Injection molding apparatus and method for automatic cycle to cycle cavity injection

A method of operating an injection molding system for initiating flow of a fluid material into multiple gates of a mold cavity during an injection cycle, wherein the system includes:

• a first selected valve comprising a first fluid flow passage having a first gate to the cavity, a first valve pin driven reciprocally along an axial upstream downstream path of travel through the first flow passage by a first actuator between gate open and gate closed positions,
• one or more downstream valves, each downstream valve comprising a downstream fluid flow passage having a downstream gate to the cavity disposed downstream of the first gate, a downstream valve pin driven reciprocally along an axial upstream downstream path of travel through the downstream fluid flow passage by a downstream actuator between a gate open and a gate closed position the method comprising:
• detecting, at a downstream detection time, a flow front of the fluid material flowing downstream at a trigger position within the cavity disposed between the first gate and at least one selected downstream gate wherein,
• instructing the actuator of the valve associated with the at least one selected downstream gate, or a control valve for the actuator, to withdraw the valve pin from the gate closed position at an instruction time (X) comprising a predetermined open gate target time (X) following the downstream detection time,
• detecting, at an actual open gate time (A), withdrawal of the valve pin from the at least one selected downstream gate,
• automatically determining an automatic adjusted instruction time (X′), for use on a subsequent injection cycle, wherein the determining step comprises decreasing the time of instruction to the valve pin to open on a subsequent injection cycle by an adjustment time equal to any delay in time (Y) between the predetermined open gate target time (A) and the actual open gate time (A),
• forming a first one or more parts or objects within a corresponding one or more mold cavities during the first injection cycle,
• inspecting or measuring the first one or more parts or objects,
• manually adjusting (Q) on the subsequent injection cycle the predetermined open gate target time (X) for one or more of the valve pins based on the inspecting or measuring,
• instructing the valve pins on the subsequent injection cycle to open at an overall adjusted instruction time that includes or accounts for the automatic adjusted instruction time (X′) and the manual adjustment (Q).

A method of initiating flow of fluid material into a gate of a mold cavity during an injection molding cycle,

• the cavity having multiple gates including an upstream gate and a downstream gate, each gate having an associated actuator and valve pin, and the valve pin being driven by the actuator between a gate closed position and a gate open position,
• a position sensor associated with the downstream gate that detects withdrawal of the valve pin from the gate closed position (GCP) toward the gate open position (GOP) at an actual open gate time (A) and generates an opening signal (SO) indicative of the actual open gate time (A),
• a cavity sensor that detects a selected physical condition of arrival (DA) of a flow front of the fluid material at a cavity sensor location (CSL) disposed within the mold cavity between the upstream and downstream gates and generates a detection arrival signal (SDA) indicative of a time (tDA) of the detected arrival of the flow front;
• a controller, communicating with the cavity sensor, position sensor and actuator, the method comprising steps of:
• during a first injection molding cycle:
• detecting, by the cavity sensor, the arrival of the flow front of the fluid material in the cavity at the cavity sensor location (CSL) and transmitting the detection signal (SDA) to the controller,
• the controller generating and transmitting to the downstream actuator, or a control valve that controls the downstream actuator, a gate open signal at an instruction time comprising a predetermined open gate target time (X) subsequent to the detected arrival time (tDA),
• sensing, by the position sensor of the downstream gate, withdrawal of the valve pin and transmitting the opening signal (SO) to the controller with the actual open gate time (A), the actual open gate time (A) being indicative of a delay time (Y) between the predetermined open gate target time (X) and the actual open gate time (A),
• the controller generating an automatic adjusted instruction time (X′) comprising the predetermined open gate target time (X) minus the delay time (Y), and
• during a subsequent injection molding cycle,
• after the cavity sensor detects and transmits the detection signal (SDA) to the controller, the controller transmitting to the downstream actuator or its control valve a gate open signal (SGO) at the automatic adjusted instruction time (X) subsequent to the detected arrival time (tDA),
• forming a first one or more parts or objects within a corresponding one or more mold cavities during the first injection cycle,
• inspecting or measuring the first one or more parts or objects,
• manually adjusting (Q) the predetermined open gate target time (X) on a subsequent injection cycle for one or more of the valve pins based on the inspecting or measuring,
• instructing the valve pins to open at an overall adjusted instruction time (X″) on the subsequent injection cycle that includes or accounts for the automatic adjusted instruction time (X′) and the manual adjustment (Q).

