EP1577033B1 - 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 formed from a wire strand spring body on a spring manufacturing machine, wherein after the shaping of the spring body - seen in the direction of production - behind this, the further supplied wire strand of two gripping jaws gripping tongs detected and between them held and thereafter separated at a predetermined distance behind the gripping tongs to form a behind the spring body projecting rear wire section. The invention further relates to an apparatus for producing spring bodies which are to be provided with an eyelet at least on their - in the spring manufacturing direction - rear end, with feed rollers for the current delivery of a wire strand, means for supplying the wire strand to the forming region of the device at least one forming tool for producing the spring bodies, gripping tongs with two gripping jaws for gripping and holding one after producing a spring body behind this projecting, rear wire section and with cutting devices for separating the spring body with the rear wire section from the wire strand from the wire feed (see, for example, US Pat. A-6 151 942).

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 stems (where the eyelet sitting on a running away from the spring body over a certain distance stem) and also so-called " _" normal German eyelets " in which the eyelet directly and without forming an intermediate stalk at the relevant end of 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 uncut wire directly in the spring manufacturing machine, such as a spring coiling machine is no longer a problem when using a slewing and can be realized in a simple manner. However, this does not apply to the production of the second eyelet, namely at the end of the spring body, for their training so far 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 gripped by a provided on the spring manufacturing machine gripper and held and then separated by a cutter from the wire. The protruding wire portion is thereafter, 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. However, a sprinkler and a separate gripping tongs are relatively expensive options and, moreover, a sprinkler is also quite complicated in its setting.

Proceeding from this, the present invention seeks to find a method of the type mentioned, with the production of the second (rear) eyelet of different Ösenart, including a German eyelet, can be realized with standard tools, the process reliability increases and overall In addition, the manufacturing process as well as the device are also cheaper to carry out or produced.

This object is achieved in a method of the type mentioned in the present invention that the gripping jaws gripping jaws in the form of a fixed shape of the eyelet corresponding mold jaw is used to the projecting rear wire section by means of a directly behind the other gripping jaws perpendicular to the longitudinal direction of the the rear wire section is bent over the latter movable shaping pin to form the eyelet around the forming jaw, wherein the relative movement required for this purpose be generated between the forming pin and mold jaws by program-controlled movements of gripping tongs and / or forming pin.

In the solution according to the invention thus a gripping pliers is used, in which one of the two gripping jaws is designed as a mold jaw, which also serves as a bending mandrel for the bending of the eyelet. This makes it possible in the method according to the invention, even in the case of only a short wire section at the end of the spring, if there is a German eyelet to be formed there to be able to capture it with the present invention designed grasping forceps, because then during the subsequent taking place Herbisiegen the rear wire section there is no need for a separate, additional space for engaging the gripper tongs outside of the curved eyelet shape on the side to which the bent-over side is required.

The method according to the invention now makes it possible, without any problems, to produce both eyelets as well as normal German eyelets or other eyelets with a set of standard tools. On the machine is no own further processing station more in the form of an adjuster required, as well as the previously required for the transport to the wringer additional gripping tongs completely eliminated.

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

The method according to the invention thus offers a clear simplification and improvement compared with the hitherto known methods for the shaping of such rear eyelets, in particular German eyelets.

Particularly advantageously, the method according to the invention can be carried out in the form that the movements of the gripper during the formation of the eyelet only along a 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 mold pin in the manufacture of the eyelet is achieved in that this in one to the longitudinal direction of the Wire section vertical movement direction and additionally along a circular path is moved.

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

A particularly advantageous embodiment of the spring manufacturing method according to the invention is achieved in that the spring body is moved out with the already formed front eyelet and the rear wire section prior to the shaping of the rear eyelet by means of the gripping pliers from the spring wind room of the spring manufacturing machine. As a result, during the formation of the rear loop of the machine already the next spring body can be produced with front eyelet, whereby the efficiency of the work of the machine is considerably increased.

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

The above-mentioned object is achieved with respect to the device mentioned above in that one of the jaws of the gripping pliers in the form of a shape of the eyelet corresponding mold jaw formed and also one on the side of the other jaw, directly behind this and above the wire section perpendicular to the Longitudinal axis, retractable molding pin is provided, by means of which the rear wire section is bendable around the forming jaws of the gripping tongs around the eyelet, wherein the gripping tongs and / or the forming pin sitting / sitting on movable support means and a program control is provided, with the movement ( en) of the wire device (s) for carrying out the required relative to the formation of an eyelet relative movement (s) between the forming pin and mold jaws is / are controllable.

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

Preferably, the device according to the invention is designed so that the movement means for gripping tongs a vertically movable holding table on which this sits, as well as a means for moving the gripping tongs perpendicular to the longitudinal direction of the projecting wire strand (or, which is equally true, the supplied wire strand) grasp. Thus, a particularly uncomplicated embodiment of the device according to the invention is also achieved.

