Friction welding apparatus

• US 4,247,346 A
• Filed: 05/11/1978
• Issued: 01/27/1981
• Est. Priority Date: 05/12/1977
• Status: Expired due to Term

• Current Assignee: Asahi Kasei Kogyo Kabushiki Kaisha (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Kogyo Kabushiki Kaisha (Asahi Kasei Corporation)
• Inventors: Sato, Isao, Maehara, Kazuo
• Primary Examiner(s): Goolkasian, John T.
• Assistant Examiner(s): Dawson, Robert A.
• Application Number:
  US05/905,018
• Time in Patent Office: 992 Days
• Field of Search: 29/505, 29/514, 72/69, 72/74, 72/112, 156/73.5, 156/580, 156/502, 156/157, 156/582, 228/2, 228/29, 228/113
• US Class Current: 156/73.5
• CPC Class Codes: B23K 20/1205 using translation movement
• CPC Class Codes: B29C 65/0636 Orbital
• CPC Class Codes: B29C 65/0645 Circular
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/82265 Eccentric mechanisms
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/93441 the speed being non-constant over time
• CPC Class Codes: B29C 66/93451 by controlling or regulating the rotational speed, i.e. the speed of revolution
• CPC Class Codes: B29C 66/939 characterised by specific speed values or ranges
• CPC Class Codes: Y10T 29/49908 Joining by deforming
• CPC Class Codes: Y10T 29/49924 of parallel side-by-side elongated members

Abstract

A friction welding apparatus for welding a pair of members in which the welding surfaces of the members are contacted under pressure with each other, relative circular orbit motion of the members producing friction therebetween thereby heating and melting the welding surfaces and the relative circular orbit motion being stopped to locate the welding surfaces in a predetermined position. The apparatus comprises an eccentric device including a rotary driving shaft, an inertia member disposed around the periphery of the rotary driving shaft, the inertia member being rotated by the rotary driving shaft and being capable of subjecting an angular movement relative thereto and an eccentric shaft rotated by the rotary driving shaft and engaged with the inertia member so as to be moved by the relative angular movement of the inertia member relative to the rotary driving shaft between a co-axial position with the axis of the rotary driving shaft and an eccentric position spaced by a predetermined distance apart therefrom, a movable table engaged through a bearing with the eccentric shaft for supporting the member to be welded, the movable table being connected by a motion restricting device to a fixed frame to be capable of causing substantial relative circular orbit motion in a plane perpendicular to the axis of the rotary driving shaft, the inertia member being angularly moved by rapid increase in the speed of the rotary driving shaft relative thereto from a first position to a second position such that the eccentric shaft is moved from the co-axial position to the eccentric position and the movable table is put in the relative circular orbit motion, and the inertia member being returned by rapid stoppage of the rotary driving shaft from the second position to the first position such that the eccentric shaft is returned to the co-axial position and the movable table is stopped at the predetermined position.

Claims

1. A friction welding apparatus for welding a pair of members in which the welding surfaces of said members are contacted under pressure with each other, relative circular orbit motion of the members causing friction therebetween thereby heating and melting said welding surfaces and the relative circular orbit motion being stopped so that said welding surfaces are positioned in a predetermined position, said apparatus comprising eccentric means including a rotary driving shaft, a cylindrical inertia member disposed around the periphery of said rotary driving shaft and coaxially supported thereon, said inertia member being capable of producing an angular movement relative to said driving shaft and an eccentric shaft rotated by said rotary driving shaft and engaged with said inertia member so as to be moved by the relative angular movement of said inertia member relative to said rotary driving shaft between a co-axial position with the axis of said rotary driving shaft and an eccentric position spaced at a predetermined distance apart therefrom, a movable table engaged through bearing means with said eccentric shaft for supporting the member to be welded, said movable table being connected by motion restricting means to a fixed frame, means for causing a substantial relative circular orbit motion in a plane perpendicular to the axis of said rotary driving shaft, said inertia member being adapted to be angularly moved by rapid increase in the speed of said rotary driving shaft relative thereto from a first position to a second position such that said eccentric shaft is moved from said co-axial position to said eccentric position and said movable table is placed in a relative circular orbit motion, said inertia member being returned by rapid stoppage of said rotary driving shaft from the second position to the first position such that the eccentric shaft is returned to the co-axial position and the movable table is stopped at said predetermined position.

2. A friction welding apparatus as claimed in claim 1 in which the eccentric shaft is engaged with the rotary driving shaft for causing a reciprocating movement in a direction in a plane perpendicular to the axis of the rotary driving shaft, and the eccentric shaft is restrained by a cam surface provided on the inertia member to cause the reciprocating movement between the eccentric and central positions.

