Solenoid Valves in Dentist Chairs
M&M International solenoid valves are utililized in dentist chairs. They are part of a system that uses hydraulic action to smoothly lift the chair to a specified height.
How a dentist chair works
Integrated station with all the necessary dental or ophthalmic equipment, complete with automatic chair and adjustable lamp. All automatic functions are easily set by the operator through a console. The chair lifting system works under the thrust of a hydraulic cylinder operated by the medium (oil). Compared to a mechanical system, the hydraulic thrust has the advantage of a “smoother” movement.
The application of solenoid valves in dentist chairs
Two solenoid valves are used in this application to regulate the height of the chair. Oil comes from the basin by the pump and is entered into the circuit at a pressure of 12-13 bar. When a button is pressed on the console the solenoid valve operates and intercepts oil in the pump and sends it to the cylinder. The cylinder enables hydraulic energy to be turned into mechanical energy thus lifting the chair to the desired height. By pushing another button, the second valve opens. Due to the effect of the overhanging weight, oil under pressure inside the cylinder exhausts into the basin, and pushes the chair down.
The Solenoid Valve that would be used in this application:
A special version of valve D263 is suitable for this application. Unlike the standard valve, it comes with a cone-shaped spring on the plunger, with a heavier load. With this option, the fixed core and plunger do not stick due to the viscosity of the medium when the valve closes (i.e. when de-energising the coil). As a result the plunger comes with a Ruby seal to guarantee very high performances.