Description:SINGLE CASTING FRAME STRUCTURE FOR TWO WHEELER
FIELD OF INVENTION
The present disclosure relates to vehicle frame structures, and more particularly to a single casting frame structure for two-wheeler vehicles that integrates front frame, battery box, and rear frame components into a single cast structure.

BACKGROUND
Two-wheeler vehicles, such as motorcycles and electric scooters, rely on frame structures to provide the fundamental structural support for various vehicle components. The frame serves as the backbone that connects and supports the engine or motor, battery systems, suspension components, steering mechanisms, and other essential vehicle elements. Traditional frame construction methods have evolved over decades to meet the demands of vehicle performance, safety, and manufacturing efficiency.
Conventional two-wheeler frames are typically constructed using multiple separate components that are assembled together through welding, bolting, or other joining methods. These multi-component frame systems generally include distinct front frame sections, rear frame sections, and separate battery housing structures. Steel has been the predominant material for frame construction due to its strength characteristics and established manufacturing processes. The assembly process involves fabricating individual frame components and subsequently joining them to create the complete frame structure.
Manufacturing processes for traditional frame structures present several challenges. Welding operations can introduce thermal stresses and dimensional variations that may compromise structural integrity and require additional correction procedures. The multi-component nature of conventional frames results in increased part counts, which can complicate manufacturing processes and inventory management. Assembly operations involving multiple separate components can be time-intensive and may introduce variability in final product quality.
Structural performance limitations also exist with conventional frame designs. Multi-piece frame assemblies may exhibit reduced torsional and longitudinal stiffness compared to integrated structures. The joints between separate frame components can represent potential points of structural weakness under operational loads. Weight optimization can be challenging when multiple components and joining elements are required to achieve the desired structural performance.
Manufacturing complexity increases with the number of individual components that must be produced, handled, and assembled. Traditional frame construction methods may require specialized tooling for each component, multiple manufacturing steps, and extensive quality control procedures. The need for precise alignment and fitment of multiple components during assembly can contribute to manufacturing cycle times and production costs.
It has been appreciated that a frame structure is needed that overcomes one or more of these problems.
SUMMARY
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description.
In a first aspect, a single casting frame structure for a two-wheeler vehicle is provided. The single casting frame structure comprises a front frame portion, a rear frame portion, and a battery box portion integrally formed as a single cast component, wherein the front frame portion includes a steering pipe configured to receive a steel insert that is press-fitted therein and plurality of reinforcement members to withstand the bending load , the battery box portion is positioned between the front frame portion and the rear frame portion and includes a removable top cover for battery access, the rear frame portion includes a swing arm mounting area with C shaped flange reinforcement to withstand wheel forces, and the single cast component has a casting thickness of at least 2.5 mm.
This integrated single casting design eliminates the need for multiple separate frame components, reducing the number of parts by 92% while providing superior structural integrity. The press-fitted steel insert in the steering pipe eliminates the need for side cores during manufacturing, simplifying the casting process and reducing production complexity. The integrated battery box as a structural member increases torsional stiffness by 2.5 times and longitudinal stiffness by 2 times compared to conventional multi-piece frame designs, while simultaneously reducing overall frame weight by 36%.
The single casting frame structure may further include side reinforcement areas for the battery box casing that are thicker at the top and narrower at the bottom.
The tapered side reinforcement design optimizes material distribution to provide maximum strength where needed while minimizing weight, and the varying thickness profile helps distribute loads effectively from the battery compartment to other frame sections.
The single casting frame structure may further include a bottom reinforcement member configured to strengthen the battery casing and distribute loads from the front frame portion to a motor mounting flange.
The bottom reinforcement member creates a continuous load path that enhances the structural integrity of the entire frame assembly, ensuring that forces from the front suspension and steering are efficiently transferred through the battery compartment to the motor mounting area, thereby improving overall vehicle stability and handling.
The C shaped flange reinforcement in the swing arm mounting area may be configured to minimize modal frequency of motor vibration and strengthen the motor mounting area.
The C shaped flange configuration provides targeted reinforcement that reduces vibration transmission from the motor to the frame while maintaining optimal stiffness characteristics, resulting in improved rider comfort and reduced fatigue loading on the frame structure.
The single cast component may be manufactured using a casting process that requires only a single slider for the integrated steering pipe.
The single slider manufacturing approach significantly reduces mold complexity and manufacturing costs while improving production efficiency and material yield, leading to faster cycle times and reduced handling costs during production.

