A core for valve body casting and a valve body wax mold forming die

Abstract

The present invention relates to a core for valve body casting and a valve body wax mold forming mold, comprising an upper mold, a lower mold and a core. The upper mold is buckled on the lower mold, and a cavity is formed at the joint surface of the upper mold and the lower mold. The cavity is connected to the outside world through a wax injection port on the side wall. The cavity is connected to the outside world through a first mounting hole, a second mounting hole and a third mounting hole. The first mounting hole is matched with a first core for forming an upper flow channel of a stop valve, the second mounting hole is matched with a second core for forming a valve stem hole of the stop valve, and the third mounting hole is matched with a third core for forming a lower flow channel of the stop valve. A lateral molding concave surface is provided at one end of the first core close to the second core, which is matched with a lateral protrusion on the second core. A locking rod extending axially along the second core is provided in the second core. The inner extending end of the locking rod passes through a column for forming a valve flap hole and is connected and fixed to a corresponding connecting hole on the third core. The two end faces of the column respectively abut against the second core and the third core.

Description

Technical Field

[0001] The invention relates to a molding device, in particular to a core for valve body casting and a valve body wax mold molding die. Background Art

[0002] Globe valves can be used to control the flow of various types of fluids, including air, water, steam, various corrosive media, mud, oil, etc. They are very suitable for shutoff and throttling. Because the valve stem of this type of valve has a relatively short opening or closing stroke and has a very reliable shutoff function. The valve body of the globe valve is usually cast using the lost wax method. During the lost wax casting process, a wax mold that imitates the finished product needs to be made. Figure 9 In the traditional casting process, the valve body wax mold 100 is composed of multiple blocks welded together, and multiple molds are required to form each block separately. Using this model to make the wax mold not only has many process steps and high costs, but also the workpiece flows between multiple stations and the introduction of welding technology will lead to a decrease in the consistency of the entire product and pose a greater quality risk. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies of the existing technology and provide a core for valve body casting and a valve body wax mold forming mold, which can complete wax mold forming in one go, improve product consistency, reduce process steps, and reduce production costs.

[0004] The object of the present invention is achieved as follows: a core for valve body casting, comprising a base, a center core pulling block is arranged on the base, the center core pulling block includes a prismatic segment, the cross-section of the center core pulling block is polygonal, each internal angle of the polygon is equal to or greater than 90° and less than 180°, the outer side wall of the center core pulling block is connected to the parting block through a concave-convex matching structure, the exposed surface of each parting block is provided with a molding surface, and the molding surfaces of adjacent parting blocks have a smooth transition, the tail of the prismatic segment is connected to the fixed base, and the tail of the parting block abuts against the end face of the base.

[0005] An axially extending convex block is provided on the side of each central core-pulling block, and a groove is provided on the matching surface of each parting block facing the prism side. The convex block and the groove cooperate to form a concave-convex matching structure.

[0006] The cross-section of the prism segment is rectangular, the left side surface of the prism segment is matched with the left parting block, and the right side surface of the prism segment is matched with the right parting block. The upward extension of the left parting block and the facing surface of the upward extension of the right parting block and the upper side surface of the prism segment form a first mounting groove, the upper parting block is embedded and fixed in the first mounting groove, the downward extension of the left parting block and the facing surface of the downward extension of the right parting block and the lower side surface of the prism segment form a second mounting groove, the lower parting block is embedded and fixed in the second mounting groove, the projected height of the upper parting block on the plane perpendicular to the prism extension direction is less than the rectangular height, the projected height of the lower parting block on the plane perpendicular to the prism extension direction is less than the rectangular height, and the projected width of the left parting block on the plane perpendicular to the prism extension direction is less than the rectangular width; the right side surface of the prism segment is matched with the right parting block, and the projected width of the right parting block on the plane perpendicular to the prism extension direction is less than the rectangular width.

