EP0397918A2 - Wire forming apparatus - Google Patents

Abstract

The invention relates to a wire-forming apparatus, namely a winding and bending machine for leg springs. …<??>The prior art is formed by apparatuses having a plurality of tools for bending wire, which is fed in a straight line, the bending tools surrounding the wire path, and by spring-winding machines having a rotatable mandrel for winding up the wire, the wire ends of the spring being shaped by means of bending tools. …<??>The disadvantage of these apparatuses is their structural complexity and limitation to the production of particular spring shapes. A different spring thus requires different tools. …<??>The object of the invention is therefore to reduce the expenditure required for the production of the apparatus and to generalise the shaping operations which can be carried out with the same tools. …<??>The solution to this object is the arrangement of a plurality of tools (86, 88, 90, 92 or 142; 162, 190, 192) on one tool holder (74; 160), which is secured on the free end of a longitudinally displaceable shaft (12) similar to the known mandrel and can be exchanged. By rotational and longitudinal positioning of the shaft by means of its drive, known from the mandrel but controlled in a different manner, each tool present can be moved into the path of the wire and hence brought into use. …<??>The advantage of this solution is the simplification of the structure of the apparatus and the possibility of producing different spring shapes by means of the same tools. …<IMAGE>…

Description

The invention relates to a device for forming wire by winding and / or bending, in particular for producing torsion springs, tension springs, tension springs with handle eyelets bent on both sides, and of bent parts with e.g. curved sections with any radii of curvature, with a continuously or optionally intermittently working wire feed device arranged on the inlet side, with a wire guide and with a plurality of controlled tools arranged on the outlet side of the wire guide, which tools can be moved in a selectable order transversely and possibly longitudinally to the wire emerging from the wire guide .

Devices of the type mentioned are already known (DE-PS 1 293 121 and DE-OS 28 43 444). In the device according to DE-PS 1 293 121 four tools are arranged at the free end of a pivot lever around the wire guide and in the vicinity thereof, the wire deflecting tools during an operating cycle by successive actuation of the pivot lever on the continuously conveyed wire to complete Forming a workpiece can be brought into plant. By more or less strong deflection of the pivot lever, d. H. If the tools are located at a more or less short distance in front of the mouth of the wire guide, which is achieved by adjusting the stroke of an assigned cam drive, curved sections of widely differing radius of curvature and wire coils can be produced on the conveyed wire.

However, the design of the four swivel levers with their adjustable and adjustable tool holders, as well as their control cams and adjustable and adjustable transmission members for executing the swivel movement coordinated in time and with respect to the workpiece to be produced, requires complex and expensive mechanical production of the device.

In the spring winding machine known from DE-OS 28 43 444 z. B. for producing a coil spring with hooks at both ends, with a wire guide, which is connected upstream of an intermittently working wire feed device, four or more tool units are arranged radially around the wire guide and in the vicinity thereof, each of which by a central wheel Pinion, a cam and a cam roller controlled, execute a radial movement against the wire emerging from the wire guide. The tools can therefore only be moved in this radial direction towards or away from the wire guide to form the supplied wire. This spring coiling machine is of somewhat simpler construction than the device according to DE-PS 1 293 121, but it is not so universally applicable.

The invention is based on the object of significantly simplifying the mechanical outlay for a device for forming wire. Furthermore, the necessary deformation operations (winches and / or bending and possibly eyelets) should be carried out as universally as possible.

This object is achieved in that the tools for forming wire by winding and / or bending are arranged in a rotary and sliding head which is interchangeably used in the lower end of a winding spindle, for example a commercially available CNC-controlled leg spring winding machine. This enables the bending and winding operations to be carried out directly on the nozzle of a special wire guide. Up to eight tools are preferably fastened in two or more superimposed levels in the rotating and sliding head. An additional device, for example an eyelet device, can also be arranged on this head in one of these levels. Thanks to the CNC-controllable, freely selectable, reversible longitudinal and rotational movements of the winding spindle, the tools can be brought into the working position in the desired position from the top or bottom, from the right or left, or even in a superimposed movement . The workpieces are shaped entirely by this multiflexible bending and winding center. By means of the invention, conventional leg spring winding and bending machines can be converted as rotating and shifting shafts of the tool head while maintaining the winding mandrel which is only to be driven differently, namely to be controlled in its rotational movement but additionally to be controlled in an axial movement, the wire feed being able to be maintained.

