Die for isostatic pressing and isostatic pressing equipment

Abstract

The utility model discloses a die for isostatic pressing forming and isostatic pressing forming equipment. The technical problems that an elastic pipe body of an internal expansion type die is difficult to fix and operate and poor in sealing effect are solved. The mold comprises an outer mold body, an inner mold body and an end supporting structure, and an annular cavity filled with metal powder is formed between the outer mold body and the inner mold body. The outer mold comprises a rigid pipe body; the inner mold comprises an elastic pipe body and a porous supporting cylinder, and the porous supporting cylinder is arranged on the inner side of the elastic pipe body; the length of the elastic pipe body is matched with that of the rigid pipe body; the end supporting structure comprises an elastic annular inserting groove matched with the total wall thickness of the rigid pipe body, the tubular blank body and the elastic pipe body. The end supporting structure further comprises a threaded steel sleeve and a threaded steel plug which are arranged at the two ends of the porous supporting cylinder and are in threaded connection, and the outer wall of the threaded steel sleeve is welded to the porous supporting cylinder. The threaded steel plug is provided with a hydraulic medium flowing channel; and the outer diameter of the threaded steel plug is matched with the inner diameter of the inner wall of the elastic annular slot.

Description

Technical Field

[0001] The utility model relates to the technical field of metal filter tube green body preparation and isostatic pressing, in particular to an isostatic pressing mold and isostatic pressing equipment. Background Art

[0002] The metal powder is pressed into a green body, and then the green body is sintered to obtain a rigid metal filter tube. Among them, the most commonly used method for metal powder molding is isostatic pressing technology. Isostatic pressing technology uses static liquid or gas as a medium to transmit pressure, and the use of molding molds is indispensable in the molding process. Isostatic pressing technology has special requirements for molding molds, including sufficient elasticity and shape retention, high tensile crack resistance and wear resistance, good demolding performance, and long service life. According to the force direction of the metal powder during the pressing process, the molding mold can be divided into external pressure mold and internal expansion mold.

[0003] The mold disclosed in Chinese utility model patent CN201784027U is an external pressure mold, whose inner mold is a solid steel rod and the outer mold is an elastic tube. The metal powder filled between the inner mold and the outer mold is squeezed from the outside to the inside by the elastic tube and finally pressed into shape. It is difficult to demold the external pressure mold, and pits are easily formed on the outer wall of the green body due to the deformation of the elastic tube, resulting in an uneven surface of the metal filter tube. The outer surface of the metal filter tube is the most commonly used filtering surface. If the surface is uneven, it is easy to cause impurities to accumulate, affecting the service life.

[0004] The inner mold of the internal expansion mold is a support tube and an elastic tube body, and the outer mold is a rigid tube body. The metal powder filled between the inner mold and the outer mold is squeezed from the inside to the outside by the elastic tube body and finally pressed into shape. The internal expansion mold is easier to demold than the external pressure mold. The outer surface of the green body obtained by processing the internal expansion mold is smooth, not easy to adhere to impurities, and easy to backblow or clean. However, the operation of fixing the elastic tube body is cumbersome, and it is difficult to ensure high sealing. For example, the mold disclosed in Chinese utility model patent CN201784027U is an internal expansion mold, which fixes the elastic tube body by making the end of the elastic tube body extend out of the end cover and then fold back and press it. For thicker elastic tube bodies, the folding operation is very difficult, and the sealing effect is poor and the service life is short. Utility Model Content

[0005] The main purpose of the utility model is to provide an isostatic pressing mold, an isostatic pressing device and a method for preparing a metal filter tube blank, so as to solve the technical problems of the difficult operation of fixing the elastic tube body and the poor sealing effect of the internal expansion mold in the prior art.

[0006] In order to achieve the above purpose, the utility model first provides two isostatic pressing molds, and the technical solutions are as follows:

[0007] The first isostatic pressing mold is used to press metal powder into a tubular blank, the mold includes an outer mold, an inner mold and an end support structure, an annular cavity filled with metal powder is formed between the outer mold and the inner mold; the outer mold includes a rigid tube body; the inner mold includes an elastic tube body and a porous support cylinder, and the porous support cylinder is arranged on the inner side of the elastic tube body; the end support structure is used to seal and fix the two ends of the mold after the metal powder is filled; the length of the elastic tube body is adapted to the length of the rigid tube body; the end support structure includes an elastic annular slot adapted to the total wall thickness of the rigid tube body, the tubular blank and the elastic tube body; the end support structure also includes a threaded steel sleeve and a threaded steel plug arranged at both ends of the porous support cylinder and threadedly connected, the outer wall of the threaded steel sleeve is welded to the porous support cylinder; the threaded steel plug has a hydraulic medium flow channel; the outer diameter of the threaded steel plug is adapted to the inner diameter of the inner wall of the elastic annular slot.

