CN212707928U

CN212707928U - Mouth core mould for large-caliber thick-wall polyethylene pipe

Info

Publication number: CN212707928U
Application number: CN202020122337.0U
Authority: CN
Inventors: 孙恩功; 屈桂照; 王荣辉; 张光涛; 甘露
Original assignee: Hebei Quanen High Tech Pipe Co ltd
Current assignee: Hebei Quanen High Tech Pipe Co ltd
Priority date: 2020-01-19
Filing date: 2020-01-19
Publication date: 2021-03-16
Anticipated expiration: 2030-01-19

Abstract

The mouth core mold for large-caliber thick-wall polyethylene pipes comprises a mouth mold and a core mold, wherein the mouth mold is sleeved on the outer side of the core mold, an annular flow passage for flowing materials is formed between the inner wall of the mouth mold and the outer wall of the core mold, the inner diameter of an inlet of the annular flow passage is smaller than the inner diameter of an outlet, and the outer diameter of the inlet of the annular flow passage is smaller than the outer diameter of the. The utility model researches the running state of the polyethylene flow in the mouth core mould, improves the structure of the mouth core mould skillfully, solves the pressurization problem in the pipeline diameter increasing process, can utilize the base mould with similar specifications to expand and process a large-diameter pipeline, and greatly reduces the equipment investment while meeting the expansion specifications of enterprise products; the utility model discloses a choked flow design of the section of contracting in the mouth mandrel can effectual reduction feed stream phenomenon of hanging down, realizes that ordinary raw materials satisfies the production quality demand under the condition of the raw materials that hangs down not using special low melting, is favorable to realizing the technological promotion of ordinary raw materials production super large super thick tubular product.

Description

Mouth core mould for large-caliber thick-wall polyethylene pipe

Technical Field

The utility model relates to a plastic conduit preparation mould especially is used for the mouth mandrel of heavy-calibre thick wall polyethylene pipe.

Background

The high-density polyethylene material has better compression resistance and environmental protection performance, and is widely applied, and the high-density large-caliber polyethylene pipe is mainly used for a water supply pipeline. At present, the production mode in the plastic pipeline industry generally meets the production requirement of a customer by purchasing a matched whole production line. Each production enterprise can encounter the situation that a large number of orders cannot be completed due to incomplete specifications of the production line. Purchasing a matched whole production line is a conventional scheme which is used continuously, but if the order quantity is insufficient, the invested equipment fund cannot be recovered, the starting rate of the equipment is seriously insufficient, the equipment is idle, and the invested cost is too high. At present, no precedent exists in the industry for transforming a production line of a small-sized pipeline to a production line of a large-sized pipeline. The main reason is that the pressurizing process of the material flow in the mouth core mold can not be realized, so that the surface defects of pipe inner wall, outer wall micro pits, stripes and the like can not be eliminated, and the compact structure can not be ensured.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a mouth mandrel for heavy-calibre thick wall polyethylene pipe to realize that supporting specification is close base mould and expand the processing to the major diameter pipeline.

The problem of the utility model is realized with following technical scheme:

the mouth core mold for large-caliber thick-wall polyethylene pipes comprises a mouth mold and a core mold, wherein the mouth mold is sleeved on the outer side of the core mold, an annular flow passage for flowing materials is formed between the inner wall of the mouth mold and the outer wall of the core mold, the inner diameter of an inlet of the annular flow passage is smaller than the inner diameter of an outlet, and the outer diameter of the inlet of the annular flow passage is smaller than the outer diameter of the.

According to the mouth core mould for the large-caliber thick-wall polyethylene pipe, the annular runner is sequentially provided with the contraction section, the expansion section and the straight section according to the material running direction, the cross sectional area at the inlet of the annular runner is the largest, the cross sectional area at the joint of the contraction section and the expansion section is the smallest, the cross sectional area of the straight section is constant, and adjacent sections are in smooth transition.

The cross-sectional area ratio of the inlet to the outlet of the annular runner compression section is 1.6-2.3, and the cross-sectional area ratio of the inlet to the outlet of the annular runner expansion section is 0.6-0.75.

The mouth core die for the large-caliber thick-wall polyethylene pipe has the axial dimension of L, the axial dimension of the compression section of L1, and the axial dimension of L1 ═ 0.15-0.22L; the axial length of the expanding section is L2, and L2 is (0.10-0.12) L.

The gap of the straight section annular runner of the mouth core mould for the large-caliber thick-wall polyethylene pipe is 1-1.4 times of the wall thickness of the processed pipe.

The utility model researches the running state of the polyethylene flow in the mouth core mould, improves the structure of the mouth core mould skillfully, solves the pressurization problem in the pipeline diameter increasing process, can utilize the base mould with similar specifications to expand and process a large-diameter pipeline, and greatly reduces the equipment investment while meeting the expansion specifications of enterprise products; the utility model discloses a choked flow design of the section of contracting in the mouth mandrel can effectual reduction feed stream phenomenon of hanging down, realizes that ordinary raw materials satisfies the production quality demand under the condition of the raw materials that hangs down not using special low melting, is favorable to realizing the technological promotion of ordinary raw materials production super large super thick tubular product.

