A die casting device for transformer housing preparation

Abstract

The present application relates to the technical field of metal die casting, and discloses a die casting device for preparing a transformer shell, which comprises a fixed mold, a movable mold and a core-pulling assembly for forming a deep cavity structure of the shell in a casting, the core-pulling assembly comprises a slope rod arranged on the movable mold and a deep cavity mold base in sliding connection with the slope rod, characterized in that a shallow mold core is fixedly connected to the deep cavity mold base, the shallow mold core is tightly arranged with a deep mold core, the deep mold core is connected with a core-pulling rod, a core-pulling hole is arranged in the deep cavity mold base, and the core-pulling rod slides in the core-pulling hole; and the device further comprises an impact vibration demolding module connected with the core-pulling rod and the core-pulling hole. During the process that the slope rod drives the deep cavity mold base to exit the casting along the axial direction, the impact vibration demolding module converts the linear motion of the core-pulling hole into high-frequency axial impact vibration of the core-pulling rod, and the impact vibration is used for destroying the adhesion between the deep mold core and the casting.

Description

Technical Field

[0001] This invention relates to the technical field of metal die casting, and more particularly to a die casting apparatus for manufacturing transformer housings. Background Technology

[0002] Die casting molds are the core tooling in die casting production. They are used to press molten metal (such as aluminum alloys and zinc alloys) into a cavity under high pressure and high speed, and after cooling, it is formed into the desired casting. It mainly consists of a fixed mold, a moving mold, and a core-pulling assembly. It is suitable for the mass production of complex, high-precision castings (such as transformer housings), and features high forming efficiency, high casting precision, and good surface quality. It is widely used in machinery, electronics, and other fields.

[0003] Patent CN102029375A discloses a die-casting mold without ejector pins, comprising a front mold and a rear mold. The right side of the front mold is provided with a bolt-fixed inclined pressure block. The lower left corner of the inclined pressure block contacts a sliding block provided on the rear mold. The left side of the inclined pressure block is inclinedly fixed with an inclined guide post on the front mold passing through an inclined hole on the sliding block. The end of the inclined guide post is placed in a process groove on the rear mold corresponding to the slider. The front mold core and the rear mold core are aligned in the middle of the front mold and the rear mold core. A sprue is provided between the front mold core and the rear mold core. Runner pins are provided directly below the two sides of the sprue.

[0004] The existing technology has the following drawbacks: In traditional mold structures for die casting transformer housings, the deep cavity often employs an integrated mold core pulling structure without an auxiliary demolding mechanism. The narrow, enclosed deep cavity allows for strong adhesion and microscopic interlocking between the mold core and the inner wall of the casting after the die-cast alloy cools. Conventional core pulling methods rely solely on rigid mechanical pulling force for direct demolding, failing to eliminate the adhesive resistance at the contact surface and easily leading to problems such as mold core jamming and core pulling difficulties. Furthermore, traditional molds often employ a simultaneous mold core demolding mode, failing to achieve step-by-step separation. This results in concentrated stress in the deep cavity, easily causing defects such as scratches, cracks, and deformation on the inner wall of the transformer housing's deep cavity during demolding, severely impacting the casting quality. Summary of the Invention

[0005] In view of the above-mentioned problems in the existing technology, a die-casting device for transformer housing preparation is proposed.

[0006] This application provides a die-casting apparatus for transformer housing preparation, the purpose of which is to effectively break the adhesion force, static friction force and micro-interlocking effect between the deep mold core and the casting when core is pulled from the deep cavity structure of the housing, and significantly reduce the demolding resistance of the deep cavity structure.

[0007] The technical solution of the present invention is as follows: a die-casting device for preparing transformer housing, comprising a fixed mold, a moving mold, and a core-pulling assembly for forming a deep cavity structure of the housing inside the casting. The core-pulling assembly includes an inclined rod disposed on the moving mold and a deep cavity mold base slidably connected to the inclined rod. A shallow mold core is fixedly connected to the deep cavity mold base. The shallow mold core is closely attached to the deep mold core. A core-pulling rod is connected to the deep mold core. A core-pulling hole is opened in the deep cavity mold base, and the core-pulling rod slides in the core-pulling hole. It also includes an impact vibration demolding module, which is connected to the core-pulling rod and the core-pulling hole respectively; During the process of the inclined rod driving the deep cavity mold base to withdraw from the casting axially, the impact vibration demolding module converts the linear motion of the core-pulling hole into high-frequency axial impact vibration on the core-pulling rod. The impact vibration is used to break the adhesion between the deep mold core and the casting.

