Method and arrangement for assembly of component parts, preferably for motor vehicles

• US 3,968,559 A
• Filed: 05/15/1973
• Issued: 07/13/1976
• Est. Priority Date: 05/19/1972
• Status: Expired due to Term

• Current Assignee: AB Volvo
• Original Assignee: AB Volvo
• Inventors: Karlsson, Sven Torgny
• Primary Examiner(s): Lanham, C. W.
• Assistant Examiner(s): Crane, Dan C.
• Application Number:
  US05/360,586
• Time in Patent Office: 1,155 Days
• Field of Search: 29/430, 29/200 R, 29/200 A, 29/429, 29/200 J, 29/208 R, 29/208 F, 180/98
• US Class Current: 29/430
• CPC Class Codes: B23Q 7/1436 using self-propelled work holders
• CPC Class Codes: B62D 65/18 Transportation, conveyor or haulage systems specially adapted for motor vehicle or trailer assembly lines conveyors and haulage in general B65G
• CPC Class Codes: Y10T 29/49829 Advancing work to successive stations [i.e., assembly line]

Abstract

A method of assembling individual units of automobiles in an assembly line in which each unit or parts of the unit are transported on individual motor-driven transport cars, the movement of the cars being individually controlled by signals from control wires connected with a control center and running in the direction of the line. The invention also comprises an apparatus as well as a transport car to be used in said method.

Claims

1. A method of assembling units, such as bodies, chassis and motors of automobiles, in which each of a plurality of incomplete units is moved forward along a main assembly line to successive assembly stations for the addition of components to the unit until the unit is complete, the method comprising placing and transporting each incomplete unit on a different one of a plurality of individually motor-driven transport cars, the transporting being along a path through the successive assembly stations, adding components to each unit while it remains placed on its transport car at at least some of such stations, and individually controlling the movement of the transport cars between the stations by signals from at least one control wire connected with a control center and running in the direction of the main assembly line whereby the speed of assembling the components to each unit at the assembly stations is independent of the speed of assembling the components to other units.

2. A method according to claim 1, and additionally comprising coupling the incomplete units to fixtures carried on the transport cars, which fixtures are adjustable to various angular positions, and thereafter setting each fixture in a selected angular position.

3. A method according to claim 1, wherein each unit is a chassis of a vehicle which is first placed on a transport car, and additionally comprising placing a body of a vehicle on the transport car in a position at a distance above the chassis and then bringing the chassis and the body together for connection to one another while on the transport car.

4. A method according to claim 1, and further comprising the step of individually selecting and switching selected ones of the transport cars onto a branch assembly line, assembling components on the units along the branch assembly line and returning the transport cars to the main assembly line without changing the orientation of the selected transport cars relative to the main assembly line.

5. A method according to claim 1, wherein an assembly line includes the main assembly line and a plurality of branch assembly lines branching off from the main assembly line, at least some of the assembly stations being located along the branch assembly lines and additionally comprising selectively moving at least some of the transport cars off the main assembly line onto and along the branch assembly lines whereby said assembly stations where components are added to the units and the sequence of units at said assembly stations is selected in dependence upon said selective moving of said transport cars.

6. A method of assembling units, such as bodies, chassis and motors of automobiles, each unit having a plurality of components, comprising:

a. placing at least a first component of each of a plurality of units on a different one of a plurality of individually controlled and individually motor-driven transport cars, each transport car being without a mechanical connection to any other transport car,

b. directing the transport cars along an assembly line to a first assembly station, the transport cars being controlled individually as to direction and speed by signals from at least one control wire connected to a control center and extending in the direction of the assembly line,

c. assembling at least a second component of a unit with the first component on each transport car at the first assembly station,

d. directing each of the transport cars along the assembly line to at least one succeeding assembly station, and

e. assembling at least one additional component of a unit with the first and second assembled components on each transport car at each succeeding assembly station to which each transport car is directed.

