A centrifugal casting mold for a flange type butterfly valve body

Abstract

The utility model relates to a centrifugal casting mould of flange type butterfly valve body, its characterized in that: including fixed mould and movable mould, the movable mould is installed in the inner chamber of fixed mould by two symmetrical semicylinders, the outer cylindrical surface of movable mould is with fixed mould inner chamber wall movable cooperation, the inner chamber splicing of two semicylinders is composed valve body pouring cavity of movable mould, valve body pouring cavity has passageway flange cavity and middle cavity flange cavity, the plane where two semicylinders inner chamber is with passageway flange cavity center line and middle cavity flange cavity center line symmetry, is equipped with the pouring hole of valve body pouring cavity in movable mould right end face center, sets up locking device between movable mould right end face and fixed mould. Have the advantages such as process environmental protection, product surface flatness is good, density is high, casting process consumable is less, molten iron loss is low, production efficiency is high, product cost is low.

Description

Technical Field

[0001] This utility model relates to a centrifugal casting mold, and more particularly to a centrifugal casting mold for a butterfly valve body. This utility model is applicable to the casting of flanged butterfly valve bodies. Background Technology

[0002] The materials and manufacturing processes of key valve components are fundamental to ensuring valve product quality. Currently, the main manufacturing processes for butterfly valve bodies are casting and forging. Casting processes commonly include sand casting and lost-wax casting. However, valve bodies produced using these methods often have defects such as sand holes and porosity, resulting in low density and low pressure resistance, making them suitable only for low-pressure valves. Furthermore, the consumption of sand and wax is high, and molten iron splashing from the pouring and riser processes can cause losses of 35-40%, leading to significant material waste and substantial environmental pollution. Therefore, these processes are listed as restricted areas for development. Consequently, high-pressure and ultra-high-pressure valve bodies are generally manufactured using forging to ensure their ability to withstand high pressure. However, forging involves multiple forging processes to form a solid valve body blank, which is then machined using turning and milling operations. This process is complex, inefficient, wasteful of materials, and costly. Utility Model Content

[0003] The purpose of this utility model is to address the shortcomings of existing technologies by providing a centrifugal casting mold for flanged butterfly valve bodies that features high pressure resistance, simple casting process, material saving, environmentally friendly production, high production efficiency, and low product cost.

[0004] The technical solution to achieve the purpose of this utility model is as follows: A centrifugal casting mold for a flanged butterfly valve body is characterized by comprising a fixed mold and a movable mold; the fixed mold has a fixed connection device for a centrifuge on one side and an inner cavity on the other side; the movable mold consists of two symmetrical semi-cylinders, which together form a single cylinder installed in the inner cavity of the fixed mold, with the outer cylindrical surface of the movable mold movably fitting against the inner cavity wall of the fixed mold; the inner cavities of the two semi-cylinders are joined to form the valve body casting cavity of the movable mold, the valve body casting cavity having a channel flange cavity and a middle flange cavity, the inner cavities of the two semi-cylinders being mirror-symmetrical about the plane containing the center lines of the channel flange cavity and the middle flange cavity; a casting hole communicating with the valve body casting cavity is provided at the center of the right end face of the movable mold, and a locking device is provided between the right end face of the movable mold and the fixed mold; the structure of the valve body casting cavity ensures that the torque generated around the center line of rotation of the mold is equal.

[0005] In the above technical solution, concentric upper shaft hole casting rod and lower shaft hole casting rod are respectively provided at the upper and lower centers of the valve body casting cavity. The structure of the upper shaft hole casting rod and the lower shaft hole casting rod makes the torque generated by the two about the rotation center line equal.

[0006] In the above technical solution, the locking device is composed of two or more radial pin holes evenly arranged in the circumferential direction of the fixed mold on the outer side of the right end face of the movable mold, in which locking pins are installed. The locking pins are inserted into the radial pin holes from the inside to the outside, with one side of the pins pressing against the right end face of the movable mold and the other side having an inclined surface.

