Claims:
1) An engine mount (100) for a vehicle comprises:
a base plate (112), a rubber mount (114) and a boss (116) are configured to form an integrated unit (109); wherein said rubber mount (114) is provided with an air cavity (130) configured to act as an resilient means of varying dynamic stiffness;
at least one first bracket (108) configured to be securely mounted on said boss (116) of said integrated unit (109); and
at least one second bracket (110) configured for accommodating said base plate (112) of said integrated unit (109), wherein said integrated unit (109) is securely mounted on chassis (106) by plurality of fasteners (120) passing through said second bracket (110).

2) The engine mount (100) as claimed in claim 1, wherein said rubber mount (114) provided with said air cavity (130) is configured to provide higher stiffness to said engine mount (100) during low frequency vibrations.

3) The engine mount (100) as claimed in claim 1, wherein said rubber mount (114) provided with said air cavity (130) is configured to provide lesser stiffness to said engine mount (100) during high frequency vibrations.

4) The engine mount (100) as claimed in claim 1, wherein said base plate (112) is provided with plurality of holes (113) to securely accommodate plurality of fasteners (120).

5) The engine mount (100) as claimed in claim 1, wherein said first bracket (108) has a hole (115) to securely mount a fastener (111) on said boss (116) of said integral unit (109).

6) The engine mount (100) as claimed in claim 1, wherein said second bracket (110) provided with plurality of through holes (117) is configured for fastening of plurality of fasteners (120) for securing said engine mount (100) on said chassis (106).
7) The engine mount (100) as claimed in claim 1, wherein said first bracket (108) provided with a locator pin (118) is configured to reduce twisting of said engine mount (100).

8) The engine mount (100) as claimed in claim 1, wherein said first bracket (108) provided with a first rubber (122) is configured to prevent metal to rubber contact of said rubber mount (114) with said first bracket (108) to avoid wear and tear of said rubber mount (114).

9) The engine mount (100) as claimed in claim 1, wherein said integrated unit (109) is configured with said boss (116) for securely mounting said engine arm (102) by said fastener (111).

10) The engine mount (100) as claimed in claim 1, wherein said base plate (112) is configured to be mounted with a second rubber (124) for preventing metal to metal contact of said first bracket (108) and said base plate (112).

11) The engine mount (100) as claimed in claim 1, wherein said second bracket (110) is configured to be mounted with a third rubber (126) for preventing metal to metal contact of said first bracket (108) and said second bracket (110).
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
AN ENGINE MOUNT FOR A VEHICLE

Applicant:
Tata Motors Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400001, Maharashtra, India

