WO2020141358A1

WO2020141358A1 - A method of manufacturing a wheel disc for a vehicle

Info

Publication number: WO2020141358A1
Application number: PCT/IB2019/050931
Authority: WO
Inventors: Vishal Kalubhai BHARODIYA; Rahul Kumar Verma; Pala LAKSHMIKANT
Original assignee: Tata Steel Limited
Priority date: 2019-01-04
Filing date: 2019-02-06
Publication date: 2020-07-09
Also published as: KR20230118707A; KR20210127147A; EP3906127A1; JP7342132B2; JP2022516340A

Abstract

The present disclosure discloses a method for manufacturing a wheel disc for a vehicle. The method comprises drawing a substantially central portion of a blank of metal into a hat-shaped profile, and forming a plurality of bolt seats and beads on an inner flat surface of the hat-shaped profile. The method further comprises bending an outer flat surface of the hat-shaped profile to define an outer flange of the wheel disc and drawing a central portion of the hat-shaped profile to define a central flange of the wheel disc. With the method of present disclosure, number of manufacturing steps to manufacture the wheel disc is reduced by about 15% - 30% when compared to manufacturing steps of a conventional method without affecting final shape of the wheel disc.

Description

TITLE:“A METHOD OF MANUFACTURING A WHEEL DISC FOR A

VEHICLE”

TECHNICAL FIELD

The present disclosure generally relates to the field of manufacturing technology. Particularly, but not exclusively, the present disclosure relates to manufacturing of a wheel disc for a vehicle. Further embodiments of the present disclosure disclose a method of manufacturing a wheel disc with reduced number of manufacturing steps.

BACKGROUND OF THE DISCLOSURE

An automobile is said to function appropriately only when all its systems are working as they are required to work. The engine produces power and gives it to the drive train through a clutch. The portion of the drive which transmits this power from the drive train to the wheel and which connects the main frame of the body with the wheels through the suspension arms is known as the wheel assembly. Generally, wheel assembly consist of a rim and a wheel disc wheels may be made of aluminium alloys or steel. The rim serves as seat of the tyre and the wheel disc connects the rim with a wheel hub. There are different ways of making the rims and wheel discs. Usually, in the conventional method of making the wheel, the rim and discs are manufactured separately and thermally joined together.

Wheels of an automobile support the total weight, resist the strains created during turning and transmit the driving torque for propelling and braking torque for bringing the automobile to halt. The wheels must have well balanced construction particularly for running at high speeds. Unbalanced wheel assemblies cause excessive vibration. Thus, wheels play a critical role in control of automobiles, as the acceleration and braking occur through them. Wheels must be rigid enough to retain their shape under all operating conditions. When subjected to abnormal impact, they should preferably buckle and must not collapse. The dimensional tolerances of the wheel should be accurate enough for carrying out wheel alignment and balancing. Additionally, wheels must be light so that the unsprung weight may be reduced. Light wheels and tyres also follow the road surface contour more accurately so that wheel bounce is minimized, resulting in improved road contact and reduced tyre wear. The most common method of making discs is using the stamping process, wherein the circular blank is cut out from a rectangular plate. After pressing to the required shape, the center portion of the material is pierced away to facilitate the mounting the wheel on the vehicle. In this process of disc making, an account of using a strip of predetermined size, substantial portion is taken away as design/engineering wastage. One such conventional method of manufacturing a wheel disc is shown in FIG. l . Conventionally, there may be a total of six steps for making a wheel disc, of which the first four steps are forming steps and last two steps are piercing steps. Firstly, circular blanks may be made of desired diameter, then the blank may be drawn to a dome (cup) shaped profile. Subsequently, a reverse draw of the dome-shaped profile may be carried out to obtain an intermediate shape of the wheel disc. Further, a central hole may be defined by trimming and correction of shape may be done to achieve desired shape of the disc. The conventional method includes forming of a bolt hole seats and beads, central and outer flange of the wheel disc which gives the final shape of the wheel disc. Additionally, bolt holes may be pierced on bole hole seats and vent holes may be pierced on outer periphery of the wheel disc.

However, the conventional method of manufacturing the wheel disc as described above involves a huge amount of tooling cum machinery cost as well as lead time.

