Assembly of motor vehicle body and a power train and chassis module

Abstract

A motor vehicle front subframe includes a pair of main longitudinal beams each formed from an extrusion with a flange casting at the rear end and a suspension tower at the other end. Two lower longitudinal beams extend parallel to the main longitudinal beams and are connected by a cross member. Each lower longitudinal beam has a vertical rear flange and a generally horizontal front flange where it is attached to a corresponding flange face at the lower end of the adjacent suspension tower. Two intermediate longitudinal beams are attached to the suspension towers and to a main cross-member and forward of this are two crush cans to which is attached a bumper armature. The front subframe is part of a power train and chassis module which includes an engine, a longitudinally extending torque tube attached to the rear of the engine by a bell housing, a rear transmission and final drive assembly attached to a rearward end of the torque tube and a rear subframe mounted on the rear transmission and final drive assembly. The vehicle has a body with a passenger compartment and vertical pillars just forward of the passenger compartment. The body is assembled to the power train and chassis module by lowering the body with the of the vertical pillars just clear of the rear faces of the flanges and until various fixing holes in the flanges and align with those in the pillars. The body is then moved forward to close the gap between the flanges and the pillars. Suitable bolts or set screws are then inserted to secure the front subframe to the body and the rear subframe is attached to the body.

1 . An assembly for supporting the engine of a motor vehicle, the assembly comprising: 
 a body defining a passenger compartment, a front pair of wheels, a rear pair of wheels, a front suspension supporting the weight of the body on the front wheels and a rear suspension supporting the weight of the body on the rear wheels; and    a power train and chassis module, said powertrain and chassis module further comprising; 
 a front subframe for supporting the front suspension, the front subframe defining a rear vertical mounting face;  
 an engine mounted in the front subframe;  
 a torque tube rigidly attached to the rear of the engine and extending longitudinally of the vehicle;  
 a rear final drive assembly for driving the rear wheels of the vehicle, the rear final drive assembly being rigidly attached to a rearward end of the torque tube; and  
 a rear subframe for supporting the rear suspension, the rear subframe being mounted on the rear final drive assembly and having rear body mountings for supporting the rear end of the body;  
 and two vertical members, each supported on the body and having a forward-facing attachment face by which the respective vertical member is attached to the front subframe through the rear vertical mounting face.  
   
   
   
       2 . The assembly of  claim 1  wherein the front subframe comprises: 
 a front cross member;    a pair of suspension towers each for supporting the weight of the vehicle on a respective one the front wheels;    a pair of main longitudinal beams each having at its rear end a flange member defining the rear vertical mounting face and at its front end a respective one of the suspension towers;    and a pair of front longitudinal beams of a uniform hollow cross-section each connected at its rear end to a respective one of the suspension towers and at its front end to the front cross member.    
   
   
       3 . The assembly of  claim 2  wherein the front subframe further comprises a pair of intermediate longitudinal beams each interposed between a respective one of the suspension towers and a respective one of the front longitudinal beams.  
   
   
       4 . The assembly of or  claim 3  wherein the front subframe further comprises a main cross-member interposed between the suspension towers and the front longitudinal beams.  
   
   
       5 . The assembly of  claim 4  wherein the main cross-member is interposed between the intermediate longitudinal beams and the front longitudinal beams.  
   
   
       6 . The assembly of any of  claim 2  wherein the front subframe further comprises a pair of lower longitudinal beams which extend below and parallel to the main longitudinal beams, each lower longitudinal beam having at its rear end means for mounting to the vehicle body and being attached at its front end to the respective suspension tower.  
   
   
       7 . The assembly of  claim 6  wherein the means for mounting each lower longitudinal beam to the vehicle body comprises a flange for connection to a respective one of the forward-facing attachment faces.  
   
   
       8 . The assembly of  claim 6  wherein each lower longitudinal beam is attached to the respective suspension tower at a horizontal flange.  
   
   
       9 . In a series of motor vehicles, each motor vehicle having a body defining a passenger compartment, a front pair of wheels, a rear pair of wheels, a front suspension supporting the weight of the body on the front wheels and a rear suspension supporting the weight of the body on the rear wheels, a front subframe for supporting the front suspension, the front subframe comprising a front cross member, a pair of suspension towers each for supporting the weight of the vehicle on a respective one the front wheels, a pair of main longitudinal beams each having at its rear end a flange member defining a rear vertical mounting face and at its front end a respective one of the suspension towers and a pair of front longitudinal beams of a uniform hollow cross-section each connected at its rear end to a respective one of the suspension towers and at its front end to the front cross member, and two vertical members, each supported on the body and having a forward-facing attachment face by which the respective vertical member is attached to the front subframe through the rear vertical mounting face: 
 a series of front subframes comprising one said subframe for one type of motor vehicle in which the or each pair of said longitudinal beams is of one respective length and another said subframe for another type of motor vehicle in which at least one of the corresponding pairs of longitudinal beams is of another length.    
   
