Heating device for injection molding machine

Abstract

When a heating device is formed which includes at least one or more heaters 4n, 4a, 4b, 4c and 4d that are provided on the outer circumferential surfaces 2f and 3f of at least one of a heating cylinder 2 and an injection nozzle 3 to heat at least one of the heating cylinder 2 and the injection nozzle 3, at least some heaters 4a, 4b, 4c, . . . of all the heaters 4n, 4a, . . . are formed with air cooling-capable heaters 4as, 4bs and 4cs in which a panel member 5 formed of a material R having thermal conductivity is interposed between the heaters 4a, 4b, 4c, . . . and the outer circumferential surfaces 2f and 3f of at least one of the heating cylinder 2 and the injection nozzle 3, in which an air path 6 for air cooling is formed in the panel member 5 and in which an air outlet and inlet portion 8 allowing air A to be passed from an air supply portion 7 is provided in the air path 6.

Description

Technical field [0001] The present invention relates to a heating device of an injection molding machine, which has a heater for heating the heating cylinder and the like by being attached to the outer peripheral surface of the heating cylinder and the like. Background technique [0002] Generally, an injection molding machine has an injection device that injects and fills molten resin into a mold. In this case, the injection device has a heating cylinder with an injection nozzle at the front end and a funnel at the rear. A screw is inserted through the inside of the heating cylinder, and a heater is attached to the outer peripheral surface of the heating cylinder. Device (heater). As a result, the solid-shaped pellets supplied from the hopper to the inside of the heating cylinder are plasticized and mixed by the shearing caused by the rotation of the screw and the heating of the heating cylinder, thereby producing molten resin for injection and filling into the mold. . On the...

AI Technical Summary

Problems solved by technology

[0008] First, there is a disadvantage that the heating structure is basically sacrificed in the structure in which a cooling pipe is wound between the heating heater and the heating cylinder to allow the cooling water to flow as in Patent Document 1.

That is, the heating structure heats the heating cylinder by transferring the heat of the heating heater to the heating cylinder. Therefore, interposing a member (cooling pipe) that inhibits heat transfer between the heating heater and the heating cylinder will increase heat loss. , which in turn greatly reduces the heating efficiency, and will lead to a decrease in the responsiveness and controllability of temperature control

Therefore, it is not suitable for use for materials that require active melting such as thermoplastic resins

[0009] On the other hand, as in Patent Document 2, the heater attached to the outer peripheral surface of the heating cylinder is blown by the fan from the outside of the heater. On the contrary, the heater is interposed between the fan and the heating cylinder. , so it will hinder the air-cooling effect, which will lead to a significant drop in air-cooling efficiency

In addition, since a fan or the like needs to be placed near the heating cylinder, it will lead to unnecessary enlargement of the molding equipment and decrease in space efficiency.

[0010] As a result, in the case of a structure in which a heater is attached to the outer peripheral surface of the heating cylinder to directly transfer heat from the heater to the heating cylinder for heating, the actual situation is that it is difficult to add a cooling structure to fully exert both the heating function and the cooling function. function, so one of them had to be sacrificed

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