[0008] Furthermore, the impact vibration demolding module includes: A ratchet sleeve is fixedly installed at the rear end of the core-pulling hole, and its inner wall is provided with multiple one-way ratchet rings; A vibrating mandrel is sleeved on the wall of the core-pulling rod and coaxially sleeved inside the ratchet sleeve. At least one spiral groove is formed on the outer circumferential surface of the vibrating mandrel. At least one rolling element is simultaneously embedded in the tooth groove and the helical groove of the one-way ratchet ring; A preload elastic element is disposed between the core-pulling hole and the vibrating mandrel to provide axial preload that forces the vibrating mandrel to move toward the casting.

[0009] Furthermore, the lead of the spiral groove is matched with the tooth pitch of the one-way ratchet ring, so that when the ratchet sleeve moves axially relative to the vibrating spindle, the rolling element rolls along the spiral groove to the last end and passes over the tooth tips of multiple one-way ratchet rings in sequence, thereby generating continuous, high-frequency axial impact vibration.

[0010] Furthermore, the rolling element is a steel ball or a roller.

[0011] Furthermore, the preload elastic element is a helical compression spring, which is fitted on the vibrating spindle. One end of the spring abuts against the shoulder of the vibrating spindle, and the other end abuts against a sleeve bolt, which is threaded into the core-pulling hole.

[0012] Furthermore, the one-way ratchet ring is provided with a contraction notch.

[0013] Furthermore, the cross-section of the unidirectional ratchet ring is a right-angled trapezoid and the inclined surface is located in the direction of the pre-compression elastic element.

[0014] Furthermore, a reset groove is provided at the corresponding front end of the one-way ratchet ring and the spiral groove, so that during the mold closing process, when the ratchet sleeve moves axially relative to the vibrating spindle, the rolling element rolls along the spiral groove to the front end and passes through the reset grooves of multiple one-way ratchet rings in sequence.

[0015] Furthermore, the outer wall of the ratchet sleeve is provided with a limiting strip arranged along the axial direction.

[0016] Furthermore, the inner wall of the ratchet sleeve is provided with a mounting groove that matches the one-way ratchet ring.

[0017] The beneficial effects of this invention are: This invention employs a combined shallow and deep mold core structure, coupled with a core-pulling assembly driven by a slant rod, to adapt to the complex molding requirements of irregularly shaped deep cavities in transformer housings, ensuring the molding accuracy and overall structural integrity of the castings. Simultaneously, it integrates a unified impact vibration demolding module, relying on pure mechanical transmission to convert the linear motion of the mold base into high-frequency axial impact vibration, effectively breaking down the adhesion, static friction, and micro-interlocking between the deep mold core and the castings, significantly reducing the demolding resistance of the deep cavity structure.

[0018] The device forms a step-by-step demolding structure in which the shallow mold core is detached first and the deep mold core is extracted later. During the separation of the shallow mold core, high-frequency vibration is continuously output to weaken the adhesion and binding, and then the deep mold core is smoothly extracted. This effectively avoids quality defects such as casting cracking, cavity tearing and mold core jamming that are prone to occur during the deep cavity demolding process, and greatly improves the yield of transformer shell die casting products.

[0019] With the coordinated operation of the unidirectional ratchet ring, spiral groove, reset groove and limit ring, continuous cyclic impact vibration can be stably generated during the mold opening stage. During mold closing, the components are automatically mechanically reset by relying on the ratchet steep surface transmission and reset groove guidance. No additional drive components are required. The overall structure has strong linkage and stable operation logic. It is compatible with the original die casting mold assembly system and has good versatility.