Apparatus for initiating flow of fluid material into a gate of a mold cavity during an injection molding cycle, the apparatus comprising:

• a manifold that receives a fluid material, the manifold having or communicating with a delivery channel that delivers the fluid material under an injection pressure to multiple gates of a mold cavity, the multiple gates including an upstream gate and a downstream gate, each gate having an associated actuator and valve pin, and the valve pin being driven by the actuator between a gate closed position GCP and a gate open position GOP,
• a position sensor associated with the downstream gate that senses initial opening movement (IOM) of the valve pin from the gate closed position toward the gate open position as an actual open gate time (A) and generates an opening signal (SO) indicative of the actual open gate time (A),
• a cavity sensor that detects a selected physical condition of arrival (DA) of a flow front of the fluid material at a cavity sensor location (CSL) disposed within the mold cavity between the upstream and downstream gates and generates a detection arrival signal (SDA) indicative of a time (tDA) of the detected arrival of the flow front;
• a controller, communicating with the cavity sensor, position sensor and actuator, the controller including instructions for generating output signals to the actuator,
• wherein, during a first injection molding cycle, the apparatus performs steps of:
• detecting, by the cavity sensor, the flow front of the fluid material in the cavity at the cavity sensor location (CSL) and transmitting the detection signal (SDA) to the controller,
• the controller generating and transmitting to the downstream actuator, or a control valve that controls the downstream actuator, a gate open signal (SGO) at a predetermined open gate target time (X) subsequent to the detected arrival time (SDA),
• sensing, by the position sensor, the initial opening movement of the valve pin and transmitting the opening signal with to the controller, the actual open gate time (A) being indicative of a delay time (Y) between the predetermined open gate target time (X) and the actual open gate time (A),
• the controller automatically generating an automatic adjusted instruction time that comprises the predetermined open gate target time (X) minus the delay time (Y), and during a subsequent injection molding cycle, the
• the cavity sensor detects and transmits the detection signal (SDA) to the controller, the controller transmitting to the downstream actuator or its control valve a gate open signal at the automatic adjusted instruction time (X″) subsequent to the detected arrival time (tDA),
• the apparatus forming a first one or more parts or objects within the mold cavity during the first injection cycle, the user inspecting or measuring the first one or more parts or objects and manually adjusting (Q) the predetermined open gate target time (X) for one or more of the valve pins on the subsequent injection cycle based on the inspecting or measuring,
• the controller including instructions that instruct the one or more valve pins on the subsequent injection cycle to open at an overall adjusted instruction time (X″) that includes or accounts for the automatic adjusted instruction time (X′) and the manual adjustment (Q).

An injection molding system for initiating flow of fluid material into multiple gates of a mold cavity during an injection molding cycle, the system comprising:

• a first selected valve comprising a first fluid flow passage having a first gate to the cavity, a first valve pin driven reciprocally along an axial upstream downstream path of travel through the first flow passage by a first actuator between gate open and gate closed positions,
• one or more downstream valves, each downstream valve comprising a downstream fluid flow passage having a downstream gate to the cavity disposed downstream of the first gate, a downstream valve pin driven reciprocally along an axial upstream downstream path of travel through the downstream fluid flow passage by a downstream actuator between a gate open and a gate closed position,
• a controller receiving a first signal, indicative of a start of injection that feeds the fluid material to the injection molding system, the controller including a set of instructions that instruct the actuator of the valve associated with the at least one selected downstream gate to open the gate by withdrawing the valve pin from the gate closed position at an instruction time (X), the instruction time comprising a predetermined open gate target time (X) based on the first signal,
• wherein the valve associated with the at least one selected downstream gate further includes a position sensor that detects an actual open gate time (A) upon withdrawal of the valve pin from the at least one selected downstream gate, the position sensor sending a signal indicative of the actual open gate time (A) to the controller,
• the controller receiving the signal from the position sensor and including a set of instructions that automatically determines an automatic adjusted instruction time (X′) for use on a subsequent injection cycle, wherein the instructions that automatically determines comprises decreasing the time of instruction to the valve pin to open on a subsequent injection cycle by an adjustment time equal to any delay in time (Y) between the predetermined open gate target time (X) and the actual open gate time (A),
• wherein the system forms a first one or more parts or objects within the mold cavity during the first injection cycle, the user inspecting or measuring the first one or more parts or objects and manually adjusting (Q) the predetermined open gate target time (X) for one or more of the valve pins on the subsequent injection cycle based on the inspecting or measuring,
• the controller including instructions that instruct the one or more valve pins on the subsequent injection cycle to open at an overall adjusted instruction time (X″) that includes or accounts for the automatic adjusted instruction time (X′) and the manual adjustment (Q).

