JPH0243702Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a heating cylinder of an injection device used for molding synthetic resin.

In an injection device in which a heating cylinder and a material tank are attached to a holding member at the tip of the injection cylinder, a synthetic resin molding material from the material tank can be supplied into the heating cylinder from a material supply section provided on the holding member. When the temperature of the material supply section rises due to heat transfer from the heating cylinder side, the molding material tends to melt and form lumps in the supply path, making it difficult to bite into the molding material during metering, resulting in problems with material supply. Often lacks smoothness. Therefore, in order to reduce heat transfer, the connecting member between the heating cylinder and the holding member is fixed to the holding member with a heat insulating plate in between, but this is not sufficient, so the injection device Most of them are used to cool the material supply section.

However, conventional cooling means mainly use water as a heat medium, and the amount of water is often inadvertently increased, thereby causing the holding member to be cooled more than necessary. This results in too much heat being drawn from the heating cylinder, which not only causes the heater to waste power, but also
Since the temperature of the molding material is below room temperature, the power required to rotate the screw until it melts is used excessively.

This invention was devised to solve the above-mentioned conventional problems, and its purpose is to slightly modify the rear part of the heating cylinder fitted in the holding member. , provides a heating cylinder that can reduce heat transfer between the heater side and the material supply section side, extremely minimize the thermal influence on both parts, and improve the efficiency of the injection device and reduce power consumption. It's about doing.

This invention for the above purpose has the rear part of a heating cylinder that has a screw inside and a heater on the outer periphery mounted on a holding member at the tip of the injection cylinder, and a supply path is provided between the holding member and the rear part of the injection cylinder. In an injection device in which a cooling water channel is provided in the material supply section of a holding member having the supply channel, a required number of blind holes are deeply drilled radially from the outside at the rear of the heating cylinder between the heater and the cooling water channel, The above problem is solved by reducing the heat transfer area of the part due to the blind hole.

This invention will be explained in detail below using illustrated examples.

In the figure, 1 is a heating cylinder equipped with a heater 1b on the outer peripheral surface, an injection screw 2 inside, and a rear part 1.
A is attached to a holding member 4 at the tip of the injection cylinder 3.

Reference numeral 5 denotes a tank, which is installed on a material supply unit 7 having a supply passage 6 extending through the heating cylinder 1 and the holding member 4, and the granular material in the tank 5 is supplied to the injection screw 2 through the supply passage 6 It is designed to be fed into a groove.

Further, the heating cylinder 1 is fixed by bringing a nut member 8 screwed into the inside of the rear portion 1a into contact with the open end of the holding member 4 via a heat insulating material 9, and tightening the nut member 8 with bolts.

A cooling water channel 12 is provided in the material supply section 7 of the holding member 4 so as to surround the rear portion 1a of the heating cylinder 1. Further, eight blind holes 10, 10 are deeply bored radially from the outside in the rear part 1a of the heating cylinder between the cooling water channel 12 and the heater 1b. The heat transfer area of this part is significantly smaller than that of other parts.

Note that reference numeral 11 denotes an annular groove provided in the blind hole portion in order to avoid contact between the inside of the opening edge of the holding member 4 and the outside of the rear portion 1a of the heating cylinder 1.

As described above, this invention is based on the heating cylinder rear part 1a between the heater 1a on the outside of the heating cylinder and the cooling water channel 12 provided in the material supply section 7 of the holding member 4.
The required number of blind holes 10, 10 are deeply drilled radially from the outside, and the heat transfer area of the part is reduced by the blind holes 10, 10, so that the amount of heat transfer in that part is , the material supply section 7 is less likely to be heated, and the material supply section 7 can be cooled with a small amount of water. In addition, since the heater side does not get too cold and unnecessary power consumption is prevented, it is also possible to maintain the temperature of the material supply section at an appropriate level by simply cooling the holding member with air, which would otherwise require water cooling. No equipment is required.

Also, since the blind hole part is located inside the holding member,
It has the advantage that the strength of the rear part of the heating cylinder does not particularly decrease, and the processing is extremely easy and does not require high costs because it is only necessary to drill blind holes radially.

[Brief explanation of drawings]

The drawings illustrate the main parts of the heating cylinder of the injection device according to the invention, and FIG. 1 is a partially longitudinal side view, and FIG. 2 is a longitudinal front view. 1b...Heater, 1...Heating cylinder, 2...
... Injection screw, 3 ... Injection cylinder, 4 ... Holding member, 5 ... Material tank, 6 ... Supply path, 7 ...
...Material supply section, 8...Nut member, 9...Insulating material, 10...Blind hole.

Claims (1)

[Scope of utility model registration request] The rear part of a heating cylinder having a screw inside and a heater on the outer periphery is enclosed in a holding member at the tip of an injection cylinder, and a supply passage is provided between the holding member and the rear part of the heating cylinder, and the holding member has the supply passage. In an injection device equipped with a cooling water channel in the material supply section, a required number of blind holes are deeply drilled radially from the outside at the rear of the heating cylinder between the heater and the cooling water channel, and the blind holes are used to cool the part in question. A heating cylinder for an injection device characterized by a reduced heat transfer area.