FR2479039A1 - Clamping-rotating unit for elongate workpieces in bending machine - uses DC motor, position transducer and sensor, and electronic computer - Google Patents

Abstract

The unit for elongate workpieces, such as metal wire lengths, comprises a member for clamping and rotation of the workpiece about its longitudinal axis. The member is subjected to the action of an assembly for clamping the workpiece in the member, a part for the rotation of the workpiece clamped in the member, and a part for the ejection of the workpiece from the member after bending. The member and parts operate in synchronism with one another and with bending elements to enable wire articles to be provided with tridimensional bends. Pref. the workpiece is rotated by an angle of up to a max. of 360 degrees by a device comprising a DC motor, a position transducer, a position sensor and an electronic computer.

Description

"LOCK AND ROTATION GROUP FOR WIRES, TUBES AND BARS AND
ITS USE IN BENDING OR BENDING MACHINES ".

The present invention relates to a blocking and bending group for wires, tubes and bars, in the form of rectilinear sections.

The invention further relates to the use of the group in multiple bending machines or benders.

 Currently for the purpose of obtaining products, in particular in the form of a wire or bar, sections are started, that is to say straight bars or sections already cut to size, in particular in wire, having a circular section, any square or polygonal, which are curved singularly in suitable machines and on the same plane by means of mechanical, hydraulic or pneumatic bending elements to be optionally assembled together in the following.

In industry, machining by means of wire bending is developing more and more, in particular for obtaining products manufactured in wire having three-dimensional bends, for use, for example, in the production of seats, springs, hooks , supports for electrodomestic equipment, armored resistors or others.

Up to now, similar bending has been carried out only by bending one end or section of barye by hand beforehand between one bending and the other, or else in successive recoveries, which brought a significant cost to the product.

The object of the present invention is that of making a machine assembly which allows bending, and, at the same time, blocking and deformation between a bending and other of the section.

In particular, the aim of the present invention is that of making a group for blocking and folding a section, in particular a wire, or tube or bar, which, moreover, makes it possible to operate easily with sections or pieces. of different section.

To better understand, the appended drawings represent a preferred, non-limiting, embodiment of the invention in object and precisely: FIG. 1 is a front elevation and schematic view of a bending machine or wire bender, which uses a group according to the invention, predisposed from among seven heads or bending elements; Figure 2 is the side view of Fig. 1; Figure 3 schematically shows a side view of a locking and rotating group; Figure 4 is the axial section of the part which supplies the pressurized fluid for blocking the wire to be bent; Figure 5 is the partial vertical section of the parts which ~ perform the curve and the expulsion of the wire; Fig. 6 is the horizontal section made along a plane passing through N-N in FIG. 3; Figure 7 is the side view of the blocking body and rotation in larger scale; FIG. 8 is a horizontal section on a larger scale made along the plane passing through Nl-Nl of FIG. 5; FIG. 9 schematically shows the contribution of the fluid under pressure to the body of FIG. 8; FIG. 10 is the partial vertical section, on a larger scale, made along the plane Pl-Pl of FIG. 6; FIG. 11 is the variant in FIG. 5, rotation and expulsion of the wire; FIG. 12 is the section taken on a plane passing through N2-N2 in FIG. ll; Figure 13 schematically shows a partial front elevation of a blocking and rotation group of the end of the wire, slidably mounted in a bending machine or bender provided with three bending elements; Figures 14a, h, c, d, e show the position of a wire during different bending phases; FIG. 15 schematically shows a variant of FIG. 13, with the displacement of the blocking and rotation group by means of a two-stage cylinder; Figure 16 shows a variant of the actuating cylinders, according to Figures 13, 15, applied to the bending elements; Figure 17 is a variant of Figures 13, 15, with the electronic movement of the blocking and rotation group; FIG. 18 is a variant of FIG. 11, for the mechanical delimitation of the angular displacement of the blocking body.

The blocking and rotation group, which will hereinafter be called simply "group", comprises a structure 1 of very limited width with two sides 2 and 3 and a head 4 (Fig. 3 and 6). The group also includes a member A (Fig. 3) for receiving, blocking and turning a section; a part B for supplying a fluid under pressure to said member A; a part C for iposing the angular rotation to the section and a part D for the impulse of the curved section of its seat, existing in said member A, once bent.

