Swing in Lock mechanism

[avatar]

Hi all,

just looking for some reassurance that his actually did exist in F1 and was banned.

I'm pretty sure I didn't invent it, but Google knows nothing about it, so maybe I have the wrong name?

what I'm referring to was a mechanical device mounted longitudinally in the car, weighted at one end with a pivot at the other. The purpose was to stop body roll in corners by literally swinging to the outside during cornering and locking the suspension on the outer wheel preventing further compression.

The main benefit from the reduced roll would have been aerodynamic stability.

It only came to mind due to it being principally similar to the theorized anti dive device that's been proposed over on the Mercedes car launch thread. For that reason, if anyone knows what I'm talking about & know under what ruling it was banned it would be much appreciated!

[allstaruk08]

do you mean a tuned mass damper?

[avatar]

no, I think it was older than that; a crude weight on an arm literally swinging in, to lock the suspension on the outer wheel.

I either heard or read about it when I was a kid, likely to have been in the 90s but could have been referring to an earlier period. I don't think I invented it. I doubt I was that creative at the time!

[DaveW]

no, I think it was older than that; a crude weight on an arm literally swinging in, to lock the suspension on the outer wheel.

I think you are referring to "g-sensitive" dampers. The "crude mass" controlling damper ports and restrained by a spring forms a mechanical accelerometer. The spring is normally preloaded to set the acceleration at which the control activates.

They have been used since 1997 (to my knowledge), and have continued to be used (sporadically) to the present day. Mostly they are used for pitch control. Roll control was also tried initially but was not desperately successful largely, I suspect, because they were prone to change the lateral balance of the car.

[Jersey Tom]

Or a simpler, lighter solution to reduce body roll - add an appropriate amount of spring. "Locking out" a suspension is going to make it infinitely stiff anyway.

[Richard]

I think the OP's description would fall foul of the rules about suspension only reacting to the wheel loads.

It is odd how the same concept is valid if a 'g' actuated lock valve is used in the damper.

Maybe a team should build a crude swing lock device as described in the OP, get it banned, then point out the function is no different to the modern devices?

That would exclude mercury filled lines, but not conventional hydraulic fluid?

[Jersey Tom]

...or again, just use an appropriate amount of spring or packer gap to control your attitude, and skip the cost and complexity.

[Richard]

JT - I was using the swing lock idea to explore the legality of the mercury filled tube idea. I'm not saying the swing lock it is a practical idea for roll.

[DaveW]

I think the OP's description would fall foul of the rules about suspension only reacting to the wheel loads.

The action of the "g-control" does not cause the suspension to move (at all). It simply modifies the way it responds to a load input. I would argue strongly, therefore, that the device satisfies the rule you quote. The argument can be taken further. If a damper that changes its characteristics in response to other inputs is considered illegal, then a damper that changes damping with temperature would be illegal. That would be all of them....

By the way, I think that "locking" a damper is misleading concept. It really means modifying damper settings (usually increasing low speed in the appropriate direction).

[avatar]

Or a simpler, lighter solution to reduce body roll - add an appropriate amount of spring. "Locking out" a suspension is going to make it infinitely stiff anyway.

As I may be apparent, my memory is a bit sketchy on this but in my head, I was thinking it acted further up the linkage e.g. locking out the rocker....
...which I guess means there's a lot more rules it may brake!

[Richard]

The action of the "g-control" does not cause the suspension to move (at all). It simply modifies the way it responds to a load input. I would argue strongly, therefore, that the device satisfies the rule you quote. The argument can be taken further. If a damper that changes its characteristics in response to other inputs is considered illegal, then a damper that changes damping with temperature would be illegal. That would be all of them....

I read 10.1.2 as meaning every response must be demonstrable by applying loads to the wheels. This means that the car plank could be put on a test bench with the wheels dangling in the air, and all the suspension behaviour replicate by applying forces to the wheels to replicate the forces applied on track (long, lat, brake, accelerate, etc).

Agree?

[DaveW]

Agree?

Not quite. Read the latter part of my argument. The response of all dampers varies with temperature. It follows that your interpretation implies that dampers are illegal...

10.1.2 reads The suspension system must be so arranged that its response results only from changes in load applied to the wheels.

I think (forgive me) that means that the suspension should respond only to changes in load applied to the wheels.

10.2.1 deals with geometry.

10.2.2 deals with powered elements.

10.2.3 states that no adjustments should be made whilst the vehicle is in motion. That might be considered to be an issue - except that no explicit adjustments are made to the suspension, & in any case the temperature sensitivity issue would also apply.

[Richard]

Surely "reasonable compliance" in 10.2.1 covers temperature effects?

To consider the swing lock mechanism, if we have a dumb bell swinging around due to yaw and that opens and closes damper valves, then does that infringe 10.1.2?

If one reads 10.1.2 to mean the suspension system behaviour can only be activated by pushing on the wheels while the car is on the bench, then the swinging dumb bell would fail?

[bhall]

There are nearly 30 pages of discussion within the Mercedes speculation thread devoted exclusively to 10.1.2. Have a look-see.

[hardingfv32]

[quote="richard_leeds"]Surely "reasonable compliance" in 10.2.1 covers temperature effects?

To consider the swing lock mechanism, if we have a dumb bell swinging around due to yaw and that opens and closes damper valves, then does that infringe 10.1.2?

1) No, the dumb bell is swinging in response to 'changes in load applied to the wheels.'

2) This system does fail 10.2.2: powered elements. Power = Force X Distance The controlling valve moves because of inertia or force over a distance. Thus, the system is powered and in violation of 10.2.2. The rule states 'power', no restriction to the common electrical or hydraulic sources of power.

This type of shock has an orientation requirement. Disregarding packaging issue, do most racing shocks (gas chamber style) require a specific orientation?

Brian