Title of Invention

A DEVICE TO MEASURE ACTUAL BODY LOADS IN AUTOMOTIVE VEHICLES

Abstract

A device to measure actual body loads in both static and dynamic conditions on body mounts of vehicles of body - over chassis construction and other automotive vehicles, which consists of three different pieces fitted together (a) an upper disc that works as a top cover, (b) a sensor body on which transducers are bonded and (c) a lower disc which is a bottom support for the device, all the three members being circular with the same diameter and have concentric holes at the center, the holes being used for fastening me device between the body and chassis, further characterized in that the sensor body <b) consists of four ribs and having transducers two on each rib from both the sides and mounted on these ribs closer to the hub which is connected to the outer ring portion which is fixed and when the device is being used to measure the loads is mounted on the outriggers by suitable means such as proper hardware and gets accommodated in the limited available space between the chassis outrigger and vehicle due to its size and low mass; measures the load at specific positions in bom static and dynamic conditions by measuring the deflections in the hub and the ribs which are under the load, wherein the deflections are proportional to the load.

Full Text

FORM 2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATIOIN (Section 10) "A DEVICE TO MEASURE ACTUAL BODY LOADS IN AUTOMOTIVE VEHICLES" MAHMDRA & MAHINDRA LTD:, R&D Centre, Auto Sector, HASHIK-422 0071 Maharastra State. India An Indian Company registered under the provisions of the Companies Act, 1956 The following specification described the nature of this invention arid the manner in which it is to Be perforned. original 618/mum/03 12/06/03 The present invention relates to the body and chassis of automotive vehicles and is more particularly directed towards a device that measures actual static and dynamic loads on body mounts of vehicles of Body-over-chassis type of construction, which will help in optimising the design of the chassis outriggers. There are two popular categories of body construction in the automobile industry: Mono-coque construction Body-over-chassis construction In the Mono-coque vehicles, the vehicle is designed without a separate chassis whereas in the Body-over-chassis category, the body and chassis are separate. In the Body-over-chassis vehicles, the body is mounted over the chassis by fixing it with the help of body mounts along with rubber dampers located at pre-determined positions known as 'chassis outriggers'. The body mounts are designed to sustain a total weight of the body and the load of passengers and/or luggage. The present invention relates to the Body-over-chassis category of vehicles. It is, however, to be understood that this invention is not limited only to Body-over-chassis vehicles, but is also equally applicable to and is useful for all categories of automotive Prior Art It is' generally known in the art that chassis outriggers are provided for mounting the body of a vehicle on the chassis in the Body-over-chassis category of automotive Positions of mounts, loading pattern at each position, the corresponding load some of the inputs that are required in designing the body mounting bracketry. It Is well known in the art that the body load on each of the chassis outriggers is estimated by proportionately distributing the total payload. Theoretical design calculations are normally not validated by actual load measurements. Load washers are sometimes used in static condition but they increase the height of body and pose difficulty while mounting in the limited space available at outrigger At present there is no contrivance to overcome these shortcomings of the design process. Also there are no direct solutions available to address this problem. There is, thus, a definite need for a suitable device for actual measurement of loads at each outrigger point With a view to overcome these and other similar shortcomings of the prior art, the present invention provides for a device that can be accommodated in the limited space available at the outriggers and measures actual body loads in both static as well as dynamic conditions. With the above and other objectives in view, as will hereinafter appear, a salient feature of the present invention is that the device of this invention is mounted with the help of proper hardware onto the outriggers so as to be able to measure dynamic loads A feature of this invention is that the electrical output of the device is independent of the point of application of load. Another feature of this invention is that the design of the device of this invention is such that size-wise the device is accommodated in the space available between the chassis outrigger and the body. The device of this invention is very small in shape, has very low mass and is constructed as an assembly consisting of only three members. This construction is very convenient to assemble even at the mounting stage. The static and dynamic loads applicable at the specific positions are considered during the designing of Yet another feature of this invention is that the transducers used for this device produce highly stable performance for long durations and are self-temperature compensated. The design of the device of this invention is such that the transducers are suitably protected from overloads and will not have any detrimental effects under mechanical shocks. One more feature of this invention is that by changing the shape of the lower used for different applications. The transducers of this device can operate over a broad range of road input frequencies giving excellent linearity over a wide range of loads. The electronic circuit also incorporates thermal compensation and auto correction so that the effect of temperature variations on data generation/acquisition is minimised. The above and other features of the invention including various details of construction and combination of parts will now be more particularly described. It will be understood that the particular device embodying the invention is described only by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. Drawings : This invention is illustrated in the accompanying drawings. Reference is made to the accompanying drawings, which show the illustrative embodiment of the invention from which its novel features and advantages will be apparent In the drawings: Figure 1 : Isometric view of sensor unit of Body mount load cell. Figure 2: Shows the three components of the device of this invention in elevation view. 