JPH10278082A - Screw for injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a density of melted resin material stored at an end of a screw constant by dividing a supply unit into a first region under a material supply port and a second region of its downstream, decreasing a material conveying amount of the first region smaller than that of the second region, and preventing occurrence of retention at the supply unit with satisfactory biting of resin material with the port. SOLUTION: A screw 10 of a full flight is sequentially formed from a rear end to a front end with a supply unit A, compressing unit B and metering unit C. The unit A is divided into a first region (a) under a material supply port 11 and a second region (b) of its downstream area. In this case, material conveying amount of the region (a) becomes smaller than that of the region (b) such that a lead width L1 of a flight 12 of the region (a) and thread root of the screw are set, for example, to L1 <L2 and equal in the thread root as compared with and that L2 of the region (a) and to the thread root of the screw. Thus, biting of the material at the port 11 can be smoothly conducted without retention, and a density of the melted resin material stored at the end of the screw becomes constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw for an injection molding machine.

[0002]

2. Description of the Related Art As shown in FIG.
Is configured to retreat from the forward limit to the retreat limit while rotating during the weighing process.
Is supplied to the supply section A from the first section, and then melted in the compression section B,
It is measured by the measuring section C in the next step, and is accumulated as a molten resin in the space 3 at the tip of the screw 1.

[0003]

However, the amount of the resin material flowing into the supply section A is reduced from the supply section A to the next compression section B.
If the amount of the molten resin material is larger than the amount of the molten resin material, it becomes difficult for the resin to flow due to friction and resistance against the inner diameter surface of the barrel, the penetration of the resin material into the material supply port 2 becomes poor, and the density of the molten resin material accumulated at the screw tip becomes poor. It was stable, not constant and adversely affected the molded product.

[0004] An object of the present invention is to eliminate the above-mentioned disadvantages, stabilize the penetration of the resin material at the material supply port,
An object of the present invention is to provide a screw of an injection molding machine in which the density of a molten resin material accumulated at a screw tip becomes constant.

[0005]

According to the present invention, there is provided a screw for a full-flight injection molding machine having a supply section, a compression section, and a measurement section from a rear end to a front end. It is divided into a first section below the supply port and a second section downstream of the supply port, and the material transport amount in the first section is the second section.
The screw of the injection molding machine was made smaller than that of the section and the penetration of the resin material in the material supply port was good so that no stagnation occurred in the supply section.

An injection molding machine characterized in that the flight lead width and screw valley diameter of the first section are smaller than those of the second section, and the screw valley diameter is the same. Screw.

Further, the flight lead width and screw valley diameter of the flight in the first area are the same as those of the second area, and the screw valley diameter is large. It was a screw of a molding machine.

[0008] As described above, the screw supply section is divided into the first section below the material supply port and the second section downstream thereof, and the material transfer amount in the first section is smaller than the material transfer amount in the second section. By forming a smooth resin flow and stabilizing the penetration of the resin material at the material supply port, the density of the molten resin material accumulated at the screw tip can be kept constant.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inside of a screw supply section is divided into a first section below a material supply port and a second section downstream of the first section, and the material transfer amount in the first section is smaller than the material transfer amount in the second section.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG.
Reference numeral 10 denotes a full-flight screw, which forms a supply section A, a compression section B, and a measurement section C from the rear end to the front end.
The inside of the supply section A is divided into a first section a below the material supply port 11 and a second section B downstream of the first section a, and the material transfer amount of the first section a is smaller than the material transfer amount of the second section b. Thus, for example, the lead width L ₁ and the screw valley diameter D ₁ of the flight 12 in the first section a are smaller than those L ₂ and D _{2 in} the second section b, and the lead width of the flight is L ₁ <L ₂ , The screw root diameter is D ₁ = D ₂ .

Here, the example in which the lead width of the flight is changed so that the material transport amount in the first area a is smaller than the material transport amount in the second area b as described above has been described. and the flight of the lead width of the first zone a second zone b constant, the second zone b from the screw root diameter D ₁ of the first zone a
Screw valley diameter ₂ may be reduced. That is, the lead width may be L ₁ = L ₂ , and the screw valley diameter may be D ₁ > D ₂ .

The resin material supplied from the material supply port 2 to the supply section A has a configuration as described above, and the material transport amount in the first section a is smaller than the material transport amount in the second section b. Therefore, the bite of the material in the material supply port 11 is smoothly performed without stagnation, and the density of the molten resin material accumulated at the screw tip becomes constant.

[0013]

As described above, the drawbacks such as those fried at the beginning are removed, and the density of the molten resin material accumulated at the tip of the screw becomes constant.

[Brief description of the drawings]

FIG. 1 is a view of a screw showing one embodiment of the present invention.

FIG. 2 is a view of a screw showing another embodiment of the present invention.

FIG. 3 is an explanatory view of a conventional screw.

[Explanation of symbols]

 Reference Signs List 10 screw 11 material supply port 12 flight A supply section B compression section C measuring section a first section b second section

Claims (3)

[Claims] 1. A screw of a full-flight injection molding machine forming a supply section, a compression section and a metering section from a rear end to a front end, wherein the supply section includes a first section below a material supply port and a second section downstream thereof. Wherein the amount of material conveyed in the first section is smaller than that in the second section. 2. A flight lead width and a screw valley diameter of the flight in the first area are smaller than those of the second area, and the screw valley diameter is the same. Item 6. An injection molding machine screw according to Item 1. 3. The flight lead width and screw valley diameter of the flight in the first area are the same as those of the second area, and the screw valley diameter is large. A screw for an injection molding machine according to claim 1.