[0008] As a further improvement of the above-mentioned first isostatic pressing mold: at least three rows of through holes are symmetrically distributed on the porous support cylinder, the diameter of the through holes is 5 to 15 mm, and the axial spacing of the through holes is 25 to 45 mm.

[0009] As a further improvement of the above-mentioned first isostatic pressing mold: the threaded steel plug has a first tube body and a second tube body, the outer wall of the first tube body is threadedly connected to the outer wall of the threaded steel sleeve, the outer diameter of the second tube body is adapted to the inner diameter of the inner wall of the elastic annular slot, and a hexagonal bolt hole is provided in the second tube body.

[0010] As a further improvement of the above-mentioned first isostatic pressing mold: the length of the porous support tube is adapted to the length of the tubular blank.

[0011] As a further improvement of the above-mentioned first isostatic pressing mold: the total length of the porous support tube and the threaded steel plug after being connected is adapted to the length of the rigid tube body and the elastic tube body.

[0012] As a further improvement of the above-mentioned first isostatic pressing mold: the end support structure also includes rubber plugs arranged at both ends of the annular cavity, the wall thickness of the rubber plugs is adapted to the wall thickness of the tubular blank, and the total length of the rubber plug and the tubular blank is adapted to the length of the rigid tube body and the elastic tube body.

[0013] As a further improvement of the above-mentioned first isostatic pressing mold: the end support structure also includes: an inner support cylinder, the inner and outer diameters of the inner support cylinder are adapted to the inner and outer diameters of the porous support cylinder; an outer support cylinder, the inner diameter of the outer support cylinder is adapted to the outer diameter of the rigid tube body; the elastic annular slot is formed between the outer support cylinder and the inner support cylinder; an end support surface, the inner edge and outer edge of the end support surface are respectively connected to the inner support cylinder and the outer support cylinder.

[0014] As a further improvement of the above-mentioned first isostatic pressing mold: the length of the inner support tube is adapted to the length of the rubber plug.

[0015] The second isostatic pressing mold is used to press metal powder into a tubular blank, the mold includes an outer mold, an inner mold and an end support structure, an annular cavity filled with metal powder is formed between the outer mold and the inner mold; the outer mold includes a rigid tube body; the inner mold includes an elastic tube body and a porous support tube, and the porous support tube is arranged on the inner side of the elastic tube body; the end support structure is used to seal and fix the two ends of the mold after the metal powder is filled; the wall thickness of the elastic tube body is ≥2mm; the length of the elastic tube body is adapted to the length of the rigid tube body; the end support structure includes: an inner support tube, the inner and outer diameters of the inner support tube are adapted to the inner and outer diameters of the porous support tube; an outer support tube, the inner diameter of the outer support tube is adapted to the outer diameter of the rigid tube body; an elastic annular slot adapted to the total wall thickness of the rigid tube body, the tubular blank and the elastic tube body is formed between the outer support tube and the inner support tube; an end support surface, the inner edge and outer edge of the end support surface are respectively connected to the inner support tube and the outer support tube.

[0016] As a further improvement of the above-mentioned second isostatic pressing mold: the outer support tube is longer than the inner support tube; the end support structure also includes a tape or a clamp adapted to the outer diameter of the outer support tube.

[0017] As a further improvement of the above-mentioned second isostatic pressing mold: the length of the inner support tube is 30 to 40 mm, and the outer support tube is 15 to 25 mm longer than the inner support tube.

[0018] As a further improvement of the above-mentioned second isostatic pressing mold: the elastic tube body is made of polyurethane and has a thickness of 2 to 5 mm.

[0019] As a further improvement of the above-mentioned second isostatic pressing mold: the total length of the inner support tube and the porous support tube is adapted to the length of the rigid tube body and the elastic tube body.

[0020] As a further improvement of the above-mentioned second isostatic pressing mold: the end support structure also includes rubber plugs arranged at both ends of the annular cavity, the wall thickness of the rubber plugs is adapted to the wall thickness of the tubular blank, and the total length of the rubber plug and the tubular blank is adapted to the length of the rigid tube body and the elastic tube body; the length of the inner support tube is adapted to the length of the rubber plug.

