A fire-proof structure for low-pressure casting machines

Abstract

This utility model relates to the field of casting equipment technology, and in particular to a fire-prevention structure for a low-pressure casting machine. The low-pressure casting machine includes a riser pipe, and the fire-prevention structure is disposed between the riser pipe and the mold cavity. The fire-prevention structure includes: two flange lips, which are disposed back-to-back on the outer periphery of the riser pipe and form a lip on the outer periphery of the riser pipe; and a flange lip sleeve, which is fitted around the outer periphery of the two flange lips. There is a vertical clearance between the flange lip sleeve and the furnace cover of the low-pressure casting machine. Because the flange lips are disposed back-to-back and have a significant curved surface structure, the buffering and sealing functions can be activated to a great extent during the rising of the casting machine furnace body, solving the fire-prevention problem caused by insufficient compression and realizing safe production operation of the low-pressure casting machine.

Description

Technical Field

[0001] This utility model relates to the field of casting equipment technology, and in particular to a fire-proof structure for a low-pressure casting machine. Background Technology

[0002] Low-pressure casting is a widely used process in metal casting production. Its core principle involves securely mounting the mold on a movable platform, precisely aligning the mold's inlet with the furnace's riser pipe. During the casting cycle, molten metal, driven by compressed air inside the furnace, rises along the riser pipe and pours into the mold cavity. After the molten metal in the cavity has filled and solidified sufficiently within a predetermined time, the gas pressure inside the furnace is released. The undiluted aluminum then flows back into the furnace under gravity along the riser pipe. Subsequently, the mold is removed from its working position, and the entire system prepares for the next casting cycle.

[0003] Although the aforementioned existing technical processes are relatively mature, their structural design has significant and dangerous defects, namely, they are prone to accidental fire. Fire mainly occurs when the seals of two key links fail: first, the gasket at the connection between the mold and the riser pipe is damaged or aged and fails; second, the mold itself ruptures during the pressurization process.

[0004] Furnace covers and bodies typically house numerous sophisticated electrical circuits and sensors. High-temperature molten metal can instantly burn these components, leading to severe equipment damage or even complete malfunction. Secondly, splashes of high-temperature molten metal can easily ignite surrounding combustibles, posing a significant fire hazard and a serious threat to personnel and equipment. Even more challenging is the post-accident handling: the solidified metal residue that leaks and solidifies in the narrow space beneath the furnace cover, on the cover surface, and in the gaps of related components adheres extremely well, making cleanup exceptionally difficult and time-consuming. Conventional cleaning methods are often insufficient for complete removal. In extremely severe cases, destructive cutting of the furnace body and cover may be necessary to restore equipment functionality, resulting in substantial repair costs and time losses, and severely impacting production efficiency and equipment lifespan. Utility Model Content

[0005] The main purpose of this utility model is to provide a fire-proof structure for low-pressure casting machines, which aims to solve the problem that low-pressure casting machines in the prior art are prone to fire accidents.

[0006] To achieve the above objectives, this utility model provides a fire-prevention structure for a low-pressure casting machine. The low-pressure casting machine includes a riser pipe, and the fire-prevention structure is disposed between the riser pipe and the mold cavity. The fire-prevention structure includes:

[0007] Two flange lips are disposed opposite to each other on the outer periphery of the riser tube, forming a lip on the outer periphery of the riser tube;

[0008] Flange lip sleeve, fitted around the outer periphery of the two flange lips;

[0009] There is a vertical clearance between the flange lip and the furnace cover of the low-pressure casting machine.

[0010] Optionally, the upper end face of the flange lip and the outer periphery of the upper flange lip form a sealing cavity.

[0011] Optionally, a sealing assembly is provided below the flange lip, the sealing assembly being used to reduce the outer diameter of the lower flange lip so that it fits into the riser pipe.

[0012] Optionally, the sealing assembly includes an upper sealing seat, a lower sealing seat, and a plurality of limiting pieces. The lower end face of the upper sealing seat is provided with a plurality of limiting grooves, the upper end face of the lower sealing seat is provided with a limiting ring, and the limiting pieces are disposed within the limiting grooves and the limiting rings.

[0013] Optionally, the upper sealing seat and the lower sealing seat are rotatably configured, and several of the limiting plates abut against the outer diameter of the lower flange lip. The pressure exerted by the limiting plates on the lower flange lip is changed by the rotation of the lower sealing seat.

