EP1577033A1 - Method of manufacturing an eyelet at the end of a spring body formed of wire and corresponding device - Google Patents

Abstract

Production of an eyelet on the end of a spring body (2) on a spring producing machine comprises using tongs having jaws (6, 7) one of which corresponds to the shape of the eyelet. A wire section (4) is passed around the jaws using a conveying pin (9) which runs perpendicular to the longitudinal axis of the wire section. An independent claim is also included for a device for producing spring bodies. Preferred Features: The movement of the tongs is perpendicular to the longitudinal axis of the wire section during production of the eyelet. The eyelet is bent around the jaw (7) after the side of the wire section.

Description

The invention relates to a method for producing an eyelet at the end of a a wire strand shaped spring body on a spring manufacturing machine, wherein the shaping of the spring body - seen in the direction of its production - behind this the further supplied wire strand of two gripping jaws gripping tongs detected and between this held and hereafter at a predetermined distance behind the tongs below Forming a behind the spring body protruding rear wire section separated becomes. The invention further relates to an apparatus for producing spring bodies, the at least on her - seen in the spring manufacturing direction - rear end with a Eyelet are to be provided, with feed rollers for the current delivery of a wire strand, a Device for feeding the wire strand to the shaping area of the device, at least one forming tool for producing the spring body, a gripping tongs with two jaws for gripping and holding a after generation of a spring body behind this projecting, rear wire section and with cutting devices for Disconnecting the spring body with the rear wire section of the wire strand from the Wire feeding.

When springs have to be used as tension springs, it is necessary to provide eyelets at their two ends during manufacture. Are known different eyelet shapes, especially stalks (where the eyelet sitting on a running away from the spring body over a certain distance stem) and so-called " _" normal German eyelets " in which the eyelet directly and without forming an intermediate stalk at the relevant end of the In the manufacture of the eyelets, especially the forming of the second, ie the rear eyelet (at the end of the spring body) is problematic, especially in the production of German eyelets.

The production of a first (front) eyelet on the uncut wire directly in the Spring manufacturing machine, such as a spring coiling machine is when using a slewing gear no problem and can be realized in a simple way. This does not apply to the production of the second eyelet, namely at the end of the spring body, for their training hitherto different methods have been used.

In the production of such an eyelet as a stem, the problem solution is also relatively simple. Thus, the spring body is provided by a spring manufacturing machine Grab gripper seized and held and then by means of a cutting device from the wire separated. The protruding wire section will hereafter, similar to the production of the first eyelet, formed by the use of a slewing gear to a second (rear) eyelet.

However, the production of a second (rear) German eyelet is much more complicated and requires additional equipment. The spring, as described above, initially provided with a first eyelet, which does not prove to be problematic in the front eyelet even when trained as a German eyelet. Thereafter, the spring body is shaped (eg, wound). To form the second, namely the rear eyelet but now only a short piece of wire would be required on which, however, a gripping tongs can no longer attack so that a slewing mechanism could be used. Therefore, the spring body, which consists of a number of formed turns and the first eyelet, so far taken to form a rear German eyelet of a separate gripper tongs and then in another processing station, a so-called "Östeller" promoted, in which by setting up the last turn now a second (German) eyelet can be generated. An oiler and a separate gripping tongs, however, are relatively expensive options and, moreover, an oiler is also quite complicated in its setting.

Proceeding from this, the present invention seeks to provide a method of the initially mentioned type, with the production of the second (rear) eyelet of different Ösenart, including a German eyelet, are realized with standard tools can, while increasing the process safety and overall the manufacturing process as well as the Device in addition also still cheaper to carry out or produced.

This object is according to the invention in a method of the type mentioned solved in that the one gripping jaws of the gripper in the form of one of the specified shape the eyelet corresponding mold baking is used to that of the above rear Wire section by means of a directly behind the other gripping jaws perpendicular to the longitudinal direction the rear wire section on the latter mobile shaping pin for forming the eyelet is bent around the mold jaws, with the required relative movement between shaping pin and form jaws by program-controlled movements of Tongs and / or forming pin are generated.

In the solution according to the invention thus a grasping forceps is used, in which one of two gripping jaws is designed as a form of baking, which is also used as a bending mandrel for the Form bending the eyelet serves. This makes it possible in the inventive method, too in the case of only a short wire section at the end of the spring, if there is a German eyelet should be trained, this still with the invention designed gripping tongs to be able to grasp, because then in the subsequent taking place Herbiegen the rear Wire section around the jaws of the gripping tongs no own, additional space for Attacking the gripper outside the curved eyelet on the side, towards the is bent, more is needed.