[0021] As a further improvement of the above-mentioned second isostatic pressing mold: at least three rows of through holes are symmetrically distributed on the porous support tube, the diameter of the through holes is 5 to 15 mm, and the axial spacing of the through holes is 25 to 45 mm.

[0022] As a further improvement of the above-mentioned second isostatic pressing mold: the end support structure also includes a threaded steel sleeve and a threaded steel plug which are arranged at both ends of the porous support tube and are threadedly connected. The outer wall of the threaded steel sleeve is welded to the porous support tube, and the threaded steel plug has a hydraulic medium flow channel; the outer diameter of the threaded steel plug is adapted to the inner diameter of the inner support tube.

[0023] In order to achieve the above purpose, the utility model secondly provides an isostatic pressing device, and the technical solution is as follows:

[0024] The isostatic pressing equipment comprises any one of the above-mentioned isostatic pressing dies.

[0025] In order to achieve the above object, the utility model further provides a method for preparing a green metal filter tube, and the technical scheme is as follows:

[0026] The method for preparing a metal filter tube green body comprises the steps of: using the above-mentioned isostatic pressing equipment to press metal powder into a tubular metal filter tube green body.

[0027] The isostatic pressing mold, isostatic pressing equipment and preparation method of the metal filter tube blank of the utility model have the following advantages: first, the end support structure has an elastic annular slot adapted to the total wall thickness of the rigid tube body, the tubular blank and the elastic tube body, which can realize the rapid positioning and installation of the elastic tube body. Secondly, the end support structure has a threaded steel sleeve and a threaded steel plug, and the outer diameter of the threaded steel plug is adapted to the inner diameter of the inner wall of the elastic annular slot, which can make the elastic annular slot more stable and improve the sealing effect. In addition, the outer wall of the threaded steel sleeve is welded to the porous support tube, the threaded steel sleeve and the threaded steel plug, which is convenient for quick assembly. It can be seen that the isostatic pressing mold of the utility model has a simple structure, and the sealing operation at both ends of the elastic tube body is convenient and has a good sealing effect. It effectively solves the technical problems of the difficult operation of fixing the elastic tube body and the poor sealing effect of the internal expansion mold in the prior art, and has strong practicality.

[0028] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of the present invention are used to assist the understanding of the present invention. The contents provided in the drawings and their related descriptions in the present invention can be used to explain the present invention, but do not constitute an improper limitation on the present invention.

[0030] In the attached picture:

[0031] Figure 1It is a schematic structural diagram of an embodiment of the isostatic pressing mold of the utility model.

[0032] Figure 2 It is a schematic structural diagram of an elastic annular slot in an embodiment of an isostatic pressing die of the utility model.

[0033] Figure 3 It is a schematic structural diagram of a threaded steel plug in an embodiment of an isostatic pressing die of the utility model.

[0034] The relevant marks in the above drawings are:

[0035] 100-rigid tube body, 210-elastic tube body, 220-porous support cylinder, 221-through hole, 300-annular cavity, 400-elastic annular slot, 410-inner support cylinder, 420-outer support cylinder, 430-end support surface, 510-threaded steel sleeve, 520-threaded steel plug, 521-first tube body, 522-second tube body, 523-hydraulic medium flow channel, 524-hexagonal bolt hole, 600-rubber plug, 700-winding fixing mechanism. DETAILED DESCRIPTION

[0036] The utility model is described clearly and completely below in conjunction with the accompanying drawings. A person skilled in the art will be able to implement the utility model based on these descriptions. Before describing the utility model in conjunction with the accompanying drawings, it should be particularly noted that:

[0037] The technical solutions and technical features provided in each part of the utility model, including the following description, can be combined with each other if there is no conflict.

[0038] In addition, the embodiments of the present invention involved in the following description are generally only a part of the embodiments of the present invention, rather than all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0039] About the terms and units in the present invention: The terms "include", "have" and any variations thereof in the specification and claims of the present invention and related parts are intended to cover non-exclusive inclusions.

[0040] Figure 1 It is a schematic structural diagram of an embodiment of the isostatic pressing mold of the utility model. Figure 2 It is a schematic structural diagram of an elastic annular slot in an embodiment of an isostatic pressing die of the utility model. Figure 3 It is a schematic structural diagram of a threaded steel plug in an embodiment of an isostatic pressing die of the utility model.

