Wax mould for pipe casting in shape of Chinese character'bu '

Abstract

The invention discloses a wax mould for a pipe casting in the shape of a Chinese character'bu ', and belongs to the technical field of investment casting moulds, the wax mould comprises a mould and a mould core, the mould comprises an upper mould and a lower mould, the upper mould and the lower mould are assembled to form a wax mould cavity in a complete shape of a Chinese character'bu', a wax injection port is formed in the outer side of the mould, and a mould wax runner is formed in the inner side of the mould; two ends of the mold wax runner are respectively connected with the wax mold cavity and the wax injection port; the wax mold cavity comprises a first wax mold cavity and a second wax mold cavity which are communicated with each other, the mold core comprises a direct-pulling mold core and a side-pulling mold core which are detachably connected, a first positioning block is fixedly arranged at one end of the direct-pulling mold core, and a second positioning block is arranged at one end of the side-pulling mold core; the mold is correspondingly provided with a first clamping groove used for limiting the first positioning block, a second clamping groove used for limiting the second positioning block and a groove used for being embedded into one end of the direct-pulling mold core. When the mold is closed, the wedge-shaped surface is attached to and tightly presses the positioning block, so that the position of the mold core in the wax mold cavity is kept fixed, and the quality defect that the wall thickness of a wax piece is not uniform is effectively avoided.

Description

Technical Field

[0001] This invention belongs to the field of investment casting mold technology, and specifically relates to a wax mold for a shaped tube casting. Background Technology

[0002] Investment casting is an important process in the field of metal casting. Before pouring molten metal, an investment mold that matches the shape of the casting must be prepared using a special mold. Then, an easily fusible and easily formable material is injected into the mold. After the material solidifies, the investment mold is removed, and the casting cavity is shaped based on it. The cavity shaping methods differ for different casting processes.

[0003] With the continuous upgrading and development of technology in the petrochemical industry, the application scenarios of core equipment such as cracking furnaces and catalytic furnaces are becoming increasingly complex, placing stringent requirements on the performance of their internal components. These components not only need to withstand high temperatures and high pressures but also possess excellent corrosion resistance and oxidation resistance. This invention addresses two types of tubular castings (refer to...). Figure 8 (), is a key spare part of the above-mentioned equipment, and has the characteristics of high production precision requirements, large batch production demand, and need for complete set processing.

[0004] In existing technologies, water-soluble cores are often used in the wax pattern preparation stage for producing this type of shaped tube castings. However, this method has technical defects in actual production. Water-soluble cores have low strength and high brittleness, making them prone to breakage during the core loading process in the mold. Furthermore, the core loading stage lacks a stable positioning structure, which can lead to core displacement and eccentricity. This results in uneven wall thickness in the wax parts after the water-soluble core is dissolved, causing a high scrap rate. At the same time, the dissolution of water-soluble cores takes a long time, reducing the efficiency of shaped tube wax pattern preparation and extending the production cycle. Summary of the Invention

[0005] The purpose of this invention is to provide a wax mold for a shaped tube casting, which aims to solve the problems existing in the prior art mentioned above.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A wax mold for a 1 / 2-shaped tube casting includes a mold and a mold core. The mold includes an upper mold and a lower mold. The upper mold and the lower mold are closed to form a wax model cavity with a complete 1 / 2-shaped structure. The mold core has a 1 / 2-shaped structure and is disposed in the wax model cavity. The outer side of the mold is provided with a wax injection port, and the inner side is provided with a wax flow channel. The two ends of the wax flow channel are respectively connected to the wax model cavity and the wax injection port. The wax model cavity includes a first wax model cavity and a second wax model cavity that are connected. The mold core includes a straight-drawing mold core disposed in the first wax model cavity and a side-drawing mold core disposed in the second wax model cavity. The straight-drawing mold core and the side-drawing mold core are detachably connected. A first positioning block is fixed at one end of the straight-drawing mold core, and a second positioning block is disposed at one end of the side-drawing mold core. The mold is correspondingly provided with a first slot for limiting the first positioning block, a second slot for limiting the second positioning block, and a groove for embedding one end of the straight-drawing mold core.

[0007] Furthermore, the first slot includes an upper mold first slot disposed on the upper mold and a lower mold first slot disposed on the lower mold, and the second slot includes an upper mold second slot disposed on the upper mold and a lower mold second slot disposed on the lower mold. The first positioning block and the second positioning block are both provided with a first wedge-shaped surface on the side away from the mold core, and both are provided with a protrusion at the high end of the first wedge-shaped surface. The upper mold first slot and the second slot are both provided with a second wedge-shaped surface that mates with the first wedge-shaped surface. The lower mold first slot and the lower mold second slot both extend to the outside of the lower mold, and the protrusions of the first positioning block and the second positioning block are respectively located in the lower mold first slot and the lower mold second slot.

