Claims:We Claim:

1. A system (100) for evaluating performance of mechanical lockingdifferential (MLD) of a vehicle (110), the system (100) adapted for testing the mechanical locking differential in adverse conditions, the system (100) comprising:
a gradient (20) having 10 degree angle thereof; and
a bridge (80) placed on the gradient (20), the bridge (80) having,
• two bars (60) arranged parallel to each other providing a space therebetween;
• a plurality of rollers (40)arrangedclosely into the space provided between the two bars (60), the plurality of rollers (40) arranged transverse to a longitudinal axis of the vehicle (110); and
• a plurality ofsupport means (30) arranged between the two bars (60) and the gradient (20) to minimize height differences therein;
wherein, the vehicle (110) is driven on the gradient (20) in a way that the wheels of any one side of the vehicle (110) are moved on the bridge (80) to create spinning of the wheels by using the plurality of rollers (40), thereby simulating tractive effort on low traction surfaceand also creatingworst scenarios of roads.

2. The system (100) as claimed in claim 1, wherein the gradient (20) holds all types of vehicles.

3. The system (100) as claimed in claim 1, wherein thetwo bars (60), the plurality of rollers (40) and the plurality of support means (30) are made of steel.

4. The system (100) as claimed in claim 1, wherein the plurality of rollers (40) are made with 75 mm diameter and 4 meters length to accommodate wheel bases upto 4 meters length of all types of vehicles.

5. The system (100) as claimed in claim 1, wherein the plurality of support means (30) is arranged at predefined distances.

6. The system (100) as claimed in claim 1, wherein overall weight of the bridge (80) is carefully managed by optimizing thickness of the plurality of rollers (40) to facilitate easy handling of the bridge (80).

7. A method of evaluating performance of mechanical locking differential (MLD) of a vehicle (110) comprising the steps of:
driving the vehicle (110) on a gradient (20) having 10 degree;
subjectingthe vehicle (110) on a bridge (80) arranged on the gradient (20)thereby aligning wheels of any one side of the vehicle (110) thereon; and
moving the wheels of the vehicle (110) on a plurality of rollers (40) arranged closely into a space provided between two bars (60) of the bridge (80)to create spinning of the wheels thereon, wherein a plurality of support means (30) arranged between the two bars (60) and the gradient (20) to minimize height differences therein;
wherein, the method is adapted for simulating tractive effort on low traction surface and also for creating worst scenarios of roads.

, Description:
Field of the invention:

The present invention relates to field of component evaluation in vehicles and more particularly, to a system for evaluating performance of mechanical lockingdifferential of the vehicles in adverse conditions and a method thereof.

Background of the invention:

While driving a vehicle in differential traction surfaces i.e. roads with snow or mud, in case if one wheel gets less traction comparing counterpart wheel which is stationary, then the wheel will become to spin. Due to this, the vehicle will not move forward. In order to avoid such circumstances ‘Mechanical Locking Differential’ (MLD) has been introduced in the vehicles. The basic principle of working of the MLD is where if there is a difference between the rpm of the wheels of the same axle, is captured by measuring wheel speed sensors and thenthe MLD will automatically lock the wheel having less traction and allow power to flow to the other wheel to overcome this situation.

Generally, in order to check the functionality of the MLDand confirm behavior of the vehicle with and without the MLD, the vehicle is driven on a split µ(mu)surface (also referred as split friction surface). The split µ surfaceis normally available for Anti-Lock Braking System (ABS)Testing Proving Ground. While the worst case of the real world includingHilly areas / Ghat sections havinggradient and snow is not getting simulated in this situation. The vehicle testing is carried out in regions like Himalayas to simulate the behavior.

However, following difficulties are faced during simulation:
a. It is difficult to find the routes with required gradient and with a required test length having split µ surface as it depends upon nature.
b. The simulation is time consuming and includes more logistics involvement.

Supplier Level Test of the MLD:
While analyzing the existing facilities available at the supplier end, it is found that the entire MLD related functional testing is conducted at Test Bed Level only. There is not any vehicle level simulation facility available at the supplier’s end.

