INJECTION MOLDING MACHINE WITH VISCOSITY MEASURING FUNCTION AND METHOD FOR MEASURING VISCOSITY USING INJECTION MOLDING MACHINE

• US 20150084221A1
• Filed: 09/12/2014
• Published: 03/26/2015
• Est. Priority Date: 09/26/2013
• Status: Abandoned Application

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: OOMORI, Akira
• Application Number:
  US14/484,340
• Publication Number:
  US 20150084221A1
• Time in Patent Office: Days
• US Class Current: 264/40.1
• CPC Class Codes: B29C 2045/2722 Nozzles or runner channels provided with a pressure sensor
• CPC Class Codes: B29C 2945/76006 Pressure
• CPC Class Codes: B29C 2945/7605 Viscosity
• CPC Class Codes: B29C 2945/7621 nozzle
• CPC Class Codes: B29C 2945/76381 Injection
• CPC Class Codes: B29C 45/2701 Details not specific to hot or cold runner channels B29C45/2725 takes precedence
• CPC Class Codes: B29C 45/7646 viscosity
• CPC Class Codes: B29C 45/77 of velocity or pressure of moulding material

Abstract

A nozzle is attached to a heating cylinder via a nozzle adapter. A sensor for pressure measurement is attached to the nozzle adapter. A molten resin is injected into the air with a front of the nozzle open, and a resin pressure is measured by pressure measuring unit while the molten resin is being injected into the air. Based on the resin pressure, the viscosity of the injected molten resin is determined.

Claims

1. An injection molding machine configured to melt a resin in a heating cylinder and then move a screw or a plunger forward to inject the molten resin through a nozzle, the injection molding machine comprising:

a nozzle adapter attached between a tip portion of the heating cylinder and the nozzle to provide a molten resin channel that connects the heating cylinder to the nozzle;

a pressure measuring unit configured to measure a resin pressure in the nozzle adapter; and

a molten resin injecting unit configured to inject the molten resin into air with a front of the nozzle open,

the injection molding machine further comprising;

a viscosity determining unit configured to determine viscosity of the injected molten resin based on the resin pressure measured by the pressure measuring unit while the molten resin injecting unit is injecting the molten resin into the air.

2. The injection molding machine according to claim 1, wherein a resin pressure measurement position in the nozzle adapter is a position closer to the nozzle than an axial position that is closest to the nozzle, among axial positions where the molten resin channel has a diameter equal to an inner diameter of a heating cylinder-side end surface.

3. The injection molding machine according to claim 1, wherein a pressure measurement position in the nozzle adapter is a cylindrical portion, of the molten resin channel, which has an inner diameter equal to an inner diameter of a nozzle-side end surface.

4. The injection molding machine according to claim 1, further comprising a storing unit configured to store a hole diameter and a length of a tube portion at a nozzle tip and a diameter of the screw or the plunger, wherein

the viscosity determining unit is configured to determine the viscosity from the resin pressure measured at a set screw position or at a set elapsed time since start of injection, an injection speed, and the stored hole diameter and length of the tube portion at the nozzle tip and the stored diameter of the screw or the plunger.

5. The injection molding machine according to claim 4, wherein information on combination of the hole diameter and the length of the tube portion at the nozzle tip is saved to a database as nozzle shape data, and the viscosity is determined by reading the information on the hole diameter and the length of the tube portion at the nozzle tip based on the attached nozzle.

6. A method for measuring resin viscosity using an injection molding machine configured to melt a resin in a heating cylinder and then moves a screw or a plunger forward to inject the molten resin through a nozzle, the method comprising:

measuring the resin pressure when the molten resin is injected into air with a front of the nozzle open, using pressure measuring unit configured to measure a resin pressure in a nozzle adapter attached between a tip portion of the heating cylinder and the nozzle to provide a molten resin channel that connects the heating cylinder to the nozzle;

determining viscosity of the injected molten resin based on the measured resin pressure.

7. The method for measuring resin viscosity using an injection molding machine according to claim 6, wherein a resin pressure measurement position in the nozzle adapter is a position closer to the nozzle than an axial position that is closest to the nozzle, among axial positions where the molten resin channel has a diameter equal to an inner diameter of a heating cylinder-side end surface.

8. The method for measuring resin viscosity using an injection molding machine according to claim 6, wherein a pressure measurement position in the nozzle adapter is a cylindrical portion, of the molten resin channel, which has an inner diameter equal to an inner diameter of a nozzle-side end surface.

9. The method for measuring resin viscosity using an injection molding machine according to claim 6, wherein the viscosity is determined from the resin pressure measured at a set screw position or at a set elapsed time since start of injection, an injection speed, a hole diameter and a length of a tube portion at a nozzle tip, and a diameter of a screw or a plunger.