linear measurement for reciprocating action
linear measurement for reciprocating action
(OP)
Hello guys,
A bit of a broad problem, and also a broad question at the minute, but I will refine as I go. I just need to know if this is a viable way to do this at first.
The problem in hand,
Measuring the reciprocating motion of a valve over its full cycle.
Test jig goes like this, a valve, follower, cam, spring, and housing is setup as a jig.
A spring returns the poppet valve to its seat position.
As the rpm increases, at some point the valve will start to bounce. Or not make it back to its seat in time for the next cycle.
I want to measure this. Is this possible?
Thoughts at first,
Attach a low mass linear electronic measuring device to the head of valve, and fix a pickup ring at close location?
Does this sort of sender exist?
Is the resolution good enough?
At the minute, I have 200 cycles per second in mind over say a 15mm distance.
What is the common way to do this?
Perhaps I could go with electrical contact on the seat(not sure this could react quick enough)
What are peoples thoughts?
High speed cameras are big bucks...
Im not really concerned as yet about anything other than if its returning to the seat, or_not at a particular rpm.
BG
A bit of a broad problem, and also a broad question at the minute, but I will refine as I go. I just need to know if this is a viable way to do this at first.
The problem in hand,
Measuring the reciprocating motion of a valve over its full cycle.
Test jig goes like this, a valve, follower, cam, spring, and housing is setup as a jig.
A spring returns the poppet valve to its seat position.
As the rpm increases, at some point the valve will start to bounce. Or not make it back to its seat in time for the next cycle.
I want to measure this. Is this possible?
Thoughts at first,
Attach a low mass linear electronic measuring device to the head of valve, and fix a pickup ring at close location?
Does this sort of sender exist?
Is the resolution good enough?
At the minute, I have 200 cycles per second in mind over say a 15mm distance.
What is the common way to do this?
Perhaps I could go with electrical contact on the seat(not sure this could react quick enough)
What are peoples thoughts?
High speed cameras are big bucks...
Im not really concerned as yet about anything other than if its returning to the seat, or_not at a particular rpm.
BG





RE: linear measurement for reciprocating action
http://174.129.32.184/patent/US3956973
Mike Halloran
Pembroke Pines, FL, USA
RE: linear measurement for reciprocating action
Will look further,
Brian,
RE: linear measurement for reciprocating action
No contacting, but must be able to mount close to a good surface on the valve
RE: linear measurement for reciprocating action
Im guessing you can hook one of those to an oscilloscope?
Looking on google there, I presume they can work off two ref points bearing in mind this is a sliding action, and not rotary?
Valve material is Ti If that makes any odds to pickup material.
Thanks a lot,
BG
RE: linear measurement for reciprocating action
The material and size of the "target" on the valve would possibly rule out prox probes, especially if you want the whole 15mm travel for the units I've used. However there might be some special purpose probes available
the operation is the probe measures the gap between the fixed probe and the moving target
RE: linear measurement for reciprocating action
You would simply need a mirrored surface on the end of the valve stem.
LVDT technology might work as well.
RE: linear measurement for reciprocating action
http://www.eng-tips.com/viewthread.cfm?qid=289831
RE: linear measurement for reciprocating action
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If we learn from our mistakes I'm getting a great education!
RE: linear measurement for reciprocating action
RE: linear measurement for reciprocating action
regards,
BG
RE: linear measurement for reciprocating action
Dan - Owner

http://www.Hi-TecDesigns.com
RE: linear measurement for reciprocating action
Sick makes a variety of laser range measurement units. This one has 10kHz rep rate and micron level accuracy/repeatability:
ht
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RE: linear measurement for reciprocating action
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: linear measurement for reciprocating action
Can you point me towards a suitable light?
Many thanks,
Brian,
RE: linear measurement for reciprocating action
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: linear measurement for reciprocating action
RE: linear measurement for reciprocating action
RE: linear measurement for reciprocating action
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: linear measurement for reciprocating action
Since its analog not sure if this would be fast enough.