CN113843295A

CN113843295A - Overturning forming process for extruding fan-shaped rib plate

Info

Publication number: CN113843295A
Application number: CN202111194399.8A
Authority: CN
Inventors: 胡福泰
Original assignee: Yanshan University
Current assignee: Yanshan University
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2021-12-28
Anticipated expiration: 2041-10-13
Also published as: CN113843295B

Abstract

The invention provides a turnover forming process for extruding a fan-shaped rib plate, which is characterized in that in the early stage of extrusion, a notch is prepared in the middle of a material to be deformed into a rib plate part, or in the early stage of rib plate forming, the notch is processed in the middle of the rib plate; and pressing the male die downwards, expanding the notch, turning and transversely moving the rib plates on two sides of the notch to two sides until the bottom of the notch exceeds the height of the preset rib plate, and cutting off the part exceeding the height of the preset rib plate. According to the invention, by arranging the notch, the stress concentration position is artificially changed, the artificially arranged notch can form a larger and larger notch along with deformation, the material near the notch becomes a rigid area, under the pushing of the material in the subsequent deformation area, the material in the rigid area rotates at a certain angle, so that the edge of the notch gradually rotates from the vertical direction to the horizontal direction, and the initial rigid rotation area forms a part of the fan-shaped rib plate along with the gradual widening of the opening of the fan-shaped rib plate, so that the fan-shaped rib plate with a larger height-thickness ratio can be formed.

Description

Overturning forming process for extruding fan-shaped rib plate

Technical Field

The invention relates to the technical field of metal plastic processing, in particular to a turnover forming process for an extruded fan-shaped rib plate.

Background

The extrusion forming of parts with rib plates has the defects of cracking, folding, wrinkling and the like at rib plate parts, the rib plate parts are integrally formed with other parts of the parts, and some parts can be formed by adopting the rib plate parts partially and firstly. The local forming of the rib plate part can effectively reduce the forming load, and has important significance for protecting the die and prolonging the service life of the die. At present, the method for avoiding defects is adopted for extrusion forming of rib plate parts, for example, the radius of a fillet is increased, stress concentration is reduced, gradual deformation is avoided from cracking, a flow resistance groove is added to enable deformation to be uniform, each fillet is repaired to achieve deformation coordination, local heating is carried out to increase the plastic deformation degree of the easy-to-crack part, and the like. The extrusion forming of the rib plates with large height-thickness ratio in the small fillet transition, especially the U-shaped rib plates, has common difficulty. As shown in FIGS. 1-6: the fan-shaped rib plate 1 of the part 2 with the fan-shaped rib plate 1 is formed by extruding through the punch 3, the punch 3 is provided with two lower pressing blocks, a gap is formed between the two lower pressing blocks, the extruded material forms the fan-shaped rib plate 1 in the gap, but in the extrusion forming process, the defects of cracking, folding, wrinkling and the like are often generated at the part of the fan-shaped rib plate 1 (as shown in figure 6). The reason is that the inner tensile stress of the fan-shaped rib plate 1 can be formed by extrusion forming of the fan-shaped rib plate 1, the compressive stress of the middle part of the fan-shaped bottom part at the opposite corner part is large, the material is less restrained by the periphery, and the flowing speed is slightly high. If the material in the middle of the fan-shaped rib plate 1 flows fast and the material at the edge flows slowly, the top of the fan-shaped rib plate 1 is subjected to larger tensile stress, and the tensile stress generates stress concentration at the small round angle of the angle part, so that the fan-shaped rib plate is cracked firstly. Once the corner part cracks, the extruded (reversely extruded) fan-shaped rib plate 1 is difficult to generate transverse deformation.

Disclosure of Invention

According to the technical problem, the overturning forming process of the extruded fan-shaped rib plate is provided.

The technical means adopted by the invention are as follows:

a turnover forming process for an extruded fan-shaped rib plate is characterized in that in the early stage of extrusion, a notch is prepared in the middle of a material to be deformed into a rib plate part, or in the early stage of rib plate forming, the notch is processed in the middle of the rib plate, and the rib plate forming is in the period that the corner part of the rib plate is not cracked; and pressing the punch downwards to enlarge the notch, turning and transversely moving the rib plates on two sides of the notch towards two sides (so called as a turning forming method, and also called as a stress transfer method), and cutting off the part exceeding the height of the preset rib plate until the bottom of the notch exceeds the height of the preset rib plate to obtain the preset rib plate. The preset rib plates are fan-shaped rib plates with large height-thickness ratio.

Preparing a plurality of cuts according to the width of a preset rib plate, wherein the cuts are in an I shape, a V shape, a Y shape or a U shape, and the shapes of the cuts are the same or are a combination of the shapes.

The depth of the cut is 1-5 mm.

Compared with the prior art, the invention has the following advantages:

the invention aims to avoid the cracking defects of transition parts and stress concentration parts of a slow deformation area, a rapid deformation area and the like in the extrusion process of corners and the like, which cause difficulty in extrusion forming. The starting point of the invention is that the cracking defect is artificially arranged at the position with relatively severe deformation, the stress concentration position is artificially changed, because the deformation is faster, the artificially arranged cracking defect can form a bigger and bigger gap along with the deformation, the material near the opening becomes a rigid area, under the push of the subsequent deformation area material, the rigid area material inevitably rotates at a certain angle because of the different deformation speeds of the surrounding related materials, so that the edge of the artificially arranged crack at the beginning stage gradually rotates from the vertical direction to the horizontal direction, and gradually widens along with the opening of the fan-shaped rib plate, the initial rigid rotation area forms a part of the fan-shaped rib plate, the fan-shaped rib plate with larger height-thickness ratio can be formed, and the invention has important significance for extrusion forming of parts with thin-wall fan-shaped structures.