The method according to the invention makes it possible to do so without any problems Both stems, as well as normal German eyelets or other eyelets with a set of Standard tools manufacture. At the machine is no own further Processing station more in the form of a Östellers required, likewise can the previously required for transport to the wringer additional gripping tongs completely eliminated.

The inventive method allows a very precise production of the thus produced rear eyelets, even with German eyelets, whereby the process reliability of Manufacturing process is increased in such tension springs. Moreover, with the inventive method, the production of the eyelets in such a short time possible, such this is not the case with conventional methods due to the intermediate steps required there can be realized. Thus, the invention proves overall Production process also as a particularly inexpensive.

The inventive method thus offers over the previously known methods for the shaping of such rear eyelets, especially German eyelets, a significant Simplification and improvement.

Particularly advantageous method of the invention can be carried out in the form that the movements of the gripping tongs during the formation of the eyelet only along one Direction of movement, most preferably perpendicular to the longitudinal direction of the rear Wire section, done.

Advantageously, in the method according to the invention, the movement of the molding pin achieved in the manufacture of the eyelet in that this in a to the longitudinal direction of the Wire section vertical movement direction and additionally moved along a circular path becomes.

When in the inventive method, the production of a German eyelet is to be made, the rear wire section immediately behind the spring body grasped and held by the gripping jaws of the gripping pliers and then then the eyelet in formed the manner described.

A particularly advantageous embodiment of the spring manufacturing method according to the invention Is achieved in that the spring body with the already formed front eyelet and the rear wire section before forming the rear eyelet by means of the gripper from the Spring wind room of the spring manufacturing machine is moved out. This can be done during Forming the rear eyelet of the machine already the next spring body with front Eyelet, thereby significantly increasing the efficiency of the work of the machine.

In the method according to the invention, the eyelet around the shaping jaw is particularly preferred bent over to the side of the wire section towards which the spring body is formed.

The above-mentioned object is characterized with respect to the device mentioned above solved that one of the jaws of the gripper tongs in the form of one of the shape of the eyelet Form baking formed and also one on the side of the other gripping jaws, directly behind this and above the wire section perpendicular to the longitudinal axis, retractable Forming pin is provided, by means of which the rear wire section to the forming jaws of Tongs around the eyelet is bendable, wherein the gripper and / or the Forming pin sits / sits on movable carrying devices and a program control provided with the movement (s) of the wire device (s) for performing the for the Forming an eyelet required relative movement (s) between shaping pin and Form baking is controllable / are.

The device according to the invention is for carrying out the method according to the invention suitable and has a much simplified compared to previously known devices Build on, because neither a Östeller, nor a second gripper tongs are needed, which is why they also cheaper than previously known devices manufactured for the same purpose can be. In addition, the measures used according to the invention, in particular the Forming the one gripping jaw of the gripping tongs as shaping jaws (in the sense of a Bending mandrel), feasible without great effort.

Preferably, the device according to the invention is designed so that the Movement devices for the gripping tongs a vertically movable holding table, on the this sits, as well as means for moving the gripper perpendicular to the longitudinal direction the protruding wire strand (or, which is equally true, the supplied Wire strands). This is also a particularly uncomplicated training of achieved device according to the invention.

Advantageously, in the inventive device of the two gripping jaws of Gripping tongs formed as a molding jaws, which when gripping the wire section on the Side is the same, to which the spring body is formed at this.

It is also advantageous in the device according to the invention, if the Movement devices for the stylus also a vertically movable holding table and means for moving the forming pin perpendicular to the longitudinal direction of the supplied wire strand, wherein here, particularly preferably, the shaping pin also still sitting on a mounted on the holding table slewing, by means of which he additionally in a circular movement is movable. This can all be used to execute the for the Training the rear eyelet necessary relative movements between mold jaws and Shaping the stylus with simple, easily controllable means.

Fig. 1 bis 5 prinzipielle Darstellungen der einzelnen Verfahrensschritte bei einem erfindungsgemäßen Verfahren, wie sie zur Herstellung einer deutschen Öse erforderlich sind.

Fig. 6 und Fig. 7 prinzipielle perspektivische Darstellungen auf den Federformungsbereich bei einer erfindungsgemäßen Vorrichtung, bei der ein Federkörper mit einer bereits angeformten vorderen Öse noch am Drahtstrang aus der Drahtzuführungseinrichtung sitzt.