• Fig. 1 eine erste Ausführungsform in Vorderansicht in teilweise abgebrochener und geschnittener Darstellung
• Fig. 2 die erste Ausführungsform im untern Teil in Draufsicht, ebenfalls teilweise geschnitten dargestellt.
• Fig. 3 eine Seitenansicht eines Ausschnitts von Fig. 1
• Fig. 4 ein Werkzeug der ersten Ausführungsform in perspek­tivischer Darstellung
• Fig. 5 eine Seitenansicht auf die in Fig. 1 dargestellte Draht­führung der ersten Ausführungsform
• Fig. 6 ein kombiniertes Biege- und Windewerkzeug (in perspetivischer Darstellung) der ersten Ausführungsform
• Fig. 7 ein mit der ersten Ausführungsform hergestelltes Drahtwerkstück
• Fig. 8 die Herstellungsstadien des Werkstücks nach Fig. 7, wobei in jeder der Teilfiguren (a bis o) rechts die in der ersten Ausführungsform enthaltene Drahtführung samt Dreh- und Verschiebekopf in Vorderansicht und links die Drahtführung in Seitenansicht dargestellt ist.
• Fig. 9 eine Fig. 1 entsprechende Darstellung einer zweiten Aus­führungsform
• Fig. 10 die zweite Ausführungsform in Draufsicht
• Fig. 11 eine Seitenansicht eines Ausschnitts von Fig. 9
• Fig. 12 ein mit der zweiten Ausführungsform hergestelltes Drahtwerkstück
• Fig. 13 die Herstellungsstadien des Werkstücks nach Fig. 12 wobei in jeder der Teilfiguren (a bis q) rechts die in der zweiten Ausführungsform enthaltene Drahtführung sowie die zum Einsatz kommenden Werkzeuge in Vorderansicht und links die Drahtführung in Seitenansicht dargestellt ist; entsprechend Fig. 8.

In the following, the invention will be explained in detail with reference to two preferred embodiments of the machine according to the invention which are shown by way of example (and partly schematically) by the drawing. Show it:

• Fig. 1 shows a first embodiment in front view in a partially broken and sectional view
• Fig. 2 shows the first embodiment in the lower part in plan view, also shown partially in section.
• 3 shows a side view of a detail from FIG. 1
• Fig. 4 shows a tool of the first embodiment in perspective
• Fig. 5 is a side view of the wire guide shown in Fig. 1 of the first embodiment
• Fig. 6 shows a combined bending and winding tool (in a perspective view) of the first embodiment
• Fig. 7 is a wire workpiece produced with the first embodiment
• Fig. 8 shows the manufacturing stages of the workpiece according to Fig. 7, wherein in each of the partial figures (a to o) on the right the wire guide contained in the first embodiment including the rotating and sliding head is shown in a front view and on the left the wire guide is shown in a side view.
• Fig. 9 is a Fig. 1 corresponding representation of a second embodiment
• Fig. 10 shows the second embodiment in plan view
• 11 is a side view of a section of FIG. 9
• 12 shows a wire workpiece produced with the second embodiment
• 13 shows the production stages of the workpiece according to FIG. 12, in each of the partial figures (a to q) on the right the wire guide contained in the second embodiment and the tools used are shown in a front view and on the left the wire guide is shown in a side view; corresponding to FIG. 8.

First embodiment

In Fig. 1, an upper part of a winding spindle (12) is rotatably supported by means of a self-aligning ball bearing (14), which is arranged between two flange stops (16, 18), while the part of the winding spindle (12) underneath is in an additional flange bearing ( 20) is supported with a plain bearing bush (22). All three flange bearings (16, 18, 20) are firmly connected to a winding spindle block (24). The winding spindle (12), which is provided with a toothing (26) over a large part of its length at the circumference, is driven by a controllable servo motor (28) via a toothed belt drive, not shown, and via a toothed pinion, also not shown, the dimension of Winding spindle rotation, the direction of rotation and standstill are freely selectable.

So that the winding spindle (12) can also perform a possibly simultaneous longitudinal movement in addition to its rotational movement, a further controllable servo motor (34) is provided, which drives a known ball screw drive via a toothed belt drive, which rotates the servomotor in a longitudinal movement for the winding spindle ( 12) converts. This longitudinal movement takes place via further transmission elements. All of these parts are known and therefore not shown. The bore diameter of the self-aligning ball bearing (14) is provided with a sliding fit for this longitudinal movement. The size of the longitudinal movement of the winding spindle (12) can also be freely selected by CNC control.

