Forming device for square hard alloy blank

Abstract

The utility model relates to a forming device for a square hard alloy blank, which is characterized in that a split assembly die is arranged on a bottom plate, a punch is arranged above the split assembly die, the split assembly die comprises a left L-shaped die frame and a right L-shaped die frame matched with the left L-shaped die frame, the left L-shaped die frame is placed in an L shape, and the right L-shaped die frame is placed in a 7 shape. The end face of the short edge of the left L-shaped mold frame is tightly attached to the inner side of the long edge of the right L-shaped mold frame, the end face of the short edge of the right L-shaped mold frame is tightly attached to the inner side of the long edge of the left L-shaped mold frame, and a square mold cavity is formed through splicing and assembling. The first magnetic stop iron is tightly attached to the outer side of the right-angle part of the left L-shaped mold frame, the third magnetic stop iron is tightly attached to the outer side of the right-angle part of the right L-shaped mold frame, and the second magnetic stop iron is tightly attached to the outer side of the joint of the end face of the short edge of the left L-shaped mold frame and the inner side of the long edge of the right L-shaped mold frame. The fourth magnetic stop iron is tightly attached to the outer side of the joint of the end face of the short edge of the right L-shaped mold frame and the inner side of the long edge of the left L-shaped mold frame, and the four magnetic stop iron fixes the two L-shaped mold frames. And the forming requirements of square blanks with different models and sizes can be met.

Description

Technical Field

[0001] This utility model relates to a forming device for a square cemented carbide billet, belonging to the field of cemented carbide product processing technology. Background Technology

[0002] Cemented carbide, often referred to as the "teeth of industry," is widely used in molds, cutting tools, and wear-resistant parts. In recent years, with the continuous expansion of its applications, the size, dimensional accuracy, and shape complexity of alloy products have become increasingly diverse, posing challenges to cemented carbide manufacturers. While cemented carbide becomes an ultra-hard material after sintering, it exists as a powder aggregate with relatively low strength in the soft blank stage. The preparation of cemented carbide soft blanks generally employs steel mold pressing or isostatic pressing processes. However, for ultra-large blanks, a complete set of molds is very expensive and lacks versatility. When the ordered specifications do not match the mold size, a new mold needs to be purchased, resulting in low powder utilization. Using steel mold pressing requires matching the appropriate pressing pressure according to the blank size, necessitating the configuration of a large-tonnage press, leading to a significant investment.

[0003] Large-scale product pressing using a single-piece steel mold results in high mold costs and requires a high-tonnage press. The mold has numerous components, including a female mold, upper and lower punches, and limiting blocks. Furthermore, due to poor venting or mold clearance issues, pressing defects such as cracks, delamination, and chipping often occur. Alternatively, a side-plate mold, consisting of four pieces joined together using a snap-fit ​​design, requires less pressing force than a single-piece steel mold, but necessitates a press with side-pressing capabilities. Considering versatility, the side plate requires multiple locking slots and multiple sets of upper and lower punches, resulting in a more complex structure and more complex assembly. While the cost of molds is slightly lower than that of overall molds, and the versatility and powder utilization of molds are improved compared to overall steel molds, certain limitations still exist. Isostatic pressing is used to make rubber or polyurethane molds, which are cheaper than steel molds, but the molds also lack versatility. During the pressing process, oil immersion may occur due to poor sheathing, leading to billet contamination or cracking. Isostatic pressing itself is a molding process with low powder utilization. The pressed billet is uneven on all six sides and requires rough leveling, resulting in a large amount of material removal and time-consuming shaping. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a forming device for cemented carbide square billets.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A forming device for a square billet of cemented carbide is characterized by: a split assembly mold on the base plate, a punch above the split assembly mold, the split assembly mold including a left L-shaped mold base and a matching right L-shaped mold base, the left L-shaped mold base being arranged in an L-shape, and the right L-shaped mold base being arranged in a number 7 shape, the short side end face of the left L-shaped mold base being close to the inner side of the long side of the right L-shaped mold base, and the short side end face of the right L-shaped mold base being close to the inner side of the long side of the left L-shaped mold base, splicing and assembling to form a square mold cavity; a first magnetic stop being close to the outer side of the right angle of the left L-shaped mold base, a third magnetic stop being close to the outer side of the right angle of the right L-shaped mold base, a second magnetic stop being close to the outer side of the junction of the short side end face of the left L-shaped mold base and the inner side of the long side of the right L-shaped mold base, and a fourth magnetic stop being close to the outer side of the junction of the short side end face of the right L-shaped mold base and the inner side of the long side of the left L-shaped mold base, the four magnetic stops fixing the two L-shaped mold bases.

