Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C1/00—Manufacture of metal sheets, wire, rods, tubes or like semi-manufactured products by drawing
  • B21C1/16—Metal drawing by machines or apparatus in which the drawing action is effected by means other than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, rods or tubes
  • B21C1/27—Carriages; Drives
  • B21C1/30—Drives, e.g. carriage-traversing mechanisms; Driving elements, e.g. drawing chains; Controlling the drive
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C1/00—Manufacture of metal sheets, wire, rods, tubes or like semi-manufactured products by drawing
  • B21C1/16—Metal drawing by machines or apparatus in which the drawing action is effected by means other than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, rods or tubes
  • B21C1/27—Carriages; Drives
  • B21C1/28—Carriages; Connections of grippers thereto; Grippers

Definitions

• the present invention concerns a drawing assembly for drawing machines for metal products, such as bars or tubes.
• the drawing assembly according to the invention is of the generally continuous type and comprises at least two opposite and counter-rotating tracks, each consisting of a plurality of links disposed in sequence and able to grip the metal products in order to achieve the axial drawing thereof.
• the invention relates also to the drawing method that uses the drawing assembly.
• Drawing machines for metal bars comprising a drawing assembly provided with two counter-rotating tracks opposite with respect to the drawing axis.
• Each track consists of a plurality of links constrained to each other in sequence, and on each of which a drawing clamp is mounted which during use acts on the bar to be drawn.
• each drawing clamp cooperates with a corresponding clamp of the opposite track, so as to grip the bar to be drawn from opposite sides.
• Each clamp is provided with a hollow, which is shaped specifically with respect to the cross section of the bar in its segment already drawn.
• the bar to be drawn is gripped between two hollows of two opposite clamps, and the rotation of the two tracks achieves the clamping and substantially continuous drawing of the bar, so as to achieve the drawing process.
• the drawing clamps are removable from the respective links, so they can be completely removed in the event of wear or a variation in section of the bar to be drawn.
• Each series of clamps has the relative hollow of a size that differs from one series to the other, so that each series of clamps is suitable to effectively grip a coordinated range of bars with different diameters. Applicant has found that in order to effect the complete replacement of the clamps from both tracks (even 50 or more for each track) it requires two qualified operators employed for about 15-20 minutes.
• Purpose of the present invention is to achieve a drawing assembly for drawing machines in which the replacement of the drawing clamps for effectively gripping bars with different diameters has reduced times and costs, of both production and management, compared with the state of the art.
• the Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
• a drawing assembly comprises at least two opposite and counter-rotating tracks, each consisting of a plurality of links constrained to each other and each supporting a relative drawing clamp able to grip the product to be drawn.
• each drawing clamp is selectively able to be clamped in a housing seating of the relative link by means of corresponding rapid attachment/detachment means associated with the link.
• the drawing clamp comprises at least two hollows having different sizes and in each of which a determinate range of cross sections of said product to be drawn is able to be positioned.
• the drawing clamp is configured to be selectively moved, for example laterally translated, with respect to the respective link, so as to align the selected hollow with the drawing axis of the product to be drawn.
• the same clamp having at least two hollows of different sizes, is able to guarantee the effective gripping of at least two different ranges in size of the product to be drawn.
• Applicant has estimated that with the solution according to the present invention, in order to equip the machine for a new range of sizes of products to be drawn, it is sufficient to have one operator intervene, with the machine shut down, for a time of about 5 minutes.
• the two hollows provided on the same drawing clamp have a size such as to allow the effective gripping of ranges in size of products to be drawn, with completely different values.
• the two hollows provided on the same drawing clamp have a size such as to allow the effective gripping of ranges in size of products to be drawn, having at least partly common values.
• - fig. 2 shows a cross section from II to II of fig. 1, with the drawing clamp in the clamped condition; - A -
• - fig. 3 shows the track from fig. 2, with the drawing clamp in its undamped condition
• - fig. 4 shows some drawing clamps usable in the drawing assembly in fig. 1.
• a drawing assembly 10 is part of a drawing machine for a bar 14, of a known type and not shown in detail in the drawings.
• the drawing assembly 10 comprises two counter-rotating tracks 11, shown partly in fig. 1, which are disposed symmetrical and opposite, above and below, with respect to the drawing axis "x" of the bar 14.
