DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 And Rule 13)

Title of the invention:
AN INTEGRATED KNUCKLE AND A METHOD OF MANUFACTURING THE INTEGRATED KNUCKLE
Applicant:
BHARAT FORGE LIMITED
An Indian Entity having address as:
Mundhwa, Pune, Maharashtra, India 411036

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[0001] The present application claims priority from IN patent application no. 202221046900, filed on 18/08/2022. The entire contents of the aforementioned application are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a knuckle and a method of manufacturing the knuckle. More particularly, the present invention relates to one-piece/integrated knuckle for an automobile and a forging method of manufacturing the same.
BACKGROUND AND INTRODUCTION
[0003] Knuckles are components of steering axle assemblies of automobiles which provides a mount for the spindle or hub of a vehicle wheel. Typically, steering knuckles are attached directly by the steering linkage system of vehicles.
[0004] The existing knuckle design is a two-piece design (Two separate parts) which needs to shrink or press fit or joined by any joining process to assemble. Such a design is found to have low strength. The conventional manufacturing process includes knuckle manufacturing by forging, spindle manufacturing by forging and press or shrink fitting or joining the knuckle and spindle. Conventional manufacturing processes are associated with several drawbacks such as processes involving large number of operations, high cycle time, low fatigue strength, more handling activities, additional manpower and the like.
[0005] Accordingly, it is envisaged to provide a forging method which can reduce the number of operations and thereby reduce cycle time without affecting the characteristics of the finished product, namely integrated knuckle.

