Isostatic combined die

Abstract

The utility model provides an isostatic pressing combined die, including outer mould, be equipped with the inner cover in the outer mould, be equipped with the inner mould in the inner cover, the inner cover is made of polyurethane soft material with the outer mould, the inner mould is alloy product, the utility model discloses a core shaft is equipped with an inner cover outside the sleeve, in the process of pressing forming, through the way of filling liquid to the annular gap between the outer periphery of core round pole and the inner periphery of inner tube to pressurize the inner tube by liquid, so that the inner tube is pressed to the inner wall of the compact, so can ensure the compaction degree of the inner and outer wall of the compact after forming, to avoid more defects after sintering, and the inner embedding ring groove and inner convex ring can improve the sealing effect, so that the liquid can not overflow from the gap between the outer ring and the first disc and the second disc, and the pressurization effect is influenced, in addition, the ring groove and the flow channel are set up and play the role of flow guide to the liquid, so that the liquid can only flow to the annular gap through the round hole.

Description

Technical Field

[0001] This utility model relates to the field of cemented carbide processing technology, and in particular to an isostatic pressing combined mold. Background Technology

[0002] Due to its high hardness, cemented carbide is difficult to machine into its shape using machine tools. Therefore, it is usually formed by compression molding followed by high-temperature sintering for alloying. However, when using this method to compress tubular workpieces, since pressure can only be applied externally, the inner circumference of the compact is often subjected to low or uneven stress, which frequently results in defects such as pores or collapses on the inner wall of the hole after sintering. Utility Model Content

[0003] This utility model provides an isostatic pressing combined mold to overcome the shortcomings of the prior art and solve the problem of uneven force on the inner and outer sides during pressing and molding, and has strong practicality.

[0004] In order to achieve the purpose of this utility model, the following technology is proposed to be adopted: An isostatic pressing combined mold includes an outer mold, an inner sleeve inside the outer mold, and an inner mold inside the inner sleeve. The inner sleeve and outer mold are made of soft polyurethane material; The inner mold is made of alloy.

[0005] Furthermore, the outer mold has a cylindrical structure, and both ends along its axial direction are open.

[0006] Furthermore, the inner sleeve includes an inner tube with openings at both ends along its axial direction. The two ends of the inner tube are connected by end plates, and an outer ring is formed on the outer periphery of the end plates. The outer periphery of the outer ring abuts against the inner periphery of the inner sleeve.

[0007] Furthermore, the inner mold includes a core rod inserted into the inner tube, with an annular gap between the outer circumference of the core rod and the inner circumference of the inner tube. One end of the core rod is formed with a screw, and the outer circumference of the screw is formed with threads. One end of the core rod is formed with a first disc, and a second disc is fitted on the screw. A through hole is coaxially opened on the second disc, and the screw passes through the through hole. A nut is threadedly connected to the screw, and the inner end of the nut abuts against the outer wall of the second disc. The first and second plates have multiple round holes; The inner walls of the first and second plates abut against the outer wall of the end plate, and the first and second plates are located within the outer ring.

[0008] Furthermore, annular grooves are formed on the inner walls of the first and second discs, and a circular hole is located at the bottom of the annular groove. Multiple flow channels are opened on the inner walls of the first and second discs. The inner end of the flow channel is connected to the annular gap between the outer circumference of the core rod and the inner circumference of the inner tube, and the outer end of the flow channel is connected to the annular groove.

[0009] Furthermore, the cross-section of the annular groove along its axial direction is an isosceles trapezoidal structure, with the bottom of the groove being the short side and the opening end being the long side.

[0010] Furthermore, the outer periphery of the first and second discs is formed with an embedded annular groove, and the inner periphery of the outer ring is formed with an inner convex ring, which is embedded in the embedded annular groove.

[0011] The advantages of the above technical solution are: This invention utilizes an inner sleeve fitted over a mandrel. During the pressing process, liquid is injected into the annular gap between the outer circumference of the mandrel and the inner circumference of the inner tube. This liquid pressurizes the inner tube, thereby pressurizing the inner wall of the pressed blank. This ensures the compaction of the inner and outer walls of the pressed blank after molding, preventing numerous defects after sintering. The embedded annular groove and inner convex ring enhance the sealing effect, preventing liquid from overflowing from the gaps between the outer ring and the first and second discs, thus affecting the pressurization effect. Furthermore, the annular groove and flow channel guide the liquid flow, ensuring that it only flows into the annular gap through the circular hole. Attached Figure Description

[0012] To make the objectives, technical solutions, and advantages of this utility model clearer, the following will provide a more detailed description of this utility model in conjunction with the accompanying drawings.

[0013] Figure 1 A three-dimensional structural diagram of one embodiment is shown.

[0014] Figure 2 A three-dimensional structural diagram of the second plate is shown.

[0015] Figure 3 A three-dimensional structural diagram of the inner mold is shown.

[0016] Figure 4 A three-dimensional structural diagram of the inner sleeve is shown.

[0017] Figure 5 A cross-sectional structural diagram of one embodiment is shown. Detailed Implementation

[0018] like Figures 1-5 As shown, an isostatic pressing combined mold includes an outer mold 3, an inner sleeve 1 inside the outer mold 3, and an inner mold 2 inside the inner sleeve 1. The inner sleeve 1 and the outer mold 3 are made of polyurethane soft material, and the inner mold 2 is an alloy product.

[0019] The outer mold 3 has a cylindrical structure, and both ends along its axial direction are open.

[0020] The inner sleeve 1 includes an inner tube 10, which is open at both ends along its axial direction. The two ends of the inner tube 10 are connected by an end plate 11, and an outer ring 12 is formed on the outer periphery of the end plate 11. The outer periphery of the outer ring 12 abuts against the inner periphery of the inner sleeve 1.