[0008] Furthermore, the straight-pull mold core is provided with a mounting groove that matches one end of the side-pull mold core, the mounting groove is provided with a positioning groove, and the end of the side-pull mold core is provided with a positioning protrusion that matches the positioning groove.

[0009] Furthermore, the side-drawing mold core includes a side-drawing mold core fixing block and a side-drawing mold core assembly block arranged circumferentially on the side-drawing mold core fixing block. One end of the fixing block is connected to a second positioning block. The number of the assembly blocks is at least two. The fixing block is provided with dovetail wedges along the axial direction. The number of dovetail wedges is the same as the number of side-drawing mold core assembly blocks. The side-drawing mold core assembly blocks are provided with dovetail grooves. The second positioning block is provided with receiving grooves for the ends of the side-drawing mold core assembly blocks to be embedded.

[0010] Furthermore, the mold has two wax model cavities, and the two wax model cavities have different structures.

[0011] Furthermore, the lower mold is provided with an venting groove, which is used to connect the wax model cavity with the outside of the outer mold.

[0012] Furthermore, the lower mold cavity is provided with a mold closing pin and a guide post, and the upper mold is provided with a mold closing hole for the mold closing pin to pass through and a guide hole for the guide post to pass through.

[0013] Furthermore, the lower mold edge is provided with a mold opening groove.

[0014] Furthermore, the mold and mold core are made of lightweight alloy.

[0015] Compared with the shortcomings and deficiencies of the prior art, the present invention has the following beneficial effects.

[0016] This invention provides a wax mold for a 1 / 2-shaped tube casting. Both the mold and the core are made of lightweight alloy. The core is a 1 / 2-shaped split structure consisting of a straight-pull core and a side-pull core, replacing the traditional water-soluble core. The lightweight alloy core has high strength and rigidity, solving the problems of brittleness and easy breakage during the core-loading process of water-soluble cores. The straight-pull core has a first positioning block, and the side-pull core has a second positioning block. The mold has a first slot and a second slot respectively. The positioning block has a first wedge-shaped surface, and the slot has a matching second wedge-shaped surface. The end of the straight-pull core can be embedded into the groove of the mold, forming a multi-dimensional precise positioning structure. This solves the problems of lack of effective positioning and easy displacement and eccentricity of the core in the existing core-loading process. When the mold is closed, the wedge-shaped surface fits and presses against the positioning block, keeping the core in a fixed position in the wax model cavity. This effectively avoids quality defects such as uneven wall thickness in the wax part and helps to reduce the scrap rate.

[0017] In this invention, the side-pulling mold core adopts a splicing structure of a side-pulling mold core fixing block and multiple side-pulling mold core assemblies. The side-pulling mold core fixing block is provided with a dovetail wedge, and the side-pulling mold core assemblies are provided with a matching dovetail groove. The fixing block and the straight-pulling mold core are engaged through the insertion of positioning protrusions and positioning grooves. The splicing structure makes the processing and disassembly of the mold core more convenient. The cooperation between the dovetail wedge and the dovetail groove ensures the splicing accuracy of the side-pulling mold core assemblies. The insertion cooperation between the positioning protrusion and the positioning groove realizes the precise docking of the straight-pulling mold core and the side-pulling mold core, further improving the overall assembly accuracy of the mold core and ensuring the quality of wax model molding. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the wax film mold in the closed state in this invention.

[0019] Figure 2 This is a schematic diagram of the internal structure of the upper mold in this invention.

[0020] Figure 3 This is a schematic diagram of the internal structure of the lower mold in the state of installing the mold core in this invention.

[0021] Figure 4 This is a three-dimensional structural diagram of the mold core in this invention.

[0022] Figure 5 This is a three-dimensional structural diagram of the straight-drawing mold core in this invention.

[0023] Figure 6 This is a three-dimensional structural diagram of the side-pulling mold core in this invention.

[0024] Figure 7 This is a schematic diagram of the side-pulling mold core fixing block in this invention.

[0025] Figure 8This is a cross-sectional view of the tube in this invention.