The following specification describes the subject matter and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present disclosure generally relates to an engine mount for a vehicle. More particularly, the present disclosure relates to a variable stiffness engine mount for a vehicle.
BACKGROUND OF THE INVENTION
An automotive engine-body-chassis system is typically subjected to unbalanced engine forces, uneven firing forces especially at the idling speeds, dynamic excitations from gearboxes and accessories, and road excitation. Conventionally, a rubber engine mount is used in vehicles to isolate vibration from engine to vehicle chassis or vice versa. The drawback of the conventional rubber engine mount is that its stiffness increases with increase in frequency. However, it is desired that the stiffness of the engine mount should reduce with increase in frequency. Several developments have been done by researchers like semi-active mount and active mounts that are configured to attain the desired stiffness of the engine mount with change in frequency. However, these mounts are costlier and also less durable as compared to rubber engine mounts.
The present disclosure is directed to overcome one or more limitations stated above and any other limitations associated with the prior arts.
OBJECTS OF THE INVENTION
Main object of the present disclosure is to provide an engine mount for a vehicle configured to exhibit dynamic stiffness inversely proportional to frequency.
Another object of the present disclosure is to provide an engine mount mounted with a rubber mount having air cavity for varying stiffness of said engine mount according to movement of powertrain.
Yet another object of the present disclosure is to provide an effective and economical engine mount for exhibiting dynamic stiffness inversely proportional to frequency.
SUMMARY OF THE INVENTION
Before the present an engine mount for a vehicle, is described, it is to be understood that this application is not limited to a particular an engine mount for a vehicle, as there may be multiple possible embodiments, which are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular implementations, versions, or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to an engine mount for a vehicle. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
In one embodiment, an engine mount is disclosed. The engine mount comprising a base plate, a rubber mount and a boss is configured to form an integrated unit, wherein said rubber mount is provided with an air cavity configured to act as a resilient means of varying dynamic stiffness. Further, at least one first bracket configured to be securely mounted on said boss of said integrated unit and at least one second bracket configured for accommodating said base plate of said integrated unit, wherein said integrated unit is securely mounted on chassis by plurality of fasteners passing through said second bracket.
BRIEF DESCRIPTION OF DRAWINGS
The foregoing detailed description of embodiments is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present subject matter, an example of construction of the present subject matter is provided as figures; however, the present subject matter is not limited to the specific an engine mount for a vehicle disclosed in the document and the figures.
The present subject matter is described in detail 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 various features of the present subject matter.
Figure 1 illustrates a side view of fitment of an engine mount on a vehicle, in accordance with one embodiment of the present subject matter.
Figure 2 illustrates a top view of fitment of an engine mount on a vehicle, in accordance with one embodiment of the present subject matter.
Figure 3 illustrates an exploded view of an engine mount, in accordance with one embodiment of the present subject matter.
Figure 4 illustrates a sectional view of an engine mount, in accordance with one embodiment of the present subject matter.
Figure 5 illustrates a mathematical model of stiffness of an engine mount, in accordance with one embodiment of the present subject matter.
DETAILED DESCRIPTION
Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any an engine mount for a vehicle and, similar or equivalent to those described herein may be used in the practice or testing of embodiments of the present disclosure, the exemplary, an engine mount for a vehicle is now described.
Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments described but is to be accorded the widest scope consist in this regard, in a generic sense.
Figures 1-5 are now described using the reference numbers stated in the below table.
Reference Numeral Description
100 Engine mount
102 Engine arm
104 Engine
106 Chassis
108 First bracket
109 Integrated unit
110 Second bracket
111 Fastener
112 Base plate
113 Plurality of holes
114 Rubber mount
115 Hole
116 Boss
117 Plurality of holes
118 Locator pin
120 Fasteners
122 First rubber
124 Second rubber
126 Third rubber
128 Top surface of air cavity
130 Air cavity
132 Bottom surface of air cavity

Figure 1 and Figure 2 illustrating a side view and a top view of fitment of an engine mount 100 on a vehicle respectively, in accordance with one embodiment of the present subject matter are now described.
The engine mount 100 is configured to be mounted on a chassis 106. Further, an engine arm 102 connected to an engine 104 is configured to be mounted on said engine mount 100.
Figure 3 and Figure 4 illustrates an exploded view and a sectional view of an engine mount 100 respectively, in accordance with one embodiment of the present subject matter.
The engine mount 100 comprises a first bracket 108, an integrated unit 109 and a second bracket 110. A locator pin 118 mounted on said first bracket 118 is configured to reduce twisting of said engine mount 100. Further, the first bracket 108 made of metal is provided with a first rubber 122 to prevent contact of a rubber mount 114 with metal of said first bracket 108. The integrated unit 109 comprises a rubber mount 114, a boss 116, a base plate 112. The integrated unit 109 mounted between said first bracket 108 and said second bracket 110 is configured for securing said first bracket 108 and said second bracket 110. The rubber mount 114 provided with an air cavity 130 is configured to act as a resilient means of varying dynamic stiffness. The integrated unit 109 provided with a boss 116 is configured for mounting an engine arm 102 through a fastener 111. At least one first bracket 108 is configured to be securely mounted on said boss 116 of said integrated unit 109. At least one second bracket 110 is configured for accommodating said base plate 112 of said integrated unit 109, wherein said integrated unit 109 is securely mounted on chassis 106 by plurality of fasteners 120 passing through said second bracket 110. The first bracket 108 has a hole 115 to securely mount a fastener 111 on said boss 116 of said integral unit 109. The first bracket 108 provided with a first rubber 122 is configured to prevent metal to rubber contact of said rubber mount 114 with said first bracket 108 to avoid wear and tear of said rubber mount 114. The base plate 112 provided with plurality of holes 113 to securely accommodate plurality of fasteners 120. The base plate 112 is configured to be mounted with a second rubber 124 for preventing metal to metal contact of said first bracket 108 and said base plate 112. The second bracket 110 provided with plurality of through holes 117 is configured for fastening of plurality of fasteners 120 for securing said engine mount 100 on said chassis 106. The second bracket 110 is configured to be mounted with a third rubber 126 for preventing metal to metal contact of said first bracket 108 and said second bracket 110.
The rubber mount 114 provided with said air cavity 130 is configured to provide higher stiffness to said engine mount 100 during low frequency vibrations. The rubber mount 114 provided with said air cavity 130 is configured to provide lesser stiffness to said engine mount 100 during high frequency vibrations.
The shape, size and position of the air cavity 130 further defined by the top surface 128, height of the air cavity 130 and bottom surface 132 depend on powertrain inertia properties and vibration.
Figure 5 illustrates a mathematical model of stiffness of an engine mount 100, in accordance with one embodiment of the present subject matter.
K_eq is the overall stiffness of the engine mount 100
K_r1 is the stiffness of the rubber mount.
? K?_(r2 ) is the stiffness of the rubber mount.
? K?_r3 is the stiffness of the rubber mount.
? K?_air is the stiffness of the air spring.
Overall stiffness of the system:
1/K_eq = 1/K_r1 + 1/(?2K?_r2+K_air ) + 1/K_r3