[0014] Optionally, the limiting grooves are arranged in a circular array with reference to the axis of the sealing upper seat, while being inclined.

[0015] Optionally, the cross-section of the limiting ring is polygonal, and the number of its corners matches the number of the limiting pieces.

[0016] Optionally, a torsion spring is provided between the upper sealing seat and the lower sealing seat.

[0017] Optionally, a gear disk is fixedly provided on the lower end face of the sealing seat, and a motor is provided below the furnace cover of the low-pressure casting machine, with the output end of the motor cooperating with the gear disk.

[0018] Optionally, the fire-proof structure further includes a flange plate disposed on the insulation sleeve inside the low-pressure casting machine, wherein both the inner and outer edges of the flange plate are provided with an inclination angle, and the inclination angle ranges from 4° to 6°.

[0019] This utility model proposes a fire-prevention structure for a low-pressure casting machine. The fire-prevention structure, located outside the riser pipe, prevents accidental fires by including a flange lip and a flange sleeve. The flange lip and flange sleeve are interlocked and jointly positioned outside the riser pipe. This structure, based on the existing gasket, uses physical sealing to reduce the risk of fires if the original gasket is damaged. Furthermore, the clearance prevents the furnace body from contacting the casting platform during its ascent, thus avoiding insufficient gasket compression and subsequent leakage or fires. The flange structure's compression... Regarding the issue of quantity, since the flange lips are set back to each other and have a significant curved structure, they can play a significant role in buffering and sealing during the rise of the furnace body (riser pipe) of the casting machine. This solves the problem of fire caused by insufficient compression and ensures safe production operation of the low-pressure casting machine. At the same time, the flow space formed by the lip allows the molten metal to flow into the lip in time to cool and solidify in case of fire, thus avoiding further accidents. Finally, the structure of the flange lips also allows the solidified metal to be quickly removed or replaced to quickly proceed to the next casting production process. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the low-pressure casting machine in an embodiment of this utility model;

[0021] Figure 2 This is a cross-sectional structural diagram of the low-pressure casting machine in an embodiment of the present invention;

[0022] Figure 3 Appendix of this utility model Figure 2 A magnified structural diagram of A in the diagram;

[0023] Figure 4 This is a schematic diagram of the sealing assembly in an embodiment of the present invention;

[0024] Figure 5 This is a partial structural schematic diagram of the sealing assembly in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the sealing lower seat in an embodiment of the present utility model;

[0026] Figure 7 This is a schematic diagram of the structure of the sealing upper seat and the limiting piece in an embodiment of this utility model.

[0027] Figure label:

[0028] 1-Anti-fire structure; 2-Low-pressure casting machine; 3-Lip; 4-Sealing cavity; 5-Sealing assembly;

[0029] 21-Liquid riser pipe, 22-Cavity, 23-Furnace cover;

[0030] 11-Flange lip, 12-Flange lip sleeve;

[0031] 51-Upper sealing seat, 52-Lower sealing seat, 53-Limiting plate, 54-Limiting groove, 55-Limiting ring, 56-Gear disc, 57-Motor, 58-Flange.

[0032] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0035] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0037] Example 1:

[0038] Please refer to the attached document as well. Figures 1 to 7 This embodiment provides a fire-prevention structure 1 for a low-pressure casting machine 2. The low-pressure casting machine 2 includes a riser pipe 21, and the fire-prevention structure 1 is disposed between the riser pipe 21 and the mold cavity 22. The fire-prevention structure 1 includes:

[0039] Two flange lips 11 are disposed facing away from each other on the outer periphery of the riser tube 21, and form a lip 3 on the outer periphery of the riser tube 21;

[0040] Flange lip sleeve 12 is fitted around the outer periphery of the two flange lips 11;

[0041] There is a vertical clearance between the flange lip 12 and the furnace cover 23 of the low-pressure casting machine 2.

