Offset type insulating part pouring mold

Abstract

The invention discloses an offset type insulating part pouring mold, which relates to the field of high-voltage electric appliance industry, and comprises an upper mold plate and a lower mold plate, the upper mold plate and the lower mold plate are closed to form a mold cavity, a sprue gate is arranged at the highest point of the mold cavity, one end of the sprue gate is communicated with the mold cavity, and the other end of the sprue gate extends to the outer surface of the mold cavity and is used for injecting castable; at least one center sleeve is arranged on the mold cavity so that an insulating part body can stretch in and be positioned, the mold is further provided with a pull-off rod, the pull-off rod penetrates through the mold pulling inclined face to be inserted into the mold cavity to facilitate demolding, the upper mold plate and the lower mold plate achieve offset positioning through a positioning block on the base and are fixedly connected with a positioning pin through a positioning hole, and a water tank with a cover can be arranged on the top of the mold cavity. The center sleeve is used for cooling, the striker plates are arranged on the two sides of the sprue gate to prevent overflow, the exhaust seam extending to the edge of the center sleeve is formed in the middle of the mold plate to exhaust gas in the mold cavity, and the mold is reasonable in structure and can effectively guarantee the casting forming quality and the demolding efficiency of the offset structure insulating part.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electrical appliances, specifically to an offset type insulator casting mold. Background Technology

[0002] In the field of high-voltage electrical equipment manufacturing, gas-insulated metal-enclosed transmission lines are widely used due to their high reliability and large capacity. In GIL equipment, three-phase common-enclosure insulation components are the core insulation components, and their performance and quality are directly related to the safe and stable operation of the entire transmission system. Currently, these insulation components are usually cast in molds using epoxy resin and other casting materials.

[0003] Existing three-phase common-box insulation casting molds typically employ two typical arrangements: one is a structure in which one phase of the three-phase conductor is placed vertically facing upwards, while the other two phases are arranged symmetrically below; the other is a structure in which the three-phase conductors are placed horizontally or symmetrically. During the casting process, in order to expel air from the mold cavity and prevent the product from developing porosity defects, existing molds usually require two or more pouring gates and risers to be opened on the mold.

[0004] However, the existing technical solutions have many inherent defects. First, the design of multiple gates and risers means that more gate and riser residues need to be dealt with after the product is poured, resulting in a large amount of subsequent grinding work. Second, due to the complex structure of the insulating parts, the existing pouring and venting methods still cannot completely prevent air bubbles from accumulating at the edge of the end insert, resulting in quality defects such as porosity and shrinkage marks in the finished product. In the existing molds, the center sleeve is usually sealed with a flexible sealing ring. This material is prone to sticking to the pouring material at high temperatures, which can easily damage the sleeve surface during demolding. Moreover, the sealing ring needs to be replaced frequently, and cleaning the sealing groove can also easily damage the mold. The slider structure used to fix the end insert in the existing molds has a cumbersome installation and positioning method, and there is a risk that the pouring material will seep into the positioning pin hole due to poor sealing, which will affect the mold accuracy and life in the long term.

[0005] Therefore, there is an urgent need for a new type of casting mold design that can fundamentally solve the above problems, achieve efficient venting through a single gate, improve product quality, extend mold life, and reduce the difficulty of production operations. Summary of the Invention

[0006] The purpose of this invention is to provide a technical solution for a casting mold for an offset type insulating component, so as to solve the problems raised in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an offset type insulating component casting mold, comprising an upper mold plate and a lower mold plate, which together form a mold cavity. The mold cavity is offset relative to the center line. A casting gate is provided at the highest point of the mold cavity. One end of the casting gate is connected to the mold cavity, and the other end extends to the outer surface of the mold cavity. At least one central sleeve is provided on the mold cavity for the insulating component to extend into. The overall offset of the mold cavity places the casting gate at the highest point. Combined with the single casting gate design, it can quickly expel gas from the mold cavity and avoid defects such as pores and shrinkage marks in the insulating component. The central sleeve provides an installation reference for the extension of the insulating component, ensuring the forming accuracy of the insulating component.