In a prior art, the invention discloses in patent US3914990 is basically used for durability simulation purpose. A dynamic terrain simulator adapted to support various wheeled and/or tracked vehicles with essentially no modification or alteration of the simulator structure is described. During working of the dynamic terrain simulator, the vehicle is on with an engine on / off condition above the rollers of the dynamic terrain simulator. The rollers are moved in different speed using a motor driven setup. The upward vertical force is imparted to the vehicle wheel as well as the horizontal force is imparted on the vehicle.However, while driving the vehicle on the rollers, the wheel of the vehicle is accelerated downwardly by the vehicle weight and suspension system. Also, the simulator setup is permanent and complicated. There is not any facility available to check the functionality of the MLD in higher gradient (10 or 15 Degree) considering the worst adverse conditions of the roads.

Accordingly, there exists need to provide a system for evaluating performance of the mechanical lockingdifferential (MLD) of the vehicles in the adverse conditions of the roads and a method thereofthat overcome the above mentioned drawbacks mentioned in the prior art.

Objects of the invention:

An object of the present invention is toevaluate performance of a mechanical locking differential.

Another object of the present invention is to test the mechanical locking differential by subjecting a vehicle to run in different traction surfaces.

Yet, another object of the present invention is to check functionality of the mechanical locking differential in higher gradient such as 10-15 degree considering worst adverse conditions of roads.

Summary of the invention:

In one aspect, the present invention providesa system for evaluating a mechanical locking differential (MLD) of a vehicle in adverse conditions. The system comprises a gradient having 10 degree angle anda bridge placed on the gradient. The bridge includes two bars, a plurality of rollers and a plurality of support means.

The two bars are arranged parallel to each other providing a space therebetween.The plurality of rollers is arranged closely into the space provided between the two bars. The plurality of rollers is arranged transverse to a longitudinal axis of the vehicle. The plurality of rollers are made with 75 mm diameter and 4 meters length to accommodate wheel bases upto 4 meters length of all types of vehicles.

The plurality of support means is arranged between the two bars and the gradient to minimize height differences therein.The plurality of support means is arranged at specific distances. The overall weight of the bridge is carefully managed to facilitate easy handling of the bridge. The two bars, the plurality of rollers and plurality of support means are made of steel.

The vehicle is driven on the gradient in a way that the wheels of any one side of the vehicle are moved on the bridge to create spinning of the wheels by using the plurality of rollers, thereby simulating tractive effort on low traction surface and also creating worst scenarios of roads.

In another aspect, the present invention provides a method of evaluating performance of the mechanical locking differential of the vehicle in adverse conditions. At first step, the method involves driving the vehicle on the gradient. Then, the vehicle is subjected to travel on the bridge in order to align wheels of any one side of the vehicle thereon. At next step, the wheels of the vehicle are moved on the plurality of rollers to create spinning of the wheels thereon. The method is adapted for simulating tractive effort on low traction surface and also for creating worst scenarios of the roads.

Brief description of the drawings:

The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein

Figure 1 shows a schematic diagram of a system for evaluating performance of mechanical locking differential (MLD) of a vehicle, in accordance with the present invention;

Figure 2 shows a schematic diagram of a method of evaluating performance of the mechanical locking differential (MLD) of the vehicle using the system, in accordance with the present invention;

Figure 3 shows a schematic diagram of a gradient of the system for evaluating performance of the mechanical locking differential (MLD) of the vehicle, in accordance with the present invention;

Figure 4 shows a schematic diagram of a bridge ofthe system for evaluating performance of the mechanical locking differential (MLD) of the vehicle, in accordance with the present invention; ; and

Figure 5 shows top vie and side view of the bridge of the system for evaluating performance of the mechanical locking differential (MLD) of the vehicle, in accordance with the present invention.

Detailed description of the embodiments:

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

The present invention provides invention the system for evaluating performance of mechanical locking differential (MLD) of a vehicle and a method thereof. The system improves productivity with in house facility. The method can be performed with lesser cost and with lesser time involvement for completion of testing. The system (100) and the method can able to do compare the vehicle behavior in normal plain road as well as gradient surface.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figures 1to5, a system (100) for evaluating performance of mechanical locking differential (hereinafter referred as, “the MLD”) of a vehicle (110). The system (100) is adapted for validating and testing the design capability of the MLD. Since, the MLD has the core purpose of providing traction force to a non-slipping wheel in worst case scenarios of roads with snow or mud to help the vehicle (110) drive out of the snow or mud. It becomes critical to test the capacity and capability of the MLD in various real world conditions. The worst case scenario for the MLD system arises when one side of a drive wheel is having less traction and the vehicle (110) has to negotiate a gradient simultaneously. This is because in this condition the vehicle (110) is subjected to an additional load due to the gradient resistance equivalent to W*Sin O, where W signifies weight of the vehicle (110) and O is an angle of the gradient. In order to validate and test functionality of the MLD, the system (100) is developed.