[0007] Furthermore, in the above-mentioned cemented carbide square blank forming apparatus, the short side end face of the left L-shaped mold frame and the short side end face of the right L-shaped mold frame are provided with assembly blocks of the same thickness, and the end face of the assembly block is consistent with the short side end face of the mold frame.

[0008] Furthermore, in the above-mentioned cemented carbide square blank forming device, the assembly block is provided with a countersunk hole, and correspondingly, a threaded hole is opened on the short side end face of the mold frame, and the assembly block is locked to the short side end face of the mold frame by screws.

[0009] Furthermore, in the above-mentioned cemented carbide square blank forming apparatus, the magnetic surfaces of the first magnetic stop and the third magnetic stop are V-shaped surfaces.

[0010] Furthermore, in the above-mentioned cemented carbide square blank forming apparatus, the magnetic surfaces of the second magnetic stop and the fourth magnetic stop are planar.

[0011] Furthermore, in the above-mentioned cemented carbide square blank forming apparatus, one or more layers of plastic, rubber or latex film are laid on the base plate.

[0012] Furthermore, in the aforementioned forming device for cemented carbide square billets, the base plate is a steel base plate, and a lifting ring is welded to each of the four sides.

[0013] Compared with the prior art, this utility model has significant advantages and beneficial effects, specifically reflected in the following aspects:

[0014] This utility model mold has a simple structure and low manufacturing cost. Two identical L-shaped mold frames are spliced ​​together to form a square mold cavity with an internal length of L. 内 The L-shaped mold base can be freely set by moving it back and forth. Without the addition of assembly blocks, the width K of the assembled mold cavity is [not specified]. 内It is a fixed value, configured with assembly blocks to improve the versatility of the mold. It uses magnetic stops to fix it tightly to the L-shaped mold frame of the enclosure, which can meet the forming needs of square blanks of different sizes and models. There is no need to configure a large-tonnage press for pressing. The six sides of the final pressed blank are basically flat, saving pressing powder, reducing the amount of shaping and shortening the shaping time. It is easy to operate, and the whole process is carried out by hoisting, which significantly reduces the labor intensity of operators.

[0015] Other features and advantages of this invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing specific embodiments of the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0016] 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.

[0017] Figure 1 : A schematic diagram of the molding device of this utility model;

[0018] Figure 2 : Structural diagram of the base plate;

[0019] Figure 3 : Schematic diagram of the modular assembly mold;

[0020] Figure 4 : Structural diagram of the left L-shaped mold frame;

[0021] Figure 5 : A schematic diagram of a modular assembly mold with assembly blocks;

[0022] Figure 6 : Assembly diagram of the assembly block and L-shaped mold frame;

[0023] Figure 7 : Schematic diagram of the assembly block. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can be arranged and designed in various different configurations. 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 present 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.

[0025] It should be noted that similar reference numerals 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. Furthermore, in the description of this utility model, directional and ordinal terms are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] like Figures 1-4 As shown, the forming device for a square carbide billet has a steel base plate 1 with a lifting ring welded to each of its four sides. A layer or more of plastic, rubber, or latex film 2 is laid on the base plate 1. A modular assembly mold 3 is placed on top of the film. A punch 4 is located above the modular assembly mold 3. The modular assembly mold 3 includes a left L-shaped mold frame 7 and a paired right L-shaped mold frame 8. The left L-shaped mold frame 7 is arranged in an L-shape, and the right L-shaped mold frame 8 is arranged in a number 7 shape. The short side of the left L-shaped mold frame 7 is tightly attached to the inner side of the long side of the right L-shaped mold frame 8, and the short side of the right L-shaped mold frame 8 is tightly attached to the inner side of the long side of the left L-shaped mold frame 7. The mold is assembled to form... A square mold cavity; the first magnetic stop 9 is attached to the outside of the right angle of the left L-shaped mold frame 7, the third magnetic stop 11 is attached to the outside of the right angle of the right L-shaped mold frame 8, the second magnetic stop 10 is attached to the outside of the junction of the short side end face of the left L-shaped mold frame 7 and the long side inner side of the right L-shaped mold frame 8, and the fourth magnetic stop 12 is attached to the outside of the junction of the short side end face of the right L-shaped mold frame 8 and the long side inner side of the left L-shaped mold frame 7. The magnetic surfaces of the first magnetic stop 9 and the third magnetic stop 11 are V-shaped, and the magnetic surfaces of the second magnetic stop 10 and the fourth magnetic stop 12 are flat. The four magnetic stops fix the two L-shaped mold frames.

[0027] like Figures 5-7 The right L-shaped mold frame 8 has a first assembly block 13 on its short side end face, and the left L-shaped mold frame 7 has a second assembly block 14 on its short side end face. The two assembly blocks have the same thickness, and their end faces are consistent with the short side end faces of the mold frames. The assembly blocks are provided with countersunk holes, and correspondingly, threaded holes are opened on the short side end faces of the mold frames. The assembly blocks are locked to the short side end faces of the mold frames by screws.

