Force to overcome the worst case

salebutterflyvalve — Thu, 14 Mar 2019 04:10:03 +0000

To improve intake valve operation and to increase valve lift, I decided to parallel two 3mm actuators.I am still using a valve spring to close the exhaust valve. One of the really exciting things about this technology is how little electrical power is required to operate the valves. It is a fraction of that required by my previous solenoid system.ViVa 12mm Piezo Flow Valve ActuatorViking 12mm Actuator, David Bowes EVIC EngineViVa Dual 3mm Actuators Driving Intake ValveFeaturing the NEW ViVa© 12mm ActuatorThese actuators are now operating the valves of my Mk2 EVIC engine with speeds up to 8600 rpm.” – David BowesNormally poppet valves on internal combustion engines are opened by a cam and closed by a valve spring. The exhaust valve was the next challenge. I also use them so that I can monitor the valve positions with my digital storage oscilloscope. Then I should be able to tune the control software for higher engine speed and greater engine performance.In my October tests the 3mm ViVa© actuator successfully operated the intake valve but with relatively low valve lift. “These actuators are now operating the valves of my Mk2 EVIC engine with speeds up to 8600 rpm. The two actuators operate the intake with more lift and without a valve spring. These actuators are now operating the valves of my Mk2 EVIC engine with speeds up to 8600 rpm. The valve spring must supply sufficient force to prevent valve float, to prevent the valve from separating from the cam. The information is fed to my computer control system so that the controls can actively measure and control the valve positions. The next step was to obtain the larger 12mm ViVa© actuator to see if it was up to the much more difficult challenge of operating the exhaust valve. My second attempt at the arm was much stiffer but it took me three tries to get a satisfactory, but not a perfect, mounting bracket.. The actuators use significantly less electrical power, about 25% of that used by the solenoids. To open the exhaust valve the actuator must overcome the high cylinder pressure at the end of the engine’s power stroke. My first attempt with this actuator was unsuccessful. This proved to be quite easy and worked well. While the intake valve can be operated with only one pound of force the exhaust valve requires at least 10 pounds of force to overcome the worst case cylinder pressure that can be in the range of 5 to 8 atmospheres. For both the cam operated valve and the solenoid operated valve, the valve is not normally connected to the cam or the solenoid armature. Back in October 2014 I successfully demonstrated a 3mm ViVa© actuator operating the intake valve of my 12cc EVIC Mk2 engine. So instead of the exhaust valve opening my 1/4” thick aluminum arm and my 1/16” UPVC Mf Single Union Ball Valve Suppliers sheet aluminum, the mounting bracket just flexed! Fortunately, when I talked to the folks at Viking AT they immediately recognized the problem and pointed me in the right direction. The valve spring must supply sufficient force to move the valve and the solenoid armature to the closed position. The control arms for both valves have magnets at the valve ends that enable linear Hall Effect sensors to measure the valve positions. When the cam is replaced by a solenoid that pushes the valve open, a valve spring is still required to close the valve. That way I can see exactly what is happening as the valves open and close and use this information to improve my controls and software. My next step will be to remove this spring and connect the exhaust valve directly to the actuator. Conclusions and Next StepsThis paper illustrates how Viking AT ViVa© actuators can operate the intake and exhaust valves of a small internal combustion engine. The actuators use significantly less electrical power, about 25% of that used by the solenoids. The mounting bracket and arm that I made proved to be too flexible when attached to the actuator. While the solenoids provided more valve lift the ViVa© actuators open and close the valves faster and as a result engine performance is similar. I started with the basic 12mm ViVa© actuator without arms. After some initial tests, I made the decision to machine a very stiff mounting bracket out of solid aluminum.— David BowesSARASOTA, FLORIDA, UNITED STATES, February 4, 2015 — IntroductionThe Viking AT ViVa© actuators are piezo electric devices designed as a solenoid replacement. Now, all the force generated by the 12mm actuator goes to open the exhaust valve.

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Force to overcome the worst case