Powder vacuum isostatic pressing forming process device and using method

Abstract

The powder vacuum isostatic pressing forming process device comprises a rubber mold used for containing powder, a filter felt is laid on the upper layer of the powder in the rubber mold, an air exhaust plug is installed at the opening end of the upper end of the rubber mold, the lower end of the air exhaust plug is inserted into the rubber mold, and a hoop is installed on the outer side of the rubber mold. And the hoop is positioned at the joint of the air exhaust plug and the rubber mold. Compared with the prior art, the internal structure of the powder material isostatic pressing forming device is simplified, meanwhile, the sealing reliability is improved, meanwhile, compared with an existing mode, the operation steps are reduced, and the powder material isostatic pressing forming device is suitable for mass production.

Description

Technical Field

[0001] The invention relates to the technical field of isostatic pressing of powder materials, and in particular to a powder vacuum isostatic pressing process device and a use method thereof. Background Art

[0002] The isostatic pressing process is a mature powder material forming process, and its main means is: wrapping the powder material in an elastic rubber mold 2, immersing them together in an ultra-high pressure liquid medium (hereinafter referred to as pressure medium) and maintaining them for a certain period of time, so as to obtain a dense and uniform product.

[0003] In order to improve the qualified rate of products, the isostatic pressing process device should have the following two characteristics. First, it should have good external ultra-high pressure sealing, so that the ultra-high pressure liquid cannot leak into the rubber mold during the forming process to prevent contamination of the product. Second, it should have the function of internal vacuuming to remove the air in the semi-finished product and avoid defects such as bubbles and pores in the product.

[0004] In traditional technology, since the isostatic pressing process equipment needs to take into account both external ultra-high pressure sealing and internal vacuum extraction at the same time, it often has disadvantages such as complex valve structure, limited maximum working pressure, and cumbersome operation, which greatly restricts mass production. Summary of the invention

[0005] In view of this, the present invention proposes a powder vacuum isostatic pressing process device and a use method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A powder vacuum isostatic pressing process device comprises a rubber mold for containing powder, a filter felt is laid on the upper layer of the powder in the rubber mold, an exhaust plug is installed at the upper open end of the rubber mold, the lower end of the exhaust plug is inserted into the rubber mold, a clamp is installed on the outer side of the rubber mold, and the clamp is located at the junction of the exhaust plug and the rubber mold.

[0008] As a further improvement of the above technical solution:

[0009] Preferably, the vacuum plug includes a plug body with a stepped cross-section and a through inner hole in the middle, an external sealing valve arranged at the upper end of the inner hole of the plug body, a baffle plate arranged at the lower end of the inner hole of the plug body, a baffle spring arranged between the upper end of the baffle plate and the lower end of the inner hole of the plug body, and an vacuum nozzle installed on the side of the plug body, and the air hole on the vacuum nozzle is connected to the inner hole of the plug body.

[0010] Preferably, an O-ring is provided between the outer sealing valve and the plug body.

[0011] Preferably, the outer edge of the lower end of the plug body is provided with a chamfer, and a transition rubber ring is provided at the chamfer.

[0012] Preferably, the cross section of the baffle plate is composed of a lower conical surface and an upper cylindrical surface, the lower end of the inner hole of the plug body matches the shape of the baffle plate to form a sealing pair, and the baffle spring is located at the upper end of the cylindrical surface.

[0013] Preferably, the external sealing valve comprises a valve stem connected to the plug body and a valve core arranged at the lower end of the valve stem.

[0014] Preferably, the bottom of the lower end of the valve stem is a concave spherical surface with a mounting hole arranged in the center of the concave spherical surface, the upper part of the valve core is a convex spherical surface matching the bottom of the valve stem, and a cylinder matching the mounting hole is arranged in the center of the convex spherical surface.

[0015] Preferably, a bushing is sleeved on the cylinder on the valve core.

[0016] Preferably, the valve stem is threadedly connected to the plug body.

[0017] The present invention also discloses a method for using a powder vacuum isostatic pressing process device, comprising the following steps:

[0018] Step 1. Put a certain amount of powder to be molded into the rubber mold, scrape the top of the powder flat, and then lay the filter felt flat on the top of the powder;

[0019] Step 2. Install the vacuum plug without the external sealing valve into the upper end of the rubber mold, then install the clamp and tighten it, and then screw the external sealing valve into the plug body, but do not tighten it completely;

[0020] Step 3. Connect the vacuum hose to the vacuum nozzle, turn on the vacuum system to extract the air in the rubber mold. When the vacuum degree of the rubber mold reaches the specified value of the process, the conical surface of the baffle plate fits with the conical surface of the body under the action of air pressure, and the inside and outside of the rubber mold are sealed;

[0021] Step 4. Tighten the outer sealing valve, close the vacuum system, and remove the vacuum hose;

[0022] Step 5, put the whole device into the isostatic pressing equipment and form it according to the process parameters;

[0023] Step 6. After molding, take out the device, remove the external sealing valve, clamp, vacuum plug and filter felt in turn, and finally take the molded workpiece out of the rubber mold.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] Compared with the prior art, the present invention simplifies the internal structure of the powder material isostatic pressing device, improves the reliability of the seal, and reduces the operating steps compared with the existing method, which is conducive to mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the air extraction plug of the present invention;

[0028] Figure 3 It is a schematic diagram of the main structure of the present invention;

[0029] Figure 4 It is a schematic diagram of the structure of the external sealing valve of the present invention.

