A wet isostatic pressing mold for forming a large-diameter ring-shaped ceramic product

Abstract

The present invention discloses a wet isostatic pressing mold for forming ceramic large-diameter annular products, comprising a first rigid cylinder, a second rigid cylinder and a flexible film sleeve, wherein the first rigid cylinder is mounted on a bottom plate, the flexible film sleeve is centered on the first rigid cylinder and is distributed around the outside of the first rigid cylinder, the flexible film sleeve is sealed and connected to the second rigid cylinder on a side away from the first rigid cylinder, and a sealed cavity for filling a material body is formed between the flexible film sleeve and the second rigid cylinder, the flexible film sleeve is provided with at least one feeding port connected to the sealed cavity, the feeding port is provided with an elastic plug, the upper and lower ends of the second rigid cylinder are provided with a closing opening concave toward a direction close to the flexible film sleeve, the flexible film sleeve is provided with a folded pleated section near the second rigid cylinder, the folded pleated section of the flexible film sleeve abuts against the inner wall of the closing portion on the second rigid cylinder, the flexible film sleeve is elastic, and the mold can ensure that the outer diameter of the blank is maximized and expand the molding range of the inner diameter of the mold.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic product production equipment, and particularly relates to a wet isostatic pressing mold for forming large-diameter annular ceramic products. Background Art

[0002] When isostatically pressing large-diameter annular ceramic products, the mold generally adopts a structure of an elastic outer rubber sleeve and an inner steel cylinder. During the forming process, the inner steel cylinder is fixed and non-compressible, and the outer elastic outer rubber sleeve is compressed from the outside to the inside after being pressurized, and the outer diameter of the powder blank body shrinks inward and becomes densified accordingly. The outer diameter of the blank obtained by forming with such a mold is 20-44% smaller than the inner diameter of the outer rubber sleeve, and due to reasons such as the uneven elasticity of the rubber sleeve, the powder filling density, the compressibility and the rebound force of each part of the mold, the outer cylindrical surface shape of the obtained blank is irregular and the surface is rough. It is necessary to remove the irregular part by machining, resulting in a further reduction in the outer diameter of the product, and it is difficult to make the outer diameter of the obtained product larger due to this limitation. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems in the background art and propose a wet isostatic pressing mold for forming large-diameter annular ceramic products.

[0004] To achieve the above purpose, the present invention proposes a wet isostatic pressing mold for forming large-diameter annular ceramic products, which includes a first rigid cylinder, a second rigid cylinder and a flexible membrane sleeve. The first rigid cylinder is installed on a bottom plate, and the flexible membrane sleeve is centered on the first rigid cylinder and is distributed around the outside of the first rigid cylinder. The side of the flexible membrane sleeve away from the first rigid cylinder is hermetically connected to the second rigid cylinder, and a sealing cavity for filling a filler body is formed between the flexible membrane sleeve and the second rigid cylinder. The flexible membrane sleeve is provided with at least one feeding port communicated with the sealing cavity, and the feeding port is provided with an elastic plug. The upper and lower ends of the second rigid cylinder are provided with inwardly concave closings towards the flexible membrane sleeve, and the flexible membrane sleeve is provided with a folding and wrinkling section near the second rigid cylinder. The folding and wrinkling section of the flexible membrane sleeve abuts against the inner wall of the closing part on the second rigid cylinder, and the flexible membrane sleeve has elasticity.

[0005] Preferably, a plurality of through holes are arranged radially on the side wall of the first rigid cylinder, and the plurality of through holes are uniformly arranged on the side wall of the first rigid cylinder from top to bottom.

[0006] Preferably, the first rigid cylinder is a hollow cylinder, and lifting lugs are arranged on the inner wall of the first rigid cylinder.

[0007] Preferably, a plurality of fastening holes are arranged on the bottom plate, and the bottom of the first rigid cylinder is connected to the bottom plate by bolts, and the bolts are fitted and installed in the fastening holes.

[0008] Preferably, the flexible membrane sleeve tightly wraps the upper and lower ends of the second rigid cylinder, and the flexible membrane sleeve and the second rigid cylinder are tightly connected by a hoop method.

[0009] Preferably, the first rigid cylinder and the second rigid cylinder are arranged parallel and concentric to each other, and both the first rigid cylinder and the second rigid cylinder are of steel cylinder structure.

[0010] Preferably, the number of the feeding ports is 4, and the 4 feeding ports are evenly distributed on the upper end surface of the flexible membrane sleeve.

[0011] Preferably, the feeding port is a circular feeding port.

[0012] Preferably, the outer diameter of the large-diameter ceramic ring-shaped product is the same as the inner diameter of the second rigid cylinder.

