We Claim: 1. An assembly for stiffness measurements on a vehicle ...

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15 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

104 εμφανίσεις

We Claim:

1. An assembly for stiffness measurements on a vehicle structure comprising: a base
frame grouted on concrete ground said base frame having at least two base channels
parallel to each other disposed within the base frame; an independently pivoted first
bea
m and an independently pivoted second beam on which beams a vehicle structure
under test is mounted, said first beam being mounted at a distance above the base
frame and said second beam mounted at a distance above the base frame and at an
adjustable dista
nce horizontally parallel to the first beam such that the distance
between the first and second beam is adjustable depending on the wheelbase of the
vehicle; means (1A) to adjust the assembly depending on the wheel track of the
vehicle said means being pro
vided on the top surface of the beams; and a loading
arrangement to apply load on the vehicle structure depending on the stiffness to be
measured.

2. The assembly as claimed in claim 1, wherein the first beam and the second
beam are independently gr
ipped by beam holding plates.

3.

The assembly as claimed in claim 1 and 2, wherein the base channels comprise

slots or stepped holes at least partially along the length of the base channels; one of the

said beam holding plate being slidably attached to the

base channels by means of said

slots or stepped holes and the other beam holding plate being fixedly attached to the

base channels, to facilitate adjustment of the length of the assembly depending on the

wheelbase of the vehicle structure.

4.

The assembly

as claimed in claim 1, wherein the means to adjust the assembly

depending on the wheel track of the vehicle comprises slotted plates.

11

5. The assembly as claimed in claim 1, wherein the loading arrangement is a
turnbuckle loading arr
angement employed to apply load at one end of the beam in
clockwise and/or anticlockwise direction when the vehicle structure is under torsional
stiffness measurement test and is provided to remain stationary and locked when the
vehicle is under bending st
iffness measurement test.

6. The assembly as claimed in any one of the preceding claims, wherein it
comprises universal joints on the first beam for loading the vehicle structure.

7. The assembly as claimed in claim 5, wherein load cells are provide
d in the vicinity
of the loading arrangement to record the corresponding loads applied on the vehicle
structure.

8. The assembly as claimed in any one of the preceding claims, wherein two cross
scales are pro
vided along with a laser pointer to mark the locations for deflection
measurements on vehicle structures due to the torsional or bending load.

9. A method for measuring the torsional stiffness of a vehicle structure, said
vehicle
structure comprising a fro
nt end and a rear end and said method comprising the
steps
of:

mounting the front end of the vehicle structure by means of universal joints on
the slotted plates provided on the first beam;

fixedly mounting the rear end of the vehicle structure by means of

fixed links
on the slotted beams provided on the second beam;

locking the turnbuckle so that no torsion is transmitted to the rear end through
the second beam;

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applying torque by means of the turnbuckle on the front end of the vehicle
structure by turning the turnbuckle arrangement either in the clockwise or
anticlockwise direction;

recording the load acting when the said torque load applied to the vehicle
structure using load cells;

determining the minimum torsional stiffness based on the torque load recorded
by the load cells.

10. The method as claimed in claim 9, wherein the minimum torsional stiffness is
determined by the following relation
(units
-

KNm/deg):


where,

K
Tmin

is the minimum torsional stiffness;

T is the torque load applied on the structure

0
L

is the twisting angle at the loading plane (front end)

9
R

is the twisting angle at the restrained plane (rear end)

11. A method for measuring the bending stiffness of a vehicle structure, said
vehicle
structure comprising a front end and a rear end and said method comprising the
steps
of:

mounting the front end of the vehicle structure by means of universal joints on
t
he slotted plates provided on the first beam such that the front end is envisaged to be
mounted on a roller
-
supported beam;

mounting the rear end of the vehicle structure with fixed links on the second
beam such that the rear end is envisaged to be mounted

on a hinged beam;

13

where,

K
Bmin

is the minimum bending stiffness
L is
the load applied to the vehicle structure
Z
„,„ is the maximum deflection.

TATA MOTORS LIMITED
By their Agent & Attorney

(Karuna Goleria)
of
DePENNING & DePENNING



locking the turnbuckle arrangement at both ends of the beam such that the front
end and the rear end of the structure remain fixed;

applying loads at predetermined points in the vehicle structure such that the
loads simulate at least the weight of the driver, the weight of the co
-
driver, the weight
of the rear passenger behind the driver and the weight of the rear passenger behind the
co
-
driver;

recording the load acting when the said weights are applied to the vehicle
structure using load cells;

determining the minimum bending stiffness based on the load recorded by the
load cells.

12. The method as claimed in claim 11, wherein the

minimum bending stiffness is
determined by the following relation
(units
-

(N/mm):

Dated this 3 day of
A uqusy
2006.