[0007] The left side of the prism segment is provided with a first dovetail protrusion and a second dovetail protrusion that are laterally raised, and the two dovetail protrusions are symmetrical about the center line of the rectangle. The first dovetail protrusion is connected to the first left parting block through a concave-convex fitting structure, and the second dovetail protrusion is connected to the second left parting block through a concave-convex fitting. The first left parting block and the second left parting block are butted against each other through a horizontal straight surface, and the horizontal straight surface passes through the axis of the rectangle. The right side of the prism segment is provided with a third dovetail protrusion and a fourth dovetail protrusion that are laterally raised, and the two dovetail protrusions are symmetrical about the horizontal center line of the rectangle. The third dovetail protrusion is connected to the third right parting block through a concave-convex fitting structure, and the fourth dovetail protrusion is connected to the fourth right parting block through a concave-convex fitting. The fourth right parting block and the third right parting block are butted against each other through a horizontal straight surface, and the horizontal straight surface passes through the axis of the rectangle.

[0008] The groove is a dovetail groove or an inverted trapezoidal groove.

[0009] A valve body wax mold forming mold, comprising an upper mold, a lower mold, and the above-mentioned core, wherein the upper mold is buckled on the lower mold, and a mold cavity is formed at the joint surface of the upper mold and the lower mold, and the mold cavity is connected to the outside world through a wax injection port on the side wall, and the mold cavity is connected to the outside world through a first mounting hole, a second mounting hole, and a third mounting hole, wherein the third mounting hole is matched with a third core for forming a lower flow channel of a stop valve, the first mounting hole is matched with a first core, and the second mounting hole is matched with a second core for forming a stem hole of the stop valve, The inward extending section of the first core and the inward extending section of the second core are spliced together to form an upper flow channel core, which is used to form the upper flow channel of the stop valve. The splicing line between the inward extending end of the first core and the inward extending end of the second core is located at the bending part of the upper flow channel core. A locking rod extending axially along the second core is provided in the second core. The inward extending end of the locking rod passes through a column for forming a valve flap hole and is connected and fixed to a corresponding connecting hole on the third core. The two end faces of the column respectively abut against the second core and the third core.

[0010] A lateral molding concave surface is provided at one end of the first core close to the second core and matches the lateral protrusion on the second core.

[0011] The angle A between the groove bottom axis of the side forming concave surface and the axis of the second core is 20° to 60°.

[0012] The projections of the parting blocks on the second core along the axial direction of the second core interfere with the end surface of the column.

[0013] A core for valve body casting comprises a base, on which a center core pulling block is arranged, the center core pulling block comprising a prismatic segment, the cross section of the center core pulling block being polygonal, each inner angle of the polygon being equal to or greater than 90° and less than 180°, the outer side wall of the center core pulling block being connected to a parting block via a concave-convex matching structure, the exposed surface of each parting block being provided with a molding surface, the molding surfaces of adjacent parting blocks being smoothly transitioned, the tail of the prismatic segment being connected to a fixed base, and the tail of the parting block being against the end face of the base. The above scheme has the beneficial effect that, before molding, when assembling the core, multiple parting blocks are assembled on the prismatic segment through a concave-convex matching structure, and each inner angle is equal to or greater than 90° and less than 180°. By adopting this structure, the parting block can be adjusted in the cavity formed after the center core-pulling block is cored out, and the inner wall of the cavity has the least effect on the spatial obstruction effect of the parting block, avoiding cavities with triangular cross-sections or cavities with concave polygonal cross-sections, and making the volume of the parting block as large as possible. While reducing the number of parting blocks, the parting blocks can be easily withdrawn to reduce the joints. After the parting blocks are assembled, the entire core can be of an integral material structure, and the wax is molded as a whole during the entire molding process. After the wax is molded, since the core is molded into a structure with a small upper opening and a large cavity in the wax mold, after molding is completed, the center core-pulling block is first extracted, and a cavity that imitates the shape of the center core-pulling block is formed after extraction, and each parting block is sequentially extracted from the cavity that imitates the shape. By adopting the present invention, the cavity structure of the wax mold can be completely formed at one time without the need to weld multiple wax molds, thereby improving the consistency of the product, reducing the process steps, and lowering the production cost.