[0042] It should be noted that in the prior art, the main occurrence of fire escape accidents in the low-pressure casting machine 2 is damage or aging failure of the sealing gasket at the connection between the mold and the riser pipe 21. Based on the above problems, this embodiment provides a fire escape prevention structure 1 for the low-pressure casting machine 2. This structure, which includes a flange lip 11 and a flange lip sleeve 12, is installed outside the riser pipe 21 to prevent fire escape accidents. The flange lip 11 and flange lip sleeve 12 are interlocked and jointly installed outside the riser pipe 21. Based on the original sealing gasket, this physical sealing method reduces the risk of fire escape after the original sealing gasket is damaged. Furthermore, the presence of a clearance prevents the furnace body from contacting the casting platform during its ascent. To address the issue of insufficient compression of the sealing gasket causing leakage and fire, the flange lips 11 are arranged back-to-back and have a distinct curved structure. During the ascent of the casting furnace body (riser pipe 21), the cushioning and sealing functions are greatly activated, resolving the fire problem caused by insufficient compression and ensuring safe operation of the low-pressure casting machine 2. Furthermore, the flow space formed by the lip 3 allows the molten metal to flow into the lip 3 and cool and solidify promptly in the event of a fire, preventing further accidents. Finally, the structure of the flange lips 11 also enables the rapid removal of solidified metal, allowing for quick replacement and transition to the next casting process.

[0043] In some embodiments, the preferred range of the mating clearance is 50 mm to 100 mm.

[0044] In some embodiments, the lip 3 formed by the two flange lips 11 has a V-shaped structure.

[0045] In some embodiments, the two flange lips 11 are arranged parallel to the casting platform.

[0046] In this embodiment, the upper end face of the flange lip 12 and the outer periphery of the upper flange lip 11 form a sealing cavity 4. When the riser pipe 21 rises under pressure and docks with the casting cavity 22, the two flange lips 11, which are arranged opposite to each other, undergo radial elastic deformation under pressure, and their outer curved surfaces form a tight dynamic fit with the inner wall of the flange lip 12. At this time, the outer curved surface of the upper flange lip 11 and the upper end face of the flange lip 12 together enclose an annular cavity structure, i.e., the sealing cavity 4. If molten metal leaks due to gasket damage or mold cracking, the high-temperature molten metal will first be confined within the upper flange lip 11. Only if the upper flange lip 11 is damaged will it fall into the lip 3 area.

[0047] Because the sealed cavity 4 has a limited volume and is exposed to relatively low-temperature air, the molten metal rapidly dissipates heat and solidifies here, forming a solid metal plug. This solidification process essentially constructs a second active sealing barrier: on the one hand, the solidified material fills the cavity space, physically blocking the leakage path and preventing the molten metal from splashing further upwards to the furnace cover 23 area; on the other hand, the presence of the sealed cavity 4 significantly prolongs the time the molten metal is exposed to the non-sealed environment, accelerating its phase change solidification using the principle of heat exchange. Even under continuous micro-leakage, a self-sealing effect can be achieved through staged solidification.

[0048] In this embodiment, a sealing component 5 is provided below the flange lip 12. The sealing component 5 is used to shrink the outer diameter of the lower flange lip 11 so that it fits into the riser pipe 21.

[0049] When the riser pipe 21, driven by hydraulic pressure, raises its flange face to fit against the metal flange of the mold cavity 22, the specially designed inverted conical sealing lip on the upper flange lip 11 converges downwards towards the sealing cavity 4 at the root of the riser pipe 21 flange. If a sudden mold crack occurs during casting or the pressure in the cavity 22 surges abnormally, the impact force of the high-temperature molten metal jet will directly act on the back of the inverted conical sealing lip. At this time, the structural advantage of the inverted conical shape becomes apparent: the axial impact component of the jet flow is converted into lateral pressure on the conical slope of the lip. This component force, in turn, drives the inverted conical sealing lip to press even tighter against the bottom and side walls, instantly enhancing the geometric wedge effect and forming an instantaneous "tighter and tighter" self-reinforcing dynamic seal, effectively preventing the horizontal flow of molten metal along the traditional flat flange joint.

[0050] In this embodiment, the sealing assembly 5 includes an upper sealing seat 51, a lower sealing seat 52, and a plurality of limiting pieces 53. The lower end face of the upper sealing seat 51 is provided with a plurality of limiting grooves 54, the upper end face of the lower sealing seat is provided with a limiting ring 55, and the limiting pieces 53 are disposed within the limiting grooves 54 and the limiting rings 55.

[0051] The upper sealing seat 51 and the lower sealing seat 52 are rotatably configured, and the plurality of limiting plates 53 abut against the outer diameter of the lower flange lip 11. The pressure exerted by the limiting plates 53 on the lower flange lip 11 is changed by the rotation of the lower sealing seat 52.