K_eq= (K_r1 K_r3 (2K_r2+K_air))/((K_r1+K_r3 )(2K_r2+K_air )+K_r1 K_r3 )

During lower engine rpm or lower frequency range, more movement of powertrain is observed, which further results in more movement of the engine mount 100. On account of more movement of the engine mount 100, the air inside air cavity 130 will be compressed more, which increases the stiffness of air spring Kair and, accordingly the overall stiffness K_eq of the engine mount 100 to effectively control the powertrain motion.
During higher engine rpm or higher frequency range, less movement of powertrain is observed, which further results in less movement of the engine mount 100. On account of less movement of the engine mount 100, the air inside the air cavity 130 will be compressed less, which decreases the stiffness of air spring Kair and, accordingly, the overall stiffness K_eq of the engine mount 100 to improve vibration isolation at higher frequency range.
An engine mount 100 for a vehicle comprises a base plate 112, a rubber mount 114 and a boss 116 are configured to form an integrated unit 109, wherein said rubber mount 114 is provided with an air cavity 130 configured to act as an resilient means of varying dynamic stiffness. Further, at least one first bracket 108 configured to be securely mounted on said boss 116 of said integrated unit 109 and at least one second bracket 110 configured for accommodating said base plate 112 of said integrated unit 109, wherein said integrated unit 109 is securely mounted on chassis 106 by plurality of fasteners 120 passing through said second bracket 110.
Said rubber mount 114 provided with said air cavity 130 is configured to provide higher stiffness to said engine mount 100 during low frequency vibrations. Said rubber mount 114 provided with said air cavity 130 is configured to provide lesser stiffness to said engine mount 100 during high frequency vibrations. Said base plate 112 is provided with plurality of holes 113 to securely accommodate plurality of fasteners 120. Said first bracket 108 has a hole 115 to securely mount a fastener 111 on said boss 116 of said integral unit 109. Said second bracket 110 provided with plurality of through holes 117 is configured for fastening of plurality of fasteners 120 for securing said engine mount 100 on said chassis 106. Said first bracket 108 provided with a locator pin 118 is configured to reduce twisting of said engine mount 100. Said first bracket 108 provided with a first rubber 122 is configured to prevent metal to rubber contact of said rubber mount 114 with said first bracket 108 to avoid wear and tear of said rubber mount. Said integrated unit 109 is configured with said boss 116 for securely mounting said engine arm 102 by said fastener 111. Said base plate 112 is configured to be mounted with a second rubber 124 for preventing metal to metal contact of said first bracket 108 and said base plate 112. Said second bracket 110 is configured to be mounted with a third rubber 126 for preventing metal to metal contact of said first bracket 108 and said second bracket 110.
Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include the following.
Some embodiments of the present subject matter discloses an engine mount configured to exhibit higher stiffness during lower frequency to effectively control the powertrain motion.
Some embodiments of the present subject matter discloses an engine mount configured to exhibit lower stiffness during higher frequency improve vibration isolation.
Some embodiments of the present subject matter provides an effective and economical engine mount for exhibiting dynamic stiffness inversely proportional to frequency.