Patent Application
20070131469
The present invention relates to a mounting apparatus for a power train of a vehicle adapted to control the displacement of the power train and increase dynamic rigidity and vibration insulation of each mount, thereby improving a ride comfort and the Noise, Vibration, and Harshness (NVH) function of the vehicle.
A power train mounting apparatus that supports the power train and insulates noise and vibration thereof is generally formed by a principal axis of inertia of three to four support points or a center of gravity of three support points.
For light automobiles, the center of gravity or principal axis of inertia of three support points is typically used. However, as the center of gravity requires a sub-frame, crossmember, or center member, the principal axis of inertia of three support points has mainly been adopted in recent vehicles for reducing the weight and improving the rate of fuel consumption thereby.
The principal axis of inertia of three support points has two main mounts, such as an engine and transmission mounts, at the vehicle body. A third mount (roll mount or roll rod) is at the crossmember.
In case of the center of gravity of three support points, all mounts are located underneath the engine, and thus, it is difficult to restrict engine roll. Hence, the Noise, Vibration, and Harshness (NVH) function and vehicle ride are inferior to that of the principal axis of inertia of three support points.
However, a drawback of the principal axis of inertia of three support points is that one mount is conventionally a roll rod that controls the displacement of engine roll; therefore, a relatively large displacement of the engine occurs in the vertical direction thereof.
Accordingly, a liquid filled hydraulic mount is added either to the engine mount or transmission mount for preventing the deterioration of the vehicle ride.
The liquid filled hydraulic mount, however, is heavy in weight and high in manufacturing cost such that the price load could fall heavily on the drivers of light vehicles.
Embodiments of the present invention help control the displacement of a power train and increase dynamic rigidity and vibration insulation of each mount, thereby improving the ride comfort and the Noise, Vibration, and Harshness (NVH) function of the vehicle.
A power train mounting apparatus of a vehicle according to one embodiment of the present invention includes an engine mount supportively connecting an engine and side member therebetween in an engine compartment. A transmission mount supportively connects a transmission and side member therebetween. A roll mount supportively connects a crossmember and the joint of the engine and transmission therebetween.
The engine mount is constituted by an upper and lower brackets, a bridge-type insulator contacting the lower bracket, and an inner pipe fixed to the insulator.
The transmission mount is constituted by an outer pipe, a bridge-type insulator contacting the outer pipe, and an inner pipe fixed to the insulator.
The roll mount is constituted by bushing-type mounts placed at both ends of the roll mount, and a roll rod that connects the bushing-type mounts therebetween.
For a better understanding of the nature and objects of the present invention, reference should be made to the following detailed description with the accompanying drawings, in which:
FIGS. 2 to 3 illustrate an engine mount of
FIGS. 4 to 5 illustrate a transmission mount of
Referring to
An engine mount 10 is located between engine 1 and left side member 3L, a transmission mount 20 is located between transmission 5 and right side member 3R, and a roll mount 30 is placed between rear crossmember 7 and the joint of engine 1 and transmission 5.
Engine mount 10, as shown in
With reference to
The bottom of bridge-type insulator 13 fastens via vulcanization to lower bracket 12. The insulator is equipped at the center thereof with an inner pipe 15 via vulcanization. When upper bracket 11 couples to lower bracket 12, upper bracket 11 presses bridge-type insulator 13 for a pre-compression.
Support bracket assembly 14 coupled on left side member 3L supports engine mount 10 via a bolt (‘B’ in
Bridge-type insulator 13 includes a primary damper 13a having inner pipe 15 at the center thereof and a plurality of split ends. Each end of primary damper 13a couples or contacts with upper and lower brackets 11 and 12. A supplementary damper 13b is distanced from primary damper 13a and secures at the bottom thereof to lower bracket 12.
An unexplained reference numeral 16 is an engine mounting bracket fixing engine mount 10 to engine 1.
As the pre-loaded insulator is fixed via vulcanization between the assembly of upper and lower brackets 11 and 12, the displacement of insulator 13 is minimized when the load is applied to engine mount 10 during engine operation.
Further, a gap between upper and lower brackets 11 and 12 and insulator 13 is minimized so that a large displacement of engine 1 can effectively be controlled and a comfortable vehicle ride is provided thereby.
Furthermore, engine mount 10 increases in damping value during a large displacement of engine 1 by the pre-compressed insulator; therefore, engine mount 10 may preferably substitute for an existed liquid filled engine mount.
Consequently, engine mount 10 improves the ride comfort by minimizing the displacement thereof in place of the costly liquid filled engine mount.
In reference to
A side member mounting bracket 24 coupled at the outside of outer pipe 21 is disposed on right side member 3R in the engine compartment.
Bridge-type insulator 22 includes a primary damper 22a and supplementary damper 22b. Primary damper 22a has inner pipes 23 at the center thereof and a plurality of split ends. Each end of primary damper 22a couples or contacts outer pipe 21. Supplementary damper 22b is distanced from primary damper 22a and couples at the bottom thereof to outer pipe 21.
An unexplained reference numeral 25 is a transmission mounting bracket fixing transmission mount 20 to transmission 5.
Bolts (‘B’ in
As for transmission mount 20, when the external force of compression is applied in the anteroposterior direction of bridge-type insulator 22 due to vehicle acceleration and engine roll, the force is absorbed by primary damper 22a of bridge-type insulator 22 to thereby reduce the noise upon acceleration by a gradual variation of the spring characteristic value.
Referring now to
Each bushing-type mount 31 has a cylindrical outer pipe 31a, and bushing-type insulators 31b fixed by means of vulcanization in the outer pipe. An inner pipe 31c is fixed at the center of the insulator by means of vulcanization in the lateral direction of the vehicle.
Unexplained reference numerals 33 are crossmember mounting brackets that fix bushing-type mounts 31 to rear crossmember 7 and the joint of engine 1 and transmission 5, respectively.
As for roll mount 30, when the external force of compression is applied in the anteroposterior direction of bushing-type mount 31 due to vehicle acceleration and engine roll, the force is absorbed by bushing-shaped insulator 31b installed sideways in the vehicle. Thus, the noise is lessened by a gradual variation of the spring characteristic value.
As apparent from the foregoing, there is an advantage in that a power train mounting apparatus according to the present invention fixes the engine and transmission to the side members and crossmember in the engine compartment by using a preloaded engine mount, transmission mount, and roll mount, thereby effectively coping with the large displacement of the engine during engine operation. The load displacement in the anteroposterior direction of the vehicle is also effectively dampened, thus improving the ride comfort.
Moreover, the liquid filled engine mount is substituted by an ordinary rubber engine mount that is preloaded or changed in installation direction thereof, contributing to a minimization of the manufacturing cost.