The invention will be explained in more detail by way of example with reference to the drawing in principle. Show it:

Fig. 1 to 5 schematic representations of the individual process steps in a method according to the invention, as required for the production of a German eyelet.

Fig. 6 and Fig. 7 are schematic perspective views of the spring forming region in a device according to the invention, in which a spring body with an already formed front eyelet still sits on the wire strand from the wire feeding device.

In the following description of the representations of the various figures are the same parts always provided with the same reference numerals.

In the figures 1 to 5 is first in an enlarged view the implementation of single process steps in the formation of a "German eyelet" shown in principle.

From the figures, first a spring 1 can be seen, which consists of one on a (not shown) Spring coiling machine already formed spring body 2 consists, which at its front End is provided with a likewise already formed front eyelet 3. At his back (in the figures on the left) end, which is facing the wire guide, protrudes from the Spring body 2, a rear wire section 4 before, already in a previous step was cut from the supplied wire strand.

As the figures show, directly behind the spring body 2, the spring 1 at the rear Wire section 4 detected by a gripper 5, the two (in the figures in principle Section shown) gripping jaws 6 and 7, which the rear wire section 4 clamp in the manner shown. Here is the gripping jaws located in the figures above 6 run slightly wider than the other jaws 7 and lies with his the spring. 1 facing side on the top of the spring body 2 and top of the rear protruding Wire section 4, whereby a total of a predetermined orientation of the spring 1 in the Achieve tongs 5.

The other jaw is in the form of one of the desired eyelet shape Forming jaw 7 is formed, which serves as a bending mandrel for the formation of the rear eyelet 10 (see FIG. 5) is used. It is arranged on the side of the rear wire section 4, to which the Spring body 2 has been formed, d. H. on the side, starting from the rear wire section 4, too towards the spring coils of the spring body 2 are formed (in Figs. 1 to 5: after below), so that the forming jaw 7 in turn can also support the spring body 2 laterally, as shown in FIGS. 1 to 5 show. This bending mandrel has a cross-section of suitable shape, by means of which it is an orientation of the last turn of the spring body 2 (and so that the latter overall) to the rear wire section 4 even during bending of the rear eyelet 10 ensures and at the same time the bending shape for the desired shape of the Eyelet 10 pretends. This is in the illustrations of Figs. 1 to 5 with a shape of Formbacken 7 reached, on their backwards (ie in the figures: to the left) directed surface 7A is formed according to the desired eyelet shape and on their side facing the spring body 2 an alignment surface 7B in the form of a plane Has contact surface.

As Figure 1 is removed, is directly behind the gripping pliers 5, above the rear protruding Wire section 4 and immediately behind the upper gripping jaw 6 and perpendicular to Longitudinal axis L of the wire section 4, a shaping pin 9 from a position behind the Drawing plane of Fig. 1 to 5 in the position shown in Fig. 1 (in the drawing plane) retracted, in which it lies above the wire section 4. The shaping pin 9 sits in turn on a rotary tool 8, by means of which he in a circular path (of course in both directions the same) is movable and in turn perpendicular to the longitudinal center axis L of the rear Wire section 4 can be moved, as shown in FIGS. 2 to 5 by the arrow a is shown.

When the forming pin 9 is retracted into the position shown in Fig. 1, it is then, (see Fig. 2) perpendicular to the rear wire section 4 in the direction a lowered until it on rear wire section 4 abuts the top. The lowering movement, as shown in Fig. 3, but still continued, whereby the rear wire section 4 over the upper curved part of the Mold portion 7A of the mold jaw 7 is bent around. Once the position shown in Fig. 3 is reached, in which the mold jaws 9 the furthest from the spring body 2 above Point of the eyelet 10 to be formed has reached (Fig. 5), it is then, as shown in FIG. 4th is removable, still something in the direction of a and in addition also along one Circular path through the slewing gear 8 is rotated in the direction of arrow b, causing the formation of the eyelet 10 also in the now right-facing mold section serving as a bending mandrel Formbacke 7 causes. At the appropriate time, the slewing gear 8 is now in opposite Direction, ie in the drawn in Fig. 5 arrow direction a, something moves upwards, wherein the rotational movement of the slewing gear 8 is still maintained somewhat. This way, how can 5, the eyelet 10 in the form of a "German eyelet" at the end of the spring body. 2 be shaped to the end.