BRIEF DESCRIPTION OF FIGURES
Fig. 1 illustrates an perspective view of a frame assembly for a two-wheeler vehicle showing the integration of front frame member, middle portion and rear portion as a single frame casting structure
Fig. 2 illustrates an exploded view of a frame assembly showing steering pipe, steel insert, mounting bolts, battery cover, reinforcement member, and structural rib components.
Fig. 3 illustrates a bottom perspective view of a frame assembly showing motor support structure, motor mounting flange, battery cover, and reinforcement member with grid-like pattern.
Fig. 4 illustrates a top view of the single casting frame structure showing the integrated design with steering tube portion, battery box section, and rear frame portion.
Fig. 5 illustrates a front view of the single casting frame structure showing the vertical integration of steering tube assembly, battery box section with reinforced sidewalls, and motor mounting provisions.
Fig. 6 illustrates a manufacturing analysis diagram showing draft considerations for the single casting frame structure with core and cavity pulling directions.
Common reference numerals are used throughout the figures to indicate similar features.
DETAILED DESCRIPTION
Referring to Fig. 1, a frame assembly 100 for a two-wheeler vehicle comprises multiple integrated components formed as a single cast structure. The frame assembly 100 includes a front frame member 10 that extends from a steering portion of the frame assembly 100. A middle portion 20 where battery module is placed is integrated with the front frame member 10 to form a continuous structural element.
The frame assembly 100 represents a departure from traditional multi-component frame construction by integrating components that are typically manufactured and assembled separately. The front frame member 10, battery box 20, and rear frame member 30 are formed as a single casting, eliminating the joints and fasteners that would otherwise connect these separate components.
The integration of multiple components into the single casting reduces the number of parts by approximately 92% compared to conventional multi-piece frame assemblies. The unified structure of the frame assembly 100 provides enhanced structural performance, including an increase in torsional stiffness of approximately 2.5 times and an increase in longitudinal stiffness of approximately 2 times compared to previous multi-component frame platforms.
The battery box 20 is provided within the frame assembly 100, contributing to the overall rigidity and load distribution throughout the structure. The motor mounting section 40 provides mounting provisions for electric drive components while maintaining structural continuity with the rear frame member 30 and battery box 20. The motor mounting section incorporates a C-shaped flange 40 configuration that provides enhanced structural performance for motor mounting applications. The C-shaped geometry 40 of the motor mounting section creates a structural arrangement that distributes mounting loads across a broader area while providing increased stiffness characteristics. The C-shaped flange 40 design may minimize modal frequency effects from motor vibration by providing a structural configuration that resists resonant vibration modes that could otherwise be transmitted through the frame assembly 100.
The steering tube of front portion 10 incorporates a steel insert 11 that is press fitted within the steering tube of front portion 10 to simply manufacturing processes and structural performance. The steel insert 11 provides enhanced durability and bearing support within the steering tube 10 while enabling simplified casting procedures for the frame assembly 100.
The press fit configuration of the steel insert 11 within the steering tube of front portion 10 eliminates the need for side cores during the casting manufacturing process. Side cores in casting operations add complexity and cost to mold design and operation. By incorporating the steel insert 11 through press fitting after casting, the steering tube of front portion 10 can be cast with a simple cylindrical bore that does not require additional mold components to create complex internal geometries.
The manufacturing of the frame assembly 100 utilizes a single slider mechanism during the casting process for the integrated steering tube of front portion 10. The single slider approach reduces mold complexity compared to multi-slider systems that would otherwise be required for more complex internal geometries. The steering tube 10 is designed with appropriate geometry to accommodate the single slider manufacturing approach while maintaining structural performance requirements.
The battery box 20 forms a structural component of the frame assembly 100 and includes a battery box sidewall which includes plurality of side reinforcement members 22 and a removable battery box cover 5. The battery box sidewall reinforcement members 22 incorporates a tapered reinforcement design that varies in thickness along the vertical dimension of the battery box 20. The battery box sidewall 22 is configured with a thicker cross-section at the top portion 22b and transitions to a narrower cross-section 22a at the bottom portion. The tapered configuration of the battery box sidewall reinforcement members 22 optimizes material distribution to provide enhanced structural support where loads are concentrated while reducing material usage in areas where lower structural demands exist.
The battery box cover 5 is designed as a removable component to enable access to battery modules housed within the battery box 20. The removable configuration of the battery box cover 5 allows for battery installation, removal, and maintenance operations without requiring disassembly of the frame assembly 100. The battery box cover 5 interfaces with the battery box sidewall 22a to create an enclosed compartment for battery module protection.
The integrated design of the battery box 20 within the frame assembly 100 eliminates separate mounting brackets and fasteners that would otherwise be required to attach a discrete battery enclosure to a conventional frame structure. The battery box 20 shares material continuity with the front frame member 10 and the rear frame member 30, creating a single load path that distributes forces throughout the frame assembly 100 during vehicle operation.
The front frame member 10 includes a reinforcement member 50 that provides structural support and load distribution throughout the front portion of the frame assembly 100. The reinforcement member 50 comprises a first portion 50a and a second portion 50b that are integrated within the casting structure to enhance the structural performance of the front frame member 10.
The reinforcement member 50 incorporates a varying thickness profile where the thickness of section 50b is greater than the thickness of section 50a. This differential thickness configuration optimizes material distribution to provide enhanced structural support where loads are concentrated while reducing material usage in areas where lower structural demands exist. The thicker section 50b may be positioned at locations where higher bending moments or concentrated loads occur during vehicle operation, while the thinner section 50a may be located in areas with reduced structural requirements.
The first portion 50a and second portion 50b of the reinforcement member 50 create a continuous structural element that transfers loads throughout the front frame member 10. The varying thickness profile of the reinforcement member 50 contributes to the overall structural efficiency of the frame assembly 100 by placing material where structural performance is required while minimizing weight in areas with lower loading demands.
The swing arm mounting bush 65 is provided at the rear portion of the frame 100 for swing arm attachment and pivot operations.
The rear portion 30 of the frame assembly 100 includes structural support 70 and support bracket 70a where buddy space is mounted. The buddy space arrangement may provide accommodation for passenger seating or additional storage compartments within the rear portion 30 of the frame assembly 100. The structural support 70 and support bracket 70a may be configured to support the loads associated with buddy space utilization while maintaining the structural integrity of the integrated casting design.
