1. Definition of ignition advance angle
The engine is actually ignited before the piston reaches the top dead center of the compression stroke. The displacement of the piston between the ignition time and the top dead center of the compression stroke is converted into the crankshaft angle, that is, the ignition advance angle.
Taking Shandong Chenlong 12V190 series gas generator set as an example, its ignition advance angle is generally 30-42 ° crankshaft angle, and the specific value is determined according to the random instructions and the specific composition of gas.
The ignition advance angle is set by the technical service personnel of the manufacturer during the installation and commissioning of the gas generator set, and the user generally does not need to adjust it. However, with the extension of the service time of the unit, the groove of the coupling between the magneto drive and the gearbox will be worn, which will cause a slight change in the ignition advance angle. Therefore, seasonal inspection and adjustment should be carried out. In addition, when replacing the magneto, the inspection and adjustment of the ignition advance angle will also be involved.
It is recommended that the user measure the current ignition advance angle of the unit after the unit is installed, commissioned and operated normally, and record it for the record.
2. Method of measuring ignition advance angle
There are usually two methods for measuring the ignition advance angle: "use the ignition timing lamp" and "drag method". "Use ignition timing lamp"
The method is simple and easy, but the measurement results have some errors; The accuracy of the measurement results of "drag method" is high.
(1) Use ignition timing lamp
① Connect the 12VDC working power supply of the ignition timing lamp.
Note: too high working power will burn out the ignition timing lamp.
② Clamp the wiring clamp of the ignition timing lamp to the main cable part of the high-voltage ignition wire of the first cylinder of the engine.
Note: before clamping, roll up the outer protective rubber of the main cable of the high-voltage ignition line, otherwise the timing lamp will not sense the ignition signal.
③ Hold the ignition timing lamp to align the lamp head with the flywheel pointer tip and point to the center of the flywheel dial.
④ Start the engine and allow it to idle. When the first cylinder of the engine is ignited, the ignition timing light will shine. The scale corresponding to the bright light is the ignition scale of the current unit. Then, the current unit ignition advance angle = (360 ° - current unit ignition scale).
(2) Drag method
① Stick oscilloscope paper (or fax paper) within 15 ° before and after the engine flywheel scale of 320 ° and make the same score on the oscilloscope paper according to the original scale of the flywheel.
Note: direction marks shall be made on oscilloscope paper (or fax paper) in advance to avoid confusion of ignition advance and delay.
② Unplug the high-voltage ignition wire of cylinder 1 of the engine and replace it with a special extended wire. Insert one end of the wire into the output end of the ignition coil and fix the other end at the flywheel pointer tip. The end of the wire is 2-4mm away from the oscilloscope paper.
③ Under the condition of cutting off the air source, press the "start" button to make the starting motor drive the engine to run. At this time, the discharge and spark between the wire end and the oscilloscope paper will break down the oscilloscope paper.
④ After a few seconds, release the "start" button, stop the starting motor, take down the oscilloscope paper for inspection, and the scale corresponding to the spark breakdown dense position is the ignition scale of the current unit. Then, the current unit ignition advance angle = (360 ° - current unit ignition scale).
3. Method of setting ignition advance angle
(1) Methods for installing the magneto and setting the ignition advance angle of the six cylinder and twelve cylinder gas engines (take adjusting the ignition advance angle of the unit to 40 ° crankshaft angle as an example) ① turn the flywheel until the first cylinder is at the 0 scale of the top dead center position of the compression stroke, and then turn back 40 °, that is, the pointer indicates 320 °. At this time, the groove inclination direction of the gearbox coupling is determined.
② Rotate the drive of the magneto to align the short red score line on the rotating shaft with the CCW line on the front panel of the magneto. At this time, the tilt direction of the magneto drive is determined.
③ Install the magneto. At this time, the ignition advance angle of the engine is approximately 40 °.
Note: when installing the magneto, ensure that its drive and the coupling of the gearbox are engaged in place.
④ Check the actual value of ignition advance angle by dragging and adjust it to the required value.
⑤ When the adjustment position of the 12 cylinder gas engine magneto reaches the limit, the bevel gear (inverted gear) needs to be adjusted. The method is:
a. Loosen the fastening screws on the side observation cover of the gearbox and remove the observation cover.
b. Loosen the 6 fastening screws fixing the connecting plate and the gearbox, and pull out the small bevel gear together with the transmission shaft to disengage the two bevel gears.
c. Rotate the small bevel gear (the ignition advance angle changes by about 12 ° for each inverted tooth), so that the direction of the coupling groove is consistent with the inclination direction of the magneto connecting plate.
d. Install the small bevel gear back to the original position, re mesh the two bevel gears, and cover the observation cover.
e. Install the magneto and recheck the ignition time.
(2) Methods for installing magneto and setting ignition advance angle of four cylinder engine (take adjusting ignition advance angle to 32 ° as an example).
① Working principle
The ignition system of 4-cylinder gas engine (4-190) is composed of magnetic block, induction coil, magneto, ignition coil and spark plug. The ignition sequence is 1-2-4-3.
Two magnetic blocks are embedded on the flywheel at 160 ° and 340 ° respectively. Two induction coils inside and outside are installed beside the flywheel. The outer induction coil is connected to cylinders 1 and 4, and the inner induction coil is connected to cylinders 2 and 3.
When the engine is working, the magnetic block on the flywheel receives a signal every time it passes through the induction coil and transmits the signal to the magneto. The magneto sends out ignition electric energy according to the sequence provided by this signal, which is transformed by the ignition coil and ignited by the spark plug.
When the outer induction coil acquires the magnetic block signal for the first time, cylinder 1 is ignited. After rotating 180 degrees, the inner induction coil acquires the magnetic block signal and cylinder 2 is ignited. After the flywheel is rotated by 180 degrees, the outer ignition coil acquires the magnetic block signal, and cylinder 4 is ignited. After the flywheel is rotated by 180 degrees, the inner induction coil acquires the signal, and cylinder 3 is ignited.
② Setting method
a. Turn the flywheel until the first cylinder is at the 0 scale of the top dead center position of the compression stroke, and then turn back 32 °, that is, the pointer indicates 328 °.
b. Rotate the plastic disk connected with the magneto to make the tilt direction consistent with the tilt direction of the turntable in the flange, and install the magneto.
c. Move the two induction coils to align with the magnetic block on the flywheel, and make the two induction coils on a concentric straight line to fix the induction coils. At this time, the ignition advance angle of the engine is approximately 32 °.
d. Check the actual value of the ignition advance angle and adjust it to the required value.
The above is the detailed introduction of the gas generator set. I hope it will help you. If you have any questions, please contact us. We will provide you with services in a professional manner https://www.huannengpower.cn