[0052] After the initial connection between the riser pipe 21 and the mold is completed in the low-pressure casting machine 2, the sealing assembly 5 is activated. The upper sealing seat 51 is fixedly connected to the lower part of the flange lip 12. Multiple limiting grooves 54 arranged in a circular array around the central axis are machined on its lower end face. These limiting grooves 54 are not vertically arranged but have a specific inclination angle. The lower sealing seat 52 is located below the upper sealing seat 51. A limiting ring 55 with a polygonal cross-section (such as hexagonal or octagonal) is machined on its upper end face, and the number of its corners strictly matches the number of limiting pieces 53. Several limiting pieces 53 with specific geometric shapes are embedded at their upper and lower ends into the inclined limiting grooves 54 of the upper sealing seat 51 and the polygonal limiting ring 55 of the lower sealing seat 52, respectively. When enhanced sealing is required, the drive source or limiting source drives the lower sealing seat 52 to rotate around the axis. Because the lower end of the limiting piece 53 is confined within the corner of the polygonal limiting ring 55 of the lower sealing seat 52, the rotational motion forces the limiting piece 53 to slide along the edge of the polygonal limiting ring 55. Simultaneously, the upper end of the limiting piece 53 is constrained by the inclined limiting groove 54 of the upper sealing seat 51. The inclined groove wall forces the tangential sliding motion of the limiting piece 53 within the limiting ring 55 into a composite motion along the inclined direction of the limiting groove 54. Guided by the inclined groove, the limiting piece 53 not only slides within the limiting ring 55 with the lower sealing seat 52, but also, under the reaction of the groove wall, generates a radially inward displacement pointing towards the axis of the riser pipe 21. This causes its inner surface to press tightly against the outer circumferential surface of the lower flange lip 11. As the rotation angle of the lower sealing seat 52 increases, the limiting piece 53 continues to radially retract, applying a uniformly increasing radial compressive force to the lower flange lip 11. The extrusion pressure overcomes the elastic deformation resistance of the lip material, forcing the lower flange lip 11 to undergo radial contraction deformation, reducing its inner diameter and thus tightly fitting against the outer wall of the riser pipe 21, eliminating any potential annular gaps. When thermal expansion and contraction or mechanical vibration causes the gap to reappear, the system can dynamically compensate for the pressure in real time by finely adjusting the rotation angle of the lower sealing seat 52, maintaining a constant sealing contact stress.

[0053] In this embodiment, the limiting grooves 54 are arranged in a circular array with reference to the axis of the sealing upper seat 51, while being inclined.

[0054] On the lower end face of the upper sealing seat 51, multiple limiting grooves 54 are not arranged in a straight radial line, but are uniformly distributed around the rotation axis of the upper sealing seat 51, strictly following the pattern of a circular array (e.g., 6-12 grooves are set in equal division of the circumference), and the extension direction of each limiting groove 54 forms a specific inclined angle with the radial plane. When the lower sealing seat 52 is driven to rotate, the lower end of the limiting piece 53 embedded in the corner of its polygonal limiting ring 55 is forced to follow the circular motion. At this time, the upper end of the limiting piece 53 is constrained by the geometric constraints of the inclined limiting groove 54 of the upper sealing seat 51. The normal reaction force exerted by the inclined groove wall on the upper end of the limiting piece 53 can be decomposed into two key components: one is the supporting force perpendicular to the groove wall, and the other is the guiding force along the groove wall direction. Due to the inclined angle of the groove, this guiding force further drives the limiting piece 53 to slide along the extension direction of the inclined groove.

[0055] In this embodiment, the cross-section of the limiting ring 55 is polygonal, and the number of its corners matches the number of the limiting pieces 53.

[0056] In some embodiments, a torsion spring is provided between the upper sealing seat 51 and the lower sealing seat 52. The torsion spring is coaxially mounted in the annular space between the upper sealing seat 51 and the lower sealing seat 52, and its two fixed arms are respectively engaged in the preset positioning holes or grooves of the upper and lower seats, so that the torsion spring applies a constant reset torque relative to the upper sealing seat 51 to the lower sealing seat 52 in its natural state. It can be understood that the torsion spring acts as a limiting source.

