Abstract:
A power train mounting apparatus for a vehicle is disclosed to improve the vehicle riding by properly restricting the displacement of the power train. The dynamic rigidity and vibration insulation in relation to an engine mount and transmission mount are also increased, thus improving the Noise, Vibration, and Harshness (NVH) function of the vehicle.

Description:
FIELD OF THE INVENTION  
       [0001]     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.  
       BACKGROUND OF THE INVENTION  
       [0002]     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.  
         [0003]     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.  
         [0004]     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.  
         [0005]     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.  
         [0006]     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.  
         [0007]     Accordingly, a liquid filled hydraulic mount is added either to the engine mount or transmission mount for preventing the deterioration of the vehicle ride.  
         [0008]     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.  
       SUMMARY OF THE INVENTION  
       [0009]     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.  
         [0010]     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.  
         [0011]     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.  
         [0012]     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.  
         [0013]     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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     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:  
         [0015]      FIG. 1 a  schematic view of a power train mounting apparatus according to an embodiment of the present invention;  
         [0016]     FIGS.  2  to  3  illustrate an engine mount of  FIG. 1 ;  
         [0017]     FIGS.  4  to  5  illustrate a transmission mount of  FIG. 1 ; and  
         [0018]      FIG. 6  illustrates a rear roll mount of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     Referring to  FIG. 1 , a preferred embodiment of the present invention includes an engine  1  and transmission  5  that attach at three places to a left and right side members  3 L and  3 R of the vehicle body and a rear crossmember  7  in an engine compartment.  
         [0020]     An engine mount  10  is located between engine  1  and left side member  3 L, a transmission mount  20  is located between transmission  5  and right side member  3 R, and a roll mount  30  is placed between rear crossmember  7  and the joint of engine  1  and transmission  5 .  
         [0021]     Engine mount  10 , as shown in  FIG. 2 , is composed of an upper and lower brackets  11  and  12 , bridge-type insulator  13 , and support bracket assembly  14 . Upper and lower brackets  11  and  12  couple to each other at both ends thereof, and bridge-type insulator  13  is fixed via vulcanization between upper and lower brackets  11  and  12 . Support bracket assembly  14  attaches engine mount  10  to left side member  3 L.  
         [0022]     With reference to  FIGS. 3   a  and  3   b , the middle portions of upper and lower brackets  11  and  12  of engine mount  10  are convexly curved in flat sheet shapes. Each end of upper and lower brackets  11  and  12  are coupled to each other by means of spot welding.  
         [0023]     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.  
         [0024]     Support bracket assembly  14  coupled on left side member  3 L supports engine mount  10  via a bolt (‘B’ in  FIG. 2 ) penetrating inner pipe  15 .  
         [0025]     Bridge-type insulator  13  includes a primary damper  13   a  having inner pipe  15  at the center thereof and a plurality of split ends. Each end of primary damper  13   a  couples or contacts with upper and lower brackets  11  and  12 . A supplementary damper  13   b  is distanced from primary damper  13   a  and secures at the bottom thereof to lower bracket  12 .  
         [0026]     An unexplained reference numeral  16  is an engine mounting bracket fixing engine mount  10  to engine  1 .  
         [0027]     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.  
         [0028]     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.  
         [0029]     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.  
         [0030]     Consequently, engine mount  10  improves the ride comfort by minimizing the displacement thereof in place of the costly liquid filled engine mount.  
         [0031]     In reference to  FIGS. 4 and 5 , transmission mount  20  is constituted by an outer pipe  21 , bridge-type insulator  22 , and inner pipes  23 . Outer pipe  21  is in the shape of a cylinder, bridge-type insulator  22  is situated via vulcanization in outer pipe  21 , and inner pipes  23  are fixed via vulcanization at the center of the insulator in the lateral direction of the vehicle.  
         [0032]     A side member mounting bracket  24  coupled at the outside of outer pipe  21  is disposed on right side member  3 R in the engine compartment.  
         [0033]     Bridge-type insulator  22  includes a primary damper  22   a  and supplementary damper  22   b . Primary damper  22   a  has inner pipes  23  at the center thereof and a plurality of split ends. Each end of primary damper  22   a  couples or contacts outer pipe  21 . Supplementary damper  22   b  is distanced from primary damper  22   a  and couples at the bottom thereof to outer pipe  21 .  
         [0034]     An unexplained reference numeral  25  is a transmission mounting bracket fixing transmission mount  20  to transmission  5 .  
         [0035]     Bolts (‘B’ in  FIG. 4 ) passing through transmission mounting bracket  25  and inner pipes  23  of bridge-type insulator  22  support transmission mount  20  by connecting right side member  3 R and transmission  5 .  
         [0036]     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  22   a  of bridge-type insulator  22  to thereby reduce the noise upon acceleration by a gradual variation of the spring characteristic value.  
         [0037]     Referring now to  FIG. 6 , roll mount  30  connects rear crossmember  7  and the joint of engine  1  and transmission  5 . Roll mount  30  includes bushing-type mounts  31  at both ends of roll mount  30 , and a roll rod  32  connecting the bushing-type mounts therebetween.  
         [0038]     Each bushing-type mount  31  has a cylindrical outer pipe  31   a , and bushing-type insulators  31   b  fixed by means of vulcanization in the outer pipe. An inner pipe  31   c  is fixed at the center of the insulator by means of vulcanization in the lateral direction of the vehicle.  
         [0039]     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.  
         [0040]     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  31   b  installed sideways in the vehicle. Thus, the noise is lessened by a gradual variation of the spring characteristic value.  
         [0041]     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.  
         [0042]     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.