[0030] In the figure: 1. vacuum plug; 2. rubber mold; 3. filter felt; 4. clamp; 101. body; 102. external sealing valve; 103. O-ring; 104. baffle plate; 105. baffle spring; 106. transition rubber ring; 107. vacuum nozzle; 108. valve stem; 109. valve core; 110. bushing. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] As attached Figure 1 As shown, the technical solution includes four parts, including: an exhaust plug 1, a rubber mold 2, a filter felt 3, and a clamp 4.

[0035] The rubber mold 2 contains powder to be molded, the top layer of the powder is covered with filter felt 3, the vacuum plug 1 is installed at the mouth of the rubber mold 2, and its lower half is wrapped in the rubber mold 2. The clamp 4 is installed at the joint of the vacuum plug 1 and the rubber mold 2, and the joint can be sealed after tightening.

[0036] As attached Figure 2 With attached Figure 3 As shown, the air extraction plug 1 includes a plug body 101, an external sealing valve 102, an O-ring 103, a baffle plate 104, a baffle spring 105, a transition rubber ring 106, and an air extraction nozzle 107;

[0037] The basic structure of the air extraction plug 1 is as follows: the plug body 101 is the main component of the air extraction plug 1, the outer sealing valve 102 is installed on the upper side of the plug body 101, that is, the pressure medium side, the baffle plate 104 and the baffle spring 105 are installed on the side of the plug body 101 close to the filter felt 3, that is, the inner side of the mold. The air extraction nozzle 107 is installed on the side of the plug body 101.

[0038] There is a group of inner holes that pass through from top to bottom inside the plug body 101. The inner holes have sealing ring grooves, threads, outer cones, inner cones and other structures from top to bottom. The inner holes are used to install O-rings 103, external sealing valves 102, and baffle plates 104. The outer cone and the inner cone are in contact with the corresponding cones of the external sealing valve 102 and the baffle plate 104 to achieve sealing. A threaded hole is provided on the side of the plug body 101 for installing the suction nozzle 107. There is a small hole connecting the threaded hole and the above-mentioned inner hole. There is a chamfer at the bottom of the plug body 101. The diameter of the large end is the same as the inner diameter of the rubber mold 2, and the diameter of the small end is the same as the diameter after the powder is formed. The transition rubber ring 106 is a rubber ring with a triangular cross-section, and its inner cone is coated with glue and bonded to the chamfered surface of the lower part of the plug body 101.

[0039] The baffle plate 104 and the baffle spring 105 are installed at the lower part of the inner hole of the plug body 101. The upper part of the baffle plate 104 is a conical surface, which cooperates with the inner conical surface of the inner hole of the plug body 101 to form a sealing pair; a truncated cone is provided at the upper part of the baffle plate, and the baffle spring 105 is assembled on the truncated cone and installed together at the lower part of the inner hole of the plug body 101. Under the condition of no external load, the baffle spring 105 can lift the baffle plate 104, so that the conical surface of the baffle plate 104 is separated from the conical surface of the plug body 101, and the inside and outside of the rubber mold 2 are connected; when the vacuum degree of the rubber mold 2 reaches the specified value of the process, the conical surface of the baffle plate 104 fits with the conical surface of the plug body 101 under the action of air pressure, and the inside and outside of the rubber mold 2 are sealed.

[0040] As attached Figure 4As shown, the external sealing valve 102 includes: a valve core 109, a valve stem 108, and a bushing 110. The valve stem 108 has threads on the outside, which are screwed with the inner hole threads of the plug body 101. The bottom of the valve stem 108 is a concave spherical surface, and there is a small hole in the center of the spherical surface. The small hole, the spherical surface, and the threads of the valve stem 108 are all coaxial. The lower part of the valve core 109 is a conical surface, which cooperates with the outer conical surface of the inner hole of the plug body 101 to form a sealing pair; the upper part of the valve core 109 is a convex spherical surface, which has the same radius as the concave spherical surface of the valve stem 108, and there is a cylinder in the center of the convex spherical surface. The conical surface, convex spherical surface, and cylinder of the valve core 109 are all coaxial. The bushing 110 is made of engineering plastic material, which has certain elasticity and self-lubricating properties. The bushing 110 is mounted on the cylinder of the valve core 109, and its outer circle is coaxial with the valve core 109. After the valve core 109 and the bushing 110 are combined, they are installed in the small hole of the valve stem 108 to form an external sealing valve 102. After assembly, the valve core 109 and the valve stem 108 are in a coaxial state, and the valve core 109 and the valve stem 108 can rotate relative to each other.