The member A (Figures 3 and 8) comprises a body 5 essentially cylindrical, provided laterally with two coaxial pivots 6 and 7, rotating in the respective supports 8 and 9, which are mounted by means of screws 10 on the head 4 of the group himself.

The body 5 (Fig. 7) has a radial notch or notch 11 frontally and continues over its entire length. Along the diameter and orthogonally to the mean plane of said notch 11, a cylindrical hole was made for receiving in its upper part 12 in the median plane of the notch 11 (or vice versa), a piston 13 or movable jaw, for blocking the section or the tip S, and in the lower part (or viceversa) a shoulder 14 or fixed jaw easily interchangeable. The piston 13, which can be single or double acting, is displaceable by means of oil under pressure and it is subjected to the prior action of a cylindrical spring 15, having the action of creating a spacing and which is housed in suitable cavities 15 ', 15 "existing in said piston 13 and in the shoulder 14. The latter is fixed in the body by means of cylindrical pivots 16, which laterally cross the shoulder 14 Zuirneme.

Approximately in the median plane of the notch 11 and in the rear portion of the body 5 there is a cylindrical through hole 18 (Fig. 8) with the axis orthogonal to the axis of the body 5 itself, for the passage in this one of a pusher better described below, for the expulsion of the section of wire or bar once bent.

A lateral pivot 7 of the body 5 is provided with a chain wheel 19 (Figg. 5, 6 and 8) to impart, by means of the bodies better described below, to the body 5 itself an angular rotation α adjustable range from 0 to around 950.

 In the body 5, the piston 13 is actuated by means of a fluid, in particular oil, which arrives here from the aforesaid part B. (Figg. 3,4) with significant pressure, by the interposition respectively of a flexible tube 13 'and an articulated element 20 (Figg. 8, 9). i1 # 1énent 20 is formed; by a small bar provided with a connection 21 to the flexible tube 13 'and a cylindrical projection 22, orthogonal to the small bar, provided with sealing rings 23, which is pivotally housed in a respective cylindrical hole 5 '' which is on one side of the body 5.

The element 20 is traversed by a hole 24 for the passage of the fluid.

During the angular rotation of the body 5 (Fig. 9), the element 20 is kept constant in an almost horizontal position for the existence of an inclined plane 20 ', against which pushes the end of the element 20 provided with a fitting 21.

Part B already mentioned (Figg. 3 and 4), which supplies the pressurized fluid necessary for controlling the piston 13, comprises a cylinder assembly 25, actuated pneumatically by the interposition of a connector 26. In this- ci, the piston 27 is subjected to the action of a return spring 28. The end 29 of the piston rod, opposite the connector 26, acts in turn like a piston to compress the oil contained in the cavity 30 of the cylinder 31, integral and coaxial with the cylinder 25; this oil, by interposing a connector 31 ', the flexible tube 13' and the articulated element 20 (Fig. 9) is used for the direct actuation of the piston 13.

The choice of a pneumatic-hydraulic pressure multiplier, horn now described, ensures, following the constant pressure exerted on the piston 13, optimal operation of the group.

To overcome the inevitable small losses of oil in the cylinder cl, and in the seat 12 of the piston 13, the assembly 25 of the cylinder is surmounted by an accumulator 32, which, thanks to a hole 33, an annular groove 34 made in the bottom 35 of the cylinder and axial grooves 36, made on the end of the rod 29, known only with said cavity 30.

It has been planned that the #n1tipliplier pnéunati'que -hydraulique, as described now, will be replaced, by a hydraulic circuit of the type already known, for example a motor pump with a directional valve, an electro-hydraulic cylinder, a mechanical assembly or by a mechanical-hydraulic or mechanical-pneumatic compound system.

Finally, all of the member A and of the part B for controlling the locking piston 13 can be produced, horn described now, or be incorporated in the body 5.