A method comprising:

• a controller receives a first signal, indicative of a start of injection or a position of a screw barrel that feeds fluid material to an injection molding system on a first injection cycle, and transmits to a downstream actuator a gate open signal at a predetermined open gate target time (X) based on the first signal;
• a downstream actuator receives the gate open signal and initiates withdrawal movement of a downstream valve pin from a downstream gate;
• a position sensor detects actual withdrawal movement of the downstream valve pin from the downstream gate and transmits a signal indicative of the actual gate open time (A) to the controller;
• the controller receives the signal from the position sensor and automatically generates an automatic adjusted instruction time (X′) based on the difference (delay time Y) between the actual gate open time (A) and the predetermined open gate target time (X), for use in subsequent cycle,
• a user forms a first one or more parts or objects within a one or more mold cavities during the first injection cycle,
• the user inspects or measures the first one or more parts or objects,
• the user manually adjusts (Q) the predetermined open gate target time (X) on the subsequent injection cycle for one or more of the valve pins based on the inspecting or measuring,
• the controller instructs the valve pins on the subsequent injection cycle to open at an overall adjusted instruction time (X″) that includes or accounts for the automatic adjusted instruction time (X′) and the manual adjustment (Q).

An injection molding system for initiating flow of fluid material into multiple gates of a mold cavity during an injection molding cycle, the system comprising:

• a first selected valve comprising a first fluid flow passage having a first gate to the cavity, a first valve pin driven reciprocally along an axial upstream downstream path of travel through the first flow passage by a first actuator between gate open and gate closed positions,
• one or more downstream valves, each downstream valve comprising a downstream fluid flow passage having a downstream gate to the cavity disposed downstream of the first gate, a downstream valve pin driven reciprocally along an axial upstream downstream path of travel through the downstream fluid flow passage by a downstream actuator between a gate open and a gate closed position,
• a controller receiving a first signal, indicative of a start of a position of a barrel screw that feeds the fluid material to the injection molding system, the controller including a set of instructions that instruct the actuator of the valve associated with the at least one selected downstream gate to open the gate on a first injection cycle by withdrawing the valve pin from the gate closed position upon arrival of the barrel screw at a predetermined open gate screw position (OGSP) occurring at an open gate screw position time (OGSPT),
• wherein the valve associated with the at least one selected downstream gate further includes a position sensor that detects an actual open gate time (A) upon withdrawal of the valve pin from the at least one selected downstream gate, the position sensor sending a signal indicative of the actual open gate time (A) to the controller,
• the controller receiving the signal from the position sensor and including a set of instructions that automatically determines an automatic adjusted open gate screw position (OGSP′) for use on a subsequent injection cycle, the instructions that automatically determines comprising automatically determining the automatic adjusted screw position (OGSP′) to be a position on a subsequent injection cycle that accounts for any delay in time (Y) on the first injection cycle between the open gate screw position time (OGSPT) and the actual open gate time (A),
• wherein the system forms a first one or more parts or objects within the mold cavity during the first injection cycle, the user inspecting or measuring the first one or more parts or objects and manually adjusting the open gate screw position (OGSP) to a manually adjusted open gate screw position (MAOGSP) for one or more of the valve pins on the subsequent injection cycle based on the inspecting or measuring,
• the controller including instructions that instruct the screw to move to an overall adjusted screw position (X″) that includes or accounts for the automatic adjusted open gate screw position (OGSP′) and the manually adjusted open gate screw position (MAOGSP).

A method of operating an injection molding system for initiating flow of a fluid material into multiple gates of a mold cavity during an injection cycle, wherein the system includes:

• a first selected valve comprising a first fluid flow passage having a first gate to the cavity, a first valve pin driven reciprocally along an axial upstream downstream path of travel through the first flow passage by a first actuator between gate open and gate closed positions,
• one or more downstream valves, each downstream valve comprising a downstream fluid flow passage having a downstream gate to the cavity disposed downstream of the first gate, a downstream valve pin driven reciprocally along an axial upstream downstream path of travel through the downstream fluid flow passage by a downstream actuator between a gate open and a gate closed position the method comprising:
• instructing the actuator of the valve associated with the at least one selected downstream gate, or a control valve for the actuator, to withdraw the valve pin from the gate closed position upon detection of arrival of a barrel screw at a predetermined open gate screw position (OGSP), the barrel screw arriving at the predetermined open gate screw position (OGSP) at an open gate screw position time (OGSPT),
• detecting, at an actual open gate time (A), withdrawal of the valve pin from the at least one selected downstream gate,
• automatically determining an automatic adjusted open gate screw position (OGSP′), for use on a subsequent injection cycle, wherein the determining step comprises determining the automatic adjusted screw position (OGSP′) to be a position on a subsequent injection cycle that accounts for any delay in time (Y) on the first injection cycle between the open gate screw position time (OGSPT) and the actual open gate time (A),
• forming a first one or more parts or objects within the mold cavity during the first injection cycle,
• inspecting or measuring the first one or more parts or objects and manually adjusting the open gate screw position (OGSP) to a manually adjusted open gate screw position (MAOGSP) for one or more of the valve pins on the subsequent injection cycle based on the inspecting or measuring,
• instructing the screw to move to an overall adjusted screw position that includes or accounts for the automatic adjusted open gate screw position (OGSP′) and the manually adjusted open gate screw position (MAOGSP).