FIELD OF THE INVENTION:-
The present invention is related to a fixture testing the component/s of automotive vehicle in laboratory. More particularly, the present invention is related to the modular fixture for stiffness measurement of the component of automotive vehicle, particularly the lower control arm of the suspension system.
BACKGROUND OF THE PRESENT INVENTION:-
Existing fixtures need to be custom fabricated for every control arm which cannot be used for any other control arm. Further the existing fixtures won't accommodate for testing for stiffness an all the three directions.
The prior art knowledge disclosed by documents Nos. CN201955244U, CN201993240U, and US7197920B2 are being used to test at the system level (suspension) and intended to dynamically test the part/s. Further these prior arts are capable of durability testing of the parts and do not have modularity to accommodate suspensions with different geometries and have fixed orientation. Furthermore, these prior arts do not have any provision for adjustments in clamping forks.
OBJECTIVES OF THE PRESENT INVENTION:-
The main object of "the present invention is to provide a fixture for stiffness measurement of the component of automotive vehicle, particularly lower control arm of the suspension system.
Another object of the present invention is to provide a fixture which is modular in nature for stiffness measurement of lower control arm.
Another objective of the present invention is to provide a fixture for static and dynamic testing of the automobile component, particularly the lower control arm.

Still another object of the present invention is to provide a fixture for testing component of an automobile which is capable of performance as well as durability test.
Still another object of the present invention is to provide a fixture for component testing of an automobile, wherein the said fixture can be used in the manufacturing setup for inspection/quality control and also in the production lines to check the alignments.
BRIEF DESCRIPTION OF THE FIGURES:-
Figure 1 shows object (lower control arm) to be tested on the fixture with the bush where the said object is fitted.
Figure 2 shows the complete modular fixture1 unit as per the present invention wherein the object to be tested is fitted.
Figure 3 shows the exploded view of the central block which is mounted between the mounting plates in the fixture assembly.
Figure 4 shows the exploded view of the mounting plate in the fixture assembly
Figure 5 shows the exploded view of the spacer which is mounted between the central block and the mounting plate in the fixture assembly.
Figure 6 shows the exploded view of the base plate with the cut slot for mounting.
Figure 7 shows the test data on time saving due the modular fixture of the present invention in comparison with the conventional fixtures.

DESCRIPTION OF THE INVENTION:-
Lower control arms play a major role in designing the suspension system of a vehicle. The stiffness of the control arm directly affects the ride and comfort of the vehicle. It is very important to measure the stiffness of the control arm. Each control arm is unique in shape and dimensions and hence requires a custom fabricated fixture for testing it. Each fabrication involves many man-hours, material, cost, etc. and more importantly high test cycle time.
Therefore, the present invention is targeted to develop a modular fixture for stiffness measurement'of lower control arm. A modular fixture, once fabricated can be used to test a wide" range of control arms and decreases the test cycle time drastically (by 94% approx).This modular fixture contains four major parts which can be assembled together such a way that it accommodates a wide range of control arms even if various parameters are different.
The fixture assembly for Lower Control Arm (LCA) Stiffness Measurement comprises of a center block, spacers, mounting plates and base plates. The two base plates are mounted to the external fixture base at perpendicular angles. The base plate is having a construction of multiple threaded holes for holding the center block. The base plate also has two long slots at two ends for mounting it to the external fixture base. The center block and base plate are fastened perpendicular to each other. The center block has a cubical geometry with plurality of holes at four sides. There are two mounting plates which clamps the Lower Control Arm rigidly between it. The mounting plates consist of threaded holes of different diameters; Spacer is a small piece of rectangular plate with two threaded holes provided at two ends. Multiple spacer elements are used for adjusting the fixture according to the bush width of the Lower Control Arm (LCA). The spacer elements are added between the centre block and the mounting plate based on the requirement. For more rigidity, the mounting plates can be clamped to the centre block and spacer elements if required.
The same fixture can also be used to test for stiffness of control arms inall the three directions. A wide range of lower control arms, irrespective of fastener

diameters, width of bushes and other parameters can be tested with one single fixture without any new additional parts or modifications. Test for stiffness in all three directions can be done using the same fixture. The fixture of the present invention just requires a space of 270X270X33mm to store. The proposed fixture of the invention is for static and dynamic testing of the part (Lower control arm) and is capable of performance as well as durability test. The said fixture can accommodate multiple designs like Double wishbone, Mc Pherson strut, trailing arm, multi link, longitudinal torsion bar system and others with different geometries for each type. Further, the fixture of the present invention can be oriented at a 45 degree angle in all the cases of lateral, longitudinal and vertical (where applicable) loading conditions. It can successfully be used in the manufacturing setup for inspection/quality control and also in the production lines to check the alignments.
The advantages imparted by this modular fixture are as under:
- One single fixture can be used to test all the control arms.
- Can be used to test in all the three directions which were not possible previously.
- Time saving by 94% approx.
- Cost saving by 83% approx/annum; only one fixture needs to be fabricated.
- Standardization of fixture.
- Error reduction as the same fixture is used for all the tests.
- Tests can be dbne immediately'without the need for waiting for the custom fabricated fixture.
- Higher strength and stiffness.

WE CLAIM:-
1. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle, comprises of a center block, spacers, mounting plates and base plates, wherein the two base plates are mounted to the external fixture base at perpendicular angles; wherein the base plate has two long slots at two ends for mounting it to the external fixture base; the center block and base plate are fastened perpendicular to each other; two mounting plates clamps the Lower Control Arm rigidly between it, wherein the mounting plates consist of threaded holes of different diameters; the spacer elements are added between the centre block and the mounting plate based on the requirement.
2. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle as claimed in claim 1, wherein the base plate is having a construction of multiple threaded holes for holding the center block.
3. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle as claimed in claim 1 wherein the center block has,a cubical geometry with plurality of holes at four sides.
4. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle as claimed above wherein the multiple spacer elements are used for adjusting the fixture according to the bush width of the Lower Control Arm (LCA).
5. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle as claimed above wherein the mounting plates can be clamped to the centre block and spacer elements for more rigidityjf required.

6. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA)'of a vehicle as claimed above wherein themodular fixturecontains four major parts which can be assembled together such a way that it accommodates a wide range of control arms for testing purpose even if various parameters are and decreases the test cycle time drastically (by 94% approx).
7. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle as claimed above wherein the fixture assembly of the invention is for static and dynamic testing of the part (Lower control arm) and is capable of performance as well as durability test.
8. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle as claimed above wherein the said fixture assembly accommodates multiple designs like Double wishbone, Mc Pherson strut, trailing arm, multi link, longitudinal torsion bar system and others with different geometries for each type.
9. The fixture assembly for stiffness measurement of an automobile components, particularly the Lower Control Arm (LCA) of a vehicle as claimed above wherein for the said fixture assembly it is possible to orient it at a 45 degree angle in all the cases of lateral, longitudinal and vertical (where applicable) loading conditions.