Parts C and D already mentioned, comprise a set of cylinders, preferably double acting and pneumatically operated. These cylinders are mounted superimposed and parallel to each other and on the same vertical plane, the part D of which with upper cylinder 40 (FIG. 5) has the task of imparting a linear displacement to the pusher 42, in order to bring out the section. 44 (Fig. 5, 10) of the cylinder, are crossed by the portions 45, 45 'of the piston rod 46, on the portion 45' a stop 47 being screwed and axially adjustable which at the limit of the advance stroke actuates a switch 48 for stopping the machine, which comprises a plurality of waxing elements and the blocking, rotation group, and for the iiiiversion of the fluid supply to effect the return of the pusher 42.

The front end of the rod 45 of the cylinder 40 is provided with an arm 49, which supports the pusher itself. I,
The cylinder 41 (Fig. 5) having the task of giving angular rotation to the CQrp3oS, has two hases 50, 50 ', which are crossed by the portions 51, 51' of the piston rod 51 ". The front end of the portion 51 of the rod is provided with an arm 52 for actuating a mesh chain 53, closed, provided with a tensioner assembly 54, which partly surrounds two toothed wheels 19, 55. A third wheel deflection gear 56, is predisposed adjacent to the actuating chair wheel 19. The gear wheels and the chain are mounted on a plane PP (Fig. 6) which is placed parallel to the plane Pl-Pi, comprising the axes longitudinal of the cylinders 40, 41.

Referring to the above, the hlocage of an end S and the range of angular rotation <of the body 5 are obtained in the following way:
The cylindrical hole 60 (FIG. 10), provided in the portion 51 ′ of the rod, is closed by means of a plug 61, which is crossed axially by the end of the rod 62 carrying at its end a magnification 63, which with the inner bottom 54 of the plug 61 determines the adjustable advancement stroke of the piston 51 ". The rod 62 also has a portion 65 provided with thread, which ends with a handle 66, carrying on its edge 66A notches for its graduation, not well shown in the drawings. The threaded portion 65 is further provided with a counter die 66 'for its blocking against the sleeve 67, axially displaceable by a measurement L' relative to the structure 68 with the interposition of a spring 69 subjected to a preventive tension. The sleeve 67 further comprises a pivot 70 provided with counter die 702, which # is provided with threads and slides freely in the part 68 already mentioned, having the function of pushing, once the sleeve stroke has ended, a micrometric switch 71, to give impetus to the bending operation.

After turning. the handle 66, according to the graduation 66A, the portion 51 'of the rod of the cylinder 41 (Pig. 10) will undergo an lcngitudinal displacement until when the respective shoulder does not touch the bottom 64 of the plug 61, printing on the rod 62, and consequently to the sleeve 67, the brief movement L ′, to control, following the impact of the pivot 70 against the switch 71, the electrical circuit for the successive bending operations.

When one or more bending elements K, K1, K2, etc. (Fig. 1) programmed have finished their work by performing one or more bends in the same plane, an electro-valve (not shown) which controls part C, deflects the flow of control (Fig. 5) on the side of the portion 51 'to that 51, to print on the piston 51 "a return stroke in the initial position (Fig. 7) and consequently the return rotation of the body 5 in the initial position which will be called from 00. The shank ends S, being held integral with the body 5 by means of the locking members 13 and 14 (Fig. 7) will also move in the position of 00. The portion 51 of the rod and, with this, the plug 61, by turning in the initial position, control a switch 72 and through that, the continuation of the bending operations of the part in a different plane compared to the previous plane.

 During the same wire bending cycle, the body 5 can rotate again by an amplitude, to remain in this new position until the requested bending operations are carried out. Subsequently, the body 5 can return to the position of OQ, rotate following a new angle <, etc. and this for an indefinite number of times, until all the bending elements, deployed. in the programmed cycle have carried out the respective bends and exactly, in the desired plane.