Advantageously, in the apparatus according to the invention of the two jaws of the gripping tongs formed as a mold jaws, which is the same when gripping the wire section on the side to which the spring body is formed at this.

It is also advantageous in the apparatus according to the invention, when the moving means for the forming pin also include a vertically movable holding table and means for moving the forming pin perpendicular to the longitudinal direction of the supplied wire strand, in which case, particularly preferably, the shaping pin also on a on the Holding table mounted slewing sits, by means of which he is additionally movable in a circular motion. This can be easily achieved with simple, easily controllable means to perform the necessary for the formation of the rear eyelet relative movements between mold jaws and forming pin.

• 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, the same parts are always provided with the same reference numerals.

In the figures 1 to 5, the implementation of the individual process steps in the formation of a "German eye" is shown in principle in an enlarged view in principle.

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

As the figures show, directly behind the spring body 2, the spring 1 at the rear wire section 4 is detected by a gripping tongs 5, the two (in the figures in a basic sectional view shown) gripping jaws 6 and 7, which the rear wire section 4 in the manner shown clamp. In this case, the gripping jaws 6 lying at the top in the figures is slightly wider than the other gripping jaws 7 and lies with its spring 1 side facing on the top of the spring body 2 and the top of the rear projecting wire section 4, resulting in a total of a predetermined orientation of the spring 1 can reach 5 in the gripping tongs.

The other jaw is formed in the form of a shape of the desired eyelet mold 7, which serves as a bending mandrel for the formation of the rear eyelet 10 (see Fig .. 5). It is arranged on the side of the rear wire section 4 to which the spring body 2 has been formed, that is, the spring wire 2 has been formed. H. on the side, starting from the rear wire section 4, to which the spring coils of the spring body 2 are formed (in Figs. 1 to 5: down), so that the molding jaws 7 in turn can also support the spring body 2 laterally, as shown in FIG 1 to 5 show. This bending mandrel has a cross-section suitable shape, by means of which it ensures an alignment of the last turn of the spring body 2 (and thus the latter overall) to the rear wire section 4 during bending of the rear eyelet 10 and at the same time the bending shape for the desired Form of the eyelet 10 pretends. This is achieved in the illustrations of FIGS. 1 to 5 with a shape of the molding jaw 7, which is formed on its back (ie in the figures: to the left) surface 7A corresponding to the desired eyelet shape and facing the spring body 2 on her Side has an alignment surface 7B in the form of a flat contact surface.

As can be seen in FIG. 1, directly behind the gripping tongs 5, above the rearwardly projecting wire section 4 and immediately behind the upper gripping jaw 6 and perpendicular to the longitudinal axis L of the wire section 4, is a shaping pin 9 from a position behind the drawing plane of FIGS. 1 to 5 into the position shown in FIG. 1 (in the drawing plane), in which it lies above the wire section 4. The forming 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 can be moved perpendicular to the longitudinal central axis L of the rear wire section 4, as shown in FIGS. 2 to 5 by the arrow a.

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 rests against the rear wire section 4 above. The lowering movement is, as shown in Fig. 3, but still continued, whereby the rear wire section 4 is bent over the upper curved portion of the mold portion 7 A of the forming jaw 7. As soon as the position shown in FIG. 3 has been reached, in which the forming jaw 9 has reached the point furthest from the spring body 2 of the eyelet 10 to be formed (FIG. 5), then, as can be seen from FIG still something in the direction of a and in addition also along a circular path through the slewing gear 8 is rotated in the direction of arrow b, thereby causing the shaping of the eyelet 10 in the right now directed to the right mold section serving as a bending mandrel 7. At the appropriate time, the slewing gear 8 is now in the opposite direction, ie in the drawn in Fig. 5 arrow direction a, moved slightly upwards, wherein the rotational movement of the slewing gear 8 is still maintained somewhat. In this way, as shown in Fig. 5, the eyelet 10 in the form of a "German eyelet" at the end of the spring body 2 are formed to the end.

During the entire bending process for the eyelet 10, the spring body 2 rests against the contact surface 7B of the molding jaw 7 on its side facing it, wherein the molding jaw 7 simultaneously serves as a counter-hold during bending of the eyelet 10.

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

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

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

But it is also possible, after removing the wire section 4 from the supplied wire strand with the help of the gripping pliers 5, first the far shaped spring 1 out of the spring wind room of the machine and make only at another position forming the eyelet 10, so that this independently can be performed in parallel to this from the actual spring production and, in the meantime, while the formation of the eyelet 10 takes place, the next spring body 1 with molded front eyelet 3 can already be produced in the spring wind room.

In Fig. 6, finally, in a basic perspective view, a section of a spring coiling machine is shown, namely a view of the spring wind room, while in Fig. 7, a larger section of this spring coiling machine (perspective) is shown, which also the vertically movable tables for a - or extending the gripping tongs and used for the eyelet production turning shows.

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

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

From Fig. 7 it can be seen that a gripping tongs 5 and another slewing gear 8 are each arranged on a vertically movable holding table 17 and 18 in such a way that they are in an upwardly driven position each by means of its own drive 19 and 20 in a 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 produced spring 1 can be moved in or away from this.