[0021] The inner mold 2 includes a core rod 20 inserted into the inner tube 10. An annular gap exists between the outer circumference of the core rod 20 and the inner circumference of the inner tube 10. One end of the core rod 20 is formed with a screw 21, the outer circumference of which is threaded. One end of the core rod 20 is formed with a first disc 22. A second disc 27 is fitted onto the screw 21. A through hole 28 is coaxially formed on the second disc 27, and the screw 21 passes through the through hole 28. A nut 29 is threadedly connected to the screw 21, and the inner end of the nut 29 abuts against the outer wall of the second disc 27. Multiple circular holes 25 are formed on the first disc 22 and the second disc 27. During connection, the inner walls of the first disc 22 and the second disc 27 abut against the outer wall of the end disc 11, and the first disc 22 and the second disc 27 are located within the outer ring 12.

[0022] The inner walls of the first plate 22 and the second plate 27 are formed with annular grooves 24. The cross-section of the annular groove 24 along its axial direction is an isosceles trapezoidal structure, with the bottom of the groove being the short side and the opening end being the long side. The circular hole 25 is located at the bottom of the annular groove 24. Multiple flow channels 26 are opened on the inner walls of the first plate 22 and the second plate 27. The inner end of the flow channel 26 is connected to the annular gap between the outer circumference of the core rod 20 and the inner circumference of the inner tube 10. The outer end of the flow channel 26 is connected to the annular groove 24.

[0023] The outer periphery of the first disc 22 and the second disc 27 is formed with an embedded annular groove 23, and the inner periphery of the outer ring 12 is formed with an inner convex ring 13, which is embedded in the embedded annular groove 23.

[0024] In this embodiment, the operator inserts the core rod 20 into the inner tube 10, and makes the inner wall of the first disc 22 abut against the outer wall of the end disc 11. Then, the second disc 27 is fitted onto the screw 21, and the nut 29 is used to make the inner walls of the first disc 22 and the second disc 27 tightly adhere to the outer wall of the end disc 11. Then, the inner sleeve 1 is partially inserted into the outer mold 3, and then sufficient alloy powder is filled into the outer mold 3. During the filling process, the inner sleeve 1 is slowly pushed inward until the filling is completed. After the filling is completed, the mold is placed in an isostatic pressing device with liquid as the medium, and then pressed and formed. During the forming process, the outside of the outer mold 3 will be subjected to equal internal pressure. During this process, the liquid will also enter the annular gap through the circular hole 25 and the flow channel 26 to press the inner circumference of the inner tube 10. This expands the stress surface of the pressed blank, makes the internal and external stress of the pressed blank uniform, and also increases the compaction density.

[0025] After pressing and forming, the operator pulls out the first disc 22, the second disc 27 and the core rod 20 from the inner sleeve 1, and then removes the outer mold 3 and pulls the inner sleeve 1 out of the blank. When pulling it out, the inner sleeve 1 needs to be squeezed and deformed to avoid damaging the blank. Both the inner sleeve 1 and the outer mold 3 are made of flexible materials, so they have the ability to deform. Moreover, they need to transmit pressure to form the blank.

[0026] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations of this utility model fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An isostatic pressing combined mold, characterized in that, Includes an outer mold (3), an inner sleeve (1) is provided inside the outer mold (3), and an inner mold (2) is provided inside the inner sleeve (1); The inner sleeve (1) and the outer mold (3) are made of polyurethane soft material; The inner mold (2) is an alloy product; The inner sleeve (1) includes an inner tube (10), which is open at both ends along its axial direction. The two ends of the inner tube (10) are connected by an end plate (11), and an outer ring (12) is formed on the outer periphery of the end plate (11). The outer periphery of the outer ring (12) abuts against the inner periphery of the inner sleeve (1). The inner mold (2) includes a core rod (20) that passes through the inner tube (10). There is an annular gap between the outer periphery of the core rod (20) and the inner periphery of the inner tube (10). One end of the core rod (20) is formed with a screw (21). The outer periphery of the screw (21) is formed with threads. One end of the core rod (20) is formed with a first disc (22). A second disc (27) is sleeved on the screw (21). A through hole (28) is coaxially opened on the second disc (27). The screw (21) passes through the through hole (28). A nut (29) is connected to the screw (21) by threads. The inner end of the nut (29) abuts against the outer wall of the second disc (27). Multiple round holes (25) are provided on the first plate (22) and the second plate (27); The inner walls of the first plate (22) and the second plate (27) abut against the outer wall of the end plate (11), and the first plate (22) and the second plate (27) are located inside the outer ring (12).

2. The isostatic pressing combined mold according to claim 1, characterized in that, The outer mold (3) has a cylindrical structure and both ends along its axial direction are open.

3. The isostatic pressing combined mold according to claim 1, characterized in that, The inner walls of the first plate (22) and the second plate (27) are formed with annular grooves (24), and the circular hole (25) is located at the bottom of the annular groove (24). Multiple flow channels (26) are opened on the inner walls of the first plate (22) and the second plate (27). The inner end of the flow channel (26) is connected to the annular gap between the outer periphery of the core rod (20) and the inner periphery of the inner tube (10). The outer end of the flow channel (26) is connected to the annular groove (24).

4. The isostatic pressing combined mold according to claim 2, characterized in that, The cross section of the annular groove (24) along its axial direction is an isosceles trapezoidal structure, with the bottom of the groove being the short side and the opening end being the long side.

5. The isostatic pressing combined mold according to claim 1, characterized in that, The outer periphery of the first plate (22) and the second plate (27) is formed with an embedded ring groove (23), and the inner periphery of the outer ring (12) is formed with an inner convex ring (13), which is embedded in the embedded ring groove (23).

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