[0008] An end insert is installed at the end of the mold cavity, and a positioning block is installed outside the mold cavity. The positioning block is provided with a draft angle. The positioning block is detachably connected to the end insert through the draft angle. The draft angle design allows the positioning block and the end insert to be quickly separated by the pull rod during demolding. The angle structure can separate the demolding force, avoiding deformation of the end insert or scratches on the mold caused by hard demolding. The positioning block and the end insert are detachably connected, which is convenient for operation.

[0009] A pull rod is installed on the edge of the mold cavity. The pull rod is fixed on the stop cover. One end of the pull rod passes through the draft angle and is inserted into the mold cavity. The other end is located on the outside of the mold cavity. The pull rod passes through the draft angle and is inserted into the mold cavity. When demolding, it can quickly detach from the connection between the positioning block and the end insert through reverse impact, simplifying the demolding process and avoiding damage to the mold or the insulating parts after molding during the demolding process.

[0010] The central sleeve is equipped with a pressure cap, and the central sleeve and the pressure cap are connected by threads. A sealing ring is provided at the connection between the central sleeve and the pressure cap. The threaded connection allows for precise adjustment of the pressure force of the pressure cap on the central sleeve, ensuring the stability of the central sleeve's position during casting and preventing sleeve displacement due to vibration or casting pressure. This ensures the consistency of the insulation structure. The sealing ring fills the gap at the connection, preventing the casting material from leaking from the gap and preventing gas from entering the mold cavity. The sealing ring, made of polytetrafluoroethylene (PTFE), also prevents it from sticking to the casting material, extending the service life of the sealing components.

[0011] The upper and lower templates are placed on the base. The side of the base that contacts the upper and lower templates is an inclined surface. The inclined surface provides an offset positioning reference for the upper and lower templates, ensuring that the offset angle of the mold cavity is accurate and stable, avoiding the offset of the mold cavity position after mold closing, and ensuring the accuracy of the offset forming of the insulating parts.

[0012] The upper and lower templates are provided with positioning holes at their relative positions. The upper and lower templates are fixedly connected by positioning pins on the positioning holes. By inserting the positioning pins into the positioning holes, the upper and lower templates are precisely aligned and firmly fixed, preventing template misalignment during the casting process and ensuring the sealing of the mold cavity and the dimensional accuracy of the molded parts.

[0013] The upper and / or lower mold plates are provided with venting slots in the middle. The two ends of the venting slots extend to the edge of the central sleeve. The venting slots extend to the edge of the central sleeve, which can discharge the air bubbles that remain in the middle of the mold cavity due to structural reasons, further optimizing the venting effect. Combined with the offset arrangement and single pouring gate, it can avoid the defects of air holes on the surface of the insulating parts in all aspects.

[0014] The gating channel extends from the inner wall of the mold cavity to the outside of the mold cavity at a certain draft angle. The gating is flared, and baffles are provided on both sides of the gating. The baffles are fixed on the upper mold plate and the lower mold plate respectively. The flared gating can make it easier to pour the mold. The baffles can prevent the pouring material from overflowing, reduce material waste, and at the same time regulate the flow of the pouring material, ensuring that the pouring material fills the mold cavity evenly and avoiding local insufficient filling or accumulation.

[0015] A water tank is provided at the top of the mold cavity, and a water tank cover is installed on the water tank. Water is injected into the water tank after pouring, which can adjust the cooling speed of the gate during the mold curing process, avoid internal stress or surface defects caused by rapid curing of the insulating parts, and improve the molding quality of the insulating parts.