When the bending of the wire in space is finished, the piston 27 of the pneumatic-hydraulic multiplier B, and, with this, the piston 13 of the body. 5 (Figs. 4 and 7), return to their respective starting positions. The body 5,. If it is not already in position 00, it returns there and only successively takes place the expulsion, by means of the pusher 42 of the curved piece or section. Parts C and D above. can be replaced by hydraulic or pneumatic cylinders, hydraulic motors, electric motors, mechanical or electromechanical systems or others. The switches, horn described, can in turn be replaced by mechanical stops (not shown in the drawings) by electronic systems, or by pneumatic logic. Finally, instead of a transmission which operates the rotation of the body 5 by means of wheels and chains, this rotation or bending may be obtained by using metal or artificial material cords, by smooth type belts or toothed, by tie rods, rods, rotating cylinders, cylindrical gear couplings with straight or helical teeth, by bevel gears of the wheel and pinion type or the like, or even with a rack, a worm and a helical wheel, or finally by mixed gear couplings with straight or helical teeth and chain.

Referring to the foregoing, it is evident that, instead of an angular rotation of the body 5 limited to approximately 950, the arc of rotation of the wire around its longitudinal axis can be 1900, that is to say say -from +950 # -endirection up, and from 950, towards yers le has (Fig. 11) ;; also at the limit 3800, while being the latter adjustable, at the same time, in any intermediate position requested. As an example, in the same bending cycle it will be possible to print on the section a rotation of +200 to perform the first bending, a rotation of 300 for the second, of +900 for the third bending, +100 for the fourth bending , +700 for the fifth, -90 for the fifth bend and so on.

With particular reference to FIGS. 11 and 12, the rotation and the control of the body 5 in the arc of rotation, for example of 190, or even at the limit of 380, is achieved by means of an electric motor 73, a position transducer 74, a lifting device or a position lever 75 and an electronic "computer" 76, for the input and processing of data during the bending and rotation of the part or of the section.

The autornatism that we have now described can also be resolved by the use of a circular transducer, not shown, predisposed on the axis of the body 5 or else on the axis of the toothed wheel 55. The electric motor can be further replaced by hydraulic motor means, cylinders, hydraulic or pneumatic or hydropneumatic cylinder, rotating cylinders or the like. A pneumatic brake (not shown)> predisposed on the body 5, ensures the stability of the different positions during the bending operations. In the latter case organs B and D remain valid, with all the different possibilities. described.

Instead of automatic mechanisms for positioning the body, 5, as described with reference to Figures 11, 12, provision has been made for the use of mechanical organs 77, 78 (Fif. 18), adjusted by hand. These organs, which are similar in execution, are predisposed in opposition and coaxial with respect to an axis 79. Each comprises a disc 80 rotating relative to the axis 79, and these discs are provided on their periphery with threaded rods 81 , 81 ', 81 ", etc. adjustable in relation to the disc itself and predisposed aligned with the rods of the opposite disc. The discs 80 are replaceable, to be mounted each time for the same succession of bends, without having to resort each time adjusting the rods. Their opposite ends are provided to strike against a stop 82, which, referring to FIG. 10, is predisposed on the rod 65. Furthermore, and, horn or can be seen in FIG. 18, the spring, which in Fig. 10 is indicated by 69, is now predisposed, opposite the mechanical member 78. This gives the mechanical variable delimitation of the stroke of the piston 51 ", for a pre-calculated rotation body 5.

It often happens that the minimum distance Q (Fig. 13) of approaching each bending element K, K1, K2, etc. is not sufficient to allow bending of the parts when the distance between each bending is very limited. This problem is now solved by providing the blocking and rotation group movable longitudinally relative to the machine el1 # itself.

 For this purpose, in Figures 13, 15, 17 there are shown variants of assemblies for effecting said movement.

The assembly 83 in FIG. 13 is such as to allow a single displacement L2, adjustable by means of threaded rods 84 and dice 85.

comprises two carriages 86, 87 sliding on the guides of the chassis, respectively inner 88 and upper 89; these. carriages are connected by a support 90 in turn secured to the rotation group
P. The rods 84 are integral with the support 90, however they pass freely through a cross member 91, which is blocked on the above guides. From the cross member 91 is secured a cylinder 92 actuated by air or oil under pressure.