Based on the reasons, the invention can be widely popularized in the fields of rib plate extrusion forming and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a top view of a part having fan-shaped ribs according to the background of the invention.

Fig. 2 is a sectional view taken along line a-a in fig. 1.

Fig. 3 is a sectional view taken along line B-B in fig. 1.

FIG. 4 is a front view of a punch press according to the background of the invention.

FIG. 5 is a top view of a punch press according to the background of the invention.

FIG. 6 is a schematic view of a corner crack occurring in the forming process of a fan-shaped rib plate in the background art of the invention.

Fig. 7 is a schematic diagram of an initial notch (I, V, Y, U) of the extrusion/rib forming according to the embodiment of the present invention.

FIG. 8 is a schematic view of the enlargement of the punch push-down notch in an embodiment of the present invention.

FIG. 9 is a schematic view of a predetermined web being cut away a portion of a web exceeding a predetermined web height in accordance with an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the absence of any contrary indication, these directional terms are not intended to indicate and imply that the device or element so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be considered as limiting the scope of the present invention: the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

As shown in fig. 7-9, the invention provides a turnover forming process for extruding a fan-shaped rib plate, wherein in the initial stage of extrusion, a notch is prepared in the middle of a material to be deformed into a part of the fan-shaped rib plate 1, or in the initial stage of forming the fan-shaped rib plate 1 (during the period that the corner of the fan-shaped rib plate 1 is not cracked), a notch 4 is processed in the middle of the fan-shaped rib plate 1, as shown in fig. 7; the formed blank has initial defects, and the purposes of stress transfer and stress concentration part and cracking part change can be achieved.

The punch is pressed down, the notch is enlarged, and the rib plates on both sides of the notch are turned and moved laterally (so called as a turning forming method, and also called as a stress transfer method) as shown in fig. 8. Until the bottom of the notch exceeds the height of the preset fan-shaped rib plate 1. After the fan-shaped rib plate 1 is provided with the notch, due to the non-uniformity of material flow, the crack of the notch is continuously enlarged, the material in the upper area near the crack is separated from the connection with the surrounding material to form a deformation rigid area with smaller internal stress, and along with the extrusion, because the flow resistance of the material at the edge part of the fan-shaped rib plate 1 is large and the flow resistance of the deformation in the middle part is small, the deformation rigid area is enabled to turn over and move transversely, and finally the rib plate with large height-thickness ratio can be smoothly formed. Because the middle part of the fan-shaped rib plate 1 has small deformation resistance, the bottom end of the notch continuously moves upwards until the bottom end of the notch rises above the cutting line shown in figure 9.

And cutting off the part exceeding the height of the preset fan-shaped rib plate 1 to obtain the preset fan-shaped rib plate 1, as shown in figure 9.

The cut is in the form of an "I", "V", "Y" or "U" shape, as shown in FIG. 7.

A plurality of the notches 4 can be prepared according to the width of the predetermined fan-shaped rib plate 1, and the shape of the plurality of the notches 4 is the same or a combination of the shapes.

The depth of the notch 4 is 1-5 mm.

The process disclosed by the specific embodiment can avoid the cracking defects of transition parts and stress concentration parts of a slow deformation area, a rapid deformation area and the like in the extrusion process of corners and the like, so that the extrusion forming is difficult. In the specific embodiment, the cracking defect is artificially set at a position with relatively severe deformation, the stress concentration position is artificially changed, the artificially set cracking defect forms a larger and larger gap along with the deformation due to the rapid deformation at the position, the material near the opening becomes a rigid area, and under the pushing of the subsequent deformation area material, the rigid area material inevitably rotates at a certain angle due to the different deformation speeds of the surrounding related materials, so that the artificially set cracking edge gradually rotates from the vertical direction to the horizontal direction at the beginning stage and gradually widens along with the opening of the fan-shaped rib plate 1, the initial rigid rotation area forms a part of the fan-shaped rib plate 1, and the fan-shaped rib plate 1 with a larger height-thickness ratio can be formed.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A turnover forming process for an extruded fan-shaped rib plate is characterized in that a notch is prepared in the middle of a material to be deformed into a rib plate part at the early stage of extrusion, or the notch is processed in the middle of the rib plate at the early stage of rib plate forming, wherein the early stage of rib plate forming is a period that the corner part of the rib plate is not cracked; and (3) pressing the male die, expanding the notch, turning and transversely moving the rib plates on two sides of the notch to two sides until the bottom of the notch exceeds the height of the preset rib plate, and cutting off the part exceeding the height of the preset rib plate to obtain the preset rib plate.

2. The roll-over forming process for extruded U-shaped rib plates according to claim 1, wherein the predetermined rib plates are fan-shaped rib plates.

3. The roll-over forming process for extruding the U-shaped rib plate according to the claim 1 or 2, wherein the notch is in an I shape, a V shape, a Y shape or a U shape.

4. The roll-over forming process for the extrusion U-shaped rib plate according to claim 1 or 2, wherein a plurality of cuts are prepared according to the width of a preset rib plate, the cuts are in an 'I' shape, a 'V' shape, a 'Y' shape or a 'U' shape, and the shapes of the cuts are the same or are a combination of the shapes.

5. The roll-over forming process of the extruded U-shaped rib plate according to claim 1, wherein the depth of the cut is 1-5 mm.