The system (100) comprises a gradient (20) and a bridge (80).The gradient (20) is constructed to make 10 degreeanglegradient with roads. The bridge (80) is placed on the gradient (20).In an embodiment, the gradient (20) is built by considering the maximum gradient of 7 degree of any types of roads with snow or mud tohold all types of vehicles thereon. The gradient (20) is constructed by using reinforced cement concrete.

The bridge (80) includes two bars (60), a plurality of rollers (40) and a plurality of support means (30). The two bars (60) are arranged parallel to each other providing a space therebetween. The two bars are made of steel.

The plurality of rollers (40) is arranged closely into the space provided between the two bars (60). The plurality of rollers (40) is arranged transverse to a longitudinal axis of the vehicle (110). The plurality of rollers (40) is made of steel. The plurality of rollers (40) are made with 75 mm diameter and 4 meters length to accommodate wheel bases upto 4 meters length of all types of vehicles.

The plurality of support means (30) are arranged between the two bars (60) and the gradient (20) to minimize height differences therein.The plurality of support means (30) is arranged at predefined distances. The plurality of support means (30) is made of steel. The overall weight of the bridge (80) is carefully managed to facilitate easy handling of the bridge (80).In a specific embodiment, thickness of the plurality of rollers (40) is optimized in such a way that the overall weight of the bridge (80) is approximately 160 kg; hence the bridge (80) can be lifted by four persons easily.

The vehicle (110) is driven on the gradient (20) in a way that the wheels of any one side of the vehicle (110) are moved on the bridge (80) to create spinning of the wheels by using the plurality of rollers (40), thereby simulating tractive effort on low traction surface and also creating worst scenarios of roads. In this way, the vehicle (110) is subjected to run in different traction surfaces.

In an embodiment, the system (100) also has a feasibility to check the functionality in higher gradient of 15 degree considering the worst adverse condition of the roads. The system (100) is movable and there is not any complicated permanent setup. The system (100) is built in in-house facility.

Again, referring to figures 1 to 5, a method of evaluating performance of mechanical locking differential (MLD) of a vehicle (110) is described. The method is described in conjunction with the system (100).

At first step, the method involves driving the vehicle (110) on a gradient (20) having 10 degree. Then, the vehicle (110) is subjected to travel on a bridge (80) that is arranged on the gradient (20) in order to align wheels of any one side of the vehicle (110) thereon.

The bridge (80) includes a plurality of rollers (40) arranged closely into a space provided between two bars (60) and a plurality of support means (30) arranged between the two bars (60) and the gradient (20) to minimize height differences therein.

At next step, the wheels of the vehicle (110) are moved on the plurality of rollers (40) to create spinning of the wheels thereon. The method is adapted for simulating tractive effort on low traction surface and also for creating worst scenarios of the roads.

The method is used to test similar vehicles fitted with open differential and those fitted with the MLD using the above simulated conditions of the system (100). Not any open differential vehicle was able to pass through the system (100) barring vehicles with the MLD system fitted. In addition to this, theadvantages of the invention are given below.

Advantages of the invention:

1. The system (100) improves productivity with in house facility
2. The method can be performed with lesser cost.
3. Lesser time involvement for completion of testing.
4. The system (100) and the method can able to do compare the vehicle behavior in normal plain road as well as gradient surface.
5. Not only for the MLD, the functional behavior of the vehicle duringAnti-Braking System(ABS), Electronic Logging Device (ELD) Compliance Test or any type of locking mechanism can be simulated.
6. During the activity, exact difference between the Vehicle’s rpm of different wheels as well as response time for the activity can be logged using Controller Area Network (CAN) parameters / Camera fitted on both side of the vehicle.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.