| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a back-flow preventing device for in-line screw type injection molding machines which enables stabilization of metering in a metering process and prevents variation of the quality and/or the weight of moldings. <P>SOLUTION: A check ring 10 is attached around the axle 5 of a screw tip 4 mounted on the front part of a screw 2 so as to prevent back-flow of a resin from the front part of a conical portion 6 of the screw tip 4 to the screw side 2. A protrusion 21 is formed on the front-end surface of the check ring 10. The back-end surface of the conical portion 6 of the screw tip 4 and the end surface of the protrusion 21 of the check ring 10 are brought into contact on metering to form a clearance 22 between the screw tip 4 and the surface of the root of the claw portion 12 of the check ring 10 in order to ensure a resin path around the contact surface between the back-end surface of the screw pit 4 and the end surface of the protrusion 21 of the check ring 10. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
