Flat extrusion container structure for reducing stress concentration

Abstract

The utility model provides a flat extrusion container structure capable of reducing stress concentration. The device sequentially comprises an outer cylinder (1), a middle cylinder (2) and an inner cylinder (3) from outside to inside, wherein an extrusion hole (4) is formed in the inner cylinder (3). The oval extrusion hole (4) is formed in the inner cylinder (3), and the liner of the inner cylinder (3) is oval (the ratio of the short axis to the long axis of the oval is 0.6-0.8), so that compared with a conventional flat extrusion cylinder, the extrusion cylinder has the advantages that the stress concentration phenomenon caused by transition from a circular arc to a horizontal line can be reduced, the maximum equivalent stress can be reduced by 5.7-10%, and therefore, the extrusion efficiency is greatly improved. And the average stress of the extrusion container during working can be effectively reduced, so that the fatigue life is prolonged, and the cost is saved.

Description

Technical Field

[0001] The utility model relates to the field of extrusion equipment, and particularly to a flat extrusion cylinder structure for reducing stress concentration. Background Technique

[0002] In recent years, with the development of fields such as aerospace, high-speed rail, and new energy vehicles in China, the demand for thin-walled wide-width industrial aluminum profiles in these industries has been increasing. Because the flat extrusion cylinder has advantages such as a short process and excellent product quality in the process of producing wide-width wall panels, the flat extrusion cylinder is often selected for conventional thin-walled wide-width industrial aluminum profiles in the above fields; however, the flat extrusion cylinder still has deficiencies: due to the incomplete symmetry of the shape of the flat extrusion cylinder, working under harsh conditions of high temperature, high pressure, and high friction, the stress distribution is uneven, and it is extremely easy to crack at the transition between the long side and the short side, and the service life is relatively low. Aiming at the technical problems existing in the prior art, there is an urgent need for a method to solve the structure of the flat extrusion cylinder to solve the phenomenon that the flat extrusion cylinder is extremely easy to crack at the transition between the long side and the short side due to uneven stress distribution. Content of the Utility Model

[0003] Aiming at the defects in the prior art, the purpose of the utility model is to provide a flat extrusion cylinder structure for reducing stress concentration.

[0004] The technical solution of the utility model is as follows:

[0005] The utility model relates to a flat extrusion cylinder structure for reducing stress concentration, which sequentially includes an outer cylinder 1, a middle cylinder 2, and an inner cylinder 3 from outside to inside; wherein, an extrusion hole 4 is arranged inside the inner cylinder 3.

[0006] Preferably, the extrusion hole 4 is oval.

[0007] Preferably, the ratio of the minor axis to the major axis of the extrusion hole 4 is 0.6 - 0.8, and this ratio can slow down the phenomenon of stress concentration generated by the transition from an arc to a horizontal line; if the ratio is lower than 0.6, the maximum stress value of the extrusion cylinder will exceed the maximum stress value of the traditional flat extrusion cylinder; if the ratio is higher than 0.8, the inner lining of the extrusion cylinder is closer to a round extrusion cylinder. Although the stress decreases and the distribution is more uniform, the extrusion pressure required for billet extrusion will increase sharply.

[0008] Preferably, the ratio of the major axis of the extrusion hole 4 to the outer diameter of the inner cylinder 3 is 0.6 - 0.9.

[0009] Preferably, the ratio of the outer diameter of the inner cylinder 3 to the outer diameter of the middle cylinder 2 is 0.4 - 0.6.

[0010] Preferably, the ratio of the outer diameter of the middle cylinder 2 to the outer diameter of the outer cylinder 1 is 0.7 - 0.9.

[0011] Preferably, the interference amount between the inner cylinder 3 and the middle cylinder 2 is 1 - 3%.