[0014] A valve body wax mold forming mold, comprising an upper mold, a lower mold, and the above-mentioned core, the upper mold being buckled on the lower mold, a mold cavity being formed at the joint surface of the upper mold and the lower mold, the mold cavity being communicated with the outside world through a wax injection port on the side wall, the mold cavity being communicated with the outside world through a first mounting hole, a second mounting hole, and a third mounting hole, the third mounting hole being matched with a third core for forming a lower flow channel of a stop valve, the first mounting hole being matched with a first core, the second mounting hole being matched with a second core for forming a stem hole of the stop valve, The inward extension section of the first core and the inward extension section of the second core are spliced together to form an upper flow channel core, which is used to form the upper flow channel of the stop valve. The splicing line between the inward extension end of the first core and the inward extension end of the second core is located at the bend of the upper flow channel core. A locking rod extending axially along the second core is provided in the second core. The inward extension end of the locking rod passes through the column used to form the valve flap hole and is connected and fixed with the corresponding connecting hole on the third core. The two end faces of the column are respectively against the second core and the third core. A lateral forming concave surface is provided at one end of the first core close to the second core, which matches the lateral protrusion on the second core. The beneficial effect is as follows: after the cores are assembled, when the first, second and third cores are fixed on the lower mold, the third core and the second core are connected by the locking rod. The third core and the second core clamp the column used to form the valve flap hole. After the locking rod is connected and fixed, the positioning and fixation of the second core, the third core and the column are achieved. Since the opening and closing part of the manual stop valve is a plug-shaped valve flap, the valve flap moves linearly along the center line of the valve seat. A column is used to connect the front end of the first core separately to form the valve flap hole of the valve body, which can ensure the molding accuracy and surface molding quality of the entire valve flap hole, avoid the poor precision, poor surface molding quality, and defects such as flash caused by the block structure, and ensure the molding accuracy of the entire valve flap hole. Sufficient molding accuracy can significantly improve the sealing of the finished valve. The inner extension section of the first core and the inner extension section of the second core are spliced together to form an upper flow channel core, which is used to form the upper flow channel of the stop valve. The splicing line between the inner extension end of the first core and the inner extension end of the second core is located at the bend of the upper flow channel core. This structure can facilitate parting and can minimize the height of the projection of the parting block of the first core in the axial direction of the first core. At the same time, the above structure can provide an installation space for the parting block of the second core to be set close to the first core, so that the above parting block has a certain strength. A lateral molding concave surface is set at one end of the first core close to the second core, which is consistent with the lateral protrusion on the second core. With this structure, first, the docking of the first core and the second core can be facilitated, and the positioning between the second core and the third core can be facilitated. At the same time, with this structure, the upper parting block of the first core can have sufficient space for up and down movement during the core pulling operation. When the upper parting block moves downward, it will not interfere with the partition between the upper runner and the lower runner in the wax mold.Since the upper flow channel and the lower flow channel have overlapping parts in the vertical direction, if the second core and the third core simply use the same structure, it is impossible to set the column of the valve flap hole of the molding valve body, and it is impossible to complete the column, the second core and the core pulling operation of the second core. The structure of the present invention is convenient for the step-by-step core pulling of the second, third and third cores. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of an embodiment of a valve body core;

[0016] Figure 2 for Figure 1 Exploded view of

[0017] Figure 3 It is a structural schematic diagram of an embodiment of a valve body wax mold;

[0018] Figure 4 for Figure 3 Cross-sectional view at AA in the middle;

[0019] Figure 5 for Figure 3 Schematic diagram of the structure of the middle core and the wax valve body;

[0020] Figure 6 for Figure 3 Schematic diagram of the structure of the core matching;

[0021] Figure 7 It is a schematic diagram of the structure of the lateral protrusion;

[0022] Figure 8 It is a schematic diagram of the structure of the cooperation between the lateral protrusion and the lateral forming concave surface;

[0023] Figure 9 It is a structural diagram of the valve body wax mold.

