The control valve is installed in the back cover of the compressor and is a self-operated monolithic pneumatic valve. The control valve is mainly composed of a cone valve and a ball valve. The cone valve controls the flow area between the rocker box and the vacuum bellows chamber, and the ball valve controls the flow area between the exhaust chamber and the rocker box. The connection between the cone valve and the ball valve through the valve stem of the cone valve makes the opening degree of the cone valve and the ball valve complement each other, and jointly controls the pressure of the rocker box.
It can be seen that the control valve converts the size of the air conditioning load into the combined force of the acting rocker, thereby realizing the function of the compressor to automatically adjust its displacement according to the air conditioning load, so the characteristics of the control valve adjust the displacement of the compressor to the off. important. The mathematical model of the control valve firstly analyzes the force of the valve stem of the control valve, establishes the force equation of the valve stem of the control valve, and obtains the relationship between the opening degree and the force of the control valve cone valve and the ball valve, and then derives the flow according to the flow equation of the cone valve and the ball valve. The flow rate of the control valve is finally determined according to the mass conservation and energy conservation equation of the control volume of the rocker box. The force equation and diagram of the control valve are the simplified diagrams of the force analysis of the valve stem and the ball valve. Since the mass of the valve stem and the ball is small, the inertial force is ignored. The force of the valve stem is the force of the vacuum bellows on the valve stem. The force of the suction pressure is only the force of the pressure of the rocker box. The force of the valve stem spring, the force of the valve stem spring, the valve stem itself gravity ball to the valve The force of the pole is everywhere.
The force on the ball is the reaction force of the valve stem to the ball. The pressure of the rocker box only affects the force of the ball. When the ball valve is closed, the force of the valve wall to the ball is the force of the exhaust pressure. The force of the spring, when the ball's own gravity wind is open when the ball valve cone valve is opened, the balance of the force of the valve stem can be obtained. When the ball valve is opened, the force balance equation of the ball is normal.