VEMS Community Forum

Technical => Fuel Injection => Topic started by: black on September 14, 2015, 03:59:34 PM

Title: Effect of leaving injector angle curve at 720°??
Post by: black on September 14, 2015, 03:59:34 PM
Im wondering about the injector angle curve.

If I use a value like 360°, the end of injection event will occur at these angle before TDC.

The injection event will be calculated backwards from this angle. So if I have a duty cycle of 50%, the injection will happen from 720° BTDC until 360° before TDC



But when I leave the injector angle curve at 720° what will happen? (Duty cycle still 50%)

Will the injection event happen from 360° before TDC until 0° before TDC??
Title: Re: Effect of leaving injector angle curve at 720°??
Post by: VEMS on September 15, 2015, 08:42:53 AM
Hello Black,

Entering 720 disables injection angle control.

Best regards, Dave
Title: Re: Effect of leaving injector angle curve at 720°??
Post by: black on September 15, 2015, 08:12:11 PM
Quote from: VEMS on September 15, 2015, 08:42:53 AM
Hello Black,

Entering 720 disables injection angle control.

Best regards, Dave

Hallo Dave,

This is clear but nevertheless vems has to calculate the end of injection event. If the injection angle Control is disabled, when will the end of  injection Happen? Best regards...
Title: Re: Effect of leaving injector angle curve at 720°??
Post by: VEMS on September 15, 2015, 10:15:30 PM
Ah
Quote from: black on September 15, 2015, 08:12:11 PM
This is clear but nevertheless vems has to calculate the end of injection event. If the injection angle Control is disabled, when will the end of  injection Happen? Best regards...
I see what you mean, when angle is set to 720: injection event is started at the trigger tooth (immediately) and ends at trigger tooth (time) + pulsewidth for that channel, so the start is fixed (degrees) and  the end is variable; when inj angle is enabled (non 720 degree in table) the start is variable, but the end is fixed (in degrees).

Best regards, Dave
Title: Re: Effect of leaving injector angle curve at 720°??
Post by: black on September 16, 2015, 12:12:41 PM
Quote from: VEMS on September 15, 2015, 10:15:30 PM
Ah
Quote from: black on September 15, 2015, 08:12:11 PM
This is clear but nevertheless vems has to calculate the end of injection event. If the injection angle Control is disabled, when will the end of  injection Happen? Best regards...
I see what you mean, when angle is set to 720: injection event is started at the trigger tooth (immediately) and ends at trigger tooth (time) + pulsewidth for that channel, so the start is fixed (degrees) and  the end is variable; when inj angle is enabled (non 720 degree in table) the start is variable, but the end is fixed (in degrees).

Best regards, Dave

Thanks... ! :D

So this means all fuel up to duty cycle of 50% will be injected before inlet valve will open... (so to speak)
Title: Re: Effect of leaving injector angle curve at 720°??
Post by: VEMS on September 18, 2015, 11:50:57 AM
Quote from: black on September 16, 2015, 12:12:41 PM
So this means all fuel up to duty cycle of 50% will be injected before inlet valve will open... (so to speak)
It would depend on where the trigger_tooth angle is (on your engine and configuration) in relation to valve closing, but short answer (with proper injection output rotation) would be yes.

Best regards, Dave
Title: Re: Effect of leaving injector angle curve at 720°??
Post by: black on September 20, 2015, 08:32:32 AM
perfect...  thanks