[0024] In the accompanying drawings, 10 is a base, 2 is a lower mold, 3 is an upper mold, 4 is a molding cavity, 6 is a locking rod, 7 is a cylinder, 11 is a center core pulling block, 121 is a left parting block, 122 is a right parting block, 123 is an upper parting block, 124 is a lower parting block, 1211 is a first left parting block, 1212 is a second left parting block, 1221 is a third right parting block, 1222 is a fourth right parting block, 11c is a prismatic segment, 1c is a first core, 1b is a second core, 1a is a third core, a is a dovetail protrusion, a1 is a first dovetail protrusion, a2 is a second dovetail protrusion, b is a groove, e is a lateral molding concave surface, f is a lateral protrusion, and 100 is a valve body wax pattern. DETAILED DESCRIPTION

[0025] Specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0026] See also Figure 1 An embodiment of a valve body core comprises a base 10, on which a center core pulling block 11 is provided, the center core pulling block 11 comprising a prism segment 11c, the cross section of the center core pulling block 11 being polygonal, each inner angle of the polygon being equal to or greater than 90° and less than 180°, the outer side wall of the center core pulling block 11 being connected to the parting block via a concave-convex matching structure, the exposed surface of each parting block being provided with a molding surface, the molding surfaces of adjacent parting blocks being smoothly transitioned, the tail of the prism segment 11c being connected to the fixed base, and the tail of the parting block being against the end face of the base. Preferably, an axially extending protrusion a is provided on the side of each center core pulling block 11, and a groove b is provided on the matching surface of each parting block facing the prism side, the protrusion and the groove b being matched to form a concave-convex matching structure, with such a structure, after the center core pulling block 11 is cored out, a larger core pulling space can be left, while the volume of each parting block can be reduced as much as possible, making it convenient for each parting block to core out.

[0027] In this embodiment, the cross-section of the prism segment may be rectangular, and the left side parting block 121 is matched with the left side parting block 121 on the left side surface of the prism segment, and the right side parting block 122 is matched with the right side parting block 122 on the right side surface of the prism segment. The upward extension of the left parting block 121 and the facing surface of the upward extension of the right parting block 122 and the upper side surface of the prism segment form a first mounting groove, and the upper parting block 123 is embedded and fixed in the first mounting groove. The downward extension of the left parting block 121 and the facing surface of the downward extension of the right parting block 122 and the lower side surface of the prism segment form a second mounting groove, and the lower parting block 124 is embedded and fixed in the second mounting groove. The projected height of the upper parting block 12 on the plane perpendicular to the extension direction of the prism is less than the height of the rectangle, and the projected height of the lower parting block 124 on the plane perpendicular to the extension direction of the prism is less than the height of the rectangle. In terms of the height of the rectangle, the projection width of the left parting block 121 on the plane perpendicular to the extension direction of the prism is smaller than the width of the rectangle; the right side surface of the prism segment is matched with the right parting block 122, and the projection width of the right parting block 122 on the plane perpendicular to the extension direction of the prism is smaller than the width of the rectangle. This arrangement structure facilitates the core pulling of the center core pulling block 11, and can leave a sufficiently large height space to facilitate the core pulling after the centripetal movement of the upper parting block 123 or the lower parting block 124. At the same time, this structure can completely cover the center core pulling block 11, and no molding surface is set on the side of the center core pulling block 11, which reduces the number of joints of the entire core, is beneficial to reducing the flash generated during molding, and is beneficial to improving the molding quality of the molding surface. At the same time, the second mounting groove and the first mounting groove can be connected to the upper parting block 123. The lower parting block 124 fits tightly after installation, and the force direction of the upper and lower sides and the left and right sides of the rectangle are perpendicular to the concave-convex matching structure, making the matching structure of the parting block of the entire core and the center core pulling block 11 more compact, ensuring that the molding surface of the entire core is more stable and the molding quality is higher. Furthermore, the left side of the prism segment is provided with a first dovetail protrusion a1 and a second dovetail protrusion a2 with a lateral protrusion f. The two dovetail protrusions a are symmetrical about the center line of the rectangle. The first dovetail protrusion a1 is connected to the first left parting block 1211 through a concave-convex matching structure, and the second dovetail protrusion a2 is connected to the second left parting block 1212 through a concave-convex matching structure. The first left parting block 1211 and the second left parting block 1212 are connected through a horizontal straight surface, and the horizontal straight surface passes through the axis of the rectangle. The right side of the prism segment is provided with a third dovetail protrusion f with a lateral protrusion f. The protrusion a and the fourth dovetail protrusion a are symmetrical about the horizontal midline of the rectangle. The third dovetail protrusion a is connected to the third right parting block 1221 through a concave-convex fitting structure. The fourth dovetail protrusion a is connected to the fourth right parting block 1222 through a concave-convex fitting structure. The fourth right parting block 1222 is connected to the third right parting block 1221 through a horizontal straight surface. The horizontal straight surface passes through the axis of the rectangle. This structure can split the lateral parting block into smaller volumes, which is more convenient when using the core-pulling space left after core-pulling through the center core-pulling block 11.