   
       10 . The series of  claim 9  wherein the difference in length between the or each pair of longitudinal beams in one type and the or each corresponding pair of longitudinal beams in the other type is used to vary, as between the one type and the other, the distance between the forward-facing attachment face and the front cross member.  
   
   
       11 . The series of  claim 9  wherein the front subframe of each assembly further comprises a main cross-member interposed between the intermediate longitudinal beams and the front longitudinal beams and wherein in said one type of motor vehicle the intermediate longitudinal beams are of one respective length and in said other type of motor vehicle the intermediate longitudinal beams are of another respective length so as to vary, as between the one type and the other, the distance between the forward-facing attachment face and the main cross member.  
   
   
       12 . The series of  claim 11  wherein the difference in length between the or each pair of longitudinal beams in one type and the or each corresponding pair of longitudinal beams in the other type is used to vary, as between the one type and the other, the distance between the forward-facing attachment face and the main cross member without substantially varying the distance between the forward-facing attachment face and the front cross member.  
   
   
       13 . A method of manufacturing a series of motor vehicles, each vehicle having a body defining a passenger compartment, a front pair of wheels, a rear pair of wheels, a front suspension supporting the weight of the body on the front wheels and a rear suspension supporting the weight of the body on the rear wheels, a front subframe for supporting the front suspension, the front subframe comprising a front cross member, a pair of suspension towers each for supporting the weight of the vehicle on a respective one the front wheels, a pair of main longitudinal beams each having at its rear end a flange member defining a rear vertical mounting face and at its front end a respective one of the suspension towers and a pair of front longitudinal beams of a uniform hollow cross-section each connected at its rear end to a respective one of the suspension towers and at its front end to the front cross member, and two vertical members, each supported on the body and having a forward-facing attachment face by which the respective vertical member is attached to the front subframe through the rear vertical mounting face, wherein the method comprises the steps of: 
 assembling one type of motor vehicle in the series with each pair of front longitudinal beams of one respective length; and    assembling of another type of motor vehicle in the series with at least one of the corresponding pair of front longitudinal beams of another length.    
   
   
       14 . The method of  claim 13  wherein the difference in length between the or each pair of longitudinal beams in one type and each corresponding pair of longitudinal beams in the other type is used to vary, as between the one type and the other, the distance between the forward-facing attachment face and the front cross member.  
   
   
       15 . The method of  claim 13  wherein the front subframe of each assembly further comprises a main cross-member interposed between the intermediate longitudinal beams and the front longitudinal beams and wherein in said one type of motor vehicle the intermediate longitudinal beams are of one respective length and in said other type of motor vehicle the intermediate longitudinal beams are of another respective length so as to vary, as between the one type and the other, the distance between the forward-facing attachment face and the main cross member.  
   
   
       16 . The method of  claim 15  wherein the difference in length between the or each pair of longitudinal beams in one type and the or each corresponding pair of longitudinal beams in the other type is used to vary, as between the one type and the other, the distance between the forward-facing attachment face and the main cross member without substantially varying the distance between the forward-facing attachment face and the front cross member.  
   
   
       17 . A method of assembling a motor vehicle a motor vehicle having a power train and chassis module, said module including a front subframe for the suspension of front wheels of the vehicle and having a rear vertical mounting face, an engine mounted in the front subframe, a torque tube rigidly attached to the rear of the engine and extending longitudinally of the vehicle, a rear final drive assembly for driving rear wheels of the vehicle rigidly attached to a rearward end of the torque tube, a rear subframe for the suspension of the rear wheels and mounted on the rear final drive assembly and a body defining a passenger compartment and supporting two vertical members, each having a forward-facing attachment face by which the respective vertical member is attached to the front subframe through the rear vertical mounting face and rear body mountings on the rear subframe for supporting the rear end of the body, the method including the steps of assembling the body to the power train and chassis module by lowering the body vertically with a clearance gap between the attachment faces of the vertical members and the rear vertical mounting faces until the body rests on the rear body mountings, moving the body forward relative to the power train and chassis module to close the clearance gap and securing the body to the power train and chassis module at the rear vertical mounting faces and the rear body mountings.  
   
   
       18 . A front subframe of a motor vehicle, the subframe comprising a pair of main longitudinal beams each having at its rear end means for mounting to a vehicle body and at its other end a respective suspension tower for supporting the weight of the vehicle on a front wheel, a pair of front longitudinal beams of a uniform hollow cross-section each connected at its rear end to a respective one of the suspension towers and at its front end to a front cross member, and a pair of intermediate longitudinal beams, each intermediate longitudinal beam being interposed between a respective one of the suspension towers and a respective one of the front longitudinal beams.  
   
   
       19 . The front subframe of  claim 18  and further comprising a main cross-member interposed between the suspension towers and the front longitudinal beams.  
   
   
       20 . The front subframe of  claim 19  wherein the main cross-member is interposed between the intermediate longitudinal beams and the front longitudinal beams.  
   
   
       21 . The front subframe of  claim 18  and further comprising a pair of lower longitudinal beams which extend below and parallel to the main longitudinal beams, each lower longitudinal beam having at its rear end means for mounting to the vehicle body and being attached at its front end to the respective suspension tower.