Drawings

The present invention will be further explained with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

fig. 3 is a schematic diagram of the utility model.

The reference numbers in the figures are: 1. the device comprises a core die, 2 parts of an annular flow channel, 2-1 parts of a compression section, 2-2 parts of an expansion section, 2-3 parts of a straight section, 3 parts of a mouth die, 4 parts of a base die, 4-1 parts of mouth die transition, and 4-2 parts of core die transition.

Detailed Description

Referring to fig. 1-3, the utility model comprises a mouth mold 3 and a core mold 1, wherein the mouth mold is sleeved outside the core mold, the mouth mold and the core mold are both connected with a base mold 4, and an annular flow passage 2 for polyethylene melting flow operation is formed between the inner wall of the mouth mold and the outer wall of the core mold. Annular runner import internal diameter is less than the export internal diameter, and annular runner import external diameter is less than the export external diameter. The annular flow channel is sequentially provided with a contraction section 2-1, an expansion section 2-2 and a flat section 2-3 according to the material running direction. The cross-sectional area of the inlet of the annular runner is the largest, the cross-sectional area of the joint of the contraction section and the expansion section is the smallest, the cross-sectional area of the straight section is constant, and the adjacent sections are in smooth transition.

Referring to fig. 2, the design idea of the present invention is as follows: after the polyethylene material enters the compression section, the cross-sectional area of the annular flow passage is greatly reduced, the pressure is sharply increased, the rapid compression process of the polyethylene material is realized, surface flaws such as micro pits and stripes on the inner wall and the outer wall of the pipeline are eliminated through the compression process, and the tissue of the pipe wall is compact. The cross-sectional area ratio of the inlet to the outlet of the annular runner compression section is 1.6-2.3, the axial size of the compression section is L1, and L1 is (0.15-0.22) L. The structural size not only considers the full compression of the polyethylene material in a certain length range, but also considers that the length of the compressed section is not easy to be too large or too small. Too large of L1 increases the cost of the die, while too small of L1 makes the polyethylene material difficult to flow and easy to coke. The expansion section realizes the purpose of increasing the pipe diameter on the basis of compressing the molten material. The cross-sectional area ratio of the inlet to the outlet of the annular flow passage expansion section is 0.6-0.75, and the length L2 of the expansion section is (0.10-0.12) L. The last stage is a straight section, and polyethylene material in the section enters the hollow sizing sleeve after being shaped by the mouth mold and the core mold.

The utility model discloses to the above-mentioned improvement of mould, changed the melting material at bush, mandrel running state, the material stream can not be full of the runner lower part like conventional mould earlier, but under the choked flow effect of strong, weak compression section, the material stream is full of even promotion to mould export direction behind the whole annular region basically, consequently can obviously reduce the effect of hanging down, improves the pipe wall degree of consistency.

Fig. 3 is a schematic view of the usage state of the present invention. It can be seen from the figure that the base mold of the mouth core mold with small specification, in other words, the base mold with similar specification is used for expanding and processing the large-diameter pipeline. Specifically, a DN1600 base die is adopted, a mouth core die for processing DN1800 is configured, and a polyethylene pipe with DN1800 and 85.7 mm wall thickness is processed. The L of the mouth core mold is 500 mm. The base die 4 is provided with a die transition 4-1 and a core die transition 4-2, the die transition is matched and connected with the die, and the core die transition is matched and connected with the core die.

Claims

1. The utility model provides an oral cavity mandrel for heavy-calibre thick wall polyethylene pipe, includes bush (3) and mandrel (1), and the bush suit constitutes annular runner (2) of flowing material operation, its characterized in that in the mandrel outside between bush inner wall, the mandrel outer wall: the inner diameter of the inlet of the annular runner is smaller than the inner diameter of the outlet, and the outer diameter of the inlet of the annular runner is smaller than the outer diameter of the outlet.

2. The mouth core mould for the large-caliber thick-wall polyethylene pipe according to claim 1, wherein: the annular flow passage is sequentially provided with a contraction section (2-1), an expansion section (2-2) and a flat section (2-3) according to the material running direction, the cross sectional area at the inlet of the annular flow passage is the largest, the cross sectional area at the joint of the contraction section and the expansion section is the smallest, the cross sectional area of the flat section is constant, and adjacent sections are in smooth transition.

3. The mouth core mould for the large-caliber thick-wall polyethylene pipe according to claim 2, wherein: the cross-sectional area ratio of the inlet to the outlet of the annular flow passage compression section is 1.6-2.3, and the cross-sectional area ratio of the inlet to the outlet of the annular flow passage expansion section is 0.6-0.75.

4. The mouth core mould for large-caliber thick-wall polyethylene pipes according to claim 3, characterized in that: the axial dimension of the mouth core die is L, the axial dimension of the compression section is L1, and L1 is 0.15L-0.22L; the axial length of the expanding section is L2, and L2 is 0.10L-0.12L.

5. The mouth core mould for large-caliber thick-wall polyethylene pipes according to claim 4, wherein: the clearance of the straight section annular flow passage is 1 to 1.4 times of the wall thickness of the processed pipe.