The present disclosure is intended to overcome one or more limitations stated above or any other limitations associated with the conventional arts.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the conventional techniques are overcome by method and apparatus, as disclosed and additional advantages are provided through the method as described in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the disclosure, a method for manufacturing a wheel disc for a vehicle is disclosed. The method comprises drawing a substantially central portion of a blank of metal into a hat-shaped profile, and forming a plurality of bolt seats and beads on an inner flat surface of the hat-shaped profile. The method further comprises bending an outer flat surface of the hat-shaped profile to define an outer flange of the wheel disc and drawing a central portion of the hat-shaped profile to define a central flange of the wheel disc.

In an embodiment of the disclosure, the method as comprises defining a through hole in each of the plurality of bolt seats and beads. The method also includes piercing vent holes on the outer flange of the wheel disc.

In an embodiment of the disclosure, the blank is circular in shape with a through hole defined at a central point of the blank.

In an embodiment of the disclosure, the plurality of bolt seats and beads are formed around the central flange of the wheel disc.

In an embodiment of the disclosure, the central flange is formed by a flange down process.

In an embodiment of the disclosure, bending of the outer flat surface is done through a triple action draw process.

In an embodiment of the disclosure, bending of the outer flat surface is done through a sheet metal forming process.

In an embodiment of the disclosure, a region of minimum thickness of the wheel disc is reduced by about 5% - 6% when compared to a wheel disc formed by a conventional method.

In an embodiment of the disclosure, number of manufacturing steps to manufacture the wheel disc is reduced by about 15% - 30% when compared to manufacturing steps of the conventional method.

In an embodiment of the disclosure, a wheel disc manufactured by a method as described above is disclosed. The wheel disc comprises a hat-shaped profile, and an outer flange defined by bending an outer flat surface of the hat-shaped profile. The wheel disc further comprises a central flange defined at a central portion of the hat shaped profile and a plurality of bolt seats and beads defined on an inner flat surface of the hat-shaped profile. In an embodiment of the disclosure, the wheel disc is made using FE360 grade of hot rolled steel with 3.6 mm thickness.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

FIG. l is a sequential representation of a conventional method of manufacturing a wheel disc.

FIG.2 is a sequential representation of a method of manufacturing a wheel disc in accordance with an embodiment of the present disclosure.

FIG.3 illustrates pictorial top views of the wheel disc at different stages during its manufacture in accordance with an embodiment of the present disclosure at different stages of manufacturing.

FIG.4 is a graphical representation showing comparison of thickness along a section of wheel disc manufactured by a conventional method and by the method of present disclosure. FIG.5 illustrates a pictorial perspective view of a wheel disc manufactured by a conventional method and by the method of present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the description of the disclosure. It should also be realized by those skilled in the art that such equivalent system and method do not depart from the scope of the disclosure. The novel features which are believed to be characteristic of the disclosure, as to method of operation, together with further objects and advantages may be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the figures and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure. The terms“comprises”,“comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a method that comprises a list of acts does not include only those acts but may include other acts not expressly listed or inherent to such method. In other words, one or more acts in a method proceeded by “comprises... a” does not, without more constraints, preclude the existence of other acts or additional acts in the method.

Embodiments of the present disclosure relate to a method of manufacturing a wheel disc. The wheel disc manufactured by a method of the present disclosure has reduced number of steps compared to a conventional method of manufacturing a wheel disc. The manufacturing of wheel disc may typically include a number of forming steps and a number of piercing steps. In an embodiment, the number of forming steps may be reduced when compared to the conventional method of manufacturing the wheel disc.

The wheel disc may be formed from a circular blank derived out of a blanking process. In an embodiment, the circular blank is of a metallic material. The method of the present disclosure firstly comprises of drawing process, wherein a substantially central portion of the circular blank may be drawn into a hat-shaped profile. The hat-shaped profile so obtained may include an inner flat surface and an outer flat surface. The method further includes defining a plurality of bolt seats and beads on the inner flat surface. Subsequently, the outer surface of the hat-shaped profile may be subject to bending process, where the outer flat surface may be bent to form an outer flange of the wheel disc. The method further includes a flange down process. In this process, the central portion of the hat-shaped profile may be drawn to define a central flange of the wheel disc. This step completes the forming process involved in the manufacturing of the wheel disc.

