Three - way machine is mainly divided into two three - way solenoid valve is normally closed type one is normally open type two.  Normally closed type refers to the coil is not energized when the gas circuit is broken, normally open type refers to the coil is not energized when the gas circuit is through.  Normally closed two three way solenoid valve action principle: to the coil is energized, the gas circuit is connected, once the coil power, the gas circuit will be disconnected, which is equivalent to the point of action.  Normally open two three single electrically controlled solenoid valve action principle: to the coil power, the gas circuit is disconnected, once the coil power, the gas circuit will be connected, this is also the point.  Two five-way double electrically controlled solenoid valve action principle: to the positive action coil is energized, then the positive action gas road is connected (the positive action air outlet is gas), even if the positive action coil power is still connected to the positive action gas road, will always be maintained to resist the coil electric stop.  When the resistance coil is energized, the resistance gas circuit is connected (the resistance gas hole has air). Even after the resistance coil is energized, the resistance gas circuit is still connected and will remain until the positive action coil is stopped.  This is tantamount to self-locking.  Two three - way solenoid valves are usually one - in - two - out series.  There is also the saying of normally open and closed.  Solenoid valve three ports are A-B-C port, there are also B to C port.  Normally closed type is the solenoid valve power, the valve is closed, normally closed type.  In other words, it cannot exit port A.  

The three-way machine technology is to use the tube billet as the original data, through the liquid pressure in the tube cavity and the axial load effect, so that the plastic deformation in the mold cavity, the tube wall and the inner surface of the mold fit, and then get the required shape parts of the molding skills.  About the rounded scale is small, difficult to molding products tend to choose sectional compression molding, namely with smaller pressure expansion tube end, first line into a large rounded corners, wall thickness is relatively uniform, at the moment, and then the pressure, forcing fittings mold joint, the rounded materials tensile deformation, the tube wall thinning, eventually get the tee.  

The forming principle of three-way hydraulic press: first put the billet into the lower die cavity, under the action of the hydraulic cylinder, the plunger head is pressed into both ends of the pipe fitting, so that the pipe fitting cavity is sealed, and then the liquid medium is injected into the pipe fitting cavity through the liquid channel in the push head;  At this moment, the upper die moves down and forms a closed cavity together with the lower die. Finally, the high pressure pump and valve control the liquid pressure to increase, the push head pushes the pipe fittings inward, the pipe wall deforms and gradually adheres to the inner wall of the mold, and the tee is formed.