Forming die for preventing bar from having a twin

Abstract

The utility model provides a kind of bar anti elephant leg forming die, specifically relates to powder metallurgy isostatic pressing forming technical field, to solve the technical problem of the tungsten, molybdenum bar blank obtained by existing die in the end face edge portion near upper end cover and lower end cover form " elephant leg shape " defect, reduce tungsten, molybdenum bar blank quality.The utility model includes rubber bushing, the rubber bushing is the elastic member of inside hollow, the inboard both ends of rubber bushing are respectively sealed and connected with end cover, the outer end of end cover is fixedly connected with guide conical platform, the large end of guide conical platform is fixedly connected with the end cover, the small end of guide conical platform is towards the outside of rubber bushing;The end face of the small end of guide conical platform is arranged between the outer end face of rubber bushing and the end cover.The utility model decomposes axial pressure into radial expansion force by setting guide conical platform, automatically compensates the wear gap of sealing surface, to effectively reduce the probability that tungsten, molybdenum bar blank end face edge portion forms " elephant leg shape ".

Description

Technical Field

[0001] This utility model relates to the field of powder metallurgy isostatic pressing technology, and more specifically, to a forming mold for a bar to prevent elephant legs. Background Technology

[0002] Tungsten and molybdenum rod blanks are often prepared using powder metallurgy. Tungsten and molybdenum powders are loaded into a forming mold, the open end of the mold is sealed, and the sealed mold is placed in an isostatic press with liquid as the medium for pressing and forming to obtain a tungsten rod blank. The tungsten rod blank is then sintered at high temperature to obtain a sintered tungsten and molybdenum rod blank. The tungsten and molybdenum rod blank is then rolled to obtain tungsten rod materials with higher density and more uniform structure, and then processed into various products as needed.

[0003] Existing tungsten rod forming dies use hollow rubber sleeves, with upper and lower end caps sealed at both ends by wire binding. During isostatic pressing, the upper and lower end caps, due to their rigidity, have weaker elastic contraction capacity than the rubber sleeves, making deformation during pressing more difficult. This affects the transmission of end pressure, resulting in "elephant leg" shapes on the end faces of the tungsten and molybdenum rod blanks near the upper and lower end caps, thus reducing the quality of the tungsten rods. Utility Model Content

[0004] The purpose of this utility model is to provide a forming mold for preventing tungsten rods from forming "elephant legs" at the edge of the end face near the upper and lower end caps, which can solve the technical problem of the tungsten rods obtained by existing molds forming "elephant legs" and reducing the quality of the tungsten rods.

[0005] The embodiments of this utility model are achieved through the following technical solutions: A forming mold for a rod-shaped anti-elephant leg includes a rubber sleeve, which is a hollow elastic element. End caps are sealed to both ends of the inner side of the rubber sleeve. A guide cone is fixedly connected to the outer end of each end cap. The large end of the guide cone is fixedly connected to the end cap, and the small end of the guide cone faces outwards from the rubber sleeve. The end face of the small end of the guide cone is positioned between the outer end face of the rubber sleeve and the end cap.

[0006] In some embodiments, the angle of inclination of the side of the guide cone ranges from 30° to 60°. In some embodiments, a spiral pressure groove is embedded on the side of the guide cone. In some embodiments, the guide cone is integrally formed and connected to the end cap.

[0007] In some embodiments, the guide cone and the end cap adopt a three-layer composite structure, wherein the outer layer is a hard layer, the middle layer is a buffer layer, and the inner layer is a support layer.

[0008] In some embodiments, a rigid support sleeve is fitted over the outer surface of the rubber sleeve.

[0009] In some embodiments, the rigid support sleeve has a plurality of through holes evenly distributed thereon.

[0010] In some embodiments, the distance between the outer end face of the rubber sleeve and the inner end face of the end cap is less than the distance between the outer end face of the rubber sleeve and the end face of the rigid support sleeve. In some embodiments, the outer periphery of the end cap is provided with an annular groove, and the outer side of the rubber sleeve is provided with a binding member corresponding to the annular groove. In some embodiments, an elastic sleeve is fitted between the end cap and the rubber sleeve. The elastic sleeve is a bottomed cylinder, and the bottom of the elastic sleeve is located inside the end cap. A clearance space is provided between the bottom and the end cap.