[0012] Preferably, the interference between the middle cylinder 2 and the outer cylinder 1 is 1-3%.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] (1) The utility model is provided with an oval extrusion hole 4 inside the inner cylinder 3. Since the inner lining of the inner cylinder 3 is oval (the ratio of the short axis to the long axis of the oval is 0.6-0.8), it can not only slow down the stress concentration phenomenon generated by the transition from the arc to the horizontal line in the traditional flat extrusion cylinder, reducing the maximum equivalent stress by 5.7-10%; but also increase the extrusion times of the extrusion cylinder, slow down the cracking phenomenon caused by uneven stress distribution, greatly improve the service life of the extrusion cylinder, and reduce the cost.

[0015] (2) The utility model has a simple structure, is easy to operate, has remarkable effects, and has a low cost. Description of the Drawings

[0016] By reading the following detailed description of the non-restrictive embodiments with reference to the accompanying drawings, other features, objects, and advantages of the utility model will become more apparent:

[0017] Figure 1 It is a schematic structural diagram of the flat extrusion cylinder of the utility model that can reduce stress concentration;

[0018] Figure 2 It is a lining diagram of the traditional flat extrusion cylinder.

[0019] Reference numerals in the drawings: 1 is the outer cylinder, 2 is the middle cylinder, 3 is the inner cylinder, and 4 is the extrusion hole. Detailed Embodiments

[0020] The following specifically describes the utility model with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the utility model, several deformations and improvements can be made. These all belong to the protection scope of the utility model.

[0021] Embodiment

[0022] The structure of the flat extrusion cylinder for reducing stress concentration in this embodiment, as Figure 1 shown, taking the flat extrusion cylinder of an 80MN extrusion press as an example, from the outside to the inside, it successively includes an outer cylinder 1, a middle cylinder 2, and an inner cylinder 3; among them, an oval extrusion hole 4 is provided inside the inner cylinder 3; the inner cylinder 3, the middle cylinder 2, and the outer cylinder 1 of the extrusion cylinder are designed according to the conventional method.

[0023] The inner cylinder 3 and the middle cylinder 2 adopt an interference fit of 1.5%, and the middle cylinder 2 and the outer cylinder 1 adopt an interference fit of 2%. The three are all assembled by hot shrinking.

[0024] The inner cylinder 3, the middle cylinder 2 and the outer cylinder 1 are all made of H13 die steel.

[0025] Compared with the structure of the traditional flat extrusion cylinder, the inner lining of the traditional flat extrusion cylinder is shown Figure 2 as follows. The dimensions are L = 670 mm and H = 300 mm. At this time, the aspect ratio of the height to the width of the inner lining of the extrusion cylinder is 0.45.

[0026] An oval extrusion hole 4 is provided inside the inner cylinder 3 of the present utility model. The ovality of this oval (the ratio of the minor axis to the major axis of the extrusion hole) is 0.6. The major axis dimension of the oval extrusion hole is 670 mm, and then the minor axis dimension is 402 mm at this time. Compared with the traditional design, the present utility model makes the working stress of the extrusion cylinder evenly distributed along the inner hole edge, slows down the stress concentration phenomenon, and can effectively reduce the stress field of the flat cylinder.

[0027] The specific embodiments of the present utility model have been described above. It should be understood that the present utility model is not limited to the above specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which do not affect the essence of the present utility model.

Claims

1. A flat extrusion container structure for reducing stress concentration, characterized in that, It successively includes an outer cylinder (1), a middle cylinder (2), and an inner cylinder (3) from outside to inside; wherein, an extrusion hole (4) is provided inside the inner cylinder (3). The extrusion hole (4) is oval, the ratio of the minor axis to the major axis of the extrusion hole (4) is 0.6 - 0.8, the ratio of the major axis of the extrusion hole (4) to the outer diameter of the inner cylinder (3) is 0.6 - 0.9, the ratio of the outer diameter of the inner cylinder (3) to the outer diameter of the middle cylinder (2) is 0.4 - 0.6, the ratio of the outer diameter of the middle cylinder (2) to the outer diameter of the outer cylinder (1) is 0.7 - 0.9, the interference amount between the inner cylinder (3) and the middle cylinder (2) is 1 - 3%, and the interference amount between the middle cylinder (2) and the outer cylinder (1) is 1 - 3%.

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