'A' is the upper disc that works as top cover, 'B' is the sensor on which the transducers are bonded and 'C is the lower disc that acts as bottom support for Figure 3 : Shows three views of (he sensor: 2a, 2b and 2c, shown as part CB' in Figure 1. Figure 2a is the plan view of the sensor. Figure 2c is the cross-sectional view along line Y-Y. T1A, TIB, T2A, T2B, T3A, T3B, T4A and T4B are the transducers. Therefore according to the present invention a device to measure actual body loads in both static and dynamic conditions on body mounts of vehicles of body - over chassis construction and oilier automotive vehicles. It consists of three different pieces fitted together (a) an upper disc mat works as a top cover, (b) a sensor body on which transducers are bonded and (c) a lower disc which is a bottom support for the device, all the three members being circular with the same diameter and have concentric holes at the center. These holes are used for fastening the device between the body and chassis, further characterized in that the sensor body (b) consists of four ribs and having transducers two on each rib from both the sides and mounted on these ribs closer to the hub which is connected to the outer ring portion which is fixed and when the device is being used to measure the loads is mounted on the outriggers by suitable means such as proper hardware and gets accommodated in the limited available space between the chassis outrigger and vehicle due to its size and low mass. It measures the load at specific yo&tfiotts. in. hxjtk static and d^n^tnic GoodUiaas. hy, raea&imng, the. deflections in. the. huh and the ribs, which are under the load, wherein the deflections are proportional to the load. Description of tfie Preferred Embodiment: Referring to the drawings, it is seen that trie illustrated assembly of the device of this invention comprises three main members, the top cover 'A', the sensor 'B' and the bottom support 'C. All the three members are circular with the same outer diameter and have through concentric holes at their centres. These holes are used for fastening the device between the body and th£ chassis. In the illustrated embodiment of the invention, the sensor body consists of four ribs and the transducers, two ori eaoh rib from bom the sides, are mounted on the four ribs, closer to the hub. The transducers measure deflections of the individual ribs. Mechanical loads on body mounts are measured at all the outrigger locations simultaneously in static as well as dynamic conditions. Referring to Figure 1, the top cover 'A' transfers the load of the body onto the hub of the sensor 'B'. This hub is connected with the help of four ribs to the outer ring portion, which is fixed. While under load, the hub and the ribs tend to deflect. The transducers sense the strain developed in the ribs due to deflectiori, which is proportional to the load. Transducers are configured in the form of a Whealstone bridge to ensure that it results in maximum imbalance and that the imbalance is a linear function of the applied load. The measured value of this voltage is directly logged onto the data acquisition For measuring the actual loads, the body mounts between the body and the chassis are removed, and are replaced by the device of this invention. Calibration of the device is done with the help of either a conditioning amplifier with an indicator or a data logger. Initially, the reading in millivolts without any load is recorded as zero load and then the rated full load is applied to the device. This millivolt output is recorded as the full-scale output It is to be understood that although the device is used for the illustrated application of measuring body loads of automotive vehicles, its use is not restricted only to tiie said application in automotive industry, but can also be used in many other areas like pedal effort measurement, etc. without deviating from the scope of this invention. Similarly, any material or combination of materials of construction suitable for the design and operation of the device depending on loading range, desired sensitivity, etc. are possible to be used for different members of the device without deviating from It is also to be understood that the present invention is by no means limited to the particular construction herein disclosed and/or shown in drawings, but also comprises any modifications or equivalents within the scope of the invention. Key to Fig.2 KevfoFig.2a - Plan View T1A - t T2B - 2 T3A - 3 T3B - 4 KevtoFig.2b - Cross section along X-X T23 - 1 T3A - 2 T3B - 3 KevtoFig.2c - Cross section along Y-Y T4B - I T1A - 2 TtB - 3 We Claim A device to measure actual body loads in both static and dynamic conditions on body mounts of vehicles of body - over chassis construction and other automotive vehicles, which consists of three different pieces fitted together (a) an upper disc that works as a top cover, (b) a sensor body on which transducers are bonded and (c) a lower disc which is a bottom support for the device, all the three members being circular with the same diameter and have concentric holes at the center, the holes being used for fastening me device between the body and chassis, further characterized in that the sensor body Dated this 18th Day of June, 2004 ( M. D.BHATE ) AGENT FOR APPLICANT

Documents:

618-mum-2003-claims(granted)-(21-06-2004).doc

618-mum-2003-claims(granted)-(21-06-2004).pdf

618-mum-2003-correspondence(14-10-2005).pdf

618-mum-2003-correspondence(ipo)-(19-10-2004).pdf

618-mum-2003-drawing(21-06-2004).pdf

618-mum-2003-form 1(13-06-2003).pdf

618-mum-2003-form 19(13-06-2003).pdf

618-mum-2003-form 2(granted)-(21-06-2004).doc

618-mum-2003-form 2(granted)-(21-06-2004).pdf

618-mum-2003-form 3(12-06-2003).pdf

618-mum-2003-form 3(21-06-2004).pdf

618-mum-2003-form 4(14-06-2004).pdf

618-mum-2003-form 5(21-06-2004).pdf

618-mum-2003-power of authority(31-05-2004).pdf

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