[0028] The two L-shaped mold frames of the split assembly mold 3 are joined together to form a square mold cavity, the cavity having an internal length of L... 内 The L-shaped mold base can be freely set by moving it back and forth. Without the addition of assembly blocks, the width K of the assembled mold cavity is [not specified]. 内 It is a fixed value. To further improve the versatility of the mold, it is equipped with assembly blocks. The length of the assembly block is consistent with the height of the mold frame, and the width is consistent with the wall thickness of the mold frame. There are multiple sets, with 2 pieces in each set. The assembly block is made with countersunk holes, which are locked with the threaded holes on the L-shaped mold frame splicing surface by screws. During assembly, each L-shaped mold frame splicing surface is equipped with assembly blocks of the same thickness. This can ensure that the mold cavity is square and the fit clearance is good, thus realizing the function of forming blanks of various models and sizes.

[0029] A lifting ring 6 is welded to each of the four sides of the steel base plate 1. The steel base plate is then lifted onto the pressing table of a small-tonnage press. A layer or multiple layers of plastic, rubber, or latex film are laid on the base plate. The modular assembly mold 3 is then assembled on the film. Since the two L-shaped mold frames are identical, they are spliced ​​together to form a square mold cavity. The length, width, pressing height, and powder weight of the mold cavity are determined according to the product model and tolerances, the design modification and processing amount, and the billet density. The length of the mold cavity is determined by moving the L-shaped mold frame back and forth. The width of the mold cavity is determined by the inner width of the L-shaped mold frame and the thickness of the assembly block, taking a slightly larger value. After the mold cavity is positioned, it is fixed tightly against the L-shaped mold frame with magnetic stops. The base plate and the L-shaped mold frame are both made of steel. The magnetic surface is V-shaped or flat. Mechanical magnetization and demagnetization are used, and the material is fixed by magnetic attraction. Powder is then loaded, and a steel ruler is used to fork the powder, ensuring a relatively uniform distribution within the mold cavity, preventing powder agglomeration, and resulting in a relatively flat powder surface. Punch 4 is then inserted for pre-pressing. The punch does not need to perfectly match the mold cavity; it only needs to be able to fit. Pre-pressing does not require high pressure; a standard 40T press is sufficient. Multi-point pressing is employed to ensure the entire cavity pressing surface is under pressure. For high-quality products, multiple powder loading and pressing steps can be used. After each pressing step, a sharp metal rod is used to scratch the pressing surface before reloading and pressing again. This process aims to expel as much air as possible from the blank, ensuring a roughly flat pressing surface and simple blank shaping with a density greater than 4 g / cm³. 3 That's all.

[0030] After pre-pressing, the L-shaped mold frame is removed, and the billet is wrapped. The film is bundled up to completely enclose the billet, and vacuum heat-sealing or bundling and knotting are performed. For plastic film, vacuum heat-sealing is used, maintaining a distance of at least 5cm between the sealed area and the product (the elastic expansion effect of plastic film is generally limited, requiring increased internal volume). Rubber or latex film is sealed by bundling or knotting, without vacuuming. After sealing, the steel base plate is hoisted into the cold isostatic press cage for secondary forming. During cold isostatic pressing, the billet volume is further compressed, air is further expelled, and the billet strength is increased, meeting the requirements for subsequent transfer and shaping. The six sides after pressing are basically flat. Throughout the entire process from pre-pressing to entering the cold isostatic press cylinder, the billet is placed on the steel base plate and does not move. Therefore, even if the billet strength is low, it will not break or crumble.

[0031] During the cold isostatic pressing of pre-pressed billets, as the pressure increases, the billet will shrink under pressure, and the density of the billet will continuously increase. The air in the billet will be continuously discharged, causing the casing to bulge and posing a risk of cracking. Therefore, plastic film is used, and the sealing position should be at a certain distance from the product, leaving a certain space. Rubber or latex film is not restricted due to its good elasticity, and sealing can be done by bundling or knotting.

[0032] The steel base plate, L-shaped mold frame, magnetic stop and the places where they may come into contact with the film must be deburred to avoid cutting the film and to prevent oil immersion during the cold isostatic pressing process; only one upper punch needs to be made, hollowed out to reduce weight, and the punch size does not need to match the mold cavity, it can be placed into the cavity.