[0020] The overall impact vibration force is gentle and controllable, and only a small amount of axial power is used to release the adhesion without damaging the mold components and the casting body. Each core mating component adopts a wear-resistant and high-strength structural design, with stable assembly and positioning, strong operational stability, and can be adapted to continuous die casting production conditions for a long time, effectively ensuring the stability of production operations and processing quality. Attached Figure Description

[0021] Figure 1 This is a perspective view of the die-casting apparatus for manufacturing transformer housings according to the present invention; Figure 2 This is a top view of the die-casting apparatus for manufacturing transformer housings according to the present invention; Figure 3 For the present invention Figure 2Sectional view at point AA; Figure 4 This is a perspective view of the core-pulling assembly in the die-casting apparatus for transformer housing preparation according to the present invention; Figure 5 This is a top view of the core-pulling assembly in the die-casting apparatus for transformer housing preparation according to the present invention; Figure 6 For the present invention Figure 5 Sectional view at point BB; Figure 7 This is an exploded view of the core-pulling assembly in the die-casting apparatus for transformer housing preparation according to the present invention; Figure 8 This is a perspective view of the impact vibration demolding module in the die-casting apparatus for transformer housing preparation according to the present invention; Figure 9 This is an anatomical diagram of the impact vibration demolding module in the die-casting apparatus for transformer housing preparation according to the present invention; Figure 10 This is a rear view of the impact vibration demolding module in the die-casting apparatus for transformer housing preparation according to the present invention; Figure 11 For the present invention Figure 10 Sectional view at CC; Figure 12 This is a front view of the unidirectional ratchet ring in the die-casting apparatus for manufacturing transformer housings according to the present invention; Figure 13 For the present invention Figure 12 Sectional view at point DD.

[0022] In the picture: 1. Fixed mold; 2. Moving mold; 3. Diagonal bar; 4. Deep cavity mold base; 5. Shallow mold core; 6. Deep mold core; 7. Core-pulling rod; 8. Core-pulling hole; 9. Impact vibration demolding module; 10. Ratchet sleeve; 11. One-way ratchet ring; 12. Vibration mandrel; 13. Spiral groove; 14. Rolling element; 15. Preload elastic element; 16. Sleeve bolt; 17. Shrinkage notch; 18. Reset groove; 19. Limiting strip; 20. Mounting groove; 21. Deep cavity structure of the shell; 22. Casting. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Example, refer to Figures 1-3This invention provides a die-casting device for transformer housing preparation, adapted for die-casting of irregular deep cavities in transformer housings. The device follows the conventional assembly structure of die-casting molds, mainly comprising two basic mold structures: a fixed mold 1 and a moving mold 2, which cooperate to achieve mold closing and casting, and mold opening and parting. The fixed mold 1 and moving mold 2 are integrally forged from high-strength mold alloy steel, possessing characteristics of high temperature resistance, high pressure resistance, and resistance to erosion by the die-casting melt. They cooperate with a precisely aligned guiding and limiting structure, and after mold closing, they enclose and form the basic forming cavity of the transformer housing casting 22, meeting the high-pressure casting requirements of commonly used housing die-casting raw materials such as aluminum alloy and zinc alloy.

[0025] The device is equipped with a core-pulling assembly on the side of the moving mold 2, which is specifically used for the integral molding of the deep cavity structure 21 inside the casting 22 and subsequent demolding and removal operations. The core of the core-pulling assembly includes components such as the inclined rod 3, the deep cavity mold base 4, the shallow mold core 5, the deep mold core 6, and the core-pulling rod 7. The inclined rod 3 is obliquely fixedly assembled to the inner wall of the moving mold 2, and a combination of bolt locking and positioning pin limiting connection is used to achieve a stable installation. The overall structure has high strength and can stably transmit the mechanical driving force during the mold opening process. The deep cavity mold base 4 and the inclined rod 3 adopt a high-precision sliding pair structure to achieve a sliding connection. The contact surface is wear-resistant polished and anti-jamming treated. Relying on the inclined layout design of the inclined rod 3, during the overall mold opening displacement process, the inclined rod 3 can drive the deep cavity mold base 4 to generate a horizontal displacement by resisting the stroke, thereby realizing the gradual withdrawal of the deep cavity mold base 4 from the inside of the transformer shell casting 22.

