Injection device and injection control method

Patent metadata

Field	Value
Publication number	US-11911944-B2
Application number	US-202117184622-A
Country	US
Kind code	B2
Filing date	Feb 25, 2021
Priority date	Feb 28, 2020
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

Provided is an injection device and an injection control method which are capable of preventing a drooping phenomenon from an injection nozzle even during high cycle molding, and capable of appropriately plasticizing and molding a resin having poor thermal stability. An injection device (10) of the disclosure includes: an injection cylinder (30) which accumulates a molding material and has an injection nozzle (33) at the front; an injection plunger (31) which is moved backward in the injection cylinder (30); an injection plunger driving device (50, 150) which moves the injection plunger (31) backward; and an injection controller (60, 160). The injection controller (60, 160) retreats the injection plunger (31) by the injection plunger driving device (50, 150) to perform metering in a plastication metering step of metering the molding material supplied into the injection cylinder (30).

First claim

What is claimed is:

1. An injection device, comprising:
an injection cylinder which accumulates a molding material and has an injection nozzle at the front;
an injection plunger which is moved backward in the injection cylinder;
an injection plunger driving device which moves the injection plunger backward; an injection controller; a position detection device which detects a position of the injection plunger; and
a pressure detection device for detecting a resin pressure of the molding material in the injection cylinder, wherein
the injection controller is configured to calculate a retreat speed of the injection plunger in a plastication metering step of an n-th injection cycle from a metering time of the injection plunger measured by the position detection device in a plastication metering step of an (n-1)-th injection cycle, and the injection controller is configured to directly control the injection plunger to retreat based on a value of the resin pressure and the retreat speed to perform metering, before a suck-back step can be omitted, wherein the n is an integer of 3 or more.

2. The injection device according to claim 1 , wherein in the plastication metering step of the n-th injection cycle, the injection controller retreats the injection plunger at the retreat speed to a position at which the injection plunger has been moved from a pre-set metering end position toward the injection nozzle side by a certain width.

3. An injection control method of an injection device which is the injection device according to claim 1 , comprising a plastication metering step in which the molding material supplied into the injection cylinder having the injection nozzle at the front is metered while the injection plunger is retreated, wherein
a retreat speed of the injection plunger in a plastication metering step of the n-th injection cycle is calculated from the metering time measured in a plastication metering step of the (n-1)-th injection cycle, and the injection plunger is retreated at the retreat speed to perform metering of the n-th injection cycle, wherein n is an integer of 3 or more.

4. The injection control method of the injection device according to claim 3 , wherein in the plastication metering step of the n-th injection cycle, the injection plunger is retreated at the retreat speed until the injection plunger reaches a position at which the injection plunger has been moved from a pre-set metering end position toward the injection nozzle side by a certain width.

Assignees

• Sodick Co Ltd

Inventors

• Aiba Shuji
• Taniguchi Shingo
• Okano Tasuku

Classifications

• B29C45/461 Primary

  Injection of measured doses · CPC title

• B29C45/586

  Injection or transfer plungers · CPC title

• B29C45/80

  of relative position of mould parts · CPC title

• B29C45/54 Primary

  and plasticising screw {(B29C45/532 takes precedence)} · CPC title

• B29C45/76

  Measuring, controlling or regulating {(measuring in general G01; controlling or regulating in general G05)} · CPC title