초록 ▼

A method for forming a variable wall thickness axle or tube with internally thickened wall sections comprises extruding a tubular metal blank within an elongated die. An elongated punch pushes the blank through the die. The punch has an end abutting and pushing the blank into and through the die an

A method for forming a variable wall thickness axle or tube with internally thickened wall sections comprises extruding a tubular metal blank within an elongated die. An elongated punch pushes the blank through the die. The punch has an end abutting and pushing the blank into and through the die and an elongated portion which is spaced from the interior wall surface of the die. Movement of the punch in pushing the blank causes the blank to partially extrude forwardly through the die until stopped and then to extrude rearwardly around the punch elongated portion through the space for forming a tube. A tubular ring is then inserted within the extruded tube at a pre-determined location and is fixed in place to provide a thick, combined tube wall and ring wall, section which extends radially inwardly of the tube. A number of spaced-apart rings may be used to provide spaced-apart thickened wall sections within the tube. The rings may be pre-formed with variable wall thickness around their circumferences for varying the thicknesses of the combined wall sections around the circumference of the tube.

대표청구항 ▼

What is claimed is: 1. A method for forming an axle having selectively internally thickened wall sections, comprising: extruding a short, tubular metal blank into an elongated tube of substantially uniform cross-section with a substantially uniform cross-sectional thickness wall; forming one end po