[0013] The beneficial effects of the present invention are as follows: In the present invention, the flexible membrane sleeve is centered on the first rigid cylinder and surrounds it on the outside. A directly sealed connection is formed between the flexible membrane sleeve and the second rigid cylinder to form a sealed cavity for filling powder. This makes the forming compression direction of the ceramic product change to be pressed from the inside to the outside, and the outer diameter of the product remains unchanged during the compression process, so as to obtain a blank with a larger size. The directly sealed connection structure between the second rigid cylinder and the soft mold sleeve minimizes the wall thickness of the outer mold, so that the outer diameter of the ceramic product can be maximized; The use of the second rigid cylinder on the outside makes the outer circular surface size of the ceramic product regular, and there is no need to reserve machining allowance for removing irregular leather materials, so as to obtain a larger product size and reduce material waste; The closing design at both ends of the second rigid cylinder and the sealing design at the connection between the top surface of the flexible membrane sleeve and it are both to reduce the radial space occupied by the mold in order to ensure the maximum outer diameter of the ceramic product; The folding and wrinkling structure on the outer side of the top surface of the flexible membrane sleeve, the top surface feeding port and the elastic plug structure can all be freely and evenly compressed downward when the top surface is pressed, which is beneficial to improving the density uniformity of the green body, increasing the compression rate in the height direction, reducing the compression rate in the inner diameter direction, and expanding the forming range of the inner diameter size of the mold.

[0014] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the drawings. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of an embodiment of the present invention.

[0016] In the figure: 1 - bottom plate, 2 - first rigid cylinder, 3 - flexible membrane sleeve, 4 - second rigid cylinder, 5 - sealed cavity, 6 - elastic plug, 21 - through hole, 22 - lifting lug, 31 - folding and wrinkling section, 41 - closing. Detailed Embodiments

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. Components of the embodiments of this application described and illustrated in the accompanying drawings here can be arranged and designed in a variety of different configurations. In the description of this application, it should be noted that the orientation or positional relationship indicated by terms such as "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship when the product of this application is normally placed. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0018] In the description of this application, it should also be noted that unless otherwise clearly specified and limited, the terms "installed", "connected" 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0019] The following will describe the present invention in detail with reference to the accompanying drawings.

[0020] Referring to Figure 1 , this embodiment provides a wet isostatic pressing mold for forming a large-diameter ring-shaped ceramic product, including a first rigid cylinder 2, a second rigid cylinder 4, and a flexible membrane sleeve 3. The first rigid cylinder 2 is installed on a bottom plate 1. The flexible membrane sleeve 3 is centered on the first rigid cylinder 2 and is distributed around the outside of the first rigid cylinder 2. One side of the flexible membrane sleeve 3 away from the first rigid cylinder 2 is hermetically connected to the second rigid cylinder 4, and a sealing cavity 5 for filling a filler body is formed between the flexible membrane sleeve 3 and the second rigid cylinder 4. The powder material is ceramic powder, the sealing cavity 5 is an annular sealing cavity, the flexible membrane sleeve 3 is provided with at least one feeding port communicating with the sealing cavity 5, the feeding port is provided with an elastic plug 6, the upper and lower ends of the second rigid cylinder 4 are provided with inwardly concave closing mouths 41 in the direction close to the flexible membrane sleeve 3, the flexible membrane sleeve 3 is provided with a folding and wrinkling section 31 at a position close to the second rigid cylinder 4, the folding and wrinkling section 31 of the flexible membrane sleeve 3 abuts against the inner wall of the closing mouth 41 part of the second rigid cylinder 4, the flexible membrane sleeve 3 has elasticity, and the folding and wrinkling section 31 of the flexible membrane sleeve 3 is for enabling it to freely move downward under pressure and having a certain buffer space.

[0021] In this solution, the number of the feeding ports includes, but is not limited to, 1, 2, 3 or 4. Preferably, the number of the feeding ports is 4, and the four feeding ports are evenly distributed on the upper end face of the flexible membrane sleeve 3. The cross-sectional shape of the feeding port is a regular shape. Preferably, the feeding port is a circular feeding port. The second rigid cylinder 4 can be an integral columnar hollow structure or can be formed by fastening and fixing two symmetric semi-columnar hollow structures.

[0022] A plurality of through holes 21 for the liquid medium to flow through are provided along the radial direction on the side wall of the first rigid cylinder 2. The plurality of through holes 21 are uniformly arranged on the side wall of the first rigid cylinder 2 from top to bottom, so that the liquid medium can evenly extrude the flexible membrane sleeve 3, making the surface of the prepared ceramic product relatively flat.

[0023] The first rigid cylinder 2 is a hollow cylinder, and two symmetrically arranged lifting lugs 22 are provided on the inner wall of the first rigid cylinder 2, which is convenient for the lifting and extraction of the first rigid cylinder 2.

[0024] A plurality of fastening holes are provided on the bottom plate 1. The bottom of the first rigid cylinder 2 is connected to the bottom plate 1 by bolts, and the bolts are fitted and installed in the fastening holes, which is convenient for the disassembly and assembly between the first rigid cylinder 2 and the bottom plate 1.

[0025] The flexible membrane sleeve 3 tightly wraps the upper and lower ends of the second rigid cylinder 4. The flexible membrane sleeve 3 and the second rigid cylinder 4 are tightly connected by a hoop method. In addition, under the condition of meeting the sealing connection between the flexible membrane sleeve 3 and the second rigid cylinder 4, the flexible membrane sleeve 3 and the second rigid cylinder 4 are also tightly connected by an adhesive method, which is convenient for disassembly and assembly to remove the large-diameter ceramic ring product.

