Abstract: The present invention provides a valve nozzle that can restrain property changes of an injecting melted resin by more strictly controlling the temperature of the injecting melted resin, wherein in the internal space or the rear space of a valve nozzle main body, a gate opening and closing mechanism is disposed which includes a torpedo provided with a coolant channel, a piston including a head portion, a shaft portion that is continued from the head portion and disposed in the internal space of the torpedo by being provided with a gap to serve as a resin flow channel on its outer circumferential surface, a tapered surface that is connected to the rear end of the shaft portion and serves as a surface for receiving the pressure of a resin in the resin flow channel, and a coil spring that presses the rear end part of the piston toward a gate, and when the pressure of the melted resin is at a predetermined value or less, the piston is pressed by the coil spring toward the gate to close the resin flow channel, and

Abstract: The valve nozzle according to the invention is constructed so that, in the internal space of a valve nozzle main body, a gate opening and closing mechanism is disposed in which a piston having a head part and a shaft part, a torpedo that is disposed in the internal space of the nozzle head and slidably supports the piston and guides the piston, and is provided with, on its outer circumferential surface, concaved grooves that are twisted with respect to a resin injection direction and serve as a plurality of wound resin flow channels, a coil spring that presses the piston in the direction toward a gate, and a cover that closes the rear end of the torpedo and serves as a spring receiving part of the coil spring are integrally assembled, and when the resin pressure is at a predetermined value or less, the entire circumference of the circular section of the head part of the piston comes into contact with the inner wall of the gate of the nozzle head to close the resin flow channels, and when the resin pressure be

Abstract: The valve nozzle according to the invention is constructed so that, in the internal space of a valve nozzle main body, a gate opening and closing mechanism is disposed in which a piston having a head part and a shaft part, a torpedo that is disposed in the internal space of the nozzle head and slidably supports the piston and guides the piston, and is provided with, on its outer circumferential surface, concaved grooves that are twisted with respect to a resin injection direction and serve as a plurality of wound resin flow channels, a coil spring that presses the piston in the direction toward a gate, and a cover that closes the rear end of the torpedo and serves as a spring receiving part of the coil spring are integrally assembled, and when the resin pressure is at a predetermined value or less, the entire circumference of the circular section of the head part of the piston comes into contact with the inner wall of the gate of the nozzle head to close the resin flow channels, and when the resin pressure be