[0007] In the above technical solution, an anti-rotation device is provided between the movable mold and the fixed mold. The anti-rotation device is composed of an axial positioning rib on the inner wall of the fixed mold and an axial positioning groove on the outer surface of the movable mold.

[0008] In the above technical solution, the two semi-cylinders of the movable mold are provided with mutually cooperating positioning holes and positioning pins in the contact plane of each other.

[0009] In the above technical solution, a push-die hole communicating with the inner cavity is provided at the center of the left end face of the fixed mold, and a push rod is provided in the push-die hole. The push rod is a pneumatic push rod in the center hole of the centrifuge shaft.

[0010] The advantages of this invention compared to existing technologies are: the valve body is produced using centrifugal casting, resulting in less pollution and avoiding material waste from sand and wax molds, as well as low molten iron loss during the casting process; the mold consists of a fixed mold and a movable mold, so when casting valve bodies of different sizes, only the movable mold with the corresponding inner cavity diameter needs to be replaced, while the fixed mold is universal and does not require disassembly, saving mold manufacturing materials and installation / replacement time. It also boasts advantages such as environmentally friendly process, good product surface smoothness, high density, low material consumption in the casting process, low molten iron loss, high production efficiency, and low product cost. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model.

[0012] Figure 2 This is a utility model Figure 1 A schematic diagram of the structure in the AA direction.

[0013] In the diagram: 1. Fixed mold, 2. Right semi-cylinder, 3. Left semi-cylinder, 4. Locking pin, 5. Casting hole, 6. Valve body casting cavity, 7. Valve body blank, 8. Lower shaft hole casting rod, 9. Push mold hole, 10. Push rod, 11. Upper shaft hole casting rod. Detailed Implementation

[0014] like Figure 1 , Figure 2The centrifugal casting mold for the flanged butterfly valve body shown is characterized by: including a fixed mold 1 and a movable mold. The fixed mold 1 is made of ordinary steel, and the movable mold is made of high-temperature resistant material, reducing the mold manufacturing cost. One side of the fixed mold 1 is provided with a device for fixed connection to the centrifuge; this connection device can be a flange connection device or a clamping device. The other side has an inner cavity, which is a cylindrical cavity. The movable mold consists of two symmetrical semi-cylinders, which are joined together to form a single cylinder installed in the inner cavity of the fixed mold 1. The outer cylindrical surface of the movable mold is movably fitted with the inner cavity wall of the fixed mold 1. The inner cavities of the two semi-cylinders are spliced ​​together to form the valve body casting cavity 6 of the movable mold. The valve body casting cavity 6 has a channel flange cavity and a middle flange cavity. The inner cavities of the two semi-cylinders are mirror-symmetrical about the plane containing the center lines of the channel flange cavity and the middle flange cavity. The structure of the valve body casting cavity 6 is the same as the shape of the valve body blank 7. Figure 2 In the design, two symmetrical semi-cylinders, left semi-cylinder 3 and right semi-cylinder 2, are joined together to form a movable mold. When casting valve bodies of different specifications, only the movable mold needs to be replaced within the cavity of the fixed mold 1, improving the versatility of the fixed mold 1 and reducing mold manufacturing costs. A casting hole 5, connecting to the valve body casting cavity 6, is located at the center of the right end face of the movable mold. Molten iron is injected into the valve body casting cavity 6 through the casting hole 5 and flows towards the cavity wall under centrifugal force, forming the valve body blank 7. Impurities in the molten iron accumulate towards the center of the valve body casting cavity 6 (i.e., the inner wall of the channel of the valve body blank 7) under centrifugal force. Therefore, the valve body blank 7 only needs to have a machining allowance in the inner hole of the channel. The valve body has high internal density and a smooth outer surface, resulting in good product quality. The diameter of the casting hole 5 is smaller than the diameter of the channel of the valve body blank 7. Under the condition of ensuring the pouring speed of molten iron, the smaller the diameter of the casting hole 5, the less molten iron is lost due to splashing from the pouring gate. A locking device is set between the right end face of the movable mold and the fixed mold 1 to lock the movable mold in the inner cavity of the fixed mold 1, preventing relative movement or relative rotation between the two. The structure of the valve body casting cavity 6 ensures that the torque generated around the mold about the rotation center line is equal, ensuring the smooth rotation of the centrifuge. The molten iron material is cast iron, cast steel, or stainless steel, depending on the operating conditions of the butterfly valve. A horizontal centrifuge is used, which makes it easy for the movable mold to be demolded from the fixed mold. A vertical centrifuge can also be used, in which case the movable mold needs to be demolded from the upper outlet of the inner cavity of the fixed mold 1.