[0033] The steel base plate 1 needs to ensure the parallelism and flatness of the working surface and its parallel surfaces are controlled within 0.1mm. The surface finish of the working surface is required to be within Ra0.4. The base plate does not require heat treatment and is made of stainless steel with a thickness of 25-50mm to ensure that the base plate will not deform during pressing. Lifting rings 6 are welded around the perimeter. The lifting rings 6 must meet the overall load-bearing requirements. The maximum load-bearing capacity is determined by adding the weight of the steel base plate, the mold, and the maximum weight of the formed blank, plus more than 200Kg. The design of the steel base plate is mainly due to the large and heavy size of the blank. Manual handling requires the blank to have a certain density and strength, otherwise the blank is prone to falling or cracking. Secondly, the labor intensity of handling is high, and there is also the risk of falling or dropping. Therefore, hoisting is used throughout the process.

[0034] Two L-shaped mold frames can move back and forth, allowing for free setting of the mold cavity length. Without the assembly blocks, the mold cavity width is a fixed value. However, since the actual product width is not fixed, multiple sets of assembly blocks are configured. These blocks are secured to the L-shaped mold frames with screws before mold assembly. It is important to ensure that the dimensions of the two assembly blocks added each time are identical. The L-shaped mold frame has a simple structure, is easy to assemble, and improves powder utilization. The mold is versatile, allowing product dimensions to fluctuate within a wide range while still meeting the requirements for compact forming. The L-shaped mold frames are made of 40Cr material, with a hardness greater than 30HRC after heat treatment. The inner wall surface finish of the L-shaped mold frame is Ra0.8 or better. The gap between the two L-shaped mold frames after assembly is guaranteed to be less than 0.1mm.

[0035] In summary, the mold structure of this utility model is simple and has low manufacturing cost. Two identical L-shaped mold frames are spliced ​​together to form a square mold cavity with an internal length of L. 内 The L-shaped mold base can be freely set by moving it back and forth. Without the addition of assembly blocks, the width K of the assembled mold cavity is [not specified]. 内 It is a fixed value, configured with assembly blocks to improve the versatility of the mold. It is fixed by using magnetic stops to tightly attach to the L-shaped mold frame of the enclosure. It has strong versatility and can meet the forming needs of square blanks of different sizes. There is no need to configure a large-tonnage press for pressing. The six sides of the final pressed blank are basically flat, which can save the powder used for pressing, reduce the amount of shaping and shorten the shaping time. It is easy to operate, and the whole process is carried out by hoisting, which significantly reduces the labor intensity of operators.

[0036] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need further definition and explanation in subsequent figures.

[0037] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A forming apparatus for cemented carbide square billets, characterized in that: A split assembly mold (3) is provided on the base plate (1). A punch (4) is provided above the split assembly mold (3). The split assembly mold (3) includes a left L-shaped mold frame (7) and a right L-shaped mold frame (8) that is paired with it. The left L-shaped mold frame (7) is arranged in an L-shape, and the right L-shaped mold frame (8) is arranged in a 7-shape. The short side end face of the left L-shaped mold frame (7) is close to the inner side of the long side of the right L-shaped mold frame (8), and the short side end face of the right L-shaped mold frame (8) is close to the inner side of the long side of the left L-shaped mold frame (7). The parts are spliced ​​and assembled to form a square mold frame. The mold cavity is formed by the first magnetic stop (9) being attached to the outside of the right angle of the left L-shaped mold frame (7), the third magnetic stop (11) being attached to the outside of the right angle of the right L-shaped mold frame (8), the second magnetic stop (10) being attached to the outside of the junction of the short side end face of the left L-shaped mold frame (7) and the long side inner side of the right L-shaped mold frame (8), and the fourth magnetic stop (12) being attached to the outside of the junction of the short side end face of the right L-shaped mold frame (8) and the long side inner side of the left L-shaped mold frame (7). The four magnetic stops fix the two L-shaped mold frames.

2. The forming apparatus for cemented carbide square billets according to claim 1, characterized in that: The short side end face of the left L-shaped mold frame (7) and the short side end face of the right L-shaped mold frame (8) are equipped with assembly blocks of the same thickness, and the end face of the assembly blocks is consistent with the short side end face of the mold frame.

3. The forming apparatus for cemented carbide square billets according to claim 2, characterized in that: The assembly block has countersunk holes, and correspondingly, the short side end face of the mold frame has threaded holes. The assembly block is locked to the short side end face of the mold frame by screws.

4. The forming apparatus for cemented carbide square billets according to claim 1, characterized in that: The magnetic surfaces of the first magnetic stop (9) and the third magnetic stop (11) are V-shaped.

5. The forming apparatus for cemented carbide square billets according to claim 1, characterized in that: The magnetic surfaces of the second magnetic stop (10) and the fourth magnetic stop (12) are planar.

6. The forming apparatus for cemented carbide square billets according to claim 1, characterized in that: A layer or more of plastic, rubber or latex film is laid on the base plate (1).

7. The forming apparatus for cemented carbide square billets according to claim 1 or 6, characterized in that: The base plate (1) is a steel base plate, with a lifting ring welded to each of the four sides.

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