Method of detecting injected amount from an injection molder

Claim 1

A method of detecting the amount of plasticized synthetic resin injected from an injection molder comprising a cylinder having a screw therein, and a flow path opening/closing mechanism capable of blocking the flow of plasticized resin between the cylinder and a cavity of a mold, the method comprising the steps of: (a) closing the flow path opening/closing mechanism to block the flow of resin prior to injecting resin from the cylinder into the cavity; (b) applying a predetermined pressure to the screw while the flow of resin is blocked, to effect a balancing movement of the screw; (c) obtaining the positional value of the screw at a first stop position where the screw stops its balancing movement, or the resin amount in the cylinder corresponding to said positional value; (d) opening said flow path opening/closing mechanism to allow the plasticized synthetic resin to flow from the cylinder to the cavity of the mold; (e) applying pressure to the screw while the flow path opening/closing mechanism is open, to inject plasticized synthetic resin into the cavity; (f) closing the flow path opening/closing mechanism to block the flow of resin upon completion of injection and dwelling; (g) applying a predetermined pressure to the screw, while the resin flow is blocked, to effect a balancing movement of the screw; (h) obtaining the positional value of the screw at a second stop position where the screw stops its balancing movement, or the resin amount in the cylinder corresponding to said positional value; and (i) obtaining the value corresponding to the injected amount or the injected amount itself, by operations including subtraction of the positional value of the screw at said second stop position or the resin amount in the cylinder corresponding to this positional value from the positional value of the screw at said first stop position or the resin amount in the cylinder corresponding to this positional value.

Claim 2

A method of detecting the amount of plasticized synthetic resin injected from an injection molder comprising a cylinder having a screw therein, and a flow path opening/closing mechanism capable of blocking the flow of plasticized resin between the cylinder and a cavity of a mold, the method comprising the steps of: (a) closing the flow path opening/closing mechanism to block the flow of resin prior to injecting resin from the cylinder into the cavity; (b) applying a predetermined pressure to the screw while the flow of resin is blocked, to effect a balancing movement of the screw; (c) obtaining the positional value of the screw at a first stop position where the screw stops its balancing movement, or the resin amount in the cylinder corresponding to said positional value; (d) opening said flow path opening/closing mechanism to allow the plasticized synthetic resin to flow from the cylinder to the cavity of the mold; (e) applying pressure to the screw while the flow path opening/closing mechanism is open, to inject plasticized synthetic resin into the cavity; (f) closing the flow path opening/closing mechanism to block the flow of resin upon completion of injection and dwelling; (g) applying a predetermined pressure to the screw, while the resin flow is blocked, to effect a balancing movement of the screw; (h) obtaining the positional value of the screw at a second stop position where the screw stops its balancing movement, or the resin amount in the cylinder corresponding to said positional value; and (i) obtaining the value corresponding to the injected amount or the injected amount itself, by operations including subtraction of the positional value of the screw at said second stop position or the resin amount in the cylinder corresponding to this positional value from the positional value of the screw at said first stop position or the resin amount in the cylinder corresponding to this positional value.