3. A friction welding apparatus as claimed in claim 1 in which the centroid of the inertia member is positioned opposite to the axis of the eccentric shaft in respect of the axis of the rotary driving shaft, when the eccentric shaft is eccentrically positioned.

4. A friction welding apparatus as claimed in claim 3 in which the following equation is established

5. A friction welding apparatus as claimed in claim 1 in which the rotatable engagement of the inertia member relative to the rotary driving shaft is made by an arrangement in which the axis of rotation of the inertia member relative to the rotary driving shaft is biased from the axis of the rotary driving shaft.

6. A friction welding apparatus as claimed in claim 5 in which the following equation is established:

space="preserve" listing-type="equation">R=α

mr/M

wherein R is the distance between the axis of rotation of the inertia member and the axis of rotation of the rotary driving shaft, α

is a constant ranging 0<

α

<

2, m is the inertial mass of the load during the friction welding operation, r is the radius of eccentricity and M is the mass of the inertia member.

7. A friction welding apparatus as claimed in claim 5 in which a shaft for the inertia member and a shaft for the eccentric shaft are secured to the rotary driving shaft, the inertia member being rotatably provided on the shaft for the inertia member, the eccentric shaft being rotatably provided on the shaft for the eccentric shaft and a pin of the inertia member being slidably engaged with a groove of the eccentric shaft.

8. A friction welding apparatus as claimed in claim 5 in which the centroid of the inertia member when it is in a position corresponding to the eccentric position of the eccentric shaft is provided within the range of the angle of 0°

-180°

rearward, in respect of the direction of rotation of the rotary driving shaft, from the plane extending through the axis of rotation of the inertia member and the axis of the rotary driving shaft, such that the centrifugal force of the inertia member acts to stabilize the eccentric position.

9. A friction welding apparatus as claimed in claim 1 or 5 in which two or more connectors spaced each other having axes in parallel with the axis of the rotary driving shaft are secured to one end of the rotary driving shaft, slots engaging with the connectors being formed in the eccentric shaft, a pin of the inertia member being slidably engaged with a groove of the eccentric shaft and the interrelation between the connectors and the slots being set so that the eccentric shaft can be moved between the central and eccentric positions.

10. A friction welding apparatus as claimed in claim 1 or 5 in which a connector engaging the eccentric shaft is pivotally mounted on the rotary driving shaft to be rotatable in a plane extending through the axis of the rotary driving shaft and the connector is engageable with an annular cam circumferentially varying its height and provided on the inertia member.

11. A friction welding apparatus as claimed in claim 1 in which there is provided a driving means on the rotary driving shaft for achieving the rapid acceleration and rapid stoppage of the rotary driving shaft to cause a sufficient force to move the eccentric shaft relative to the rotary driving shaft when acceleration and stoppage of rotation of the rotary driving shaft.

12. A friction welding apparatus as claimed in claim 11 in which the driving means comprises a rotary prime mover, a clutch and a brake.

13. A friction welding apparatus as claimed in claim 1 in which said eccentric means further comprise a click stop mechanism for stabilizing the eccentric means in the co-axial position or in the eccentric position or in both of them.

14. A friction welding apparatus as claimed in claim 13 in which the click stop mechanism is provided between the rotary driving shaft and the eccentric shaft.

15. A friction welding apparatus as claimed in claim 14 in which the click stop mechanism is provided between the eccentric shaft and the inertia member.

16. A friction welding apparatus as claimed in claim 14 in which the click stop mechanism is provided between the rotary driving shaft and the inertia member.

17. A friction welding apparatus as claimed in any of claims 14 to 16 in which the click stop mechanism comprises a follower including a ball or roller, a spring for biasing the follower and a concave portion formed to be engaged with said follower at a position corrsponding to the eccentric and/or co-axial position.

18. A friction welding apparatus as claimed in any of claims 14 to 16 in which the click stop mechanism comprises a leaf spring, a follower in sliding engagement with the leaf spring while deforming the latter, and the stress applied by the follower to the leaf spring to deform the latter becoming minimum at the co-axial and/or eccentric position.

19. A friction welding method comprising placing a pair of members to be welded in such a manner that their surfaces to be welded are contacted under pressure with each other and causing the members to make frictional movements due to a circular orbit motion by the apparatus as claimed in claim 1, thereby welding the members.

20. A friction welding method as claimed in claim 19 in which the minimum width of the surfaces to be welded of said members is larger than the diameter of the circular orbit.

21. A friction welding method for welding a thermoplastic resin material as claimed in claim 20 in which the circulating speed of the circular orbit motion satisfies the following expression:

space="preserve" listing-type="equation">N≧

15/D (Sec.sup.-1)

wherein N is the circulating cycle of the circular orbit motion and D is the diameter of the circular orbit motion expressed by the unit of centimeter.