[0016] The upper and / or lower templates are equipped with several lifting rings and support legs. The lifting rings facilitate the hoisting and handling of the mold and reduce the difficulty of mold transportation. The support legs provide stable support for the vertical placement of the mold, ensuring the overall stability of the mold during the pouring process and preventing it from tipping over or shifting.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. Significantly improve product quality and effectively eliminate porosity defects: Through a unique offset mold design, the gate is located at the highest point of the mold, and the resin surface around the inclined end insert, combined with the venting seam set on the mold closing surface, ensures that the gas in the mold cavity is discharged during the pouring process, avoiding defects such as porosity and shrinkage marks at the edge of the end insert and inside the product.

[0018] 2. Significantly improves production efficiency and reduces subsequent processing costs. The offset structure and optimized runner design allow the mold to complete high-quality casting with only one gate. Compared with the existing technology that requires multiple gates, this reduces the workload of gate grinding after product demolding, reduces labor and time costs, and improves overall production efficiency.

[0019] 3. Optimize mold structure and operation to improve convenience and economy. The single gate and conformal design make the mold structure more compact, significantly reducing its size and weight, thus reducing the manufacturing cost and material consumption of the mold. This makes it more convenient to handle, install, and place the mold on the pouring tray. More molds can be accommodated in a single pour, improving space utilization. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the lower template of an offset insulating component casting mold according to the present invention; Figure 2 This is a schematic diagram of the structure of an offset type insulating casting mold according to the present invention; Figure 3 This is a schematic diagram of the side view of a casting mold for an offset insulating component according to the present invention; Figure 4 This is a schematic diagram of the cross-section of the center sleeve and the gland of an offset insulating component according to the present invention.

[0021] The following are the labeling elements in the diagram: 1. Lower template; 1-1. Demolding seam; 1-2. Venting seam; 1-3. Gating gate; 1-4. Draft slope; 2. Upper template; 3. Baffle plate; 4. Water tank cover; 5. Baffle cover; 6. Pressure cap; 7. Support leg; 8. Lifting ring; 9. Foot; 10. Positioning block; 11. Positioning pin; 12. Center sleeve; 13. End insert; 14. Pull-out rod; 15. Sealing ring. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example: This embodiment provides an offset type insulating casting mold.

[0024] like Figure 1-2 As shown, the main structure of the mold consists of an upper mold plate 2 and a lower mold plate 1. The two are fixedly installed by positioning holes and positioning pins 11 to form a closed mold cavity that matches the shape of the target insulating part. The bottom of the mold is equipped with feet 9 for stable standing during vertical pouring, and the sides of the mold are equipped with support legs 7 for horizontal placement. To facilitate handling, multiple lifting rings 8 are provided on the upper mold plate 2.

[0025] The external functional components of the mold mainly include: baffle plates 3 located on both sides of the sprue 1-3 to prevent resin overflow, a water tank cover 4 covering the cooling water tank, a baffle cover 5 for closing the non-sprue side opening of the mold cavity, and a pressure cover 6 for pressing and sealing the central sleeve 12.

[0026] The core internal components of the mold mainly include: a central sleeve 12 for the insertion of insulating parts, an end insert 13 that forms the electrical connection end of the product, a foot 9 for offset mold arrangement, a positioning pin 11 for precise positioning of the upper template 2 and the lower template 1, a pull rod 14 for assisting in pulling out the baffle plate 3 during demolding, and a sealing ring 15 for achieving dynamic sealing of the central sleeve 12.

[0027] The lower template 1 is the base template, which is placed horizontally on the workbench or mounting surface. The upper template 2 is located on top of the lower template 1. After the two are closed, their inner surfaces together form the mold cavity. The mold closing surface can be designed with the corresponding shape according to the product type and requirements to ensure smooth demolding.

[0028] A foot 9 is installed at the bottom of the mold. The foot 9 has a specific slope and height. When the upper mold plate 2 and the lower mold plate 1 fall, their corresponding sides will contact the slope of the foot 9, thereby creating a fixed fulcrum for the upper mold plate 2 and the lower mold plate 1 to offset laterally, and finally forming the required mold cavity offset angle.

