A powder vacuum isostatic pressing forming process device and use method

Abstract

The application discloses a powder vacuum isostatic pressing forming process device, including rubber mould for containing powder material, the upper layer of the powder material in the rubber mould is laid with filter felt, the upper end opening end of the rubber mould is provided with a suction plug, the lower end of the suction plug is inserted into the rubber mould, the outer side of the rubber mould is provided with a clamp, and the clamp is located at the joint of the suction plug and the rubber mould. Compared with the prior art, the internal structure of the powder material isostatic pressing forming device is simplified, the sealing reliability is improved, the operation steps are reduced compared with the prior art, and the device is suitable for mass production.

Description

Technical Field

[0001] The present 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] Isostatic pressing is a mature powder material forming process. Its main method is to wrap the powder material in an elastic rubber mold 2, immerse it in an ultra-high pressure liquid medium (hereinafter referred to as pressure medium) and maintain it for a certain period of time, so as to obtain a dense and uniform product.

[0003] To improve the yield rate of finished products, isostatic pressing equipment should possess the following two characteristics. First, it must have excellent external ultrahigh-pressure sealing to prevent leakage of ultrahigh-pressure liquid into the rubber mold during the forming process, thereby preventing contamination of the finished product. Second, it must have an internal vacuum function to remove air trapped in the semi-finished product, thus preventing defects such as bubbles and voids in the finished product.

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

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

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

[0007] A powder vacuum isostatic pressing process device includes a rubber mold for holding powder, a filter felt is laid on the upper layer of the powder in the rubber mold, an exhaust plug is installed at the open end of the upper end of the rubber mold, the lower end of the exhaust plug is inserted into the rubber mold, and a clamp is installed on the outside 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 vent 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 includes 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 provided 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 the center of the convex spherical surface is a cylinder matching the mounting hole.

[0015] Preferably, a bushing is provided 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 formed 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 and start the vacuum system to extract the air from the rubber mold. When the vacuum degree of the rubber mold reaches the specified value, 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: Place the entire 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, exhaust plug and filter felt in turn, and finally take the molded workpiece out of the rubber mold.

[0024] Compared with the existing technology, the beneficial effects of the present invention are:

[0025] Compared with the prior art, the present invention simplifies the internal structure of the isostatic pressing device for powder materials, 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 Schematic diagram of the overall structure of the device of the present invention;

[0027] Figure 2 This 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 structural diagram 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. Main 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 clearly and completely described 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; terms such as "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," and "tail" indicate positions or relationships based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] As attached Figure 1 As shown, this 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 is filled with powder to be molded, and 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 by the rubber mold 2. The clamp 4 is installed at the junction of the vacuum plug 1 and the rubber mold 2. When tightened, the joint can be sealed.

[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 vacuum plug 1 is as follows: the plug body 101 is the main component of the vacuum plug 1. The external sealing valve 102 is installed on the upper side of the plug body 101, that is, the pressure medium side. The material retaining plate 104 and retaining plate 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 vacuum nozzle 107 is installed on the side of the plug body 101.

[0038] There is a group of inner holes that pass through the plug body 101 from top to bottom. The inner holes have sealing ring grooves, threads, outer conical surfaces, inner conical surfaces 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 conical surface and the inner conical surface are in contact with the corresponding conical surfaces of the external sealing valve 102 and the baffle plate 104 respectively to achieve sealing. A threaded hole is provided on the side of the plug body 101 for installing the vacuum 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. Its inner conical surface 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 baffle spring 105 are installed at the lower portion of the inner bore of the plug body 101. The baffle plate 104 has a conical upper surface that mates with the inner conical surface of the plug body 101 to form a sealing pair. A frustum is mounted on the upper portion of the baffle plate, and the baffle spring 105 is mounted on the frustum and together they are installed at the lower portion of the inner bore of the plug body 101. In the absence of external load, the baffle spring 105 lifts the baffle plate 104, separating its conical surface from that of the plug body 101 and connecting the interior and exterior of the rubber mold 2. When the vacuum level of the rubber mold 2 reaches the specified process value, the air pressure causes the conical surface of the baffle plate 104 to mate with the conical surface of the plug body 101, sealing the interior and exterior of the rubber mold 2.

[0040] As attached Figure 4As shown, the external sealing valve 102 comprises a valve core 109, a valve stem 108, and a bushing 110. The valve stem 108 is externally threaded and screwed into the internal thread of the plug body 101. The bottom of the valve stem 108 is a concave spherical surface with a small hole in the center. The hole, spherical surface, and the threads of the valve stem 108 are all coaxial. The lower portion of the valve core 109 has a conical surface that mates with the outer conical surface of the inner hole of the plug body 101 to form a sealing pair. The upper portion of the valve core 109 has a convex spherical surface with the same radius as the concave spherical surface of the valve stem 108. The convex spherical surface has a cylinder in the center. The conical surface, convex spherical surface, and cylinder of the valve core 109 are all coaxial. The bushing 110 is made of engineering plastic with a certain degree of elasticity and self-lubrication. The bushing 110 fits over the cylindrical surface of the valve core 109, and its outer diameter 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 the 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 formed 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 (excluding the external sealing valve 102) into the rubber mold 2, 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 process specified value, 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, remove 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 remove the molded workpiece from the rubber mold 2.

[0048] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection 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 clamping hoop (4) is installed on the outside of the rubber mold (2), and the clamping hoop (4) is located at the junction of the exhaust plug (1) and the rubber mold (2); The exhaust 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 an exhaust nozzle (107) installed on the side of the plug body (101), wherein the vent hole on the exhaust nozzle (107) is connected to the inner hole of the plug body (101); The cross section of the baffle plate (104) is composed of a lower conical surface and an upper cylindrical surface. 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. 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); A bushing (110) is sleeved on the cylinder on the valve core (109); The valve stem (108) is threadedly connected to the plug body (101).

2. The powder vacuum isostatic pressing process device according to claim 1, characterized in that: An O-type sealing ring (103) is provided between the outer sealing valve (102) and the plug body (101).

3. The powder vacuum isostatic pressing process device according to claim 1, 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.

4. The powder vacuum isostatic pressing process device according to claim 1, characterized in that: The bottom of the lower end of the valve stem (108) is a concave spherical surface with a mounting hole provided at the center thereof, and the upper portion of the valve core (109) is a convex spherical surface matching the bottom of the valve stem (108), with a cylinder matching the mounting hole provided at the center thereof.

5. A method for using the powder vacuum isostatic pressing process device according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Place a fixed 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 plug 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: Place the entire device into the isostatic pressing equipment and form it according to the process parameters; Step 6: After molding, remove the device, remove the outer sealing valve (102), the clamp (4), the air extraction plug (1) and the filter felt (3) in sequence, and finally remove the molded workpiece from the rubber mold (2).

Images