As shown in FIGS. 1 and 2, to the left of the winding spindle (12) in a bearing block (40), which is only indicated, by means of a clamping cover (42) is a receptacle (44) for a divided, adapted to the workpiece to be manufactured, from an upper part (46) and lower part (48) existing special wire guide (50) clamped. This receptacle (44) can be adjusted transversely to its longitudinal axis by means of an adjusting screw (52) and thus can be adjusted with respect to the shape grooves of molding tools in tool holders (74, 160). The wire guide (50) is held in the receptacle (44) by means of a cover (54).

The bearing block (40) can be adjusted in the direction of the winding spindle (12), as a result of which the length of the wire guide can be adapted to the wire workpiece to be manufactured. A support (58) for the wire guide (50) protruding from the receptacle (44) is provided on the flange bearing (20). An additional wire guide (62) adjoins the wire guide (50) up to the wire feed rollers (not shown). The wire feed rollers are driven by a further controllable servo motor via a toothed belt gear, so that an endless wire (64) is CNC-controlled, intermittently in a straight line horizontally through the guide channels of the wire guides (62, 50) into the bending and winding center (68) in front of the Winding spindle (12) can be advanced.

At the lower end of the winding spindle (12), a conical receptacle is provided which receives the cone (72) of a tool holder (74), the so-called rotating and sliding head, and holds it in place by means of a fastening screw (76) reaching through the winding spindle (12) from above becomes. The cone (72) is adjoined by a rectangular part (80) of the tool holder (74), which is recessed in the longitudinal direction over most of its length up to over half its width. The recess is necessary so that the wire workpiece can move freely during the shaping process. In the part (82) of the tool holder (74) which is still standing, four processing tools (86, 88, 90, 92) with a total of ten effective zones (96, 98, 100, 102, 104, 106, 108, 110, 112, 114), one above the other. The tool (86) lying in plane (I) is designed as a bending tool and is fastened with its prismatic part (118) into a prismatic guide (120) of the tool holder (74) by means of a screw. The bending tool (86) is provided on its left side with a nose (122) in which a guide or working groove (124) is incorporated. In order that the tool (86) can be pushed securely over the wire (64), lead-in slopes are provided. With this working groove (124), the bends are carried out on the straight leg, for example of the workpiece shown in FIG. 4.

At the prismatic portion (118) of the bending tool (86) a further bending edge (126) is also provided for downward bends, take place when the bending tool (86) has been implicated previously by a 180 ^o rotation of the winding spindle (12) in bending position and it moves down. The fact that the bending edge (126) is followed by an upward-facing surface (128) which is inclined towards the tool holder (74), can be achieved by an additional brief wire feed after the bending process, a bending angle greater than 90 ^o , that is, an overbend.

The leveling tool (88) is fastened in plane (II) with a cross-sectional profile which is semicircular in its longitudinal direction by means of a screw in a suitable receptacle of the tool holder (74). The winding tool (88) has two lateral, downwardly sloping end faces (100, 102), into each of which (at least) one guide groove (130) for the running wire (64) is incorporated. So that the groove (130) can be adapted to the wind direction of the spring body to be produced, a milling with a rounded base (134) is provided in the tool holder (74). The winch tool (88) is clamped by means of a screw (138) by means of a disk (136) which is concavely rounded on one side with a corresponding radius. As a result, the wind tool (88) can be pivoted up or down by a few angular degrees. When the tool holder (74) now is through the spindle (12) moves downward, so that the tool (88) is on and in plane (II) in operative position in front of the wire guide (50), the spindle ^o rotated 90 counterclockwise the effective zone (100) of the winch tool (88) is used. The running wire (64) forms a spring body which grows out of the plane of the drawing and is wound downwards with left-handed turns. After a rotation of 180 ^o from this position, the effective zone (102) is used. The result is a spring body that grows into the plane of the drawing and also coils downward with right-hand turns. When the upward-acting zone (104) of the winch tool (90) is in use in level (III), an upwardly wound spring body, which grows out of the plane of the drawing, forms with right-handed windings and at the effective zone (106) of the winch tool (90) spring body growing into the drawing plane with left-handed turns.