[0041] The use process of the present invention:

[0042] 1. Put a certain amount of powder to be molded into the rubber mold 2, scrape the top of the powder flat, and then lay the filter felt 3 flat on the top of the powder;

[0043] 2. Install the vacuum plug 1 (without the external sealing valve 102) into the rubber mold 2, and then install the clamp 4 and tighten it. Then screw the external sealing valve 102 into the plug body 101, but do not tighten it completely.

[0044] 3. Connect the vacuum hose to the vacuum nozzle 107, turn on the vacuum system to extract the air in the rubber mold 2. When the vacuum degree of the rubber mold 2 reaches the specified value of the process, the conical surface of the baffle plate 104 fits with the conical surface of the plug body 101 under the action of air pressure, and the inside and outside of the rubber mold 2 are sealed.

[0045] 4. Tighten the external sealing valve 102, close the vacuum system, and remove the vacuum hose.

[0046] 5. Place the entire device into the isostatic pressing equipment and shape it according to the process parameters.

[0047] 6. After molding, take out the device, remove the external sealing valve 102, the clamp 4, the exhaust plug 1 and the filter felt 3 in turn, and finally take the molded workpiece out of the rubber mold 2.

[0048] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A powder vacuum isostatic pressing process device, comprising a rubber mold (2) for containing powder, wherein a filter felt (3) is laid on the upper layer of the powder in the rubber mold (2), characterized in that: An exhaust plug (1) is installed at the upper open end of the rubber mold (2), and the lower end of the exhaust plug (1) is inserted into the rubber mold (2). A clamp (4) is installed on the outer side of the rubber mold (2), and the clamp (4) is located at the junction of the exhaust plug (1) and the rubber mold (2).

2. The powder vacuum isostatic pressing process device according to claim 1, characterized in that: The vacuum plug (1) comprises a plug body (101) having a stepped cross section and a through inner hole in the middle, an external sealing valve (102) arranged at the upper end of the inner hole of the plug body (101), a baffle plate (104) arranged at the lower end of the inner hole of the plug body (101), a baffle spring (105) arranged between the upper end of the baffle plate (104) and the lower end of the inner hole of the plug body (101), and a vacuum nozzle (107) installed on the side of the plug body (101), wherein the ventilation hole on the vacuum nozzle (107) is connected to the inner hole of the plug body (101).

3. The powder vacuum isostatic pressing process device according to claim 2, characterized in that: An O-type sealing ring (103) is provided between the outer sealing valve (102) and the plug body (101).

4. The powder vacuum isostatic pressing process device according to claim 2, characterized in that: The outer edge of the lower end of the plug body (101) is provided with a chamfer, and a transition rubber ring (106) is provided at the chamfer.

5. The powder vacuum isostatic pressing process device according to claim 2, characterized in that: The cross section of the baffle plate (104) is composed of a conical surface at the lower end and a cylindrical surface at the upper end. The lower end of the inner hole of the plug body (101) matches the shape of the baffle plate (104) to form a sealing pair. The baffle spring (105) is located at the upper end of the cylindrical surface.

6. The powder vacuum isostatic pressing process device according to claim 2, characterized in that: The external sealing valve (102) comprises a valve stem (108) connected to the plug body (101) and a valve core (109) arranged at the lower end of the valve stem (108).

7. The powder vacuum isostatic pressing process device according to claim 6, characterized in that: The bottom of the lower end of the valve stem (108) is a concave spherical surface with a mounting hole arranged in the center of the concave spherical surface, and the upper part of the valve core (109) is a convex spherical surface matching the bottom of the valve stem (108), and a cylinder matching the mounting hole is arranged in the center of the convex spherical surface.

8. The powder vacuum isostatic pressing process device according to claim 7, characterized in that: A bushing (110) is sleeved on the cylinder on the valve core (109).

9. The powder vacuum isostatic pressing process device according to claim 6, characterized in that: The valve stem (108) is threadedly connected to the plug body (101).

10. A method for using a powder vacuum isostatic pressing process device, characterized in that: The following steps are involved: Step 1, put a certain amount of powder to be molded into the rubber mold (2), scrape the top of the powder flat, and then lay the filter felt (3) flat on the top of the powder; Step 2, install the vacuum plug (1) without the external sealing valve (102) into the upper end of the rubber mold (2), then install the clamp (4) and tighten it, and then screw the external sealing valve (102) into the plug body (101), but do not tighten it completely; Step 3, connect the vacuum hose to the vacuum nozzle (107), start the vacuum system to extract the air in the rubber mold (2), when the vacuum degree of the rubber mold (2) reaches the process specified value, under the action of air pressure, the conical surface of the baffle plate (104) fits with the conical surface of the body (101), and the inside and outside of the rubber mold (2) are sealed; Step 4, tighten the outer sealing valve (102), close the vacuum system, and remove the vacuum hose; Step 5, put the whole device into isostatic pressing equipment and form it according to the process parameters; Step 6. After molding, take out the device, remove the external sealing valve (102), the clamp (4), the air extraction plug (1) and the filter felt (3) in sequence, and finally take out the molded workpiece from the rubber mold (2).

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