[0026] The first rigid cylinder 2 and the second rigid cylinder 4 are arranged parallel and concentric to each other. The first rigid cylinder 2 and the second rigid cylinder 4 are both steel cylinder structures, so that the first rigid cylinder 2 and the second rigid cylinder 4 have good hardness and are convenient for processing and manufacturing.

[0027] The outer diameter of the large-diameter ceramic ring product is the same as the inner diameter of the second rigid cylinder 4 and is close to the inner diameter of the high-pressure cylinder of the isostatic press. Taking an isostatic press with a cylinder diameter of 450 mm as an example, generally, the maximum outer diameter size of the product after inner pressure die forming can only reach about 310 mm, while for the external pressure die of this application, the outer diameter size of the product can reach about 410 mm.

[0028] The working process of the present invention:

[0029] During the working process of the wet isostatic pressing die for the formed large-diameter ceramic ring-shaped product, the first rigid cylinder 2 is fixed on the bottom plate 1 with bolts. A flexible soft film 3 is arranged around the outside of the first rigid cylinder 2. The flexible soft film 3 is folded downwards and outwards, and part of the folded edge wraps the upper and lower edges of the second rigid cylinder 4 and is fixed together with a clamp in a sealed manner. Ceramic powder is added into the sealed cavity 5. During the filling process, a certain shaking is carried out to ensure relatively compact feeding. After the feeding is completed, the elastic plug 6 is sealed. The whole die is placed in an isostatic press for forming. During the forming process, the hydraulic oil squeezes the flexible soft film 3 from the inside to the outside, so as to make the density between the ceramic powders inside it. After the forming is completed, the die is removed to obtain the corresponding ceramic ring-shaped product.

[0030] The above embodiments are illustrative of the present invention, not limiting of the present invention. Any solution obtained by simply transforming the present invention belongs to the protection scope of the present invention.

Claims

1. A wet isostatic pressing mold for forming a large-diameter ring-shaped ceramic product, characterized in that: It includes a first rigid cylinder, a second rigid cylinder and a flexible membrane sleeve. The first rigid cylinder is installed on the bottom plate. The flexible membrane sleeve is centered on the first rigid cylinder and is distributed around the outside of the first rigid cylinder. One side of the flexible membrane sleeve away from the first rigid cylinder is hermetically connected to the second rigid cylinder, and a sealing cavity for filling a filler body is formed between the flexible membrane sleeve and the second rigid cylinder. The flexible membrane sleeve is provided with at least one feeding port communicated with the sealing cavity, and the feeding port is provided with an elastic plug. The upper end and the lower end of the second rigid cylinder are provided with inwardly concave openings towards the flexible membrane sleeve. The flexible membrane sleeve is provided with a folding and wrinkling section near the second rigid cylinder, and the folding and wrinkling section of the flexible membrane sleeve abuts against the inner wall of the upper opening part of the second rigid cylinder.

2. The wet isostatic pressing mold for forming a large-diameter ring-shaped ceramic product as described in claim 1, wherein: A plurality of through holes are arranged radially on the side wall of the first rigid cylinder, and the plurality of through holes are uniformly arranged on the side wall of the first rigid cylinder from top to bottom.

3. The wet isostatic pressing mold for forming a large-diameter ring-shaped ceramic product according to claim 1, characterized in that: The first rigid cylinder is a hollow cylinder, and lifting lugs are arranged on the inner wall of the first rigid cylinder.

4. The wet isostatic pressing mold for forming a large-diameter ring-shaped ceramic product as claimed in claim 1, wherein: A plurality of fastening holes are arranged on the bottom plate, and the bottom of the first rigid cylinder is connected to the bottom plate by bolts, and the bolts are fitted and installed in the fastening holes.

5. The wet isostatic pressing mold for forming a large-diameter ring-shaped ceramic product according to claim 1, wherein: The flexible membrane sleeve tightly wraps the upper and lower ends of the second rigid cylinder, and the flexible membrane sleeve and the second rigid cylinder are tightly connected by a hoop method.

6. The wet isostatic pressing die for forming a large-diameter ring-shaped ceramic product as claimed in claim 1, characterized in that: The first rigid cylinder and the second rigid cylinder are arranged parallel and concentric to each other, and both the first rigid cylinder and the second rigid cylinder are of a steel cylinder structure.

7. The wet isostatic pressing die for forming a large-diameter ring-shaped ceramic product as claimed in claim 1, wherein: The number of the feeding ports is 4, and the 4 feeding ports are uniformly distributed on the upper end surface of the flexible membrane sleeve.

8. The wet isostatic pressing die for forming a large-diameter ring-shaped ceramic product according to any one of claims 1 to 7, characterized in that: The feeding port is a circular feeding port.

9. The wet isostatic pressing die for forming a large-diameter ring-shaped ceramic product as described in claim 8, wherein: The outer diameter of the large-diameter ceramic ring-shaped product is the same as the inner diameter of the second rigid cylinder.

Images