[0026] The outer end face of the deep cavity mold base 4 is fixedly installed with the shallow mold core 5 through an integral milling process and bolt fastening. The overall contour of the shallow mold core 5 fits the shallow cavity forming surface of the transformer shell. The deep mold core 6 is attached and spliced ​​to the side of the shallow mold core 5. The mating surfaces of the shallow mold core 5 and the deep mold core 6 are mutually fitted and positioned using a concave-convex interlocking limiting structure. After the two are spliced ​​and combined, they form a complete exclusive forming mold core for the deep cavity structure 21 of the transformer shell. The mold core is made of wear-resistant and heat-resistant mold steel, and the surface is treated with an anti-stick coating to reduce the adhesion of alloy melt during die casting. The inner end face of the deep mold core 6 is integrally connected to the core-pulling rod 7. The end of the core-pulling rod 7 is machined into a connecting thread section, which is locked and fixed to the deep mold core 6 through a detachable connection of thread engagement, which facilitates the later disassembly, replacement, maintenance, grinding and repair of the deep mold core 6.

[0027] The deep cavity mold base 4 has a core-pulling hole 8 of appropriate size that runs through the core-pulling rod 7 along the extension and retraction direction. The inner wall of the core-pulling hole 8 is smoothed and treated with wear-resistant protection. The core-pulling rod 7 is inserted into the core-pulling hole 8 and forms a sliding fit structure with it. The core-pulling rod 7 can slide smoothly back and forth along the axial direction of the core-pulling hole 8 to ensure the stability and smoothness of the core-pulling action. At the same time, the core-pulling hole 8 can play a radial limiting and guiding role for the core-pulling rod 7 to avoid the problems of displacement, jamming or core misalignment during the core-pulling process, and ensure the dimensional accuracy of the deep cavity structure.

[0028] This die-casting device is also equipped with an integrated impact vibration demolding module 9. This module is concealed and integrated inside the deep cavity mold base 4, and is stably connected and fixed to the core-pulling rod 7 and the wall structure of the core-pulling hole 8. Each connection part is reinforced with an anti-vibration locking structure to prevent loosening and falling off during operation. During the mold opening stage, the inclined rod 3 continuously drives the deep cavity mold base 4 to slowly detach from the transformer housing casting 22 along the horizontal axis. The deep cavity mold base 4 and the core-pulling hole 8 move in a linear displacement synchronously. At this time, the impact vibration demolding module 9 senses the mechanical motion status in real time and automatically converts the smooth linear motion of the core-pulling hole 8 into power, continuously outputting high-frequency axial impact force and vibration force, and stably transmitting it to the core-pulling rod 7.

[0029] Under the action of high-frequency axial impact vibration, the core-pulling rod 7 drives the deep mold core 6 connected to its end to generate small-amplitude reciprocating vibration and axial impact simultaneously. This continuously acts on the contact and contact position between the deep mold core 6 and the inner wall of the deep cavity of the transformer housing casting 22. Through the synergistic effect of high-frequency vibration and intermittent impact, it effectively destroys the physical adhesion force, micro-interlocking force, and adhesion and binding of solidified slag formed between the deep mold core 6 and the metal inner wall of the casting 22 after die casting cooling. This weakens the bonding strength between the mold core and the casting 22, and eliminates defects such as demolding jamming, cracking of the casting 22, and mold core damage that are prone to occur in the deep cavity due to the narrow structure and closed space. While the deep cavity mold base 4 retracts as a whole to pull the core, it assists in the smooth release of the deep mold core 6, greatly reducing the demolding difficulty in the deep cavity of the transformer housing, ensuring the overall molding integrity and appearance quality of the casting 22, and adapting to the large-scale die casting production of deep and complex irregular-shaped transformer housings.