[0026] In the diagram: 100, upper mold; 101, handle; 110, mold closing hole; 120, guide hole; 200, lower mold; 201, mold opening groove; 202, venting groove; 210, guide post; 220, mold closing pin; 310, first wax model cavity; 320, second wax model cavity; 330, second slot; 340, wax flow channel; 350, wax injection port; 360, first slot; 370, groove; 410, straight pull mold core; 411, mounting groove; 412, positioning groove; 420, side pull mold core; 421, positioning protrusion; 430, first positioning block; 440, second positioning block; 441, receiving groove; 451, first wedge surface; 452, protrusion; 460, side pull mold core fixing block; 461, dovetail wedge; 462, side pull mold core assembly; 500, U-shaped tube. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] Reference Figures 1-3 This invention discloses a wax mold for a shaped tube casting, including a mold and a mold core that cooperates with it. The mold has a shaped tube wax model cavity and a wax flow channel 340. The mold surface is provided with a wax injection port 350. One end of the wax flow channel 340 is connected to the wax model cavity, and the other end extends to the wax injection port 350. The wax liquid is injected through the wax injection port 350 and enters the wax model cavity through the wax flow channel 340. The mold core is set in the shaped tube wax model cavity, and the wax liquid is shaped by the cooperation between the wax model cavity and the mold core.

[0029] The molds and cores are made of lightweight alloys with low density, high specific strength and stiffness, such as aluminum alloys and magnesium alloys. These materials are easy to process, lightweight, and easy to handle manually in actual production.

[0030] The mold includes an upper mold 100 and a lower mold 200. The upper mold 100 and the lower mold 200 are independent split structures. The upper mold 100 has an upper model cavity, and the lower mold 200 has a lower model cavity. Both the upper model cavity and the lower model cavity are part of the wax model cavity. The two are joined together to form a complete wax model cavity outline. That is, when the upper mold 100 and the lower mold 200 are closed, the two contact surfaces on both sides are joined to form a complete tube-shaped wax model cavity.

[0031] At least one lobed wax model cavity can be formed within a mold. When two or more wax model cavities are formed within the mold, the structures of each lobed wax model cavity can be the same or different. In this embodiment, two lobed wax model cavities are formed within the mold, and the structures of the two lobed wax model cavities are different.

[0032] Reference Figures 4-6 The mold core includes a detachably connected straight mold core 410 and a side mold core 420. After assembly, the straight mold core 410 and the side mold core 420 form a U-shaped structure. Specifically, the straight mold core 410 has an overall cylindrical structure and an installation groove 411 is provided on it. The end of the side mold core 420 is adapted to the shape of the installation groove 411, so that the joint between the side mold core 420 and the straight mold core 410 after installation is smooth and flat.

[0033] One end of the straight mold core 410 is fixedly connected to a first positioning block 430, and the end of the side mold core 420 away from the straight mold core 410 is fixedly connected to a second positioning block 440. The first positioning block 430 and the second positioning block 440 have the same structure. The side of the first positioning block 430 away from the straight mold core 410 and the side of the second positioning block 440 away from the straight mold core 410 both have a first wedge-shaped surface 451 and a protrusion 452. The protrusion 452 is located at the high end of the first wedge-shaped surface 451, and after the mold is closed, the side wall of the protrusion 452 adjacent to the first wedge-shaped surface 451 is parallel to the contact surface of the upper mold 100.

[0034] The wax model cavity consists of a first wax model cavity 310 for installing a straight-pull mold core 410 and a second wax model cavity 320 for installing a side-pull mold core 420. The mold has a first slot 360 communicating with one end of the first wax model cavity 310 and a second slot 330 communicating with the second wax model cavity 320. The upper mold 100 has an upper mold first slot and an upper mold second slot, and the lower mold 200 has a lower mold first slot and a lower mold second slot. The upper mold first slot and the lower mold first slot align to form the first slot 360, and the upper mold second slot aligns with the lower mold second slot. The second slot 330 is formed by the mating of the upper mold and the second slot. The upper mold and the second slot each have a second wedge-shaped surface. The second wedge-shaped surface of the upper mold and the first wedge-shaped surface 451 of the first positioning block 430 are fitted together. The second wedge-shaped surface of the upper mold and the second slot are fitted together with the first wedge-shaped surface 451 of the second positioning block 440. The lower mold and the second slot both extend to communicate with the outside of the lower mold 200. The protrusions 452 of the first positioning block 430 and the second positioning block 440 are located within the lower mold and the second slot, respectively. When the upper mold 100 and the lower mold 200 are closed, the first positioning block 430 and the second positioning block 440 are pressed and positioned by the wedge-shaped surfaces.

