characteristics at the time of loading and shutting off of the load are improved, so that the injection of gas into the sub-chamber during the exhaust stroke is prevented, and the gas does not blow through.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. In claim 1, the inside of the sub-chamber 7
In the sub-chamber gas engine in which the check valve 13 is arranged,
A solenoid 20 for driving the check valve 13 is provided.
Exhaust temperature sensor that constantly detects the temperature of exhaust gas
-21 and the check valve 13 in the sub chamber 7
Opening / closing stopped by biting carbon, which is slag, causing a misfire
The ignition coil 12 that ignites in the sub chamber 7
A voltage is applied to the solenoid 20 based on the signal of the pulser 15.
Open / close the check valve 13 to recover the misfire
After that, the solenoid 20 is stopped .

According to the second aspect, a check is made in the sub-chamber 7.
In a subchamber gas engine in which the valve 13 is arranged,
A solenoid 20 for driving the intake valve 13 is attached,
The pressure Pa in the air supply pipe from the pressure sensor 22 in the trachea,
From the engine speed signal from the pickup 29,
The power supply time to the cylinder 20 is determined, and the TDC signal of each cylinder is turned on.
Received from the fire pulsar 15 and used as a reference pulse
When the solenoid 20 is energized, the check valve 13 is
Proper valve opening by always driving with the solenoid 20
Engine to reduce the variation between cylinders and reduce NOx
It is intended to reduce and improve the combustion characteristics at the time of loading and shutting off the load .

According to claim 3, claim 1 or 2 is provided.
In the check valve drive mechanism of the sub-chamber type gas engine ,
Adjust the solenoid 20 on the check valve 13 with the adjusting screw 3
0, the solenoid drive pin 24 of the solenoid 20 is floated by the springs 25 and 26 so as not to normally contact the check valve 13, the check valve 13 is driven only when the solenoid 20 is energized, and the adjusting screw 30 is turned on. By adjusting the gap, the gap between the solenoid drive pin 24 of the solenoid 20 and the check valve 13 can be adjusted.

[0007]

Next, the operation will be described. According to the first aspect, it is possible to eliminate a misfire caused by carbon biting of the check valve 13 or the like. The check valve 13 is normally opened and closed by pressure, but the solenoid 20 operates only when the sub-chamber combustion is misfired. Therefore, the forced valve opening mechanism by the solenoid 20 is replaced with a conventional sub-chamber gas engine. It has become possible to retrofit it.

According to the second aspect, the variation between the proper valve-opening engine and the cylinder is reduced, the NOx is reduced, and
It was possible to improve the combustion characteristics at the time of shutoff.
Further, the variation in the gas supply amount to the sub chamber can be eliminated, and the NOx can be reduced. Further, gas injection into the sub-chamber during the exhaust stroke was prevented, and blow-by of exhaust gas did not occur.

According to the third aspect, the gap between the solenoid drive portion and the check valve can be adjusted, so that the solenoid drive pin 24 is always floating, and operates only when a misfire occurs, so that the life of the solenoid is extended. It is. Further, the solenoid 20 can be retrofitted to a conventional sub-chamber type gas engine having only a check valve.
Further, the distance between the solenoid drive pin 24 and the check valve 13 can be adjusted by the adjusting screw 30.

[0010]

Next, an embodiment will be described. FIG. 1 is a fuel supply circuit diagram showing a check valve driving mechanism of a sub-chamber type gas engine of the present invention, FIG. 2 is a diagram showing a timing of driving a check valve by a solenoid, and FIG. 3 is a diagram showing a state in which a misfire alarm is judged. FIG. 4 is a fuel supply circuit diagram showing an embodiment in which the check valve 13 of the sub-chamber 7 is constantly opened and closed by a solenoid 20, and FIG. 5 is a drawing showing the relationship between a solenoid lift, a pipe pressure, and a check valve lift with respect to a crank angle. 6 is a drawing showing the relationship between the load and the pressure Pa in the supply pipe, and FIG. 7 is a drawing showing the state in which the opening time of the check valve 13 is controlled with respect to a change in the number of revolutions when the load is turned on and off. 8 is a drawing showing the relationship between the pressure Pa in the air supply pipe and the valve opening time, FIG. 9 is a drawing showing the change of the NOx concentration with time, FIG. 10 is a drawing showing the solenoid 20 and the check valve 13 Sectional view of a portion of the fire plugs 14, 11 is solenoid 2
It is an exploded view of the part of 0.

The first embodiment of the present invention will be described with reference to FIGS. From gas tanks, such as pro-Pas Ngasu, fuel gas, while being controlled amount supply by the regulator 2 is supplied to the venturi mixer 1, it is mixed with intake air coming sucked through the air filter. In the venturi mixer 1, the fuel gas in which the gas fuel and the intake air are mixed passes through the intercooler 3 and passes through the throttle 4 which is controlled and controlled by the electronic governor 5. And it is supplied to the combustion chamber constituted by the piston 6 and the cylinder.