[0030] The impact vibration demolding module 9 is integrated and assembled in the rear end area of ​​the core-pulling hole 8 inside the deep cavity mold base 4. All components are coaxially arranged around the core-pulling rod 7. The overall structure is compact and suitable for narrow installation space. The materials of each component are wear-resistant alloy materials that are suitable for the high temperature environment of die casting and high frequency reciprocating impact conditions. They have the characteristics of fatigue resistance, wear resistance and deformation resistance. The components are combined and assembled using a variety of stable connection methods such as limit fit, thread locking and nested assembly to ensure the structural stability and fit accuracy under long-term high frequency vibration operation.

[0031] Reference Figures 4-11The ratchet sleeve 10 is fixedly embedded at the rear end of the core-pulling hole 8. It is an integral cylindrical rotating structure. The outer wall of the ratchet sleeve 10 is integrally formed with a limiting strip 19 arranged along the axial direction. The limiting strip 19 and the corresponding limiting groove on the inner wall of the core-pulling hole 8 are engaged and matched with each other to restrict the circumferential rotation of the ratchet sleeve 10, retaining only the axial displacement degree of freedom, and preventing the sleeve from rotating and shifting during operation. The inner wall of the ratchet sleeve 10 is provided with a matching mounting groove 20. Multiple layers of unidirectional ratchet rings 11 are fixedly embedded in the mounting groove 20. The unidirectional ratchet rings 11 are interference-fitted with the mounting groove 20, and the assembly position is stable and not easy to loosen. The overall cross section of the unidirectional ratchet ring 11 is set as a right-angled trapezoidal structure, and the inclined surface of the trapezoid is uniformly facing the direction of the pre-compression elastic element 15. The side of the unidirectional ratchet ring 11 is reserved with a shrinkage notch 17. Relying on the elastic shrinkage structure of the notch, the insertion, installation and disassembly of the unidirectional ratchet ring 11 can be easily completed, ensuring the convenience of the assembly process.

[0032] The vibrating mandrel 12 has a hollow bushing structure and is coaxially sleeved on the outer wall surface of the core-pulling rod 7. It is also coaxially nested inside the ratchet sleeve 10, maintaining a clearance fit with the inner wall of the ratchet sleeve 10, allowing for axial relative sliding and slight circumferential adjustment. The outer circumferential surface of the vibrating mandrel 12 is uniformly provided with several helical grooves 13. These grooves extend obliquely along the axial direction, with smooth and regular contours. The overall lead of the helical grooves 13 matches the pitch of the unidirectional ratchet ring 11, providing a structural basis for the stable rolling and continuous reversing motion of the rolling element 14. Preferably, there are four helical grooves 13, evenly spaced.

[0033] Each spiral groove 13 is fitted with a set of rolling elements 14. The rolling elements 14 are made of high-strength steel balls or cylindrical rollers, and their surfaces are hardened and polished, resulting in excellent wear resistance. The rolling elements 14 are simultaneously engaged and embedded in the tooth groove of the one-way ratchet ring 11 and the groove of the spiral groove 13. Relying on the limiting constraint of the two-way groove, the rolling elements 14 are restricted from disengaging and can only roll along a predetermined trajectory.

[0034] The preload elastic element 15 is a helical compression spring structure, which is integrally fitted onto the outer shaft of the vibrating spindle 12 to achieve a coaxial nested arrangement. One axial end of the preload elastic element 15 tightly abuts against the positioning shoulder end face of the vibrating spindle 12, and the other end fits against the end face of the sleeve bolt 16. The sleeve bolt 16 is screwed into the rear threaded section of the inner wall of the core-pulling hole 8 through an external thread structure, forming a detachable sealing and limiting structure. This structure can both lock and limit the installation position of the preload elastic element 15, and can also adjust the preload pressure through screwing. The preload elastic element 15 continuously maintains a compressed and stored state, and under normal conditions, it stably provides preload pressure that forces the vibrating spindle 12 to move axially toward the casting 22, providing basic power support for the energy release of subsequent impact vibration.