[0035] The first wax model cavity 310 has a groove 370 at the end away from the first slot 360 that is adapted to the end of the straight mold core 410. When the straight mold core 410 is assembled into the first wax model cavity 310, the end of the straight mold core 410 is embedded in the groove 370, and the surface of the straight mold core 410 is kept at a distance from the inner wall of the first wax model cavity 310.

[0036] The side-drawing mold core 420 adopts a modular assembly structure, including a side-drawing mold core fixing block 460 and a side-drawing mold core assembly block 462. There are at least two side-drawing mold core assemblies 462. The side-drawing mold core fixing block 460 is located at the central axis. A second positioning block 440 is fixedly connected to one end of the side-drawing mold core fixing block 460. The side-drawing mold core assembly block 462 is detachably connected to the side-drawing mold core fixing block 460. The other end face of the side-drawing mold core fixing block 460 is provided with a cylindrical positioning protrusion 421 (see reference). Figure 7 A cylindrical positioning groove 412 is provided in the mounting groove 411 of the straight drawing mold core 410. After the side drawing mold core 420 is installed, the positioning protrusion 421 is inserted into the positioning groove 412.

[0037] In this embodiment, there are six side-drawing mold core blocks 462, and the splicing surfaces of the side-drawing mold core blocks 462 and the side-drawing mold core fixing blocks 460 are provided with dovetail grooves. The sidewalls of the side-drawing mold core fixing blocks 460 are provided with dovetail wedges 461 along the axial direction, and the six dovetail wedges 461 are arranged at intervals around the circumference of the side-drawing mold core fixing blocks 460. The second positioning block 440 has a circular positioning groove 441 on the side facing the straight mold core 410. After the six side-drawing mold core blocks are installed, their ends are located in the receiving groove 441.

[0038] The contact surface of the lower mold 200 is provided with an exhaust groove 202. The exhaust groove 202 connects the wax model cavity with the outside of the lower mold 200. Multiple exhaust grooves 202 are evenly distributed to expel the air inside the wax model cavity when the wax liquid is injected.

[0039] Along the outer side of the lower mold 200 towards the wax model cavity, the flow area of ​​the venting groove 202 gradually decreases. In this embodiment, the depth of the venting groove 202 communicating with the outer surface of the lower mold 200 is 0.1 mm, and the depth of the venting groove 202 communicating with the wax model cavity is 0.05 mm. After the wax fills the cavity after venting, due to the viscosity of the wax, the gap of the inner venting groove 202 is very small, and the wax on the surface of the wax model cavity has solidified, sealing the venting groove 202, and the wax will not flow out of the venting groove 202.

[0040] The contact surface of the lower mold 200 is provided with a mold-closing pin 220 and a guide post 210 that are vertically and fixedly connected thereto. The contact surface of the upper mold 100 is correspondingly provided with a mold-closing hole 110 and a guide hole 120. In this embodiment, two sets of mold-closing pins 220 are arranged diagonally on the lower mold 200, and two sets of guide posts 210 are distributed diagonally on the other side. The guide post 210 has a cylindrical structure with rounded corners at the head, and the height of the guide post 210 is higher than that of the mold-closing pin 220. The mold-closing pin 220 has a conical structure.

[0041] The lower mold 200 has an opening groove 201 on the edge of its contact surface. This groove is used to pry the upper mold 100 with a tool when the wax injection is finished, facilitating the separation of the upper mold 100 from the lower mold 200. In this embodiment, the lower mold 200 and the upper mold 100 are rectangular structures, and the opening grooves 201 are located at the four corners of the lower mold 200.

[0042] The upper mold 100 is fixedly provided with a handle 101, which can be fixedly connected to the upper mold 100 by bolts. Handles 101 are provided on opposite sides of the upper mold 100 to facilitate manual handling for mold closing or opening.

[0043] Method for preparing 500mm wax mold of tube-shaped tube First, the preparatory work before mold closing is carried out by core pulling assembly. The side pulling mold core fixing block 460 and the other 6 side pulling mold core assembly blocks 462 are assembled together by dovetail wedges 461 and dovetail grooves to form a side pulling mold core 420. Then, the side pulling mold core 420 is connected to the mounting groove 411 on the straight pulling mold core 410. Finally, the positioning protrusion 421 on the side pulling mold core fixing block 460 is inserted into the positioning groove 412 on the inner surface of the mounting groove 411 of the straight pulling mold core 410, thereby completing the mold core assembly. Then, the assembled mold core is placed in the wax model cavity on the lower mold 200.