[0028] See also Figures 1 to 9 , an embodiment of a valve body wax mold molding mold, comprising an upper mold 3, a lower mold 2 and the core in the above embodiment, the upper mold 3 is buckled on the lower mold 2, and a cavity 4 is formed at the joint surface of the upper mold 3 and the lower mold 2, the cavity 4 is communicated with the outside world through the wax injection port on the side wall, the cavity 4 is communicated with the outside world through a first mounting hole 41, a second mounting hole 42, and a third mounting hole 43, the third mounting hole 43 is matched with a third core 1a for forming the lower flow channel of the stop valve, the third core 1a is provided with an inclined slope of a molding partition at one end facing the first core 1c, the first mounting hole 41 is matched with the first core 1c, the second mounting hole 42 is matched with the molding The second core 1b for the stem hole of the stop valve has an inwardly extending section of the first core and an inwardly extending section of the second core joined together to form an upper flow channel core. The upper flow channel core is used to form the upper flow channel of the stop valve. The joining line between the inwardly extending end of the first core and the inwardly extending end of the second core is located at the bend of the upper flow channel core. A locking rod 6 extending axially along the second core 1b is provided within the second core 1b. The inwardly extending end of the locking rod 6 passes through a column 7 for forming the valve flap hole and is fixedly connected to a corresponding connecting hole on the third core 1a. The end of the locking rod may be provided with an external thread, which is fixedly connected to the internal threaded hole in the connecting hole. The two end faces of the column respectively abut against the second and third cores. Furthermore, a lateral concave surface e is provided on one end of the first core 1c near the second core 1b, which aligns with a lateral protrusion f on the second core 1b. The angle A between the bottom axis of the groove of the lateral concave surface e and the axis of the second core 1b is 20° to 60°. This arrangement optimizes the layout of the first and second cores, facilitating core pulling. The projections of the splitting blocks on the second core along the axial direction interfere with the end faces of the cylinder. This structure limits the axial position of the splitting blocks on the second core, preventing them from moving.

[0029] Before using the above scheme to mold the valve body wax mold 100, first assemble each parting block on the corresponding center core pulling block 11, then put the column 7 on the locking rod, and then lock the third core 1a and the second core 1b through the locking rod, and then assemble the first core 1c. After the core assembly is completed, fasten the mold and inject molding wax through the wax injection port. After the molding wax is molded, first pull out the center core pulling block of the first core 1c, and then gradually pull out each parting block, release the locking rod, and then pull out the second core and the third core respectively, and then take out the column 7 to complete the core pulling of the entire valve body.

[0030] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It is apparent that various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the present invention. Thus, the present invention is intended to encompass such modifications and variations as long as they fall within the scope of the claims and their equivalents.