[0035] The working principle is as follows: In the initial stage of mold opening, the inclined rod 3 continuously drives the deep cavity mold base 4 to move backward as a whole. The core-pulling hole 8 moves backward synchronously with the deep cavity mold base 4, and the ratchet sleeve 10 fixed at the rear end of the core-pulling hole 8 moves backward axially in sync. At this time, the transformer housing casting 22 completely wraps and binds the deep mold core 6 and the core-pulling rod 7. The core-pulling rod 7 is kept stationary by the limiting effect of the casting 22 and cannot move synchronously with the mold base. This forms a relative motion state in which the ratchet sleeve 10 moves backward and the vibrating spindle 12 is relatively stationary. Macroscopically, the vibrating spindle 12 moves axially relative to the ratchet sleeve 10 towards the casting 22. In this motion state, the rolling element 14, which is fitted between the grooves, is pushed by the groove wall of the spiral groove 13. Combined with the trapezoidal inclined guide structure of the one-way ratchet ring 11, the rolling element 14 is forced to slide upward gradually along the gentle slope of the one-way ratchet ring 11, while rolling smoothly along the trajectory of the spiral groove 13.

[0036] As the deep cavity mold base 4 continues to retreat, the rolling element 14 continuously climbs up the inclined plane and gradually moves to the tooth tip position of the one-way ratchet ring 11. Under the lateral thrust of the rolling element 14 and the oblique transmission of the spiral groove 13, the vibrating spindle 12 is slightly driven to move backward slightly, synchronously compressing the pre-compression elastic element 15 sleeved on the outside, increasing the compression deformation of the pre-compression elastic element 15, and continuously accumulating elastic potential energy. During this stage, the axial pulling force on the core-pulling rod 7 gradually increases, forming a stable energy storage process.

[0037] Once the rolling element 14 has completely passed the tooth tip of the one-way ratchet ring 11, the original inclined support limiting structure is instantly released. The rolling element 14 loses its slope constraint and, under the continuous axial preload released by the preload elastic element 15, quickly slides down and engages in the next adjacent ratchet groove, completing an instantaneous settlement displacement. Simultaneously, the preload elastic element 15, which has been compressed, releases its accumulated elastic potential energy, rapidly propelling the vibrating mandrel 12 towards the casting 22 in a short, rapid axial thrust. The vibrating mandrel 12 directly transmits the instantaneous axial force to the inner core-pulling rod 7, thus completing a precise and short axial impact action. This instantaneous impact force is gentle and instantaneous, preventing hard compression damage to the mold structure and the casting 22 body. It also effectively breaks down the solidified adhesion layer, micro-interlocking structure, and static adsorption force formed between the deep mold core 6 and the inner wall of the casting 22 after molding.

[0038] Throughout the entire process of core pulling in the deep cavity of the transformer housing casting 22, the deep cavity mold base 4 maintains a continuous and stable backward movement. The relative axial displacement between the ratchet sleeve 10 and the vibrating spindle 12 continues, and the rolling element 14 repeatedly performs the cycle of climbing over the teeth and returning to the groove, sequentially passing over the tooth top structure of multiple sets of unidirectional ratchet rings 11, completing the complete cycle of energy storage, energy release, and impact. The continuous cycle of the action mode continuously generates a high-frequency, regular axial impact vibration effect. Relying on the uninterrupted micro-impact and high-frequency vibration, the bonding strength between the deep mold core 6 and the inner wall of the deep cavity of the casting 22 is continuously weakened, and the adhesive contact surface is gradually peeled off. This completely avoids molding defects such as demolding jamming, casting 22 scratches, and cavity cracking in the narrow space of the deep cavity, allowing the deep mold core 6 to smoothly and steadily complete the core pulling and demolding with the core pulling rod 7, adapting to the die casting demolding production requirements of the complex deep cavity structure of the transformer housing.

[0039] Reference Figures 11-13 In the area where the foremost ends of the one-way ratchet ring 11 and the spiral groove 13 directly face each other, a resetting groove 18 with a connected tooth structure is integrally formed. The resetting groove 18 adopts an inwardly concave molding structure with a smooth transition. It is integrally connected and machined with the tooth structure of the one-way ratchet ring 11. The groove wall is smoothly polished to reduce the sliding friction resistance of the rolling element 14. The resetting groove 18 and the one-way ratchet ring 11 are integrally molded from the same high-strength wear-resistant material, and the overall structure is continuous and stable, which can meet the long-term working conditions of repeated sliding of the rolling element 14 across the groove. The resetting groove 18 is reasonably arranged around the circumference of the one-way ratchet ring 11 and precisely corresponds to the front end stroke trajectory of the spiral groove 13. It provides a dedicated avoidance channel and guide space for the reverse sliding reset of the rolling element 14 during the mold closing stage, ensuring that there is no jamming or hard interference during the reverse movement process.