[0057] In some embodiments, a gear disk 56 is fixedly disposed on the lower end face of the sealing lower seat 52, and a motor 57 is disposed below the furnace cover 23 of the low-pressure casting machine 2. The output end of the motor 57 cooperates with the gear disk 56. It can be understood that the motor 57 acts as a drive source, and the gear disk 56 is rigidly connected to the bottom of the sealing lower seat 52. Its tooth profile is precisely designed and forms a meshing pair with the drive gear on the output shaft of the motor 57. When the casting cycle starts or the sealing state needs to be adjusted due to changes in the working conditions, the control system sends a command to the motor 57, and the output shaft of the motor 57 rotates. Through the torque transmission and speed conversion of the gear pair, the gear disk 56 drives the sealing lower seat 52 to rotate precisely around the axis. This rotational motion is forcibly and synchronously pushed by the polygonal limit ring 55 to make all the limit plates 53 rotate in a circular motion, and then guided by the limit groove 54, which is efficiently converted into the radial displacement of the limit plates 53, thereby precisely controlling the clamping force of the lower flange lip 11 on the riser pipe 21.

[0058] In some embodiments, the fire-prevention structure 1 further includes a flange 58 disposed on the insulation sleeve inside the low-pressure casting machine 2. Both the inner and outer edges of the flange 58 are inclined, with the angle ranging from 4° to 6°. The flange 58, installed on the top of the insulation sleeve, has its inner and outer edges machined into inclined surfaces at specific angles, forming a symmetrical conical transition zone. When molten metal accidentally leaks during the casting process, the sprayed or overflowing molten metal first impacts the surface of the flange 58. At this time, the inclination of the inner edge constitutes the first flow-guiding barrier—the inclined surface forces the molten metal flow to change its direction of movement, from vertical impact to tangential flow along the inclined surface. Furthermore, it ensures that the molten metal can be quickly removed after solidification following a fire, preventing damage to the furnace cover 23 and platform due to the clamping force during solidification.

[0059] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A fire-prevention structure for a low-pressure casting machine, characterized in that, The low-pressure casting machine includes a riser pipe, and the fire-prevention structure is disposed between the riser pipe and the mold cavity. The fire-prevention structure includes: Two flange lips are disposed opposite to each other on the outer periphery of the riser tube, forming a lip on the outer periphery of the riser tube; Flange lip sleeve, fitted around the outer periphery of the two flange lips; There is a vertical clearance between the flange lip and the furnace cover of the low-pressure casting machine.

2. The fire-prevention structure for a low-pressure casting machine as described in claim 1, characterized in that, The upper end face of the flange lip and the outer periphery of the upper flange lip form a sealing cavity.

3. The fire-prevention structure for a low-pressure casting machine as described in claim 1, characterized in that, A sealing assembly is provided below the flange lip, which is used to shrink the outer diameter of the lower flange lip so that it fits into the riser pipe.

4. The fire-prevention structure for a low-pressure casting machine as described in claim 3, characterized in that, The sealing assembly includes an upper sealing seat, a lower sealing seat, and several limiting pieces. The lower end face of the upper sealing seat is provided with several limiting grooves, and the upper end face of the lower sealing seat is provided with a limiting ring. The limiting pieces are disposed within the limiting grooves and the limiting rings.

5. The fire-prevention structure for a low-pressure casting machine as described in claim 4, characterized in that, The upper and lower sealing seats are rotatably configured, and several of the limiting plates abut against the outer diameter of the lower flange lip. The rotation of the lower sealing seat changes the compressive force of the limiting plates on the lower flange lip.

6. The fire-prevention structure for a low-pressure casting machine as described in claim 4, characterized in that, The limiting grooves are arranged in a circular array with the axis of the sealing upper seat as the reference, and are also inclined.

7. The fire-prevention structure for a low-pressure casting machine as described in claim 4, characterized in that, The cross-section of the limiting ring is polygonal, and the number of its corners matches the number of the limiting pieces.

8. The fire-prevention structure for a low-pressure casting machine as described in claim 5, characterized in that, A torsion spring is provided between the upper sealing seat and the lower sealing seat.

9. The fire-prevention structure for a low-pressure casting machine as described in claim 5, characterized in that, A gear disk is fixedly installed on the lower end face of the sealing seat, and a motor is installed below the furnace cover of the low-pressure casting machine. The output end of the motor is engaged with the gear disk.

10. The fire-prevention structure for a low-pressure casting machine as described in claim 1, characterized in that, The fire-proof structure also includes a flange plate installed on the insulation sleeve inside the low-pressure casting machine. The inner and outer edges of the flange plate are both provided with an inclination angle, and the angle range of the inclination angle is 4° to 6°.

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