Low pressure casting mold

Abstract

The utility model relates to the field of aluminium alloy wheel hub casting mould, and disclose a low pressure casting mould, it includes the mould body that is constituted by upper die, side mould and bottom die, the upper die swing joint has the swing block in the wheel hub inner flange groove part, and the swing block outer edge is made according to the contour of wheel hub inner flange groove part. The core innovation of the utility model lies in: swing block rotation avoidance mechanism, swing block is hinged in upper die through pin shaft, and is rotated around the shaft when being extruded by wheel hub casting, forms arc demoulding path, thoroughly solves the demoulding interference problem of inner flange groove and negative angle structure, gravity self-resetting design, swing block adopts inverted T section and the front edge is heavy, and is automatically reset after demoulding, and external driving mechanism is saved, split flange coordination system, split flange part and swing block are matched through wedge surface, and when descending, both provide casting surface contact ejection (prevent deflection scratch), and swing block swing gives the action space.

Description

Technical Field

[0001] This utility model relates to the field of aluminum alloy wheel hub casting molds, and in particular to a low-pressure casting mold. Background Technology

[0002] In the field of low-pressure casting of aluminum alloy wheels, with the increasing demand for lightweight automobiles, wheel designs are becoming increasingly complex. Inner rim grooves, deep concave structures, and negative angle features (such as the inner rim grooves of sports wheels) have gradually become mainstream design trends. However, such structures face serious technical bottlenecks when using traditional casting molds for production, mainly in the following two aspects: 1. Demolding interference problem: Traditional integral upper molds need to separate along a straight line during demolding. However, the negative angle structure and complex grooves at the inner rim of the wheel hub will form a mechanical locking zone, resulting in rigid interference between the casting and the mold. Forced demolding can easily cause the casting to be scratched, deformed, or even cracked, resulting in a high scrap rate; 2. To overcome the above demolding problems, the blank is forced to retain too much machining allowance or thicken the wall in key areas such as the root of the groove to avoid demolding difficulties and defects caused by insufficient allowance during subsequent machining. This results in a large amount of "ineffective metal," making it difficult to effectively improve metal utilization and increasing the workload of subsequent machining.

[0003] Therefore, developing a low-pressure casting mold for practical production is an urgent problem to be solved. Utility Model Content

[0004] The purpose of this invention is to address the above-mentioned problems by providing a low-pressure casting mold to solve the demolding problem of complex grooved wheel hubs, thereby breaking through the bottleneck of metal utilization and meeting the industry's demand for high-performance, lightweight, and low-cost wheel hub manufacturing.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A low-pressure casting mold includes a mold body consisting of an upper mold, a side mold, and a bottom mold. The upper mold is movably connected to a swing block corresponding to the inner rim groove of the wheel hub. The outer edge of the swing block is made according to the contour of the inner rim groove of the wheel hub, thus forming the forming structure of the inner rim groove of the wheel hub casting.

[0006] Preferably, a connecting rod is fixedly provided on the upper mold, and the swing block is hinged to the connecting rod by a pin, so that the swing block can swing radially relative to the upper mold.

[0007] Preferably, the swing block has a front edge structure and a rear edge structure, and its cross-section is an inverted T-shaped structure. The front edge structure is set in the inner rim groove of the wheel hub, and the mass of the front edge structure is greater than that of the rear edge structure.

[0008] Preferably, the rear edge structure of the swing block is slidably connected to the upper mold through mutually cooperating wedge-shaped surfaces to ensure smooth swing block movement.

[0009] Preferably, the upper mold is movably connected to a split flange portion corresponding to the flange area of ​​the wheel hub casting, and the split flange portion is connected to a push rod, which can serve as a demolding and ejection component for the wheel hub casting.

[0010] Preferably, a positioning structure is provided corresponding to the split flange portion. The positioning structure includes a positioning column that is fixedly connected to the top template. The positioning column slides through the top plate and has a downward limiting part at the lower end of the positioning column, which serves as a downward limiting structure for the split flange portion. The beneficial effects of this utility model are as follows: This invention achieves efficient demolding: the innovative swing block mechanism enables smooth and damage-free demolding of wheel hub castings (especially deep grooves and negative angle areas), significantly reducing the risk of demolding damage and deformation, and improving the product qualification rate.

[0011] Improved metal utilization: It solves the problem of having to increase machining allowance or wall thickness due to difficulties in demolding, making the design of wheel hub castings more compact and lighter, achieving 360° circumferential weight reduction. It is estimated that the metal utilization of wheel hub castings can be increased by about 15%, especially for grooved products.

[0012] Reasonable and reliable structure: This utility model has a simple structure, stable and reliable operation, and is easy to manufacture and maintain. The center of gravity configuration of the inverted T-shaped swing block realizes zero-power automatic reset, eliminating the need for drive components such as springs / cylinders, reducing the failure rate and maintenance costs, and improving equipment reliability. Attached Figure Description

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 This is a schematic diagram of the planar structure of this utility model.

[0015] Figure 2 This is a three-dimensional structural diagram of the upper mold of this utility model.

