Method and apparatus for controlled injection fluid flow

A valve for use with an injection molding apparatus, the injection molding apparatus arranged, via an injection molding machine, to inject a flow of injection fluid to a heated manifold, the heated manifold arranged to distribute the injection fluid to a distribution channel, the distribution channel arranged to deliver the injection fluid to a gate of a mold cavity, the valve, comprising:

• a channel having an upstream portion and a downstream portion, the downstream portion having a control surface, wherein the control surface is sloped or configured, conical, cylindrical, straight or curvilinear and wherein the control surface forms a channel gap (CG) having a certain size and configuration disposed upstream of the gate to the mold cavity;
• a valve pin arranged within the channel, the valve pin having a distal axial portion that is adapted to be controllably drivable upstream and downstream along a linear axis (A) of travel through the channel gap (CG);
• an actuator interconnected to the valve pin, the actuator adapted to controllably drive the distal axial portion upstream through the channel gap (CG) beginning from a gate closed, zero velocity position up to a selected reduced upstream velocity that is less than a maximum velocity at which the valve pin is drivable,
• wherein the control surface is disposed along an axial length (CT) of the channel gap (CG) between about 3 mm and about 6 mm, and wherein the control surface or a portion of the control surface has a smallest radial diameter (CD) that is greater than a largest radial diameter of the distal axial portion by between about 0.1 mm and about 0.8 mm;
• and
• wherein the valve pin is adapted to be driven at a single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel between about 1 mm and about 5 mm.

A valve for use with an injection molding apparatus, the injection molding apparatus arranged, via an injection molding machine, to inject a flow of injection fluid to a heated manifold, the heated manifold arranged to distribute the injection fluid to a distribution channel, the distribution channel arranged to deliver the injection fluid to a gate of a mold cavity, the valve, comprising:

• a valve pin having a distal axial portion that is adapted to be controllably driven upstream beginning from a gate closed, zero velocity position at a single selected rate of upstream acceleration up to a selected upstream velocity greater than zero;
• a downstream channel having a downstream portion, the downstream portion having a conical or tapered or sloped or configured surface that is sloped or angled relative to a linear axis (A) along which the valve pin travels and that forms a channel gap (CG) disposed upstream of the gate to the mold cavity;
• an actuator interconnected to the valve pin and configured to controllably drive the interconnected valve pin upstream and downstream through the downstream channel,
• wherein a slope or taper of the conical or tapered or sloped or configured surface of the downstream channel is arranged to cooperate with the distal axial portion to control a flow of injection fluid through the channel gap (CG) to a selected rate of flow by controllably driving the valve pin upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position up to the selected upstream velocity greater than zero;
• and
• wherein the valve pin is adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel between about 1 mm and about 5 mm.