By moving the point of impact downwards or upwards of the wire (64) emerging from the mouth of the wire guide (50) in the effective zones (100 to 106) of the winch tools (88, 90) of levels (II) or (III), it is possible within the effective zone area smaller and larger winding diameters are generated. This shift can take place before the winch or during the winch. To produce a spring body with pitch sections, the winding spindle (12) is rotated clockwise or counterclockwise according to the degree of the pitch during the winding process, as a result of which the running wire is deflected by the grooves (130). By adjusting against the direction of the slope, spring bodies with a preload can be achieved.

In plane (IV) the further bending tool (92) shown in perspective in FIG. 4 is fastened with its two working planes (IV 1) and (IV 2). The bending tool (92) has the four effective zones (108, 110, 112, 114), each with two bending edges, e.g. (108 ′; 108˝) or (114 ′; 114˝). FIG. 5 illustrates which of the four space quadrants can be covered with which effective zone in order to carry out turns. The bending edges (114 ′, 114˝) of the active zone (114) are for all bends in the 3rd quadrant, facing forwards or backwards, upwards or downwards and standing in space, which are caused by superimposed longitudinal and rotational movements of the winding spindle ( 12) are generated. Effective zone (108) executes all turns in the 1st, effective zone (112) all in the 2nd and effective zone (110) all in the 4th quadrant by appropriate movements of the winding spindle after the effective zones have been brought into the effective position by the winding spindle.

A tool (142) shown in FIG. 6, which can be inserted into the prismatic guide (120) of the tool holder (74) instead of the bending tool (86), is designed more universally. With this tool (142), its inclined surface (144) corresponds to the surface (128) and a groove (146) corresponds to the working groove (124) of the tool (86) in FIGS. 1 and 3; it is to be used for corresponding operations (turns).

Disc segments (148, 150), each with a groove (152, 154), adjoin the surface (144) on both sides. If the disc segment (148) comes into operative position in front of the wire guide (50) due to the rotation of the winding spindle (12), the running wire (64) forms a left-handed spring body which is formed downwards. If, on the other hand, disk segment (150) is in use, a right-hand wound spring body that also progresses downward forms. Since the axis of rotation (156) of the winding spindle (12) and the axis of production (158) of the disc segments (148, 150) are separated by the dimension (e), the diameters of the spring bodies can be varied within the effective range of the two disc segments, depending on how large the angle of rotation of the winding spindle (12) was to bring the disc segments into operative position. A larger spring body diameter results in a smaller spring body diameter.

Second embodiment

On a tool holder (160) shown in FIGS. 9, 11 there is in addition to a winding tool (162) lying in plane (I ') with working zones (164, 166) ground on both sides, the working zone (164) being used to produce an area for smaller winding diameters , while zone (166) results in a larger diameter, provided it has been previously brought by rotation of the winding spindle (12) 180 ⁰ in operative position in front of the wire guide (50), a plane shown on the right, described below, other in a in Fig. 9 (II ′) acting additional device for molding eyelets attached. The tool (162) is fastened in the tool holder (160) by means of a clamping bolt (168). For the manufacture of the handle eyelet spring shown in FIG. 12, there is no need for a recess in the tool holder (160) since there are no disturbing circumferential spring parts.

A side holder (172) is fastened to the tool holder (160) and a single-acting compressed air cylinder (174) with a return spring (for the extended piston rod) is screwed into it, the piston rod (176) of which carries a fork head (178). The fork head (178) is connected via a movable bracket (180) to a swivel lever (182) which is articulated on the holder (172) by means of a bolt (184). A head (186) is screwed onto the swivel lever (182) and carries eyelets (190). These consist of a tool (192), the front edge of which is partially provided with a cutting edge and is used to separate and bend the turns, a guide plate (194) for guiding the spring body and a bending edge (196) molded onto the head (186) Bend the eyelets.