The method also includes piercing steps to form through holes in the wheel disc. In an embodiment, the through holes may be defined in each of the plurality of bolt seats and beads. Further, the method includes piercing vent holes on the outer flange of the wheel disc. Thus, the present disclosure discloses manufacturing of the wheel disc with reduced number of steps without affecting the final shape of the wheel disc. In an embodiment, the number of manufacturing steps to manufacture the wheel disc may be reduced by about 15-30% when compared to manufacturing steps of a conventional method. In the following detailed description, embodiments of the disclosure are explained with reference of accompanying figures that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

FIG.2 illustrates a method of manufacturing a wheel disc (100). The method may involve a sequence of operations or stages. In an embodiment, as shown in FIG.2, the method of manufacturing the wheel disc (100) involves five stages - 1 to 5. The manufacturing of the wheel disc (100) may broadly include formation process and piercing process. Stages 1 to 3 refers to formation process, while stages 4 and 5 refers to piercing process. The manufacturing steps as may be carried is described herein stage wise -

A blank (101) derived out of a blanking operation may be considered for manufacturing the wheel disc (100). The blank (101) may be made of metal material such as but not limited to steel . In an embodiment, the blank (101) may be a circular blank, with a hole (101a) at a central point of the blank (101). At stage 1, a substantially central portion of the circular blank (101) may be subjected to drawing process, wherein the central portion may be drawn into a hat-shaped profde (102). Each stage of manufacturing operation shows top view and front view, where top view is shown below the front view. In an embodiment, at stage 1, the front view clearly shows the shape of the profde and hence the name hat-shaped profde (102). The hat-shaped profde (102) so obtained may include an inner flat surface (102a) and an outer flat surface (102b). In the same stage of manufacturing operation, a plurality of bolt seats and beads (103) may be formed on the inner flat surface (102a) of the hat-shaped profde (102). In an embodiment, the seats and beads may be formed alternatively. In an exemplary embodiment, the plurality of seats and beads (103) may be defined by punching operation. A solid model of the profde so obtained is also shown in FIG.3 at stage 1.

Further, at stage 2, the outer flat surface (102b) of the hat-shaped profde (102) may be subjected to bending process. Bending of the outer flat surface (102b) defines an outer flange ( 104) of the wheel disc ( 100) . In an embodiment, the bending of the outer surface (102b) may be done through a triple action draw process. A triple action drawing process may include three moving slides, where two slides move in the same direction and the third or lower slide moves upward through a fixed bed in a direction opposite to that of the other two slides. This action allows bending of the outer flat surface (102b). In an embodiment, the bending of the outer flat surface (102b) may be done through a sheet metal forming process. A corresponding profile of the solid model at this stage is shown in stage 2 of FIG.3.

At stage 3, the hat-shaped profile (102) may be subjected to a drawing process. A central portion of the hat-shaped profile (102) may be subjected to drawing to define a central flange (105) ofthe wheel disc (100). In an embodiment, the central flange (105) may be obtained by a flange down process. A corresponding profile of the solid model at this stage is shown in stage 3 of FIG.3. With stage 3, forming process of the wheel disc (100) may be concluded.

Further, stage 4 marks the beginning of the piercing process of manufacturing the wheel disc (100). At stage 4, through holes (106) may be defined in each of the plurality of bolt seats and beads (103). These through holes (106) may be defined by processes such as but not limited to drilling, reaming and milling. The through holes (106) allow insertion of bolts and thus the wheel disc (100) may be assembled to hub of a vehicle.

At stage 5, the method further includes formation of a number of vent holes (107). The vent holes (107) may be pierced on the outer flange (104) of the wheel disc (100).

In an embodiment, the number of manufacturing steps involved in the present disclosure is reduced in comparison with the number of manufacturing steps involved in a conventional method of manufacturing a wheel disc (100). In an embodiment, the reduction in manufacturing steps may be 15-30% when compared to manufacturing steps involved in the conventional method.