Referring to Fig. 2, an exploded view of the frame assembly 100 incorporates a steering insert 11. The steering pipe is supported by outer race top bearing 3. The steering insert 11 is press fitted in the hole for easy of assembly
The battery cover 5 incorporates sealing gasket for water ingress protection for battery box 20. The battery cover 5 provides protection for battery components while enabling access when battery service or replacement operations are required. The battery box 20 has a battery module placement portion 7 in which battery module is arranged.
Referring to Fig. 3, a motor support structure 300a, 300b is integrated within the frame assembly 100 to provide mounting provisions for electric motor components. The motor support structure 300a forms a structural foundation that accommodates motor installation while maintaining continuity with the casting structure of the frame assembly 100. The motor support structure 300a distributes mounting loads across the rear portion 30 of the frame assembly 100 and creates a stable platform for motor operation.
A motor mounting flange 300b is incorporated within the motor support structure 300a to provide attachment interfaces for motor housing components. The motor mounting flange 300b creates mounting surfaces that align with motor attachment points and distributes mounting forces across the motor support structure 300a. The motor mounting flange 300b accommodates fasteners and mounting hardware while maintaining structural integrity of the motor support structure 300a during motor operation.
The motor mounting flange 300b incorporates a C-shaped flange configuration that enhances structural performance for motor mounting applications. The C-shaped geometry of the motor mounting flange 300b provides enhanced stiffness characteristics that resist deflection under operational loads and maintain motor alignment during vehicle operation. The C-shaped configuration of the motor mounting flange 300b distributes mounting loads across a broader area of the motor support structure 300a, reducing stress concentrations at discrete mounting points.
The motor mounting flange 300b minimizes modal frequency effects from motor vibration through the C-shaped structural configuration. The C-shaped geometry provides a structural arrangement that resists resonant vibration modes that would otherwise be transmitted through the frame assembly 100. The motor mounting flange 300b strengthens the motor mounting area to accommodate forces applied to motor casing components during operation while reducing vibration transmission to other portions of the frame assembly 100. Rear portion 30 includes a rear suspension mounting bracket 310 to mount suspension for rear wheel of the two wheeler.
The battery box 20 has plurality of reinforcement members 320 in the bottom of the battery box 20. The reinforcement members are integrated within the frame assembly 100 to provide structural support and load distribution throughout the casting structure. The reinforcement member 320 incorporates a grid-like pattern that creates a network of structural elements extending across sections of the frame assembly 100. The grid-like pattern of the reinforcement member 320 distributes loads across multiple load paths and reduces stress concentrations that would otherwise occur at discrete structural points.
The reinforcement member 320 functions as a bottom reinforcement member that strengthens battery casing areas within the frame assembly 100. The reinforcement member 320 distributes loads from the front frame member 10 to the motor mounting flange 300b, creating a continuous load path that transfers forces through the battery compartment region of the frame assembly 100. The reinforcement member 320 enhances structural continuity between front suspension loads and motor mounting loads while maintaining the integrated casting configuration of the frame assembly 100.
The grid-like pattern of the reinforcement member 320 creates multiple intersecting structural elements that provide enhanced load distribution compared to single-direction reinforcement approaches. The grid-like configuration distributes concentrated loads across broader areas of the frame assembly 100 and creates redundant load paths that maintain structural performance if localized stress concentrations occur during vehicle operation. The reinforcement member 320 contributes to the enhanced structural performance of the frame assembly 100 while maintaining material continuity through the single casting manufacturing process.
The integration of the motor support structure 300a, the motor mounting flange 300b, the battery cover 5, and the reinforcement member 320 within the single casting of the frame assembly 100 creates a single structural system that accommodates motor mounting, battery access, and load distribution functions without requiring separate components or additional fasteners. The integrated configuration eliminates joints and interfaces that would otherwise connect discrete components, reducing part count while enhancing structural performance and manufacturing efficiency.
Referring to Fig. 4, the frame structure demonstrates an integrated design approach that combines multiple structural components into a single casting configuration when viewed from above.
The rear portion of the frame structure extends from the battery box section and curves toward the rear of the vehicle, incorporating mounting points and structural supports throughout the transition. The design demonstrates a single construction approach where components that would traditionally be manufactured as separate elements and subsequently assembled are merged into one continuous cast piece. The frame structure maintains structural continuity from the steering tube portion through the battery box section to the rear frame portion without joints or fasteners that would otherwise connect discrete components.
The integrated design incorporates various reinforcement features distributed throughout the structure to accommodate operational loads while maintaining the single casting configuration. The frame structure includes mounting provisions positioned at strategic locations to accommodate vehicle components and systems without compromising the structural integrity of the single casting. The mounting provisions are integrated into the casting design to distribute attachment loads across broader areas of the frame structure.
The battery box section incorporates a rectangular configuration that maximizes internal volume for battery module accommodation while maintaining structural performance characteristics. The flat mounting surface of the battery box section provides a stable platform for battery installation and creates uniform load distribution across the battery mounting interface. The bolt hole pattern around the perimeter of the battery box section accommodates standard fastening hardware while distributing attachment loads across the frame structure.
Referring to Fig. 5, the front view of the frame structure demonstrates the vertical integration of components that extends from the steering tube assembly at the top through the battery box 20 section. The frame structure exhibits a single design where multiple structural elements are combined into a single casting that maintains structural continuity throughout the vertical dimension of the assembly.
Referring to Fig. 6, the manufacturing analysis demonstrates the draft considerations incorporated into the single casting frame structure to facilitate efficient mold removal during the casting process. The diagram illustrates the directional requirements for both core and cavity portions of the casting mold, with the core pulling direction indicated by an upward arrow and the cavity pulling direction shown by a downward arrow.
The frame structure incorporates a side view configuration that extends from a front portion with a steering tube section through a horizontal mid-section that forms part of the battery housing area to an angled rear portion. The geometry of the frame structure accommodates the bidirectional mold removal requirements by incorporating appropriate draft angles throughout the casting design that enable smooth ejection from both the upper core and lower cavity portions of the mold.
The frame structure design avoids undercuts in both the core and cavity pulling directions, eliminating the need for additional mold components such as side cores or complex slider mechanisms that would increase manufacturing complexity and cost.