[0015] At the upper and lower ends of the contact surfaces of the left semi-cylinder 3 and the right semi-cylinder 2, respectively, there are concentrically arranged upper shaft hole casting rods 11 and 8 extending into the valve body casting cavity 6. The upper end of the upper shaft hole casting rod 11 and the lower end of the lower shaft hole casting rod 8 are respectively fitted into the upper and lower circular or square concave holes formed by the splicing of the left semi-cylinder 3 and the right semi-cylinder 2 using radial annular shoulders or radial square shoulders. The lower part of the upper shaft hole casting rod 11 is a valve stem mounting hole, and the upper part is a packing mounting hole. The structure of the upper shaft hole casting rod 11 and the lower shaft hole casting rod 8 makes the torque generated by both about the rotation center line equal. In this embodiment, both adopt the same structure. The lower shaft hole casting rod 8 can also be formed by extending the lower end of the upper shaft hole casting rod 11 to the bottom of the valve body casting cavity 6.

[0016] The technical advantage of this feature is that the cast valve body blank 7 has valve stem mounting holes and packing mounting holes, which avoids the process of machining valve stem mounting holes and packing mounting holes in the valve body blank 7, further reducing material loss and lowering casting costs.

[0017] The locking device consists of locking pins 4 installed in two or more radially spaced holes evenly distributed around the circumference of the fixed mold on the outer side of the right end face of the movable mold. The locking pins 4 are inserted into the radial holes from the inside out, with one side of their flat surface pressing against the right end face of the movable mold, and the other side having a beveled surface. The end of the locking pin extends outward from the radial hole, facilitating its removal by tapping. The locking pins 4 can be pressure pins with matching square holes, or semi-cylindrical pins with a conical semi-cylindrical surface and matching round holes.

[0018] The technical effect of this technology is that by using the locking pin 4 to press the right end face of the movable mold, the movable mold can be pressed in or released from the mold. The movable mold is reliably pressed in and installed, and is easy to install and remove.

[0019] An anti-rotation device is provided between the movable mold and the fixed mold 1. The anti-rotation device is composed of an axial positioning rib provided on the inner wall of the fixed mold 1 and an axial positioning groove on the outer surface of the movable mold.

[0020] The technical effect of this feature is that when the centrifuge rotates at high speed, the axial positioning ribs and axial positioning grooves cooperate with each other to prevent relative rotation between the movable mold and the fixed mold 1, thereby improving the reliability of the movable mold clamping installation.

[0021] The left semi-cylinder 3 and the right semi-cylinder 2 are provided with matching positioning holes and positioning pins in the contact plane.

[0022] The technical effect of this feature is that by using positioning holes and positioning pins to insert into each other, the assembly positioning accuracy of the left semi-cylinder 3 and the right semi-cylinder 2 can be improved.

[0023] A push-die hole 9, communicating with the inner cavity of the fixed mold 1, is provided at the center of the left end face. A push rod 10 is installed inside the push-die hole 9. The push rod 10 is a pneumatic ejector rod inside the central hole of the centrifuge shaft. The pneumatic ejector rod and the central hole of the centrifuge shaft form a pneumatic piston mechanism. After the valve body blank 7 is cast, the pneumatic piston mechanism is activated to push the pneumatic ejector rod to push the movable mold out of the inner hole of the fixed mold 1, thereby achieving demolding.