Another fuel gas passes through the compressor 11, is concentrated, and is supplied into the sub-chamber 7 through the sub-chamber gas supply pipe 9 while the supply amount is controlled by the sub-chamber regulator 10. You. The fuel gas for the sub-chamber supplied to the sub-chamber 7 is ignited at a fixed timing by the ignition plug 14, and the ignition of the gas in the sub-chamber ignites the fuel gas in the main combustion chamber defined by the piston 6. .

The ignition plug 14 is supplied with a high-voltage current by the ignition coil 12 at a predetermined timing. Exhaust gas after combustion in the combustion chamber is discharged to the supercharger 8 via the exhaust gas temperature sensor 21. The turbine is rotated by the exhaust gas in the supercharger 8, and the fuel gas is compressed and supplied from the venturi mixer 1 by the charger.

In the present invention, the check valve 13 provided at the portion for supplying the sub-chamber gas from the sub-chamber gas supply pipe 9 into the sub-chamber 7 bites the carbon that is the combustion residue and stops opening and closing. In this case, since a misfire occurs, the misfire state is detected by the exhaust gas temperature sensor 21, the solenoid 20 is operated, and the check valve 13 is pushed by the solenoid 20 to return the valve to the normal state. .

The exhaust temperature sensor 21 is a multi-cylinder
The exhaust gas temperature is detected for each cylinder, and if the detected exhaust gas temperature exceeds a threshold value, it is determined that a misfire state has occurred in the cylinder. FIG.
Shows a state in which, in a six-cylinder multi-cylinder engine, misfire has been detected in the fourth cylinder. When the misfire state is detected in this manner, as shown in FIG. 2, a voltage is applied to the solenoid 20, and the pressing pin of the solenoid 20 is protruded for a certain period of time.
The operation of pushing 3 is performed.

Normally, the check valve 13 attached to the sub-chamber 7 is operated by the differential pressure between the gas pressure and the pressure in the sub-chamber 7. The operation of the check valve 13 is performed during the intake stroke, but when the check valve 13 is not operated, a deviation occurs in the exhaust gas temperature measured by the exhaust gas temperature sensor 21 attached to each cylinder as shown in FIG. Therefore, the controller 16 turns on the power of the driver 18 and starts driving the solenoid 20.

The driver 18 applies a voltage to the solenoid 20 based on a signal before the overlap TDC of the ignition pulser 15. Even if a voltage is applied, no current is generated immediately, so that after a certain time lag, the check valve 13 is depressed by overcoming the carbon bitten by the spring of the check valve 13. The voltage is cut off during the valve open period of the check valve 13 which has been measured in advance. When the exhaust gas temperature falls within the deviation threshold, the driver 18 is turned off. 17 is an igniter and 19 is a relay.

Referring to FIG. 4, the second aspect of the present invention will be described. In FIG. 4, the air supply pipe pressure Pa from the air supply pipe pressure sensor 22 and the engine speed signal from the electromagnetic pickup 29 are input to the controller 16. From the pressure Pa in the supply pipe and the engine speed signal, the solenoid 20
Is determined. The determined energization time is sent to the driver 18 by voltage, and the driver 18 receives the TDC signal of each cylinder from the ignition pulser 15 and energizes the solenoid 20 as a reference pulse.

The solenoid 20 overcomes the spring of the check valve 13, opens the check valve 13, and when the energization ends, the check valve 13 is closed by the spring.
Here, as shown in FIG. 6, the gas supplied to the check valve 13 is obtained by adding a constant value to the air supply pipe pressure Pa, and the spring of the check valve 13 is set to a value larger than this constant value. . The valve opening time is as shown in FIG.
Control so that it becomes longer as the load increases. As shown in FIG. 7, the control at the time of load application and at the time of load shutoff is controlled so as to be longer when the engine speed is lower and shorter when the engine speed is higher. As a result, when the check valve 13 is opened and closed with the pressure so far, as shown in FIG. 9, the NOx tends to increase with time, but the variation between the cylinders is reduced, and the NOx concentration is prevented from increasing. You can do it.

Referring to FIGS. 10 and 11, the solenoid 20
Is screwed into the lower part of the body 23 with a screw part integrally engraved. The body 23 is provided with a fine hole having a diameter of 2 mm so that when the solenoid drive pin 24 moves up and down, fuel gas flows above and below the solenoid 20 to reduce the resistance of the movement of the solenoid drive pin 24. . The solenoid drive pin 24 is in contact with the upper plate 27, and the plate 27 is floated by upper and lower springs 25 and 26. When the solenoid 20 is not energized, the solenoid drive pin 24 Are supported in a floating state by springs 25 and 26.

When energized, a suction force acts on the solenoid 20, so that the solenoid drive pin 24 is pushed downward, and the screw 29 at the upper end of the check valve 13 is pressed, whereby the check valve 13 is urged. The valve is lowered against the spring 28 and opens. When the energization to the solenoid 20 is stopped, the solenoid drive pin 24 is returned by the springs 25 and 26. In the above configuration, adjustment of the interval between the solenoid drive pin 24 and the solenoid 20 can be performed by rotating the adjustment screw 30 provided at the upper end.