7. A method of assembling motor vehicles comprising the steps of:

a. placing at least a first component of each of a plurality of motor vehicle chassis on a different one of a first plurality of individually controlled and individually motor-driven transport cars, each transport car being without a mechanical connection to any other transport car,

b. directing each of the first plurality of transport cars along a first assembly line to a first assembly station, said transport cars being controlled individually as to direction and speed by signals from at least one first control wire connected to a control center and extending in the direction of the first assembly line,

c. assembling at least a second component of a chassis with the first component on each of the first plurality of transport cars at the first assembly station,

d. directing each of the first plurality of transport cars along the first assembly line to at least one succeeding assembly station,

e. assembling at least one additional component of a chassis with the first and second assembled components on each of the first plurality of transport cars at each succeeding assembly station to which each of said transport cars is directed,

f. concurrently with at least one of steps (a), (b), (c), (d) and (e), directing each of a second plurality of individually controlled and individually motordriven transport cars along a second assembly line located above the first assembly line, each of the second plurality of transport cars being without a mechanical connection to any other of said transport cars and carrying at least one component of a body for a motor vehicle, said second plurality of transport cars being controlled individually as to direction and speed by signals from at least one second control wire connected to a control center and extending in the direction of the second assembly line, and

g. at a predetermined point, removing motor vehicle bodies from the second plurality of transport cars and conveying said bodies in a downward direction onto different ones of the first plurality of transport cars so that individual bodies can be coupled to individual chassis supported on the first plurality of transport cars.

8. Apparatus for assembling motor vehicles comprising a multiplicity of motor-driven transport cars, each of which is adapted to receive an individual one of a multiplicity of incomplete units of the motor vehicles, means for controlling the movement of each of the transport cars independently of the movement of any of the others of the transport cars such that each transport car may be moved along an assembly line at a pace that is independent of the movement of any of the other transport cars along the assembly line, whereby assembly operations may be performed on each motor vehicle along the assembly line at a pace which is independent of assembly operations on the other motor vehicles, and means located at each of a multiplicity of assembly stations along the assembly line for performing the assembly operations on the incomplete units of the vehicles on the transport cars to add elements to the incomplete units.

9. Apparatus for the assembly of units, such as bodies, chassis and motors of motor vehicles, having a plurality of component parts, said apparatus comprising:

a. at least one first control wire defining a first flow path,

b. means at assembly stations positioned along the length of the control wire for adding component parts to the units, and

c. a first plurality of separate, individually controllable transport cars adapted to travel along the first flow path, each of the first plurality of transport cars including;

i. a first suspension means for supporting a unit,

ii. a motor,

iii. at least one wheel driven by the motor,

iv. at least two additional wheels,

v. means for steering at least one of the wheels, and

vi. at least one means for receiving control signals from the first control wire, the receiving means being coupled to the motor and the steering means and being adapted to control the speed and direction of the transport car in response to the control signals from the first control wire whereby the component parts are assembled to the units, while the units are supported on the transport cars, at an individual speed corresponding to the individual control of said transport cars.

10. Apparatus according to claim 9, also comprising:

d. at least one second control wire supported above said at least one first control wire and defining a second flow path above the first flow path,

e. a second plurality of separate, individually controllable transport cars adapted to travel along the second flow path, each of said second plurality of transport cars including;

i. suspension means for supporting a unit,

ii. a motor,

iii. at least one wheel driven by the motor,

iv. at least two additional wheels,

v. means for steering at least one of the wheels, and

vi. at least one means for receiving control signals from the second control wire, the receiving means being coupled to the motor and the steering means and being adapted to control the speed and direction of the transport car in response to control signals from the second control wire; and

f. means for conveying a unit from one of the second plurality of transport cars downwardly onto one of the first plurality of transport cars.

11. Apparatus according to claim 10, wherein each of the first plurality of transport cars also includes:

vii. a second suspension means for receiving and supporting a unit from one of the second plurality of transport cars, and

viii. means for vertically raising and lowering the first suspension means.

12. Apparatus according to claim 11, wherein the first suspension means is located underneath the second suspension means.

13. Apparatus according to claim 10, also comprising a plurality of mounting frames each releasably attachable to a unit and adapted to be releasably coupled to a suspension means, and wherein each suspension means of the second plurality of transport cars includes means for tilting a mounting frame and an attached unit relative to an associated transpot car.

14. Apparatus according to claim 9, wherein at least some of the first plurality of transport cars also include floors positioned to provide work platforms underneath units supported by the first suspension means of said at least some of the first plurality of transport cars.

15. Apparatus according to claim 9, wherein some of the first plurality of transport cars have first suspension means positioned so as to support units at relatively short distances above a surface on which the transport cars travel and others of the first plurality of transport cars have first suspension means positioned so as to support units at relatively large distances above said surface, the others of the first plurality of transport cars also being constructed so that each of said others of the first plurality of transport cars can be driven over one of said some of the first plurality of transport cars and units supported on said others of the transport cars can thereby be positioned to overlie units supported on said some of the transport cars.