What is claimed is: 1. A method for forming an axle having selectively internally thickened wall sections, comprising: extruding a short, tubular metal blank into an elongated tube of substantially uniform cross-section with a substantially uniform cross-sectional thickness wall; forming one end portion of the tube into a wheel end support, with the opposite end of the tube being open and with said opening being of the same cross-sectional shape as the elongated tube cross-section; providing a tubular ring of an axial length substantially equal to the length of a pre-determined thickened location of the wall of the tube, that is, to a section of the wall of the tube to be thickened; said ring being of an outside circumference that is slightly greater than the internal diameter of the tube and having an interior opening of selected shape, size and location so as to define desired axle wall thicknesses along the circumference of the ring when the ring is positioned at a desired axial location within the tube; inserting the ring into the tube opening and positioning the ring within the tube to overlap the section of the tube wall to be thickened while orienting the ring within the tube portion for creating desired wall section thicknesses at pre-determined circumferential locations relative to the tube wall; permanently fixing the ring in said location for forming a combined ring and tube wall thickness at said location; whereby the axle is formed with a wall section which extends radially inwardly relative to the inner wall of the tube and which is thicker than the extruded tube wall thickness. 2. A method for forming an axle as defined in claim 1, and including extruding the wheel end support integrally with the tube when the tube is extruded. 3. A method for forming an axle as defined in claim 1, and including forming the wheel support separately from the tube; permanently securing the wheel support to an end of the tube to form the wheel support end of the tube. 4. A method as defined in claim 1, and including extruding the tubular blank within an elongated die having a die wall through which the blank is extruded, comprising: placing the blank within an elongated die, having a die wall co-axially with the die wall, with the tube having an entry end into which the blank is inserted, and the blank having a remote end portion and a proximal end portion; pushing the blank endwise into the die, for extruding the blank remote end through the die with an elongated punch; said punch being of a cross-sectional shape that is smaller than the interior cross-sectional shape of the die wall, for providing a space between the punch and the die wall; stopping the endwise movement of the blank after it is partially extruded through the die; continuing pushing the blank forwardly, that is, away from the entry end of the die, and extruding the proximal end portion of the blank rearwardly, that is, towards the entry end of the die, through the space between the punch and die wall to form an elongated, substantially uniform in cross-section, tube portion; removing the punch and removing the extruded tube from the die; providing a short, tubular ring having an exterior circumferential shape corresponding to the shape and size of the interior wall formed in the elongated tube portion; inserting the ring into the tube portion and positioning the ring at a pre-determined location within the tube; permanently fixing the ring at said location for forming an inwardly thickened wall section from the combined tube and ring walls at the pre-determined location within the tube portion. 5. A method as defined in claim 4, and including providing a second ring, similar to the first mentioned ring, within the tube at a second pre-determined location for providing a second thicker wall section spaced from the first mentioned section, within the tube portion. 6. A method as defined in claim 4, and said ring being secured within the tube by press-fitting the ring into the tube for frictionally interlocking the ring to the tube wall. 7. A method as defined in claim 4, and including shrink-fitting the ring within the tube by relatively reducing the exterior circumferential dimensions of the ring with respect to the tube wall and then reestablishing the relative sizes of the ring and the tube wall for fixing the ring permanently to the tube wall. 8. A method as defined in claim 1, wherein said interior opening of said ring is circularly-shaped. 9. A method as defined in claim 1, wherein said interior opening of said ring is non-circularly-shaped. 10. A method as defined in claim 1, wherein said interior opening of said ring has a central axis that is offset from a central axis of said ring. 11. A method for forming an elongated tube having internally thickened wall sections, comprising: extruding a short, tubular, metal blank into an elongated tube of substantially uniform cross-section with a substantially uniform cross-sectional thickness wall; forming one end of the extruded tube with an opening corresponding to the cross-sectional shape of the interior wall of the elongated tube cross-section; providing a tubular ring of an axial length substantially equal to the length of a pre-determined increased wall thickness location of the wall of the tube, that is, a section of the tube wall to be thickened; said ring being formed of an outside circumference that corresponds to, but is slightly greater than the internal shape of the tube and having an interior opening of selected shape, size and location so as to define desired tube wall thicknesses along the circumference of the ring when the ring is positioned at a desired axial location within the tube; inserting the ring into the tube opening and positioning the ring to overlap the section of the tube wall to be thickened while orienting the ring within the tube portion for creating desired wall section thicknesses at pre-determined circumferential locations relative to the tube wall; fixing the tube wall to the interior, overlapped wall portion of the tube for forming an inwardly thickened, combined ring wall and tube wall section at said pre-determined location. 12. A method as defined in claim 11, and including providing a second ring, similar to the first mentioned ring within the tube at a second pre-determined location within the tube, for providing a second thicker wall section, spaced from the first mentioned wall section, within the tube. 13. A method as defined in claim 11, wherein said interior opening of said ring is circularly-shaped. 14. A method defined in claim 11, wherein said interior opening of said ring is non-circularly-shaped. 15. A method as defined in claim 11, wherein said interior opening of said ring has a central axis that is offset from a central axis of said ring. 16. A method for forming an elongated tube with at least one inwardly thickened wall section, comprising: preparing a tubular blank of a pre-determined length for forming the tube by extrusion; positioning the blank within a die having an elongated die opening for receiving the tube; pushing the tube with a punch, through the die opening for extruding the blank through an end portion of the die; said punch being formed of a cross-sectional shape that is smaller than the interior cross-sectional shape of the die to provide a space between the punch and the wall forming the opening in the die; stopping end-wise extrusion movement of the blank in a forward direction while continuing the pressure upon the blank in the forward direction to cause the blank to rearwardly extrude, that is, relative to the movement of the punch, into the space between the punch and the die to form an elongated tube extrusion in said space; removing the punch and removing the extruded tube from the die; and inserting at least one short, tubular ring within the extruded tube and fixing the ring within a location that is pre-determined for thickening a portion of the tube wall inwardly; said ring having an exterior peripheral surface engaged with the wall forming the interior surface of the tube for forming a combined thickened, radially inwardly extended, wall section within the tube; said ring being pre-formed with an interior opening of selected shape, size and location so as to define desired tube wall thicknesses along the circumference of the ring when the ring is positioned at a desired axial location within the tube. 17. A method as defined in claim 16, and pre-forming the ring with a wall of varying thickness around the periphery of the ring for circumferentially varying the radially directed thickness of the combined ring and tube wall. 18. A method defined in claim 16, wherein said interior opening of said ring is circularly-shaped. 19. A method as defined in claim 16, wherein said interior opening of said ring is non-circularly-shaped. 20. A method defined in claim 16, wherein said interior opening of said ring has a central axis that is offset from a central axis of said ring.