[0024] The technical advantage of this technology is that it utilizes centrifugal air pressure for automatic demolding, solving the problems of high labor intensity and cumbersome operation associated with manual demolding and improving production efficiency.

[0025] The directional terms such as "left," "right," "up," and "down" used in this utility model are only for the convenience of description in the accompanying drawings and should not be regarded as limiting the technical solution of this utility model.

Claims

1. A centrifugal casting mold for a flanged butterfly valve body, characterized in that: It includes a fixed mold (1) and a movable mold; the fixed mold (1) has a fixed connection device for the centrifuge on one side and an inner cavity on the other side; the movable mold is composed of two symmetrical left semi-cylinders (3) and right semi-cylinders (2) spliced ​​together to form a cylindrical structure. The movable mold is installed in the inner cavity of the fixed mold (1), and its outer cylindrical surface is movably fitted with the inner cavity wall of the fixed mold (1). The left semi-cylinder (3) and the right semi-cylinder (2) have symmetrical inner cavities, and the two inner cavities are spliced ​​together to form the valve body casting cavity (6) of the movable mold; the valve body casting cavity (6) has a channel. The inner cavities of the two semi-cylinders are mirror-symmetrical about the plane containing the center lines of the channel flange cavity and the center line of the middle flange cavity. The structure of the valve body casting cavity (6) is the same as the shape of the valve body blank (7). A casting hole (5) connecting the valve body casting cavity (6) is provided at the center of the right end face of the movable mold. The diameter of the casting hole (5) is smaller than the channel diameter of the valve body blank (7). A locking device is provided between the right end face of the movable mold and the fixed mold (1). The structure of the valve body casting cavity (6) makes the torque generated around the center line of rotation equal around the mold.

2. The centrifugal casting mold for the flanged butterfly valve body according to claim 1, characterized in that: in The upper and lower ends of the contact surfaces between the left semi-cylinder (3) and the right semi-cylinder (2) are respectively provided with an upper shaft hole casting rod (11) and a lower shaft hole casting rod (8) that extend into the valve body casting cavity (6).

3. The centrifugal casting mold for the flanged butterfly valve body according to claim 1 or 2, characterized in that: The locking device consists of two or more radial pin holes evenly arranged in the circumferential direction of the fixed mold (1) on the outside of the right end face of the movable mold, in which locking pins (4) are installed. The locking pins (4) are inserted into the radial pin holes from the inside to the outside, with one side of the plane pressing against the right end face of the movable mold, and the other side having an inclined surface, with the end extending to the outside of the radial pin holes.

4. The centrifugal casting mold for the flanged butterfly valve body according to claim 3, characterized in that: An anti-rotation device is provided between the movable mold and the fixed mold (1). The anti-rotation device is composed of an axial positioning rib provided on the inner wall of the fixed mold (1) and an axial positioning groove on the outer surface of the movable mold.

5. The centrifugal casting mold for the flanged butterfly valve body according to claim 4, characterized in that: The left semi-cylinder (3) and the right semi-cylinder (2) are provided with a positioning hole and a positioning pin that cooperate with each other in the contact plane.

6. The centrifugal casting mold for the flanged butterfly valve body according to claim 1, 2, 4, or 5, characterized in that: A push-die hole (9) is provided at the center of the left end face of the fixed mold (1) to connect its inner cavity. A push rod (10) is provided in the push-die hole (9). The push rod (10) is a hydraulic push rod in the center hole of the centrifuge shaft.

7. The centrifugal casting mold for the flanged butterfly valve body according to claim 3, characterized in that: A push-die hole (9) is provided at the center of the left end face of the fixed mold (1) to connect its inner cavity. A push rod (10) is provided in the push-die hole (9). The push rod (10) is a hydraulic push rod in the center hole of the centrifuge shaft.

Images