[0011] The technical solution of this utility model embodiment has at least the following advantages and beneficial effects: 1. This utility model decomposes axial pressure into radial expansion force by setting a guide cone, automatically compensating for the wear gap of the sealing surface, thereby effectively reducing the probability of "elephant leg" formation at the edge of the end face of tungsten and molybdenum rod blanks.

[0012] 2. The guide cone and end cap adopt a three-layer composite structure, with an outer hard layer, a middle buffer layer, and an inner support layer. During pressing, the outer layer first comes into contact with the high-pressure liquid and undergoes slight deformation, the middle layer buffers the pressure like a spring, and the inner corrugated steel mesh unfolds with the contraction. The combination of these three elements maintains the shape of the end cap while allowing for overall elastic contraction, thus balancing the sealing requirements of the rubber sleeve end and the end pressure transmission requirements, further reducing the probability of "elephant leg" formation at the edge of the tungsten and molybdenum billet end face. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of a forming mold for a rod-shaped anti-elephant leg provided in an embodiment of this utility model; Figure 2 This is a schematic diagram illustrating the pressure application of a forming mold for a rod-shaped anti-elephant leg, provided in an embodiment of this utility model. Figure 3 This is a schematic diagram of the internal structure of the guide cone provided in Embodiment 1 of this utility model.

[0015] Icons: 1. Rubber sleeve; 2. End cap; 3. Guide cone; 4. Spiral pressure groove; 5. Hard layer; 6. Buffer layer; 7. Support layer; 8. Rigid support sleeve; 9. Through hole; 10. Annular groove; 11. Bundling component; 12. Bottom seal; 13. Clearance space. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0018] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0019] In the description of this utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0020] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] Please see Figures 1-3 As shown, the main body of this embodiment is a forming mold for a rod-shaped anti-elephant leg, including a rubber sleeve 1. The rubber sleeve 1 is an elastic element with a hollow interior. End caps 2 are respectively sealed to the inner two ends of the rubber sleeve 1. A guide cone 3 is fixedly connected to the outer end of the end cap 2. The large end of the guide cone 3 is fixedly connected to the end cap 2, and the small end of the guide cone 3 faces the outer side of the rubber sleeve 1. The end face of the small end of the guide cone 3 is located between the outer end face of the rubber sleeve 1 and the end cap 2.

[0022] Furthermore, the side of the guide cone 3 is tilted at an angle of 60°. When the isostatic press applies pressure, it applies axial pressure to the rubber sleeve 1. Part of the liquid medium, guided by the side of the guide cone 3, is redirected to apply pressure from the inside out to the rubber sleeve 1. This causes the rubber sleeve 1 on the outer side of the end cap 2 to deform inwards, folding in the same direction as the radial pressure applied by the isostatic press. This facilitates the radial contraction of the rubber sleeve 1, effectively compensating for the pressure at the ends of the tungsten and molybdenum rods and preventing material accumulation at the ends. In other words, it decomposes the axial pressure into radial expansion force, automatically compensating for wear gaps on the sealing surface, thereby effectively reducing the probability of "elephant leg" shaped defects forming at the edge of the tungsten and molybdenum rod end face.

[0023] Furthermore, a spiral pressure groove 4 is embedded on the side of the guide cone 3. During pressing, the high-pressure liquid medium permeates through the spiral pressure guide groove 4 to the sealing contact surface between the end cap 2 and the rubber sleeve 1, forming a water film lubrication layer, which allows the end cap 2 to slide and adjust its position slightly with pressure changes.

[0024] Furthermore, the guide cone 3 is integrally formed and connected with the end cap 2.

[0025] Furthermore, the guide cone 3 and the end cap 2 adopt a three-layer composite structure, wherein the outer layer is a hard layer 5, the middle layer is a buffer layer 6, and the inner layer is a support layer 7.

[0026] The rigid layer 5 is made of polyurethane elastomer to resist external liquid pressure. The buffer layer 6 is made of silicone rubber to absorb the impact during pressing. The support layer 7 is a corrugated stainless steel mesh embedded inside the silicone rubber layer, providing skeletal support while allowing radial contraction. During pressing, the outer layer first comes into contact with the high-pressure liquid and undergoes slight deformation, the middle layer buffers the pressure like a spring, and the inner corrugated steel mesh unfolds with the contraction. The combination of these three elements maintains the shape of the end cap 2 while allowing for overall elastic contraction, thus balancing the sealing of the end of the sleeve 1 and the end pressure transmission requirements, further reducing the probability of "elephant leg" formation at the edge of the tungsten and molybdenum rod blank end face.