Referring now to an example of bending carried out by the above-mentioned sand 83, having three elements K, K1, K2 of bending, these operations are carried out by following the succession of operations as follows: a) The element of bending K performs a first bending of the part S (obl = 900); after that, the head of the element K moves in the rearward direction to allow the part S to move freely in a plane parallel to the above-mentioned guides 88, 89.

b) The part S is turned upwards by 900 by means of the rotation group P.

c) Movement to the right of group P and by means of this of the part S already subjected to a first bending (&alpha; 1 = 900). The minimum obtainable distance between the two elements K, K1 becomes per that
Q2.

d) The element K1 now performs a second centering by moving its head backwards, similar to what has been described under point a).

e) At the center of group P, the room is turned towards. the position of 0, starting, and successively it is subjected to a last bending by means of .1 bending element X2, after which is carried out, mEintenant, the expulsion of the workpiece or section hanger.

By the displacement assembly 93, shown in FIG. 15 and which allows two different displacements, it is possible to subsequently reduce even the distance Q3, horn can be seen in point d) (Fig. 14) and this thanks to the use of a piston cylinder with two stages and having two different diameters . In the cylinder 93, a piston 94 with the smaller diameter is secured to the group (P) by means of a rod 95, while the successive piston 96, which is sliding in the cylinder with the larger diameter, is crossed by an adjustable threaded rod 97. The piston 94 will carry out the stroke L3 until it strikes the rod 97, thereby obtaining a first reduction in distance (Example Q2 at point c) in FIG. 14). Once finished. the bending in this position, it is possible to obtain another reduction in distance between the bending now made and the successive, by removing the pressure at the rear part of the cylinder having the larger diameter, with the consequent displacement of the piston 94, 96 of an L4 race.

The displacement group shown in FIG. 17 can provide an unlimited number of positions, thanks to an electric motor 98, through the interposition of a reduction gear 99, a pinion 99 'and a rack 99 ", a position transducer 100, a raising or raising device 101 and a "computer" (not shown). The embodiment as now described can also be carried out by other components already described previously.

The sets of longitudinal displacement knocks mentioned can also be applied to the bending elements, when, because of a size or bends: symmetrical, of the thickness, or for other reasons; for example with the intention of giving a different displacement value to the elements K, K1, etc.

 (Fig. 16) it is not possible to apply them to the rotation group.

In special cases, the displacement assembly can be applied, at the same time, either to the bending elements or to the rotation group.

In Fig. 16 there is shown a group P next to two groups (K5, K3, K1), (K, K2, K4) for bending, actuated by piston cylinders (92, 93), already horn. described in Figg. 13, 15.

Claims (17)