[0022]

As described above, the present invention has the following advantages. In claim 1,
In a sub-chamber gas engine, the temperature of the exhaust gas is constantly detected, and if a misfire occurs, the check valve is forcibly driven by the solenoid to drive the check valve and stop the solenoid after the misfire condition is recovered. By doing so, it is possible to eliminate a misfire caused by the bite of carbon in the check valve 13 or the like.
The check valve 13 is normally opened and closed by pressure, but only when the sub-chamber combustion is misfired, the solenoid 20 is opened.
Operates, so that the forcible valve opening mechanism by the solenoid 20 can be retrofitted to a conventional sub-chamber gas engine.

According to a second aspect of the present invention, in a sub-chamber type gas engine, a check valve for supplying fuel to the sub-chamber is driven by a solenoid, so that an appropriate valve-opening engine is provided to reduce variations among cylinders. To reduce NOx,
It was possible to improve the combustion characteristics when the load was turned on and off. Further, the variation in the gas supply amount to the sub chamber can be eliminated, and NOx is reduced. Further, gas injection into the sub-chamber during the exhaust stroke was prevented, and blow-by of exhaust gas did not occur.

According to a third aspect of the present invention, in the sub-chamber type gas engine, a solenoid is mounted on a check valve for supplying fuel to the sub-chamber with a screw, and a driving portion of the solenoid is floated by a spring so that the check valve does not always contact. As described above, the check valve is driven only when the solenoid is energized, and by adjusting the screw, the gap between the drive portion of the solenoid and the check valve can be adjusted. Since it is floating and operates only when a misfire occurs, the life of the solenoid is extended. Further, the solenoid 20 can be retrofitted to a conventional sub-chamber type gas engine having only a check valve. Further, the distance between the solenoid drive pin 24 and the check valve 13 can be adjusted by the adjusting screw 30.

[Brief description of the drawings]

FIG. 1 is a fuel supply circuit diagram showing a check valve driving mechanism of a sub-chamber type gas engine of the present invention.

FIG. 2 is a diagram showing timing for driving a check valve by a solenoid.

FIG. 3 is a diagram showing a state in which a misfire alarm is determined.

FIG. 4 is a fuel supply circuit diagram showing an embodiment in which a check valve 13 of a sub chamber 7 is constantly driven to open and close by a solenoid 20.

FIG. 5 is a view showing a relationship among a solenoid lift, a pipe pressure, and a check valve lift with respect to a crank angle.

FIG. 6 is a diagram showing a relationship between a load and a pressure Pa in an air supply pipe.

FIG. 7 is a diagram showing a state in which the valve opening time of a check valve 13 is controlled with respect to a change in the number of rotations in the case of loading and shutting off a load.

FIG. 8 is a drawing showing the relationship between the pressure Pa in the air supply pipe and the valve opening time.

FIG. 9 is a diagram showing a change in NOx concentration with time.

FIG. 10 is a sectional view of a solenoid 20, a check valve 13, and a spark plug 14;

FIG. 11 is an exploded view of a portion of a solenoid 20.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Venturi mixer 7 Sub chamber 13 Check valve 20 Solenoid 24 Solenoid drive pin 30 Adjustment screw

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02M 21/02 301 F02B 19/10 F02B 43/00 F02D 45/00 345

Claims (3)

(57) [Claims] A check valve (13) is arranged in a sub-chamber (7 ).
In the sub-chamber gas engine, the check valve 13 is driven.
Operating solenoid 20 and further control the exhaust gas temperature.
An exhaust temperature sensor 21 which constantly detects the temperature is provided,
Check valve 13 bites carbon, which is combustion residue
In the event of a misfire caused by stopping the opening and closing
Based on the signal of the ignition pulser 15 of the ignition coil 12
Then, a voltage is applied to the solenoid 20 and the check valve 13
The solenoid 20 is opened and closed, and the solenoid 20
A check valve driving mechanism for a sub-chamber gas engine, wherein the check valve is stopped . 2. A check valve 13 is disposed in the sub chamber 7.
In the sub-chamber gas engine, the check valve 13 is driven.
With a solenoid 20 that moves, a pressure sensor in the air supply pipe
22 to supply air pressure Pa and electromagnetic pickup 29
Energizing time to the solenoid 20 from these engine speed signals
Is determined, and the TDC signal of each cylinder is
Receives and uses this as a reference pulse to energize solenoid 20
The check valve 13 is normally operated by the solenoid 20.
Time drive to obtain an appropriate valve opening engine,
Between the two, reducing NOx and loading
A check valve drive mechanism for a sub-chamber gas engine characterized by improving combustion characteristics when shut off . 3. The sub-chamber gas engine according to claim 1, wherein
In the check valve drive mechanism, the check valve 13
The solenoid 20 is mounted on the upper surface with an adjusting screw 30, and the solenoid drive pin 24 of the solenoid 20 is connected to a spring 25.2.
6 so as not to contact the check valve 13 normally, and only when the solenoid 20 is energized, the check valve 13 is driven. By adjusting the adjusting screw 30, the solenoid drive pin 24 of the solenoid 20 and the check valve 13 A check valve drive mechanism for a sub-chamber gas engine, wherein a gap between the check valve and the gas chamber is adjustable.