[0029] Several sets of positioning holes are evenly distributed on the upper mold plate 2 and the lower mold plate 1. When the mold is closed, the positioning pin 11 is inserted into the corresponding positioning holes located on the upper mold plate 2 and the lower mold plate 1 respectively to achieve precise positioning and alignment of the two and prevent mold misalignment during the casting process.

[0030] The sprue 1-3 is located at the highest point of the mold cavity. The sprue 1-3 channel starts from the inner wall of the mold cavity and extends outward with a certain draft angle, forming a funnel shape, and finally extends to the outer surface of the mold. This design facilitates the inflow of casting material and the backflow of gas.

[0031] The venting seam 1-2 is located in the middle of the upper mold plate 2, where air bubbles are prone to form. The venting seam 1-2 penetrates the upper mold plate 2, connecting the mold cavity and the outside of the mold cavity. Its main function is to allow the casting material to be poured smoothly while expelling air bubbles.

[0032] The end insert 13 is located inside the mold cavity, and its molding surface is covered with resin. The pull rod is fixed on the stop cover 5. One end of the pull rod 14 passes through the draft slope 1-4 and is inserted into the mold cavity, while the other end is located outside the mold cavity. The pull rod 14 passes through the draft slope 1-4 and is inserted into the mold cavity. During demolding, it can quickly detach from the connection between the positioning block 10 and the end insert 13 by reverse impact.

[0033] The demolding slit 1-1 reserved on the lower template 1 is connected to the mold cavity. The demolding slit 1-1 is reasonably distributed along the edge of the mold cavity, which can further release the adsorption force between the template and the molded insulating part during the demolding process. With the help of the pull rod 14, the demolding operation is smoother, and at the same time, it avoids scratches or damage to the surface of the insulating part due to excessive demolding force.

[0034] During installation, before or after mold closing, first place the end insert 13 into the cavity of the positioning block 10 and initially fix it from the back of the positioning block 10 with screws. Then, install the entire assembly into the preset position of the template with bolts.

[0035] After the product has cured, first remove the bolts connecting the fixing positioning block 10 and the template. Then, the operator pulls outward or uses a soft hammer to gently tap the exposed end of the pull rod 14. Since the hole through which the pull rod 14 passes is an inclined hole with a draft angle 1-4, pulling the pull rod 14 outward will generate a component force that causes the positioning block 10 to separate from the template bonding surface. At the same time, the pull rod 14 directly acts on the end insert 13, which can be smoothly pulled out of the cured resin. This design realizes the rapid demolding of the end insert 13 and the positioning block 10, avoiding damage to the fragile resin part.

[0036] like Figure 3 As shown, the central sleeve 12 is a long cylindrical component that runs through the mold cavity along the length of the mold. Both ends of the central sleeve 12 are located outside the mold plate. On each central sleeve 12, a sealing ring 15 and a pressure cap 6 are sequentially fitted. The pressure cap 6 is connected to the central sleeve 12 by threads.

[0037] The sealing ring 15 is made of polytetrafluoroethylene. Its inner hole slides with the outer circle of the central sleeve 12, its outer conical surface fits with the inner conical hole at the end of the template, and its end face contacts the inner end face of the pressure cap 6.

[0038] like Figure 4 As shown, under the action of the clamping force F, the gland 6 pushes the sealing ring 15 forward, and the forward axial displacement is converted into the clamping force of the sealing ring 15 on the central sleeve 12 through the inclined surface, forming a radial seal.

[0039] Polytetrafluoroethylene (PTFE) has a certain coefficient of thermal expansion. When the temperature rises during the casting heating cycle, the sealing ring 15 expands due to heat, and its radial clamping force is further enhanced, achieving a hot self-tightening seal and effectively compensating for the gaps that may be caused by the difference in thermal expansion between different materials.

[0040] This sealing system completely replaces the traditional "O" ring seal. Its advantages include: reliable sealing force, non-adhesion between PTFE material and epoxy resin, easy separation during demolding, protection of the sleeve surface finish, and the sealing ring 15 being a rigid component that does not require frequent replacement, making cleaning convenient, extending mold life, and avoiding leakage problems caused by rubber ring groove machining errors.