• Each track 11 substantially consists of a plurality of links 12 constrained to each other by means of suitable articulated joints.
• a relative drawing clamp 13 is mounted, selectively removably on each link 12.
• Each drawing clamp 13 is provided on the upper part, in this case, with two hollows, respectively a first 15 and a second 16, substantially parallel to the axis of feed "x".
• Each hollow 15 or 16 is selectively positionable in an operating condition in which it is aligned with the axis of feed "x" and cooperates with a corresponding hollow 15 or 16 of the opposite track 11, to retain a segment of the bar 14. In this way, the bar 14 is drawn by the tracks 11 during the drawing process.
• the first hollow 15 and the second hollow 16 have different sizes, coordinated with different ranges of size of bars 14 to be drawn.
• the first hollow 15 is conformed to allow the effective gripping of a bar 14 with a diameter comprised between about 17 mm and about 22 mm.
• the second hollow 16, of a much smaller size than the first hollow 15, is conformed to allow the effective clamping of a bar 14 with a diameter comprised between about 5 mm and about 7.5 mm.
• the two hollows 15 and 16 provided on each drawing clamp 13 are conformed in such a manner as to allow the effective gripping not only of very different ranges of sizes of bars 14, but also of ranges of sizes that have common limit values, for example from about 11 mm to about 17 mm the first 15, and from about 7.5 mm to about 11 mm the second; or ranges of sizes that intersect for some values, for example from about 11 mm to about 17 mm the first 15 and from about 9 mm to about 14 mm the second 16.
• the two tracks 11, in a known manner, are mounted on respective rigid supporting plates 17, they are made to rotate continuously by toothed wheels 19 and exert a pressure on the bar 14, in cooperation with intermediate chains 20 of the roller type, imparting to the bar 14 the drawing action along the axis "x".
• Each clamp 13 has two front faces 13 a, inclined and converging towards the outside, and is disposed in a relative housing seating 21 with a dovetailed conformation.
• the housing seating 21 is made transversely through on the external face of the respective link 12.
• the dovetailed couplings of the links 12 and the relative clamps 13 determine a constraint that prevents both the accidental fall and also the longitudinal removal of the clamps 13.
• the clamps 13 can be released from the relative links 12 only by means of lateral extraction from the relative housing seatings 21.
• Each link 12 comprises a rapid attachment/detachment member 22, provided with a central clamping element and a relative activation element, in order to clamp stably, and removably, the relative clamp 13 inside the housing seating 21.
• the clamping element consists of a ball 23, while the activation element consists of a thruster 25 associated at the rear with a spring 26.
• the thruster 25 comprises at the upper part a cavity 27, substantially semi- spherical in shape, which functions as a positioning cam profile for the ball 23.
• the first blind hole 29 is made in a position such that the partial insertion therein of the ball 23 guarantees the aligned positioning of the first hollow 15 with the axis of feed "x". Displacing the thruster 25 axially in the release position (fig. 3), by compressing the spring 26, the ball 23 is located inside the cavity 27, lowering itself and becoming released from the blind hole 29.
• the clamp 13 can be translated until it takes the ball 23 into substantial alignment with a second blind hole 30 provided on the lower surface of the clamp 13.
• the second blind hole 30 is made in a position such that the partial insertion therein of the ball 23 guarantees the aligned positioning of the second hollow 16 with the axis of feed "x".
• each drawing clamp 13 is provided with three or more hollows of different sizes and each conformed to effectively grip a different range of sizes of bars 14.
• the central clamping element comprises a clamping pin, mounted axially sliding inside a cavity made on the link 12, substantially orthogonal to the plane on which the clamp 13 lies and communicating with the housing seating
• the activation element comprises a thruster mounted laterally on the link 12 and located substantially orthogonal to said clamping pin.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Metal Extraction Processes (AREA)
• Loading And Unloading Of Fuel Tanks Or Ships (AREA)
• Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)
• Earth Drilling (AREA)
• Superconductors And Manufacturing Methods Therefor (AREA)
• Forging (AREA)

Applications Claiming Priority (2)

Publications (2)

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Cited By (1)

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Family Cites Families (8)

• 2007
  • 2007-09-20 IT IT000170A patent/ITUD20070170A1/it unknown
• 2008
  • 2008-09-18 ES ES08832327T patent/ES2363841T3/es active Active
  • 2008-09-18 CN CN200880107810XA patent/CN101801554B/zh active Active
  • 2008-09-18 WO PCT/EP2008/062463 patent/WO2009037320A1/en not_active Ceased
  • 2008-09-18 AT AT08832327T patent/ATE503595T1/de active
  • 2008-09-18 DE DE602008005908T patent/DE602008005908D1/de active Active
  • 2008-09-18 EP EP08832327A patent/EP2197601B1/de active Active

Non-Patent Citations (1)

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