[0041] like Figure 1-3 The isostatic pressing mold shown is used to press metal powder into a tubular blank, and the mold includes an outer mold, an inner mold and an end support structure, and an annular cavity 300 filled with metal powder is formed between the outer mold and the inner mold; the outer mold includes a rigid tube body 100; the inner mold includes an elastic tube body 210 and a porous support tube 220, and the porous support tube 220 is arranged on the inner side of the elastic tube body 210; the end support structure is used to seal and fix the two ends of the mold after the metal powder is filled.

[0042] At least three rows of through holes 221 are symmetrically distributed on the porous support tube 220 . The diameter of the through holes 221 is 5 to 15 mm, and the axial spacing of the through holes 221 is 25 to 45 mm. This can make the elastic tube 210 more evenly stressed.

[0043] The elastic tube body 210 is made of polyurethane and has a thickness of 2 to 5 mm. When the elastic tube body 210 is very thin, although the hydraulic pressure can be reduced, a depression is formed on the inner surface of the green body opposite to the through hole 221 of the porous support tube 220. When the elastic tube body 210 is very thick, although the formation of the depression will be reduced, the hydraulic pressure will be increased.

[0044] First, the end support structure includes an elastic annular slot 400 adapted to the total wall thickness of the rigid tube body 100, the tubular blank and the elastic tube body 210; specifically, the end support structure includes an inner support cylinder 410, an outer support cylinder 420 and an end support surface 430; the inner diameter of the outer support cylinder 420 is adapted to the outer diameter of the rigid tube body 100; the elastic annular slot 400 is formed between the outer support cylinder 420 and the inner support cylinder 410; the inner edge and outer edge of the end support surface 430 are respectively connected to the inner support cylinder 410 and the outer support cylinder 420.

[0045] Secondly, the end support structure also includes a threaded steel sleeve 510 and a threaded steel plug 520 which are arranged at both ends of the porous support cylinder 220 and are threadedly connected. The outer wall of the threaded steel sleeve 510 is welded to the porous support cylinder 220; the threaded steel plug 520 has a hydraulic medium flow channel 523.

[0046] Furthermore, the end support structure also includes rubber plugs 600 provided at both ends of the annular cavity 300, and the wall thickness of the rubber plugs 600 is adapted to the wall thickness of the tubular blank. Depending on the specific shape of the green body, the wall thickness of the rubber plugs 600 at both ends of the annular cavity 300 can be the same or different.

[0047] The threaded steel plug 520 comprises a first tube body 521 and a second tube body 522, the outer wall of the first tube body 521 is threadedly connected to the outer wall of the threaded steel sleeve 510, the outer diameter of the second tube body 522 is adapted to the inner diameter of the inner wall of the elastic annular slot 400, and a hexagonal bolt hole 524 is provided in the second tube body 522. Such a threaded steel plug 520 has a better fit with the inner wall of the elastic annular slot 400 (i.e., the inner support cylinder 410), and has a better fixing and sealing effect.

[0048] Each component of the mold has special size requirements, specifically: the length of the elastic tube body 210 is adapted to the length of the rigid tube body 100, the total length of the rubber plug 600 and the tubular blank is adapted to the length of the rigid tube body 100 and the elastic tube body 210, the length of the porous support tube 220 is adapted to the length of the tubular blank, the inner and outer diameters of the inner support tube 410 are adapted to the inner and outer diameters of the porous support tube 220, the length of the inner support tube 410 is adapted to the length of the rubber plug 600, the total length of the inner support tube 410 and the porous support tube 220 is adapted to the length of the rigid tube body 100 and the elastic tube body 210, the total length after the porous support tube 220 and the threaded steel plug 520 are connected is adapted to the length of the rigid tube body 100 and the elastic tube body 210, the outer diameter of the threaded steel plug 520 is adapted to the inner diameter of the inner wall of the elastic annular slot 400, so that the end support structure assembled in this way has the best sealing performance.

[0049] The end support structure also includes a winding and fixing mechanism 700 adapted to the outer diameter of the outer support tube 420. The winding and fixing mechanism 700 is a tape or a clamp. The outer support tube 420 is longer than the inner support tube 410. The tape or clamp acts on the portion of the outer support tube 420 that exceeds the inner support tube 410, which can achieve a better fixing effect. The length of the inner support tube 410 is 30 to 40 mm, and the outer support tube 420 is 15 to 25 mm longer than the inner support tube 410. At this time, the fixing and sealing effects are the best.

[0050] In addition to being smooth and free of burrs, having uniform wall thickness, and being free of defects such as cracks, it is preferred that the hardness of the rigid tube body 100 is heat-treated HRC50-55, the hardness of the elastic tube body 210, the elastic annular slot 400 and the rubber plug 600 is plastic Shore hardness HSA70-75, and the hardness of the porous support tube 220, the threaded steel sleeve 510 and the threaded steel plug 520 is heat-treated HRC40-45.