[0040] The device has a single integrated limiting ring at the foremost position of the multiple sets of unidirectional ratchet rings 11. This limiting ring is integrated into a unidirectional ratchet ring 11 with a special structure. The overall tooth height and blocking strength are higher than the other conventional unidirectional ratchet rings 11, forming an axial end limiting barrier. Relying on its own closed tooth surface structure to form a blocking limit, it can effectively limit the extreme sliding stroke of the rolling element 14, prevent the rolling element 14 from sliding out of the meshing area during the core pulling and demolding process, ensure the stability of the overall meshing structure of the impact vibration demolding module 9, and prevent the component from disengaging and failing.

[0041] The working principle is as follows: In the complete process of die casting mold opening and demolding, the deep cavity mold base 4 continuously moves backward axially, and the shallow mold core 5 moves away from the cavity of the casting 22 synchronously with the deep cavity mold base 4, realizing the priority separation of the shallow mold core 5 from the transformer housing casting 22, thereby releasing the forming constraint of the shallow cavity position in advance. During this process, the rolling element 14 gradually climbs and moves along the one-way ratchet ring 11. When the rolling element 14 climbs to the position of the last set of one-way ratchet rings 11, the deep cavity mold base 4 continues to maintain a stable backward stroke. The continuous displacement force of the mold base is gradually transmitted to the core-pulling rod 7 and the deep mold core 6 through each transmission component, overcoming the adhesion resistance of the casting 22, and gradually driving the core-pulling rod 7 and the deep mold core 6 fixed at the end to slowly detach from the deep cavity structure 21 of the housing. This forms a step-by-step demolding logic in which the shallow mold core 5 separates first and the deep mold core 6 is pulled out later. Throughout the entire process of the shallow mold core 5 being detached, the impact vibration demolding module 9 continuously maintains high-frequency axial impact vibration output, continuously damaging and weakening the alloy solidification adhesion force, contact surface static friction force, and micro-interlocking structure between the deep mold core 6 and the inner wall of the deep cavity of the casting 22, continuously loosening the bonding state between the mold core and the casting 22, creating favorable conditions for the smooth extraction of the deep mold core 6 in the future, and effectively avoiding problems such as tensile deformation, cavity damage, and mold core jamming caused by single synchronous demolding.

[0042] After the die-cast product is completely removed, the mold enters the mold closing and reset process. The deep cavity mold base 4 drives the ratchet sleeve 10 to move axially forward toward the casting 22, and the ratchet sleeve 10 and the vibrating spindle 12 form a reverse relative displacement. Relying on the right-angled trapezoidal cross-section structure of the one-way ratchet ring 11, its steep surface facing the reset direction forms a rigid pushing structure. The steep surface has high hardness and high structural strength, which can stably press against the rolling element 14. With the mechanical thrust of the axial relative movement, the rolling element 14 is forced to be pushed along the trajectory of the spiral groove 13 to the other end of the spiral groove 13, so that the rolling element 14 is accurately aligned with the axial area that matches the reset groove 18. As the mold closing action continues, the ratchet sleeve 10 moves forward axially relative to the vibrating spindle 12. The rolling element 14, which is pushed by the limit, rolls smoothly towards the front end along the spiral groove 13, passing over the reset grooves 18 on each set of unidirectional ratchet rings 11 in turn. The smooth groove structure of the reset groove 18 can avoid and guide the rolling element 14, eliminating the obstruction and interference of the ratchet structure when moving in the opposite direction, so that the rolling element 14 can smoothly complete the cross-tooth reset movement.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A die-casting apparatus for preparing transformer housings, comprising a fixed mold (1), a moving mold (2), and a core-pulling assembly for forming a deep cavity structure (21) of the housing within a casting (22), the core-pulling assembly comprising a slanted rod (3) disposed on the moving mold (2) and a deep cavity mold base (4) slidably connected to the slanted rod (3), characterized in that: A shallow mold core (5) is fixedly connected to the deep cavity mold base (4). A deep mold core (6) is closely attached to the shallow mold core (5). A core-pulling rod (7) is connected to the deep mold core (6). A core-pulling hole (8) is opened in the deep cavity mold base (4). The core-pulling rod (7) slides in the core-pulling hole (8). It also includes an impact vibration demolding module (9), which is connected to the core-pulling rod (7) and the core-pulling hole (8) respectively; During the process of the inclined rod (3) driving the deep cavity mold base (4) to exit the casting (22) axially, the impact vibration demolding module (9) converts the linear motion of the core-pulling hole (8) into high-frequency axial impact vibration on the core-pulling rod (7). The impact vibration is used to break the adhesion between the deep mold core (6) and the casting (22).