Claims

1. A valve body wax mold, characterized by: The present invention comprises an upper mold (3), a lower mold (2), and a core, wherein the upper mold (3) is fastened to the lower mold (2), and a cavity (4) is formed at the joint surface of the upper mold (3) and the lower mold (2), wherein the cavity (4) is communicated with the outside world through a wax injection port on the side wall, and the cavity (4) is communicated with the outside world through a first mounting hole (41), a second mounting hole (42), and a third mounting hole (43), wherein the third mounting hole (43) is matched with a third core (1a) for forming a lower flow channel of a stop valve, the first mounting hole (41) is matched with a first core (1c), and the second mounting hole (42) is matched with a third core (1c) for forming a stop valve. A second core (1b) for the valve stem hole, wherein the inner extension section of the first core and the inner extension section of the second core are spliced together to form an upper flow channel core, wherein the upper flow channel core is used to form the upper flow channel of the stop valve, and the splicing line between the inner extension end of the first core and the inner extension end of the second core is located at the bending part of the upper flow channel core, and a locking rod (6) extending axially along the second core (1b) is provided in the second core (1b), and the inner extension end of the locking rod (6) passes through a column (7) for forming the valve flap hole and is connected and fixed to a corresponding connecting hole on the third core (1a), and both end faces of the column respectively abut against the second core and the third core; The core comprises a base (10), a central core pulling block (11) is arranged on the base (10), the central core pulling block (11) comprises a prism segment, the cross section of the central core pulling block (11) is polygonal, each inner angle of the polygon is equal to or greater than 90° and less than 180°, the outer side wall of the central core pulling block (11) is connected to the parting block (12) through a concave-convex matching structure, the exposed surface of each parting block (12) is provided with a molding surface, and the molding surfaces of adjacent parting blocks are smoothly transitioned, the tail of the prism segment is connected to the fixed base, and the tail of the parting block (12) abuts against the end face of the base; A lateral molding concave surface (e) is provided at one end of the first core (1c) close to the second core (1b) and matches the lateral protrusion (f) on the second core (1b); the angle A between the groove bottom axis of the lateral molding concave surface (e) and the axis of the second core (1b) is 20° to 60°; and the projections of each parting block on the second core along the axial direction of the second core interfere with the end face of the column.

2. A valve body wax mold according to claim 1, characterized in that: An axially extending protrusion (a) is provided on the side of each central core-pulling block (11), and a groove (b) is provided on the mating surface of each parting block (12) facing the side of the prism, wherein the protrusion cooperates with the groove (b) to form a concave-convex matching structure.

3. The valve body wax mold according to claim 1, characterized in that: The cross section of the prism segment is rectangular, the left side surface of the prism segment cooperates with the left parting block (121), and the right side surface of the prism segment cooperates with the right parting block (122), the upward extension of the left parting block (121) and the facing surface of the upward extension of the right parting block (122) and the upper side surface of the prism segment form a first mounting groove, the upper parting block (123) is embedded and fixed in the first mounting groove, the downward extension of the left parting block (121) and the facing surface of the downward extension of the right parting block (122) and the lower side surface of the prism segment form a first mounting groove, A second mounting groove is formed, in which a lower parting block (124) is embedded and fixed, the projection height of the upper parting block (12) on a plane perpendicular to the prism extension direction is less than the height of the rectangle, the projection height of the lower parting block (124) on a plane perpendicular to the prism extension direction is less than the height of the rectangle, the projection width of the left parting block (121) on a plane perpendicular to the prism extension direction is less than the width of the rectangle; and the projection width of the right parting block (122) on a plane perpendicular to the prism extension direction is less than the width of the rectangle.

4. The valve body wax mold according to claim 3, characterized in that: A first dovetail protrusion (a1) and a second dovetail protrusion (a2) are provided on the left side of the prism segment, and the two dovetail protrusions are symmetrical about the center line of the rectangle. The first dovetail protrusion (a1) is connected to the first left parting block (1211) through a concave-convex fitting structure, and the second dovetail protrusion (a2) is connected to the second left parting block (1212) through a concave-convex fitting. The first left parting block (1211) and the second left parting block (1212) are connected through a horizontal straight surface, and the horizontal straight surface passes through the axis of the rectangle. A third dovetail protrusion and a fourth dovetail protrusion are provided on the right side of the prism segment, and the two dovetail protrusions are symmetrical about the horizontal center line of the rectangle. The third dovetail protrusion is connected to the third right parting block (1221) through a concave-convex fitting structure, and the fourth dovetail protrusion is connected to the fourth right parting block (1222) through a concave-convex fitting. The fourth right parting block (1222) and the third right parting block (1221) are connected through a horizontal straight surface, and the horizontal straight surface passes through the axis of the rectangle.

5. The valve body wax mold according to claim 2, characterized in that: The groove (b) is a dovetail groove or an inverted trapezoidal groove.

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