SUMMARY OF THE INVENTION
[0006] Before the present system (or apparatus) and method, and its components are described, it is to be understood that this disclosure is not limited to the system and its arrangement as described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the versions or embodiments only and is not intended to limit the scope of the present application. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in detecting or limiting the scope of the claimed subject matter.
[0007] In one non-limiting embodiment, an integrated steering knuckle is disclosed. The integrated steering knuckle includes a knuckle. Further, the knuckle may have fixation points for fixing an upper wishbone and a lower wishbone respectively. Further, the integrated steering knuckle may include a spindle. Furthermore, the spindle may be attached to a wheel. Also, the spindle may be an integral part of the knuckle.
[0008] In another non-limiting embodiment, a method for manufacturing an integrated knuckle is disclosed. Further, the integrated steering knuckle includes fixation points for fixing an upper wishbone and a lower wishbone respectively and a spindle. Further, the spindle may be configured to attach a wheel and the spindle may be an integral part of the knuckle. Furthermore, the method may include steps as follows: Initially, a billet as a raw material may be provided. Also, the billet may be heated up to desired temperature. In addition, the heated billet may be transformed to upsetter/ Preform dies. Further, the preform may be transferred to a blocker die to obtain a blocker preform. Also, the blocker preform may be transferred to finisher dies. The finisher forging may be carried to obtain the integrated steering knuckle.
[0009] Further, in another embodiment, the billet may be a forged, extruded or rolled billet. Typically, the billet can be cylindrical or rounded cross section (RCS) billet. Further, the billet may be heated in an oil fired or gas fired or electric or induction furnace and heated in the temperature range of 1150°C to 1250°C. Further, the billet material may be steel alloy, or any suitable material based on the required strength and flexibility of operation.
[0010] In another embodiment of the method the heated billet may be transferred to upsetter/preform dies and the heated billet may be deformed to produce the required bias in the shape of preform towards the spindle of the integrated knuckle. The output of this stage may be upsetter or preform. Further, the preform may be transferred to the blocker dies where blocker operation takes place. The blocker forging operation produces rough shape of the integrated knuckle with maximum material flow happening in this stage with some access material thrown out as flash. The output of this stage may be the blocker preform.
[0011] In another embodiment of the method, the blocker preform may be transferred to the finisher dies where the finisher forging operation takes place. In this operation, the final shape of the integrated knuckle may be formed with a small amount of material thrown in the form of flash. Further, the finisher operation is followed by post forging operations like trimming, padding, shot blasting, heat treatment, machining etc. which produces the final integrated knuckle. Further the method may include a step of subjecting the integrated knuckle to post forging and finishing operation.
BRIEF DESCRIPTION OF DRAWINGS
[0012] The detailed description is described with reference to the accompanying figures. In the Figures, the left-most digit(s) of a reference number identifies the Figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
[0013] Figure 1 illustrates a steering knuckle (100) as disclosed in the prior art;
[0014] Figure 2 illustrates an integrated steering knuckle (200), in accordance with various embodiment of the present invention; and
[0015] Figure 3 illustrates a method (300) for manufacturing an integrated steering knuckle, in accordance with various embodiment of the present invention.
DESCRIPTION OF THE INVENTION
[0016] As used in the specification and claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “an article” may include a plurality of articles unless the context clearly dictates otherwise. Those with ordinary skill in the art will appreciate that the elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated, relative to other elements, in order to improve the understanding of the present invention. There may be additional components described in the foregoing application that are not depicted on one of the described drawings. In the event such a component is described, but not depicted in a drawing, the absence of such a drawing should not be considered as an omission of such design from the specification.
[0017] In the accompanying drawings components have been represented, showing only specific details that are pertinent for an understanding of the present invention so as not to obscure the disclosure with details that will be readily apparent to those with ordinary skill in the art having the benefit of the description herein.
[0018] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.
[0019] A conventional two-piece steering knuckle design (100) is shown in figure 1, which includes a knuckle (102) and a spindle (104) which are press fitted at a position (106). To overcome the aforementioned drawbacks of the conventional design of steering knuckle, the present invention is directed to a one–piece/integrated steering knuckle (200) includes a knuckle (202) and a spindle (204). The invented integrated steering knuckle (200) is shown in Figure 2. Said knuckle (200) is manufactured by a forging process. The integral design of steering knuckle of the present invention eliminates the requirement of assembling the two separate parts. The existing two-piece design is found to lower the fatigue life of the assembly due to higher stress concentration in the fitment region. Also, the two-piece design has more weight and is costlier since the two parts are required to be manufactured separately. The one–piece/integrated steering knuckle manufactured by forging process is found to have improved strength.
[0020] In accordance with one aspect of the present invention, there is provided a forging method for manufacturing integrated steering knuckle. In one embodiment, the integrated steering knuckle (200) may include fixation points (206, 208). The fixation point (206) may be configured to fix an upper wishbone. Similarly, the fixation point (208) may be configured to fix a lower wishbone. The lower wishbone may be fixed at point (208) using a ball joint.
[0021] Further, the integrated steering knuckle (200) may include a keyhole or a locking mechanism to lock the wheel to the spindle (204). Further, the integrated steering knuckle (200) may include a vehicle speed sensor mount. The vehicle speed sensor judges the speed of the vehicle based on the number of rotations of the wheel per unit time. Further, the integrated steering knuckle (200) may include tie rod fixation holes. A tie rod connects to both the front wheels and enables steering.
[0022] Further, the knuckle (202) may include a cavity. The cavity may be configured to fix the movement of the lower wishbone and provide adequate strength to the overall structure of integrated steering knuckle (200). Further, the integrated steering knuckle (200) may include features like ribs, webs, and bosses. Ribs or webs provide extension to the surface and at the end of these ribs and webs bosses may be configured to allow attachment of any external component as per requirements of the user.
[0023] In one embodiment, the process involves one or more steps including billet heating, upsetting/ preform formation, blocking operation, finishing operation, post forging operations. The inventors of the present invention have to perform more than workshop modification in known forging technique as there were several challenges faced during the integral forging which include but are not limited to:
Dies to be split in different planes.
Thin wall thickness of the knuckle surfaces.
Deep cavity of the spindle.
Knuckle features like ribs and bosses.
[0024] The integrated steering knuckle (200) can be manufactured using machining process or forging process. However, machining process may require lot of time and material to manufacture single piece of the integrated steering knuckle (200). However, forging process is cost effective and less time consuming. Therefore, current invention uses forging process for manufacturing the integrated steering knuckle (200) as explained in following paragraphs.
[0025] Now, referring to figure 3 a method (300) of manufacturing the integrated steering knuckle is disclosed. In one illustrative embodiment, the forging process of the present invention includes the following steps:
providing a billet as a raw material (301);
heating the billet (302);
transferring the heated billet to upsetter/preform dies (303) and deforming to obtain a preform;
transferring the preform to blocker die to obtain a blocker preform (304);
transferring the blocker preform to finisher dies (305). In addition, the finisher forging is carried to obtain an integrated knuckle.
[0026] Further, in another embodiment, the billet may be a forged, extruded or rolled billet. Typically, the billet can be cylindrical or rounded cross section (RCS) billet. In one embodiment of the method (300), at step (301) the billet may be heated to the required temperature in a furnace. In the method (300), at step (302) the billet may be heated in an oil fired or gas fired or electric or induction furnace. In one embodiment of method (300), at step (302) the billet may be heated in the temperature range of 1150°C to 1250°C for steel alloys and range of 450°C to 550°C for Aluminum (Al) alloys. Therefore, the temperature ranges may vary from 450°C to 1250°C based on the type of material being used for forging. In one embodiment of the present invention, the billet material may be steel alloy, or any suitable material based on the required strength and flexibility of operation.
[0027] In another embodiment of the method (300), at step (303) the heated billet may be transferred to upsetter/preform dies. During this operation, the heated billet may be deformed to produce the required bias in the shape of preform towards the spindle of the integrated knuckle. The output of this stage may be upsetter or preform.
[0028] In yet another embodiment of the method (300), at step (304) the preform may be transferred to the blocker dies where blocker operation takes place. The blocker forging operation produces rough shape of the integrated knuckle with maximum material flow happening in this stage with some access material thrown out as flash. The output of this stage may be the blocker preform.
[0029] In another embodiment of the method (300), at step (305) the blocker preform may be transferred to the finisher dies where the finisher forging operation takes place. In this operation, the final shape of the integrated knuckle may be formed with a small amount of material thrown in the form of flash.
[0030] In yet another embodiment of the method (300), at step (305) the finisher operation is followed by post forging operations like trimming, padding, shot blasting, heat treatment, machining etc. which produces the final integrated knuckle. Further the method (300) may include a step of subjecting the integrated knuckle to post forging and finishing operation.
Technical Advancement and Economic Significance
1. The process of the present invention is cost effective manufacturing process due to integral one-piece design.
2. The integral design of the present invention is lightweight compared to the existing design.
3. The integral design of the present invention has less stress concentration area as compared to existing design.
4. The integral design of the present invention has improved strength to weight ratio.
5. The integral design of the present invention has improved fatigue life.
[0031] Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