For the production of a handle eyelet spring (226) shown in FIGS. 10, 12 with a double-conical spring body part (228) with changing slope sections (230) according to FIG. 12, the procedure according to FIG. 13, a to q. The winding spindle (12) is rotated from the position shown in FIG. 9 by 90 ^o clockwise and moved downward, so that the wire (64) fed through the guide (50) onto the downward oblique effective zone (164) of the now in Position of standing winch tool (162) in holder (160) (Fig. 13a). Then the winding spindle moves a little further downwards without wire feed until the winch tool is in position for the winch process (level I '), whereby the wire is deflected downward (FIG. 13b). When the wire feed begins again, a half turn is formed (FIG. 13c). While the wire feed is stopped, the winding spindle pivots 90 ^o counterclockwise. Compressed air is now applied to the cylinder (174), causing the head (186) with the loosening tools (190) to be moved by the swivel lever (182), which is moved from the position shown in broken lines in FIG. 9 to the position shown in solid lines there. is swung in. At the same time, the winding spindle moves upwards so that the loosening tools are in the open position (Fig. 9). Wire is pushed in again until the previously formed half turn and the short straight leg are in the open position between the tool (192) and the bending tool (196) (FIG. 13d). The wire feed stops and the winding spindle is turned 90 ^o counterclockwise and the handle eyelet is bent over the bending edge of the tool (192) (Fig. 13e). The cylinder (174) is then vented via a control valve, so that the piston rod (176) is retracted by the force of the return spring and the loosening tools swing out. The winding spindle turns 180 ^o clockwise. At the same time, the wire (64) with the molded-on eyelet is pulled back until it lies against the winding tool (162) (FIG. 13f) after the winding spindle has moved down as far as shown in FIG. 13a. Now the spindle moves a little further down into the winch position, whereby the wire is bent slightly (Fig. 13g).

When the wire is fed again and the winding spindle moves slowly upwards, the conical part is wound with the adjacent turns as the diameter of the spring increases (the deflection point for the wire on the winch tool moves away from the wire guide over the slope) (Fig. 13h). For the subsequent spring section (230) with a slope, the winding spindle is rotated clockwise in accordance with the degree of the slope, as a result of which the running wire is deflected to the rear by the guide groove cut in the winch tool (this is not shown in the schematically depicted stages of operation for the sake of simplicity) (Fig. 13i) and turned back by the same amount for the transition into the spring body part with adjacent turns (Fig. 13j). For the now tapering conical part, the winding spindle with the winch tool slowly moves down again (Fig. 13k). Now, the spindle rotates again through 90 ^o in the counterclockwise direction and the öswerkzeuge as described above in operative position brought (level II '). Now enough wire is pushed in until the spring body, guided through the guide plate (194), is in the open position away from the wire guide (50) and the tool (192) with the cutting edge has bitten between the two last coiled turns until the bending edge (196) of the head (186) is in the bending position (Fig. 13l). The wire feed stops again and the winding spindle is turned 90 ^o clockwise and the turn is made (Fig.13m). The piston rod now moves back as described, which separates the loosening tools from the spring body. Now wire for the long spring leg is inserted (Fig. 13n). The winding spindle moves downwards, which causes the spring leg to bend downwards until it comes to rest in the groove of the winding tool (Fig. 13o) and a half turn is generated when the wire feed is running (Fig. 13p). Subsequently, the shaped handle eyelet spring 226 is cut off from the wire supply with a knife against the wire guide (FIG. 13q). All movements are program-controlled. This also applies to the movements with which the stages of production of the spring shown in FIG. 8 shown in the partial figures a to o of FIG. 8 are achieved.

Claims (4)

1.) Device for forming wire, in particular leg spring winding and bending machine; with a wire guide (50, 62), a wire feed device arranged at its mouth, a shaft (12) arranged at the mouth of the wire guide, the longitudinal and rotational axes of which are close to the wire path outside the wire guide, and at least one tool for winding and / or bending of the supplied wire (64), which can be moved one after the other into the wire path, characterized in that the tools (86, 88, 90, 92 or 142; 162, 190, 192) are fastened to a tool holder (74; 160) common to them , which is arranged on the free end of the shaft (12) in a detachable, non-rotatable manner and displaceable in the longitudinal direction thereof, and in that the rotation and displacement movement of the shaft (12) can be program-controlled. 2.) Device according to claim 1, characterized in that the tools (86, 88, 90, 92; 162, 190, 192) are distributed over the circumference of the tool holder (74; 160) and over its length. 3.) Device according to claim 1 or 2, characterized by a multiple bending tool (92), each in two working planes (IV 1, IV 2) two working zones (110, 114 or 108, 112) with two bending edges (108 ', 108˝ and 114', 114˝). 4.) Device according to one of claims 1 to 3, characterized in that the tool holder (160) carries an additional device (172, 174, 176, 178, 180, 182, 184, 186) which is provided with loosening tools (190) and has a pneumatic cylinder (174) positioning it.

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