Features of any of the examples or embodiments outlined above may be combined to create additional examples or embodiments without losing the intended effect. It should be understood that the description of an embodiment or example provided above is by way of example only, and various modifications could be made by one skilled in the art. Furthermore, one skilled in the art will recognise that numerous further modifications and combinations of various aspects are possible. Accordingly, the described aspects are intended to encompass all such alterations, modifications, and variations that fall within the scope of the appended claims. , Claims:I/We claim
1. A frame assembly (100) for a two-wheeler vehicle comprising:
a front frame member (10);
a rear frame member (30); and
wherein the front frame member (10), the rear frame member (30), and the battery box (20) are integrally formed as a single cast component, and wherein the battery box (20) is positioned between the front frame member (10) and the rear frame member (30) and structurally connects the front frame member (10) and the rear frame member (30), and wherein the front frame member (10) has a plurality of reinforcement members (50) and each reinforcement member (50) has a first portion (50a) and a second portion (50b), wherein a thickness of the second portion (50b) is greater than a thickness of the first portion (50a).

2. The frame assembly (100) of claim 1, wherein a sidewall of the battery box (20) comprises a plurality of reinforcement members (22), wherein each reinforcement member (22) has a top portion (22b) and a bottom portion (22a), and wherein the top portion (22a) and the bottom portion (22b) have a tapered profile.

3. The frame assembly (100) of claim 1, wherein the rear portion (30) has a bracket (70) which has a C-shaped flange (40) profile for mounting motor.

4. The frame assembly (100) of claim 1, further comprising a steering tube (10) configured to receive a steel insert (11) that is press-fitted therein.

5. The frame assembly (100) of claim 1, wherein the battery box (20) includes a removable battery box cover (5) for access the battery.

6. The frame assembly (100) of claim 1, further comprising a reinforcement member (320) having a grid-like pattern configured to strengthen the battery box (20) and distribute loads from the front frame member (10) to the motor mounting section (300a).
7. A method of manufacturing the frame assembly (100) of claim 4, wherein the casting operation requires only a single slider for the integrated steering tube (10).

8. The frame assembly (100) of claim 1, wherein the single cast component is for a two-wheeler vehicle.