l.Group for blocking and rotating sections or ends of metal wire, characterized in that it comprises a member (A) for blocking the wire and for rotating it around its longitudinal axis, this member being subjected to the action of 'a part (B) to allow the blocking of the section or end in said member (A), a part (C) to perform the rotation of the blocked section and a part (D) for the expulsion of the section in the same member ( A) after the bending carried out, being the member (A) and the screens (B, C, D) operating in synchronism with one another and with the elements (K, Kl, K2 etc.) for bending the same section. 2. Blocking and rotation group according to claim 1, characterized in that the member (A) is capable of performing an angular rotation of magnitude (&alpha;) adjustable within the limits of 0 to at least 950. 3. Group according to the claims. 1 and 2, characterized in that the member (A) comprises a body (5) laterally provided with pivots (6, 7) for rotation coaxial with the axis of the same body (5), the body (5) being mounted by means of supports (8, 9), lateral on the head (4) of the same group (Fig. 8). 4. Group according to claim 3, characterized in that the body (5) has a radial notch (11), which extends over its entire length, orthogonally to the median plane of the notch (11) being obtained a cylindrical hole (12), which extends diametrically to receive in the upper part of said plane (11) a piston (13), subjected to the adjustable action of a fluid and in the lower part (or viceversa) at the same plane (11) an anvil or stop (14) removable for hlocage together with the piston (13) of the section (S) (Fig. 7). 5. Group according to claims 1 to 4, characterized in that the pressurized fluid necessary for the advancement of the piston (13) comprises a part (B) of the same group, and that said fluid arrives at the body (5) of blocking and rotation through a flexible tube (13 ') by the interposition of a rigid element (20) provided with a cylindrical extension (22), the latter being predisposed so as to continuously assume a position at least approximately horizontal by means of an inclined plane (20 ') against which pushes its opposite end to said cylindrical extension (20) (Figg. 8 and 9). 6. Group according to claims 1 and 5, characterized in that the part (B), which supplies the fluid under pressure to the piston (13) blocking the section (S), is constituted by a pneumatic-hydraulic multiplier which comprises a cylinder assembly (25), the end (29) of the piston rod (27) being formed so as to act as a piston horn in the cavity (30) of a cylinder (31) filled with oil, adjacent to the same cylinder assembly (25) (Fig. 4). 7. Group according to claim 1, characterized. in that the part (D) having the function of eliminating the already bent section (S) comprises a set of cylinders (4Q), the bases (43, 44) of which are crossed by the respective portions (45, 45 ') of the piston rod (46), these portions extending from respective opposite faces of the piston itself, the portion (45i) being provided with a stop (47) which acts to stop the n> bending line and to invert the direction of the fluid, for the return of the pusher (42) (Fig. 5). 8. Group according to claims 1 and 7, characterized in that the part (C) for the rotation of the body (5) comprises a cylinder (41), which is disposed at the bottom and in the same vertical plane of the part (B); and in that the bases (50, 50 ') of this cylinder (41) are crossed by portions (51, 51') of the piston rod (51 "), a portion (51) of which acts on a set of yoke (53) to transform its linear movement into a rotational movement of the body (5), with the interposition of toothed wheels (19, 55), one of which (19) is mounted on the body itself (Fig. 5 ). 9. Group according to claims 7 and 8, characterized in that the chalne (53) and the gear wheels, actuation (19) and return (55), are predisposed on a plane (PP) which is parallel to the plane (Pl-Pl), containing the axis of the expulsion cylinders (40) and for the rotation (41) of the body (5) (Fig. 6). 10. Group according to claim 1, characterized. in that the control of all the parts (A, B, C, D) which constitute the group itself is carried out by means of an adjustable synchronism between them and at the same time in synchronism with the bending elements (K, KI, K2, etc.); and in that the predisposition of said parts makes it possible to produce a group having a space requirement of minimum width. 11. Group according to claim 1, characterized. in that it is used in a structure with a plurality of bending elements K, K1, K2, etc. (Fig. 1). 12. Group according to - claim -1, characterized in that the rotation and control of the body- (5) is heard along an arc of 1900, at the limit 38oye, and that for this one uses a motor (73) with direct current, a position transducer (74), a position lifting or raising device (75) and an electronic "computer" (76) (Fig. 11). 13. Group according to claim 1, characterized in that the position of the body (5) for blocking and rotation of the wire is effected by mechanical members (77, 78) adjustable by hand (Fig. 18). 14. Group according to claims 1 and 13, characterized in that the mechanical members (77, 78) each comprise a disc (80) these torunant discs being coaxial with each other, provided at their periphery with rods (81, 81 ') axially adaptable , the rods belonging to the opposite disks (80) being aligned with one another; and in that the ends of the opposite rods strike a stop (82) integral with the cylinder rod (C) to delimit the extent of rotation, the discs (80) being easily replaceable by other discs, having the rods ( 81, 81 ', - etc.) already suitably predisposed to undergo other subsequent bends.  15. Group according to claims 1 and 11, characterized in that the group (P) is movable by means of carriages (86, 87), subjected to the action of a cylinder (92) along guides (88, 89) of the structure, which further carries a plurality of bending elements (K, KI, K2, etc.) (Fig. 13).  16. Group according to claim 15, characterized in that the assembly (93), which allows two different displacements, has a cylinder with two stages having different diameters, including a piston (94), which is integral with the group (P ) performs a first movement (L3) and a second piston (96), which is crossed by an adjustable rod (97) makes it possible to carry out another movement (L4), (Fig. 15). 17. Group according to claims 1, 15, 16, characterized in that the longitudinal displacement of the group (P) is effected in addition to that by carriages, by means of an electric motor (98), a reduction gear (99), a pinion (99 ') and a rack (99 "), a position transducer (100), a position lifting or raising device (101) and a computer (Fig. 17).