[0041] Inside the mold near the pouring port 1-3, a hollow cavity is cast or machined to form an internal water tank. The water tank is sealed with a water tank cover 4, which has a water inlet and an air vent. Cooling water is injected into the water tank through the water inlet, which can accelerate resin curing and improve work efficiency during pouring.

[0042] The baffle plates 3 are installed in pairs on both sides of the pouring ports 1-3 and are fixed to the template with bolts to form a guide groove to prevent resin from splashing or overflowing into non-target areas during pouring.

[0043] The lifting rings 8 are symmetrically arranged above the center of gravity of the mold for hoisting by overhead crane. The feet 9 are adjustable bolt-type supports installed at the bottom of the mold. When the mold needs to be placed vertically for pouring, the feet 9 are adjusted to ensure that the mold is vertical and stable. The legs 7 are fixed or retractable brackets used when the mold is placed horizontally for assembly, cleaning or storage.

[0044] During installation, clean the work area thoroughly to ensure there is no dust or impurities, and place the lower template 1 horizontally and securely using the support legs 7.

[0045] Insert the central sleeve 12 through the reserved hole on one side of the lower template 1. On the sleeve end of the lower template 1, put the sealing ring 15 and the pressure cap 6 in sequence. Manually pre-screw the pressure cap 6 to make the sealing ring 15 initially in place, but not completely tightened.

[0046] Place the end insert 13 into the cavity of the corresponding positioning block 10 and initially fix it from the back of the positioning block 10 with hexagonal screws. Then, install the assembled mold assembly onto the designated outer mounting surface of the lower template 1 with connecting bolts to ensure that the positioning block 10 is in close contact with the template surface.

[0047] Screw the pull-out rod 14 into or insert it into the connecting threaded hole on the back of the end insert 13 from the outside of the positioning block 10, and install the baffle plate 3 and baffle cover 5 on the side of the lower template 1.

[0048] When closing the mold, use an overhead crane to lift the upper template 2 through the lifting ring 8, clean the mold closing surface of the upper template 2, operate the overhead crane to slowly lower the upper template 2, first use the guide surface of the positioning block 10 installed on the lower template 1 to guide the upper template 2 into the offset position, and then make fine adjustments to align all the positioning pins 11 holes of the upper and lower templates 1.

[0049] Insert all the locating pins 11 to ensure that the upper and lower templates 1 are completely aligned. Then, using a torque wrench, tighten all the mold closing bolts in a diagonal sequence to reach the specified preload. Finally, install the baffle plate 3 and baffle cover 5 on the side of the upper template 2.

[0050] Using an overhead crane, rotate the overall mold after mold closing at a certain angle to make it vertical and place it stably on the leveled feet 9. Install the other end of the center sleeve 12 for sealing: At the top of the mold, install the other end of the center sleeve 12, sealing ring 15 and pressure cap 6.

[0051] Using a wrench, tighten all the caps 6 evenly in a symmetrical order. During the tightening process, observe the compression of the sealing ring 15 to ensure that it evenly grips the central sleeve 12 and forms an effective seal. Similarly, check and ensure that all baffles 5 and baffle plates 3 are securely installed. Temporarily seal the outer ends of the pouring ports 1-3 with high-temperature resistant tape to prevent dust from entering.

[0052] During casting, the assembled mold is placed in an oven or preheated using a heating belt to reach the temperature required for the casting process, while the sealing ring 15 undergoes thermal expansion to achieve the best sealing state.

[0053] Move the mold to the casting station, remove the tape from the sprue 1-3, connect the sprue nozzle, start the sprue, and inject the vacuum-degassed epoxy resin mixture into the mold cavity through the sprue 1-3. Due to the offset of the mold cavity and the fact that the sprue 1-3 is at the highest point, the resin fills smoothly from bottom to top, and the gas is naturally pushed to the sprue 1-3 to be discharged. The venting slit 1-2 assists in the discharge of local gas.

