Oil & Fuel General diesel question

[Soundguy]

But first we need to look up the term computer itself. Here's Wiki:

"A computer is a machine that manipulates data according to a list of instructions."

That's not the only definition, but it is a pretty good one. Mechanical injection pumps don't even come close to meeting it.

Sure it does... the injection pump is getting imput from the throttle lever..

As for the instructions.. those are encoded in the precision machined parts.

Did you bother to look at any of the links i posted??

soundguy

 

[john_bud]

I would think that for a variable set of input parameters (rpm, lever position, governor position (engine load), etc) a mechanical computer would be able to account for those variables and adjust, or compute the output parameter of quantity of fuel to be injected. That seems to be computing by the broad definition. It would also fit the example of a control system PID, if memory serves (but no guarantees on that one)

A silicon based computer could be used to do the same thing with more accuracy and speed and take into account more parameters. The instructions it has are set with non-volatile ram. The instructions in a fuel injection pump are also non-volatile ram, just a bit more non-volatile.

But, aside from a good thought process, what does it have to do with the OP's question? (which I have forgotten myself)

 

[Egon]

Are all statements on Wikipedia true?

 

[N80]

The question of what is an analog computer and what isn't is purely academic and for the most part purely archaic. In today's parlance 'analog computer' is an oxymoron. The further you delve into precise definitions the closer you get to calling a post hole digger a computer. And if a thermometer is a computer, so is a wind-up alarm clock. And if you go around calling a thermometer, a clock and a post hole digger a computer, the only thing you will accomplish is confusion and argument.

So back to my point: you can defend archaic definitions all you want, and you can be technically and symantically correct, but from a practical standpoint calling a mechanical speed control on a tractor a computer is pointless and confusing.

Back in the old days a 'barber' was the same as a 'doctor'. Mistaking your barber for a doctor or your doctor for a barber nowadays is a sure fire way of getting a bad appendectomy, a bad haircut, or both.

 

[jinman]

I'm going to show my general ignorance of how tractors work. How is the fuel and throttle governed on a diesel tractor? I can picture a common small engine and a governor opens up the throttle blade as needed. Of course in your car you open up the throttle with your right foot. How does this work on a tractor? You normally set the throttle by hand. Then does the throttle stay open the same no matter the load? How does the fuel injection work? As far as I know most tractors still don't have computers to tell them how much and when to inject the fuel. Its a mechanical set up I assume but as the engine hits a heavy load, how does it know to deliver more fuel? Or do tractors have a govenor to open up the throttle when it hits a heavy load?

Thanks in advance for the answers.

Wow! This seems like such a simple question to have generated so many pages in this thread. It must be a TBN phenomena.

Tallyho8 gave the simple answer, perhaps I can add to that. My tractor has a governor that is mechanized by the camshaft drivegears. It uses flyweights and a movable slider cone that is attached to the injection pump rack. When you move the fuel hand lever (or foot lever), you adjust the tension on the linkage to the rack. As the rack moves (mine is rearward), the engine rpm increases until the flyweights move outward and force the cone to move forward. This movement is linked to the rack and causes it to decreas fuel flow so that the engine's rpm becomes balanced to the input lever position.

If, under load, the engine's rpm decreases, the flyweights move inward, the cone moves, and the rack is adjusted to bring the engine back to the desired rpm. Of course, there are hard limits for how fast (high-speed stop) and how slow (idle speed) the rack can move.

I don't know how many engines are this way, but my diesel is manufactured by Shibaura and that's the way it's governor works. Gasoline engine governors are well documented here in previous posts. I'm not sure if Kubota or other diesels work this way, but it surely seems possible if not probable.

So Tallyho8's post is surely correct. Diesels do have governors. They have many of the same parts as gasoline engine governors, but they are just mechanized differently as needed. I can certainly see how this could also work with a computer or electronic governor servo, but reliability would be my only worry. I'd want a good hard mechanical stop to ensure if the electronics fried, the engine rpm would be limited.

 

[Soundguy]

In trying to be modern and PC.. you are not seeing out of the paper bag. It's easy to grab a handfull of electronic components and build a small feedback system that would work in conjunction with a machine, to make an automated unit capable of repititous work, with simple variables programmed by toggle switchs, using pin switches as limit switches. Nothing digital about the circuit.. and no 'central processor" .. but it will meet the definition of an analog computer, but will not in any meaningfull way be compariable to a modern computer with cpu.

being different does not make either statement wrong... it just makes them different.