During the entire bending process for the eyelet 10, the spring body 2 is against the Contact surface 7 B of the mold jaw 7 on its side facing him, wherein the Mold jaws 7 serves as a counter-stop during the bending of the eyelet 10 at the same time.

After the eyelet 10 is bent at the rear end of the spring 1, by opening the Tong 5 the spring 1 are issued from that, after which the gripping tongs 5 a new Spring 1 can take.

In the situation as shown in Fig. 1, are on a spring manufacturing machine already some processing steps have been executed. So there was already the first eyelet 3 bent and erected by means of a slewing gear and then the spring body. 2 wound. Thereafter, by means of the gripping tongs 5 with their jaws 6 and 7 of the rear above. Wire section 4 of the supplied from a wire supply wire strand separated, wherein the spring 1 is retained in the gripper 5.

In the then reached position can of course immediately the eyelet in the above be formed form.

But it is also possible, after the separation of the wire section 4 from supplied wire strand with the help of gripping tongs 5, first the spring 1 formed so far to move out of the spring wind room of the machine and only at another position the Forming the eyelet 10 make so that this regardless of the actual Spring manufacturing parallel to this can be done and in the meantime, while the formation of the eyelet 10 takes place in the spring wind room already the next spring body 1 with molded front eyelet 3 can be made.

In Fig. 6, finally, in a basic perspective view, a section of a spring coiling machine shown, namely a view of the spring wind room, while in FIG. 7 is a larger section of this spring winding machine (perspective view) is shown, the also the vertically movable tables for extending and retracting the tongs and for the Eyelet production turned turning shows.

6 and 7, a situation is shown, in which already a spring body 2 with molded and erected front eyelet 3 is generated and still at the end of by a Wire feed 11 supplied wire strand 12 is located.

A cutting device 13, a forming tool 14 and a slewing gear 15 are from the Winding room for the already wound spring body 2 extended.

From Fig. 7 it can be seen that a gripping tongs 5 and another slewing gear 8 each on a vertically movable holding table 17 and 18 are arranged in such a way that they are in an upwardly driven position each by means of its own drive 19 and 20 in one perpendicular to the travel direction a of the vertically extendable tables (and at the same time perpendicular to the wire feed direction of the wire strand 12) to the already manufactured Spring 1 can be moved in and out of this wegfahrbar.

As can be clearly seen in FIG. 6, the shaping pin 9 is seated on the spring body 2 facing end of a tool which is mounted on the turntable 8 and through this can be rotated in the direction of rotation b. Since the forming pin 9 is not on the axis of rotation, but at a distance to this is attached to the turntable 8, performs a rotation in Direction of rotation b to the fact that the shaping pin 9 according to its distance from the Rotary axis of the turntable 8 corresponding radius along a circular path b (and in Both directions of the same) is movable.

The representations of FIGS. 6 and 7, but in particular the slightly enlarged view of Fig. 6, clearly show the gripper 5 with the two gripping jaws, namely the upper Gripping jaws 6 and the lower than mold jaws 7 formed second gripping jaws. The Fig. 6 and 7 show the gripping tongs 5 and the forming pin 9 in a not yet retracted Position.

In order to complete the desired spring 1, the gripping pliers 5 are subsequently moved from the position shown in FIGS. 6 and 7 in the direction of the wire strand 12 running out of the wire guide 11 and grip it directly behind the spring body 3. Thereafter, the cutting tool 13 moves and cuts off the leaked out of the wire guide 11 wire strand, so that then behind the spring body 2 of the rear wire section 4 is formed. Then moves the gripping device 5 by means of the effective movement means for them by lowering the supporting table 17 together with the spring 1, which holds them, from the Federwindebereich of the device shown in the figures down (in direction a ) out; Similarly, the slewing gear 8 with the rotary tool 8, which holds the forming pin 9, lowered over the holder table 18 vertically downwards (in direction a ), after which in the extended down end position, the mutually opposite with respect to the rear wire section 4 tools 5 and 9 perform the manufacturing steps shown in FIGS. 1 to 5 for forming the rear eyelet 10.

In the meantime, a new one could already be found in the upper spring wind range Spring body 2 are formed with a front eyelet 3. By a suitable coordination The steps carried out can be ensured that when the in Figs. 6 and 7 spring formation has been shown, the shaping of the eyelet 10 at the before finished spring body 2 is completed outside the spring wind room, the finished Spring 1 has been released by the gripper 5 and gripping pliers 5 and shaping pin 10th are again transferred to their extended position, as shown in Fig. 7.