[0051] The embodiment of the isostatic pressing device of the utility model has the above-mentioned isostatic pressing mold. When the mold is used, first assemble one end of the mold, then fill the annular cavity 300 with metal powder (usually with adhesive), and then assemble the other end of the mold to complete the assembly of the mold. Connect the hexagonal bolt holes 524 at both ends of the assembled mold to the hydraulic medium pipeline, and then perform isostatic pressing.

[0052] The embodiment of the method for preparing the metal filter tube green body of the present invention comprises the steps of: using the above-mentioned isostatic pressing equipment to press metal powder into a tubular metal filter tube green body, and then sintering the green body to obtain the metal filter tube.

[0053] The above is an explanation of the relevant contents of the utility model. A person skilled in the art will be able to implement the utility model based on these explanations. Based on the above contents of the utility model, all other embodiments obtained by a person skilled in the art without creative work shall fall within the scope of protection of the utility model.

Claims

1. An isostatic pressing mold, used for pressing metal powder into a tubular blank, the mold comprising an outer mold, an inner mold and an end support structure, an annular cavity (300) filled with metal powder is formed between the outer mold and the inner mold; the outer mold comprises a rigid tube body (100); the inner mold comprises an elastic tube body (210) and a porous support cylinder (220), the porous support cylinder (220) being arranged on the inner side of the elastic tube body (210); the end support structure is used for sealing and fixing the two ends of the mold after the metal powder is filled; it is characterized in that: The length of the elastic tube (210) matches the length of the rigid tube (100); The end support structure comprises an elastic annular slot (400) adapted to the total wall thickness of the rigid tube body (100), the tubular blank and the elastic tube body (210); The end support structure also includes a threaded steel sleeve (510) and a threaded steel plug (520) which are arranged at both ends of the porous support cylinder (220) and are threadedly connected. The outer wall of the threaded steel sleeve (510) is welded to the porous support cylinder (220); the threaded steel plug (520) has a hydraulic medium flow channel (523); and the outer diameter of the threaded steel plug (520) is adapted to the inner diameter of the inner wall of the elastic annular slot (400).

2. The isostatic pressing mold according to claim 1, wherein: At least three rows of through holes (221) are symmetrically distributed on the porous support cylinder (220), the diameter of the through holes (221) is 5 to 15 mm, and the axial spacing of the through holes (221) is 25 to 45 mm.

3. The isostatic pressing mold according to claim 1, wherein: The threaded steel plug (520) comprises a first tube body (521) and a second tube body (522), wherein the outer wall of the first tube body (521) is threadedly connected to the outer wall of the threaded steel sleeve (510), the outer diameter of the second tube body (522) is adapted to the inner diameter of the inner wall of the elastic annular slot (400), and a hexagonal bolt hole (524) is provided in the second tube body (522).

4. The isostatic pressing mold according to claim 1, wherein: The length of the porous support tube (220) is adapted to the length of the tubular blank.

5. The isostatic pressing mold according to claim 1, wherein: The total length of the porous support tube (220) and the threaded steel plug (520) after being connected is adapted to the length of the rigid tube body (100) and the elastic tube body (210).

6. The isostatic pressing mold according to claim 1, wherein: The end support structure also includes rubber plugs (600) arranged at both ends of the annular cavity (300), the wall thickness of the rubber plug (600) is adapted to the wall thickness of the tubular blank, and the total length of the rubber plug (600) and the tubular blank is adapted to the length of the rigid tube body (100) and the elastic tube body (210).

7. The isostatic pressing die according to claim 6, wherein: The end support structure also includes: An inner support tube (410), wherein the inner and outer diameters of the inner support tube (410) are adapted to the inner and outer diameters of the porous support tube (220); An outer support tube (420), the inner diameter of which is adapted to the outer diameter of the rigid tube body (100); the elastic annular slot (400) is formed between the outer support tube (420) and the inner support tube (410); An end support surface (430), wherein the inner edge and the outer edge of the end support surface (430) are respectively connected to the inner support tube (410) and the outer support tube (420).

8. The isostatic pressing mold according to claim 7, wherein: The length of the inner support tube (410) is adapted to the length of the rubber stopper (600).

9. The isostatic pressing mold according to claim 7, wherein: The outer support tube (420) is longer than the inner support tube (410).

10. Isostatic pressing equipment, characterized in that: A mold according to any one of claims 1 to 9.

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