[0044] When the mold is closed, the upper mold 100 is lifted and placed on the lower mold 200 by the handle 101 on the upper mold 100. The guide post 210 on the lower mold 200 is aligned with the guide hole 120 on the upper mold 100. The guide post 210 extends into the guide hole 120. The mold closing pin 220 on the lower mold 200 extends into the mold closing hole 110 on the upper mold 100. Finally, the upper mold 100 falls on the lower mold 200, completing the mold closing.

[0045] Under the pressure of the wax injection machine's mold plate, the upper mold 100 and lower mold 200 are pressed tightly together to prevent wax from splashing out of the mold gaps. After wax injection is completed and the wax cools and solidifies, the upper mold 100 is pried open at the mold opening slot 201 using a tool to separate it from the lower mold 200. First, the side-pulling mold core 420 in the shaped tube 500 wax model is removed. When removing the side-pulling mold core 420, the middle side-pulling mold core fixing block 460 must be removed first, and then the remaining 6 side-pulling mold core blocks are removed one by one. After the side-pulling mold core 420 is removed, the final step is to remove the straight-pulling mold core 410 from the two types of shaped tube 500 wax models. Finally, the shaped tube 500 wax model is completed.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wax mold for a U-shaped tube casting, comprising a mold and a core, characterized in that, The mold includes an upper mold (100) and a lower mold (200). The upper mold (100) and the lower mold (200) are closed to form a complete 1-shaped wax model cavity. The mold core has a 1-shaped structure and is set in the wax model cavity. The outer side of the mold is provided with a wax injection port (350), and the inner side is provided with a wax flow channel (340). The two ends of the wax flow channel (340) are respectively connected to the wax model cavity and the wax injection port (350). The wax model cavity includes a first wax model cavity (310) and a second wax model cavity (320) that are connected. The mold core includes a straight-pull mold core (410) disposed in the first wax model cavity (310) and a side-pull mold core (420) disposed in the second wax model cavity (320). The straight-pull mold core (410) and the side-pull mold core (420) are detachably connected. A first positioning block (430) is fixedly provided at one end of the straight-pull mold core (410), and a second positioning block (440) is provided at one end of the side-pull mold core (420). The mold is correspondingly provided with a first slot (360) for limiting the first positioning block (430), a second slot (330) for limiting the second positioning block (440), and a groove (370) for embedding one end of the straight-pull mold core (410).

2. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The first slot (360) includes an upper mold first slot disposed on the upper mold (100) and a lower mold first slot disposed on the lower mold (200). The second slot (330) includes an upper mold second slot disposed on the upper mold (100) and a lower mold second slot disposed on the lower mold (200). The first positioning block (430) and the second positioning block (440) are each provided with a first wedge surface (451) on the side away from the mold core, and each is provided with a protrusion (452) at the high end of the first wedge surface (451). The upper mold first slot and the upper mold second slot are each provided with a second wedge surface that cooperates with the first wedge surface (451). The lower mold first slot and the lower mold second slot both extend to the outside of the lower mold (200). The protrusions (452) of the first positioning block (430) and the second positioning block (440) are respectively located in the lower mold first slot and the lower mold second slot.

3. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The straight drawing core (410) is provided with a mounting groove (411) that is adapted to one end of the side drawing core (420). The mounting groove (411) is provided with a positioning groove (412). The end of the side drawing core (420) is provided with a positioning protrusion (421) that is adapted to the positioning groove (412).

4. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The side-drawing mold core (420) includes a side-drawing mold core fixing block (460) and a side-drawing mold core assembly (462) arranged circumferentially on the side-drawing mold core fixing block (460). One end of the side-drawing mold core fixing block (460) is connected to a second positioning block (440). The number of side-drawing mold core assemblies (462) is at least two. The side-drawing mold core fixing block (460) is provided with dovetail wedges (461) along the axial direction. The number of dovetail wedges (461) is the same as the number of side-drawing mold core assemblies (462). The side-drawing mold core assemblies (462) are provided with dovetail grooves. The second positioning block (440) is provided with receiving grooves (441) for the ends of the side-drawing mold core assemblies (462) to be embedded.

5. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The mold has two wax model cavities, and the two wax model cavities have different structures.

6. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The lower mold (200) is provided with an exhaust groove (202), which is used to connect the wax model cavity with the outside of the lower mold (200).

7. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The lower mold (200) is provided with a mold closing pin (220) and a guide post (210), and the upper mold (100) is provided with a mold closing hole (110) for the mold closing pin (220) to pass through, and a guide hole (120) for the guide post (210) to pass through.

8. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The lower mold (200) has a mold opening groove (201) on its edge.

9. The wax mold for the shaped tube casting as described in claim 1, characterized in that, The mold and mold core are made of lightweight alloy.

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