2. The die-casting apparatus for manufacturing transformer housings according to claim 1, characterized in that: The impact vibration demolding module (9) includes: A ratchet sleeve (10) is fixedly installed at the rear end of the core-pulling hole (8), and its inner wall is provided with multiple one-way ratchet rings (11). A vibrating mandrel (12) is sleeved on the wall of the core-pulling rod (7) and coaxially sleeved in the ratchet sleeve (10). At least one spiral groove (13) is opened on the outer circumferential surface of the vibrating mandrel (12). At least one rolling element (14) is simultaneously embedded in the tooth groove of the one-way ratchet ring (11) and the helical groove (13); A preload elastic element (15) is disposed between the core-pulling hole (8) and the vibrating mandrel (12) to provide axial preload that forces the vibrating mandrel (12) to move toward the casting (22).

3. The die-casting apparatus for transformer housing preparation according to claim 2, characterized in that: The lead of the spiral groove (13) matches the pitch of the one-way ratchet ring (11), so that the rolling element (14) rolls along the spiral groove (13) to the last end and passes over the tooth tips of multiple one-way ratchet rings (11) in sequence when the ratchet sleeve (10) moves axially relative to the vibrating spindle (12), thereby generating continuous, high-frequency axial impact vibration.

4. The die-casting apparatus for transformer housing preparation according to claim 2, characterized in that: The rolling element (14) is a steel ball or a roller.

5. The die-casting apparatus for manufacturing transformer housings according to claim 2, characterized in that: The pre-compression elastic element (15) is a helical compression spring, which is fitted on the vibrating spindle (12). One end of the spring abuts against the shoulder of the vibrating spindle (12), and the other end abuts against a sleeve bolt (16). The sleeve bolt (16) is threadedly engaged with the core-pulling hole (8).

6. The die-casting apparatus for manufacturing transformer housings according to claim 2, characterized in that: The one-way ratchet ring (11) is provided with a contraction notch (17).

7. The die-casting apparatus for manufacturing transformer housings according to claim 2, characterized in that: The cross section of the unidirectional ratchet ring (11) is a right trapezoid and the inclined surface is located in the direction of the preloaded elastic element (15).

8. The die-casting apparatus for manufacturing transformer housings according to claim 2, characterized in that: The one-way ratchet ring (11) and the spiral groove (13) have a reset groove (18) at the front end corresponding to each other. During the mold closing process, when the ratchet sleeve (10) moves axially relative to the vibrating spindle (12), the rolling element (14) rolls along the spiral groove (13) to the front end and passes through the reset grooves (18) of multiple one-way ratchet rings (11) in sequence.

9. The die-casting apparatus for manufacturing transformer housings according to claim 2, characterized in that: The outer wall of the ratchet sleeve (10) is provided with a limiting strip (19) arranged along the axial direction.

10. The die-casting apparatus for manufacturing transformer housings according to claim 2, characterized in that: The inner wall of the ratchet sleeve (10) is provided with a mounting groove (20) that matches the one-way ratchet ring (11).

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