[0054] After pouring, a short-term pressure holding is required. Then, immediately inject a certain amount of cooling water into the built-in water tank through the water inlet on the water tank cover 4 to begin controlled cooling of the pouring port 1-3 area.

[0055] After the mold has cooled to an operable temperature, remove the outer components such as the pressure cap 6, baffle plate 3, and baffle cover 5, and then remove the connecting bolts between the fixing positioning block 10 and the template.

[0056] Using a special wrench or soft hammer, apply force evenly to the ends of each pull rod 14. Guided by the draft angle 1-4, pull the positioning block 10 and the end insert 13 out of the mold together.

[0057] Insert steel wedges at the mold opening seam or use a hydraulic mold opener to carefully and gradually separate the upper mold plate 2 and the lower mold plate 1.

[0058] After completely separating the template, carefully remove the formed insulating part along with the central sleeve 12 from the mold cavity.

[0059] Clean the mold for future use. For insulating parts, only the 1-3 remnants of the single pouring gate need to be cut and polished to obtain a smooth product surface.

[0060] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An offset type insulating component casting mold, characterized in that: It includes an upper template (2) and a lower template (1). After the upper template (2) and the lower template (1) are closed, a mold cavity is formed. The mold cavity is offset relative to the center line. A pouring port (1-3) is provided at the highest point of the mold cavity. One end of the pouring port (1-3) is connected to the mold cavity, and the other end extends to the outer surface of the mold cavity. At least one central sleeve (12) is provided on the mold cavity for the insulation component to extend into.

2. The offset type insulating casting mold according to claim 1, characterized in that: An end insert (13) is installed at the end of the mold cavity, and a positioning block (10) is installed outside the mold cavity. A draft angle (1-4) is provided on the positioning block (10). The positioning block (10) is detachably connected to the end insert (13) through the draft angle (1-4).

3. The offset type insulating casting mold according to claim 2, characterized in that: A pull rod (14) is installed on the edge of the mold cavity. The pull rod is fixed on the baffle cover (5). One end of the pull rod (14) passes through the draft angle (1-4) and is inserted into the mold cavity, while the other end is located on the outside of the mold cavity.

4. The offset type insulating casting mold according to claim 1, characterized in that: The central sleeve (12) is provided with a pressure cap (6), and the central sleeve (12) and the pressure cap (6) are connected by threads. A sealing ring (15) is provided at the connection between the central sleeve (12) and the pressure cap (6).

5. The offset type insulating casting mold according to claim 1, characterized in that: The upper template (2) and the lower template (1) are placed on the foot (9), and the side of the foot (9) that contacts the upper template (2) and the lower template (1) is an inclined surface.

6. The offset type insulating casting mold according to claim 1, characterized in that: The upper template (2) and the lower template (1) are provided with positioning holes at their relative positions, and the upper template (2) and the lower template (1) are fixedly connected by positioning pins (11) on the positioning holes.

7. The offset type insulating casting mold according to claim 1, characterized in that: The upper template (2) and / or the lower template (1) are provided with venting slots (1-2) in the middle, and the two ends of the venting slots (1-2) extend to the edge of the central sleeve (12).

8. The offset type insulating casting mold according to claim 1, characterized in that: The gating gate (1-3) extends from the inner wall of the mold cavity to the outside of the mold cavity with a certain draft angle. The gating gate (1-3) is flared. Baffle plates (3) are provided on both sides of the gating gate (1-3). The baffle plates (3) are fixed on the upper template (2) and the lower template (1) respectively.

9. The offset type insulating casting mold according to claim 1, characterized in that: A water tank is provided at the top of the mold cavity, and a water tank cover (4) is installed on the water tank.

10. The offset type insulating casting mold according to claim 1, characterized in that: The upper template (2) and / or lower template (1) are provided with a number of lifting rings (8) and support legs (7).

Images