[0016] Figure 3 for Figure 2 A schematic diagram of the hidden upper mold's three-dimensional structure.

[0017] Figure 4 This is a schematic diagram of the structure of the present invention in the demolded state.

[0018] In the diagram: 10--Upper mold; 11--Top plate; 12--Top template; 13--Top rod; 20--Swing block; 21--Front edge structure; 22--Rear edge structure; 23--Wedge surface; 30--Connecting rod; 31--Pin; 40--Split flange part; 50--Positioning pin; 51--Downward limit part; 52--Upward limit part. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0020] like Figure 1-4 As shown, a low-pressure casting mold includes a mold body composed of an upper mold 10, a side mold, and a bottom mold. During casting, the upper mold, side mold, and bottom mold are closed to form a cavity for filling with molten aluminum; during mold opening, the side mold opens, and the wheel hub blank is ejected from the mold body, completing the demolding. Addressing the problems of current molds hindering demolding and low metal utilization for grooved products, this invention provides a movable swing block 20 connected to the upper mold 10 corresponding to the inner rim groove of the wheel hub. The outer edge of the swing block 20 is molded according to the contour of the inner rim groove, forming the forming structure of the inner rim groove of the wheel hub casting. Through the movable connection between the swing block 20 and the upper mold 10, the radial dimension of the upper mold 10 corresponding to the inner rim groove is adjustable, thereby eliminating the obstruction of the groove to the wheel hub casting during demolding. During casting, the swing block 20 is in its initial position, serving as the forming structure for the inner rim groove of the wheel hub casting. Upon mold opening, the top plate 11 drives the ejector rod 13 downwards, pushing the wheel hub casting out of the mold. During this process, the swing block 20 moves inwards to detach from the wheel hub casting, simultaneously reducing the diameter of the upper mold 10 corresponding to the inner rim groove of the wheel hub. This effectively avoids the concave structures, complex grooves, and negative angle structures on the wheel hub casting, ensuring the wheel hub casting is smoothly and completely removed without damage. This design fundamentally solves the demolding problem of complex wheel hub structures (especially inner rim grooves and negative angles), significantly improving the demolding success rate and casting yield, and reducing casting damage and mold wear caused by demolding difficulties.

[0021] In a preferred embodiment, a connecting rod 30 is fixedly mounted on the upper mold 10, and the swing block 20 is hinged to the connecting rod 30 via a pin 31, allowing the swing block 20 to swing radially relative to the upper mold 10. During casting, the swing block 20 swings to its initial position at the lower end of the upper mold 10, forming the molding structure of the inner rim groove of the wheel hub casting. During mold opening, as the wheel hub casting continues to move downwards, its inner rim groove compresses the swing block 20, forcing the swing block 20 to rotate and swing around the pin 31. The rotational movement of the swing block 20 avoids the complex grooves and negative angle structures on the wheel hub casting, forming a non-linear arc-shaped demolding path, thereby smoothly and completely removing the wheel hub casting from the mold cavity (especially the groove area) without damage. After demolding, the swing block 20 swings back to its initial position, ready to execute the next casting cycle. The rotary swing demolding method achieved by this hinge structure cleverly transforms the downward linear motion of the casting into the rotational avoidance motion of the swing block 20, providing a dynamic and non-interference demolding path for complex cavities, and effectively avoiding the jamming and tearing problems caused by traditional linear demolding.

[0022] The swing block 20 has a leading edge structure 21 and a trailing edge structure 22, with an inverted T-shaped cross-section. The leading edge structure 21 is positioned corresponding to the inner rim groove of the wheel hub, and its mass is greater than that of the trailing edge structure 22, causing the leading edge of the swing block 20 to tilt downwards in a free state. This center of gravity configuration allows the swing block 20 to automatically reset by gravity after the wheel hub casting is demolded, eliminating the need for a separate reset drive mechanism and simplifying the overall structure. This gravity-based self-resetting design not only simplifies the mold structure and control system, eliminating the need for additional drive components (such as springs and cylinders) and their maintenance, but also improves the reliability and cycle efficiency of the mold operation.

[0023] Preferably, the trailing edge structure 22 of the swing block 20 is slidably connected to the upper mold 10 via a wedge-shaped surface 23, ensuring smooth movement of the swing block 20. During mold opening, the swing block 20 swings inward, and its trailing edge structure 22 slides backward and upward along the wedge-shaped surface 23, completing the retraction action. The wedge-shaped surface 23 provides precise sliding guidance, effectively constraining the movement trajectory of the swing block 20, ensuring smooth and precise rotational swing and retraction actions, reducing friction and jamming risks during movement, and improving operational reliability and mold life.