Referring now to FIG.4, it shows a graphical representation of a thickness along a section of wheel disc (100) manufactured by conventional method and by a method of the present disclosure. In FIG.4, cl represents conventional method and il represents the method of the present disclosure. In an embodiment, the wheel disc (100) may be made of FE360 and the input thickness of the material may be considered as 3.6 mm. In an embodiment, as may be seen from FIG.4, the minimum thickness in the method of present disclosure may be reduced by 5-6% compared to minimum thickness of the wheel disc manufactured by the conventional method. This is within the acceptable limit. Further, the thinning at other location remains unaffected from drastic change. Therefore, the wheel disc (100) manufactured by the method of the present disclosure may have same characteristics and shape when compared to a wheel disc manufactured by the conventional method.

FIG.5 shows the wheel disc (100) obtained by a conventional method indicated as‘C’ and by the method of present disclosure, indicated as T. It may be seen from FIG.5, that the shape of the wheel disc (100) manufactured by the present disclosure largely remains unaffected while obtaining the benefit of reduction in number of steps involved while manufacturing the wheel disc (100). Also fatigue life and other properties of the wheel disc (100) remains unaffected. With the reduction in number of manufacturing steps, it results in reduction of the manufacturing and tooling cost.

Equivalents

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral Numerals

Claims

Claims:

1. A method of manufacturing a wheel disc (100) for a vehicle, the method comprising:

drawing a substantially central portion of a blank (101) of metal into a hat shaped profile (102);

forming a plurality of bolt seats and beads (103) on an inner flat surface (102a) of the hat-shaped profile (102);

bending an outer flat surface (102b) of the hat-shaped profile (102) to define an outer flange (104) of the wheel disc (100); and

drawing a central portion of the hat-shaped profile (102) to define a central flange (105) of the wheel disc (100).

2. The method as claimed in claim 1 comprises defining a through hole (106) in each of the plurality of bolt seats and beads (103).

3. The method as claimed in claim 1 comprises piercing vent holes (107) on the outer flange (104) of the wheel disc (100).

4. The method as claimed in claim 1, wherein the blank (101) is circular in shape with a through hole (101a) defined at a central point of the blank (101).

5. The method as claimed in claim 1, wherein the plurality of bolt seats and beads (101) are formed around the central flange (105) of the wheel disc (100).

6. The method as claimed in claim 1, wherein the central flange (105) is formed by a flange down process.

7. The method as claimed in claim 1, wherein the bending of the outer flat surface (102b) is done through a triple action draw process.

8. The method as claimed in claim 1, wherein the bending of the outer flat surface (102b) is done through a sheet metal forming process.

9. The method as claimed in claim 1, wherein a region of minimum thickness of the wheel disc (100) is reduced by about 5% - 6% when compared to a wheel disc formed by a conventional method.

10. The method as claimed in claim 1, wherein number of manufacturing steps to manufacture the wheel disc (100) is reduced by about 15% - 30% when compared to manufacturing steps of the conventional method.

11. A wheel disc (100) manufactured by a method as claimed in claim 1, the wheel disc (100) comprising:

a hat-shaped profile (102);

an outer flange (104) defined by bending an outer flat surface (102b) of the hat shaped profile (102);

a central flange (105) defined at a central portion of the hat-shaped profile ( 102); and

a plurality of bolt seats and beads (103) defined on an inner flat surface (102a) of the hat-shaped profile (102).

12. The wheel disc (100) as claimed in claim 11 comprises a through hole (106) defined in each of the plurality of bolt seats and beads (103).

13. The wheel disc (100) as claimed in claim 11 comprises vent holes (107) defined on the outer flange (104) of the wheel disc (100).

14. The wheel disc (100) as claimed in claim 11, wherein the plurality of bolt seats and beads (103) are formed around the central flange (105).

15. The wheel disc (100) as claimed in claim 11, wherein the wheel disc (100) is made using FE360 grade of hot rolled steel with 3.6 mm thickness.

16. The wheel disc (100) as claimed in claim 11, wherein a region of minimum thickness of the wheel disc (100) is reduced by 5% - 6% when compared to a wheel disc formed by a conventional method.