Some very simple dedicated electronic control systems are not compairable to laptops and mainframes.. yet perform simple tasks based on programmed criteria and analog input.

soundguy

The question of what is an analog computer and what isn't is purely academic and for the most part purely archaic. In today's parlance 'analog computer' is an oxymoron. The further you delve into precise definitions the closer you get to calling a post hole digger a computer. And if a thermometer is a computer, so is a wind-up alarm clock. And if you go around calling a thermometer, a clock and a post hole digger a computer, the only thing you will accomplish is confusion and argument.

So back to my point: you can defend archaic definitions all you want, and you can be technically and symantically correct, but from a practical standpoint calling a mechanical speed control on a tractor a computer is pointless and confusing.

Back in the old days a 'barber' was the same as a 'doctor'. Mistaking your barber for a doctor or your doctor for a barber nowadays is a sure fire way of getting a bad appendectomy, a bad haricut, or both.

 

[Reg]

But first we need to look up the term computer itself. Here's Wiki:

"A computer is a machine that manipulates data according to a list of instructions."

That's not the only definition, but it is a pretty good one. Mechanical injection pumps don't even come close to meeting it.

Right, not the only definition, but probably the one now most frequently used in common parlance, it has come to mean only a Von Neumann machine to many/most people.

The "digital" is assumed nowadays, it wasn't always so.

"Guitar" used to mean an instrument that now has to be called an "Acoustic guitar".
"British English" ? {Hmmm,,,}
"Football" ? -- "Soccer" or "American football" ?
on and on

 

[N80]

I'm not arguing digital vs analog or simple vs complex. I'm not even saying that calling a mechanical speed control a computer is wrong, since technically it can be correct.

My only point is to question the purpose or utility of using the term 'computer' for a mechanical device. Even if it is technically correct, most people will not understand it. In other words, if I took my tractor (basic, no digital or electrical computer components regulating the speed control) to a mechanic and told him that my speed control computer was malfunctioning? What would he say? He'd tell me that there was no such computer on this model. Then what would I say to him? Tell him that he is mistaken and that he should consult Wikipedia or an engineering text and that my tractor does indeed have an analog computerized speed control? See my point?

 

[Reg]

The question of what is an analog computer and what isn't is purely academic and for the most part purely archaic. In today's parlance 'analog computer' is an oxymoron. The further you delve into precise definitions the closer you get to calling a post hole digger a computer. And if a thermometer is a computer, so is a wind-up alarm clock. And if you go around calling a thermometer, a clock and a post hole digger a computer, the only thing you will accomplish is confusion and argument.

So back to my point: you can defend archaic definitions all you want, and you can be technically and symantically correct, but from a practical standpoint calling a mechanical speed control on a tractor a computer is pointless and confusing.

Back in the old days a 'barber' was the same as a 'doctor'. Mistaking your barber for a doctor or your doctor for a barber nowadays is a sure fire way of getting a bad appendectomy, a bad haircut, or both.

Barbers used to pull teeth.
WAY before my time, so I have no direct knowledge of it - but I havn't seen Australia either, though I believe it exists.

If you REALLY want to get into this STUFF pick up a classical text;
"Handbook of Automation, Computation and Control" (approx) authors forgotten.
I have it "SOMEWHERE", if the attic squirrels havn't eaten it - yet.
That reminds me, gotta evict them guys - 2DAY !!!

 

[Soundguy]

I'm not arguing digital vs analog or simple vs complex. I'm not even saying that calling a mechanical speed control a computer is wrong, since technically it can be correct.

My only point is to question the purpose or utility of using the term 'computer' for a mechanical device. Even if it is technically correct, most people will not understand it. In other words, if I took my tractor (basic, no digital or electrical computer components regulating the speed control) to a mechanic and told him that my speed control computer was malfunctioning? What would he say? He'd tell me that there was no such computer on this model. Then what would I say to him? Tell him that he is mistaken and that he should consult Wikipedia or an engineering text and that my tractor does indeed have an analog computerized speed control? See my point?

I believe your example would be something like me bringing my car into a filling station and saying that i had a rotary inclined plane penetrating once of my pnumatized power couplings and was having a problem keeping the pressure differential up.

Of course the guy would look at me like I was an idiot, and he probably wouldn't be thinking that I had a screw in my tire and needed it fixed because it was leaking.

Using over technical wording when not needed does not negate the basic meaning of the system.

Everything has a proper application.

Just because a diesel injection pump can be 'classified' as a mechanical computer does not mean that's what it's proper name is to identify it.


soundguy