[0024] Preferably, to optimize demolding, the upper mold 10 is movably connected to a split flange portion 40 corresponding to the flange area of ​​the wheel hub casting. The wedge-shaped surface 23 is located between the split flange portion 40 and the swing block 20. The split flange portion 40 is connected to the ejector rod 13 and can serve as a demolding ejection component for the wheel hub casting. During casting, the split flange portion 40, the swing block 20, and the upper mold 10 together form a complete upper mold structure; during demolding, the top plate 11 drives the split flange portion 40 to move downward as a whole through the ejector rod 13, pushing the wheel hub casting away from the upper mold 10 simultaneously. The split flange portion 40 has a dual function: firstly, its downward displacement provides the necessary clearance space for the swing block 20 to flip and swing, completely avoiding motion interference; secondly, as an integral ejection component, it achieves surface contact ejection of the wheel hub casting, significantly increasing the contact area compared to the traditional point contact ejector rod 13 structure. The introduction of the split flange section 40 serves two purposes. First, its active downward movement creates interference-free conditions for the swing block 20, ensuring smooth demolding. Second, its large ejection contact surface significantly improves the uniformity and stability of the ejection force, effectively preventing the wheel hub casting from skewing, deforming, or surface scratching during ejection, thus ensuring the geometric accuracy and surface quality of the casting. Simultaneously, surface contact ejection reduces the pressure per unit area, minimizing the risk of damage to the flange area of ​​the casting.

[0025] Preferably, a positioning structure is provided for the split flange portion 40 to ensure its movement and positioning accuracy. The positioning structure includes a positioning post 50 fixed to the top mold plate 12, which slides through the top plate 11. The lower end of the positioning post 50 is provided with a downward limiting part 51, which serves as a downward limiting structure for the split flange portion 40. During demolding, the top plate 11 moves vertically downward under the guidance of the positioning post 50, driving the ejector rod 13, the split flange portion 40, and the wheel hub casting to move synchronously, while simultaneously pushing the swing block 20 to swing inward. When the wheel hub casting is completely detached from the upper mold 10, the top plate 11 just abuts against the downward limiting part 51, restricting the split flange portion 40 from continuing to move downward. The positioning structure formed by the positioning post 50 and the limiting part provides precise vertical guidance and stroke endpoint control for the downward movement of the split flange portion 40, ensuring that the demolding ejection action is strictly carried out along the predetermined path, preventing skewing, and precisely controlling the demolding stroke to avoid over-ejection or under-ejection, thus ensuring the accuracy and reliability of the demolding action.

[0026] Preferably, the top of the positioning post 50 is provided with an upward limiting part 52, which serves as an upward limiting structure for the split flange part 40. After demolding, the top plate 11 moves upward, causing the split flange part 40 to reset. When the top plate 11 abuts against the upward limiting part 52, the split flange part 40 accurately resets into position, re-enclosing with the swing block 20 and the upper mold 10 to form a complete upper mold structure. The upward limiting structure ensures that the split flange part 40 can accurately return to its initial casting position during reset, ensuring a sealed fit between it and the upper mold 10 and the swing block 20, preventing flash or dimensional deviations during casting, and providing a reliable positioning reference for the next casting cycle, maintaining the repeatability of the mold's positioning accuracy. The above-disclosed embodiments are merely specific examples of this utility model, but this utility model is not limited thereto. For those skilled in the art, any modifications made without departing from the principle of this utility model should be considered as protected by this utility model.

Claims

1. A low-pressure casting mold, characterized in that: The mold body consists of an upper mold (10), a side mold, and a bottom mold. The upper mold (10) is movably connected to a swing block (20) corresponding to the inner rim groove of the wheel hub. The outer edge of the swing block (20) is made according to the contour of the inner rim groove of the wheel hub, forming the forming structure of the inner rim groove of the wheel hub casting.

2. The low-pressure casting mold according to claim 1, characterized in that: A connecting rod (30) is fixedly provided on the upper mold (10), and the swing block (20) is hinged to the connecting rod (30) through a pin (31) so that the swing block (20) can swing radially relative to the upper mold (10).

3. A low-pressure casting mold according to claim 2, characterized in that: The swing block (20) has a front edge structure (21) and a rear edge structure (22), and its cross-section is an inverted T-shaped structure. The front edge structure (21) is set in the inner rim groove of the hub, and the mass of the front edge structure (21) is greater than that of the rear edge structure (22).

4. A low-pressure casting mold according to claim 3, characterized in that: The rear edge structure (22) of the swing block (20) is slidably connected to the upper mold (10) through a wedge-shaped surface (23) that cooperates with each other.

5. A low-pressure casting mold according to claim 1, characterized in that: The upper mold (10) is movably connected to the flange area of ​​the wheel hub casting with a split flange part (40), and the split flange part (40) is connected to the ejector rod (13), which can be used as a demolding ejection component for the wheel hub casting.

6. A low-pressure casting mold according to claim 5, characterized in that: A positioning structure is provided corresponding to the split flange part (40). The positioning structure includes a positioning column (50) that is fixedly connected to the top template (12). The positioning column (50) slides through the top plate (11). The lower end of the positioning column (50) is provided with a downward limiting part (51) as a downward limiting structure for the split flange part (40).

7. A low-pressure casting mold according to claim 6, characterized in that: The top of the positioning column (50) is provided with an upward limiting part (52), which serves as the upward limiting structure of the split flange part (40).

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