The movements of the gripping tongs 5 and the forming pin 9 via the drives 19, 20 and the vertically movable tables 17, 18 are to form the eyelet 10 a total of a (in the figures not shown) program control controlled.

Of course, can be with the described method and described Device in principle also on the outside to produce curved eyelets, d. H. on the the spring body 2 with respect to the wire section 4 opposite side. It is only for this required to use the tongs 5 so that their mold jaws 7 on the other than in the figures shown side of the wire section 4, and the program control change accordingly.

Claims (10)

Method for producing an eyelet (10) at the end of a spring body (2) formed from a wire strand on a spring manufacturing machine (1), after which - seen in its direction of production - the further supplied wire strand of two gripping jaws (6, 7) behind it a grasping forceps (5) detected and held between them and hereafter separated at a predetermined distance behind the gripping pliers (5) to form a behind the spring body (2) projecting rear wire section (4),
characterized in that the one of the two jaws (6, 7) of the gripping tongs (5) in the form of one of the shape of the eyelet (10) corresponding mold jaw (7) is used, by which the wire section (4) by means of a forming pin (9) , which is retracted perpendicular to the longitudinal axis (2) of the wire section (4) behind the other gripping jaws (6) over the wire section (4), is bent around to form the eyelet (10), wherein the relative movement between the shaping pin (9) and Forming jaws (7) by program-controlled movements of gripping tongs (5) and / or forming pin (9) is generated. A method according to claim 1, characterized in that the movements of the gripping tongs (5) during the formation of the eyelet (10) only along a direction of movement, preferably perpendicular to the longitudinal axis (2) of the wire section (4), take place. Method according to claim 1 or 2, characterized in that during the production of the eyelet (10) the shaping pin (9) executes movements in the direction perpendicular (a) to the longitudinal axis (L) of the wire section (4) and additionally in the direction of a circular path (b) run. Method according to one of claims 1 to 3, characterized in that the eyelet (10) is bent around the forming jaw (7) towards the side of the wire section (4) towards which the spring body (2) is formed. Method according to one of claims 1 to 4, characterized in that the spring body (2) with the already formed front eyelet (3) and the rear wire section (4) before the production of the rear eyelet (10) with the gripping tongs (5) the spring wind room of the spring manufacturing machine is extended. Apparatus for producing spring bodies (2), which are to be provided with an eyelet (10) at least on their - seen in their direction of production - with feed rollers for the continuous supply of a wire strand, a wire feed (11), at least one forming tool (14 ) for producing the spring body (2), a gripping tongs (5) with two gripping jaws (6, 7) for gripping and holding a after producing a spring body (2) behind this projecting wire section (4) and with cutting means (13) for separating the Spring body (2) with wire section (4) from the wire strand (12) from the wire feed (11),
characterized in that one of the gripping jaws of the gripping tongs (5) in the form of a shape of the eyelet (10) corresponding to the mold jaw (7) and further formed on the side of the other gripping jaw (6) directly behind this and on the wire section (4) perpendicular to the longitudinal axis (L) retractable shaping pin (9) is provided, by means of which the wire section (4) to the forming jaws (7) of the gripping tongs (5) around the eyelet (10) is bendable, wherein the gripping tongs (5) and / or the forming pin (9) sitting / sitting on movable support means and a program control is provided with the movement (s) of the support means (s) for performing the required for the formation of an eyelet (10) relative movement (s) between the forming pin (9) and mold jaws (7) is / are controllable. Apparatus according to claim 6, characterized in that the movement means for the gripping tongs (5) a vertically movable holding table (17) on which the gripping tongs (5) sits, and means (19) for moving the gripping tongs (5) perpendicular to the longitudinal direction (L) of the supplied wire strand. Apparatus according to claim 6 or 7, characterized in that the movement means for the forming pin (9) comprises a vertically movable holding table (18) and means (20) for moving the forming pin (9) perpendicular to the longitudinal direction (L) of the supplied wire strand. Device according to claim 7, characterized in that the forming pin (9) is mounted on a slewing gear (8) mounted on its holding table (18) by means of which it is additionally movable in a circular movement (b). Device according to one of claims 6 to 9, characterized in that the forming jaw (7) of the gripping tongs (5) is the gripping jaws which when gripping the wire portion (4) on the side thereof, formed towards the spring body (2) is.

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