,CLAIMS:WE CLAIM:
1. An integrated steering knuckle (200) comprising:
a knuckle (202), wherein the knuckle (202) comprises fixation points (206, 208) for fixing an upper wishbone and a lower wishbone respectively; and
a spindle (204), wherein the spindle (204) is configured to attach a wheel, characterised in that, the spindle (204) is an integral part of the knuckle (202).
2. The integrated steering knuckle (200) as claimed in claim 1, wherein the spindle (204) comprises a keyhole or a locking mechanism to lock the wheel to the spindle (204).
3. The integrated steering knuckle (200) as claimed in claim 1, wherein the knuckle (202) comprises a vehicle speed sensor mount.
4. The integrated steering knuckle (200) as claimed in claim 1, wherein the knuckle (202) comprises tie rod fixation holes.
5. The integrated steering knuckle (200) as claimed in claim 1, wherein the lower wishbone in attached to the knuckle (202) at the fixation point (208) using a ball joint.
6. The integrated steering knuckle (200) as claimed in claim 1, wherein the knuckle (202) comprises a cavity to fix to allow movement of the lower wishbone.
7. The integrated steering knuckle (200) as claimed in claim 1, wherein the knuckle (202) comprises one or more feature such as ribs and bosses.
8. A method (300) for manufacturing an integrated knuckle (200) wherein the integrated steering knuckle comprising the knuckle (202), wherein the knuckle (202) comprises fixation points (206, 208) for fixing an upper wishbone and a lower wishbone respectively and a spindle (204), wherein the spindle (204) is configured to attach a wheel and the spindle (204) is integral part of the knuckle (202) wherein the method comprising:
providing a billet as a raw material (301);
heating the billet (302);
transforming the heated billet to upsetter/ Preform dies (303);
transferring the preform to a blocker die to obtain a blocker preform (304); and
transferring the blocker preform to finisher dies (305), wherein the finisher forging is carried to obtain the integrated steering knuckle.
9. The method (300) as claimed in claim 8, wherein a billet used for manufacturing the integrated steering knuckle (200) is cylindrical or rounded cross section (RCS) billet.
10. The method (300) as claimed in claim 8, wherein the billet is heated in an oil fired or gas fired or electric or induction furnace.
11. The method (300) as claimed in claim 8, wherein the billet is heated in the temperature range of 450°C or 1250 °C; wherein the temperature range varies based on the type of material being used.
12. The method (300) as claimed in claim 8, wherein upsetter or preform is produced, wherein the heated billet is deformed to produce the required bias in the shape of preform towards the spindle of the integrated knuckle.
13. The method (300) as claimed in claim 8, wherein the blocker preform is produced by the blocker forging operation producing a rough shape of the integrated knuckle with maximum material flow and excess material is thrown out as flash.
14. The method (300) as claimed in claim 8, wherein the blocker preform is transferred to the finisher dies and the finisher forging operation are performed, wherein the final shape of the integrated knuckle is formed, and small amount of material thrown in the form of flash.
15. The method (300) as claimed in claim 8, wherein the finisher operation is followed by post forging operations, wherein the finisher operation comprising trimming, padding, shot blasting, heat treatment, and machining to produces the final integrated knuckle.
Dated 18th Day of August 2022

Deepak Pawar
Agent for the Applicant
IN/PA-2052