[0027] Furthermore, a rigid support sleeve 8 is fitted over the outside of the rubber sleeve 1.

[0028] Furthermore, the rigid support sleeve 8 has a plurality of through holes 9 evenly distributed on it.

[0029] The rigid support sleeve 8 provides support for the rubber sleeve 1, restricting radial expansion and ensuring dimensional accuracy. Multiple through holes 9 evenly arranged on the rigid support sleeve 8 allow the liquid medium to enter during pressing, facilitating pressure transmission.

[0030] Furthermore, the distance between the outer end face of the rubber sleeve 1 and the inner end face of the end cap 2 is less than the distance between the outer end face of the rubber sleeve 1 and the end face of the rigid support sleeve 8. The rigid support sleeve 8 only wraps around the body section of the rubber sleeve 1 and maintains a certain distance from the end cap 2 to ensure that it does not interfere with the sealing deformation and pressure transmission of the end cap 2.

[0031] Furthermore, the outer periphery of the end cap 2 is provided with an annular groove 10, and the outer side of the rubber sleeve 1 is provided with a binding member 11 corresponding to the annular groove 10.

[0032] The binding member 11 and the annular groove 10 work together to make the rubber sleeve 1 and the end cap 2 bonded and sealed together.

[0033] Furthermore, an elastic sleeve is fitted between the end cap 2 and the rubber sleeve 1. The elastic sleeve is a bottomed cylinder. The bottom sealing 12 of the elastic sleeve is located inside the end cap 2. A clearance space 13 is provided between the bottom sealing 12 and the end cap 2.

[0034] During pressing, the elastic bottom cover 12 replaces the rigid end cap 2 to abut against the tungsten and molybdenum rod blanks, and a clearance space 13 is provided between the bottom cover 12 and the end cap 2, so that the bottom cover 12 can achieve elastic contraction in sufficient space, making it easy to deform during pressing. This is beneficial for the transmission of pressure at the end of the tungsten and molybdenum rod blanks, thereby further reducing the probability of the edge of the end face of the tungsten and molybdenum rod blanks forming an "elephant leg" shape.

[0035] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A forming mold for preventing elephant legs from bar stock, characterized in that, Includes a rubber sleeve (1), which is an elastic element with a hollow interior. The inner two ends of the rubber sleeve (1) are respectively sealed and connected to end caps (2). The outer end of the end cap (2) is fixedly connected to a guide cone (3). The large end of the guide cone (3) is fixedly connected to the end cap (2), and the small end of the guide cone (3) faces the outside of the rubber sleeve (1). The end face of the small end of the guide cone (3) is located between the outer end face of the rubber sleeve (1) and the end cap (2).

2. The forming mold for a rod-shaped anti-elephant leg according to claim 1, characterized in that, The angle range of the side inclination of the guide cone (3) is 30°-60°.

3. The forming mold for a rod-shaped anti-elephant leg according to claim 1, characterized in that, The side of the guide cone (3) is provided with a spiral pressure groove (4).

4. The forming mold for a rod-shaped anti-elephant leg according to claim 1, characterized in that, The guide cone (3) is integrally formed and connected with the end cap (2).

5. The forming mold for a rod-shaped anti-elephant leg according to claim 4, characterized in that, The guide cone (3) and the end cap (2) adopt a three-layer composite structure, wherein the outer layer is a hard layer (5), the middle layer is a buffer layer (6), and the inner layer is a support layer (7).

6. The forming mold for a rod-shaped anti-elephant leg according to claim 1, characterized in that, The outer side of the rubber sleeve (1) is fitted with a rigid support sleeve (8); the distance between the outer end face of the rubber sleeve (1) and the inner end face of the end cap (2) is less than the distance between the outer end face of the rubber sleeve (1) and the end face of the rigid support sleeve (8).

7. The forming mold for a rod-shaped anti-elephant leg according to claim 1, characterized in that, The outer periphery of the end cap (2) is provided with an annular groove (10), and the outer side of the rubber sleeve (1) is provided with a binding member (11) corresponding to the annular groove (10).

8. The forming mold for a rod-shaped anti-elephant leg according to claim 1, characterized in that, An elastic sleeve is fitted between the end cap (2) and the rubber sleeve (1). The elastic sleeve is a bottomed cylinder. The bottom seal (12) of the elastic sleeve is located inside the end cap (2). A clearance space (13) is provided between the bottom seal (12) and the end cap (2).

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