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

The representations of FIGS. 6 and 7, but in particular the somewhat enlarged view of FIG. 6, clearly show the gripping tongs 5 with the two gripping jaws, namely the upper gripping jaw 6 and the lower gripping jaw formed as a forming jaw 7. Figs. 6 and 7 show the gripping tongs 5 and the shaping 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 support table 18 vertically downwards (in the 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 spring body 2 with a front eyelet 3 could already be formed in the upper spring wind range. By a suitable coordination of the executed steps can be ensured that when the spring training shown in Figs. 6 and 7 is carried out, the formation of the eyelet 10 is completed on the previously prepared spring body 2 outside the spring wind room, the finished spring. 1 has been released from the gripping tongs 5 and gripping tongs 5 and shaping pin 10 are again transferred to their extended position, as shown in Fig. 7.

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

Of course, can be produced with the described method and apparatus described in principle on the outside curved eyelets, d. H. on the spring body 2 with respect to the wire section 4 opposite side. For this purpose, it is only necessary to use the gripping tongs 5 so that their mold jaws 7 is located on the other side of the wire section 4 shown in the figures, and to change the program control accordingly.

Claims (10)

1. A method of producing an eyelet (10) at the end of a spring body (2) formed from a strand of wire on a spring manufacturing machine (1), wherein after its forming - as viewed in its generating direction - the further feed strand of wire behind it is seized by two gripping jaws (6, 7) of gripping tongs (5) and is securely held between them as well as, thereafter, cut off a predetermined distance behind the gripping tongs (5), thus forming a rear wire portion (4) which protrudes behind the spring body (2),
   characterized in that
   one of the two gripping jaws (6, 7) of the gripping tongs (5) is employed in the form of a forming jaw (7) corresponding to the shape of the eyelet (10), the wire portion (4) being bent around said forming jaw (7) by means of a forming pin (9) which is advanced perpendicular to the longitudinal axis (2) of the wire portion (4) the other gripping jaw (6) above the wire portion (4), so as to form the eyelet (10), wherein the required relative movement between the forming pin (9) and the forming jaw (7) is generated by program-controlled movements of the gripping tongs (5) and/or of the forming pin (9).
2. Method according to claim 1, characterized in that the movements of the gripping tongs (5) during the forming of the eyelet (10) are effected only along one direction of movement, preferably perpendicular to the longitudinal axis (2) of the wire portion (4).
3. The method according to claim 1 or 2, characterized in that in order to produce the eyelet (10), the forming pin (9) executes movements which extend perpendicular (a) to the longitudinal axis (L) of the wire portion (4) as well as, in addition, in the direction of a circular path (b).
4. Method according to any one of claims 1 to 3, characterized in that the eyelet (10) is bent around the forming jaw (7), to that side of the wire portion (4) on which the spring body (2) is formed.
5. Method according to any one of claims 1 to 4, characterized in that the spring body (2) with the front eyelet (3) already formed thereon and with the rear wire portion (4) is extended out of the spring winding space of the spring manufacturing machine by the gripping tongs (5) prior to producing the rear eyelet (10).
6. Device for manufacturing spring bodies (2) which are to be provided with an eyelet (10) at least at their rear end - when viewed in the generating direction thereof - comprising feed rollers to continuously feed a strand of wire, a wire feed (11), at least one forming tool (14) for manufacturing the spring bodies (2), gripping tongs (5) having two gripping jaws (6, 7) to seize and securely hold a wire portion (4) which protrudes behind the spring body (2) after the latter has been generated, and further comprising cutting means (13) for cutting the spring body (2) with the wire portion (4) off the strand of wire (12) from the wire feed (11),
   characterized in that
   one of the gripping jaws of the gripping tongs (5) is provided as a forming jaw (7) corresponding to the shape of the eyelet (10) and, further, a forming pin (9) is provided on the side of the other gripping jaw (6), which pin can be advanced directly behind said jaw as well as above the wire portion (4), perpendicular to the longitudinal axis (L) thereof, by means of which pin the wire portion (4) is bendable around the forming jaw (7) of the gripping tongs (5) so as to form the eyelet (10), the gripping tongs (5) and/or the forming pin (9) being fitted on movable carrier means, and a program control being provided by which the movement(s) of the carrier means is (are) controllable in order to effect the relative movement(s) between the forming pin (9) and the forming jaw (7) required to form an eyelet (10).
7. Device according to claim 6, characterized in that the moving means for the gripping tongs (5) comprise a vertically displaceable holding table (17), on which the gripping tongs (5) are arranged, as well as means (19) for moving the gripping tongs (5) perpendicular to the longitudinal direction (L) of the feed strand of wire.
8. Device according to claim 6 or 7, characterized in that the movement means for the forming pin (9) comprise a vertically displaceable holding table (18) and means (20) for displacing the forming pin (9) perpendicular to the longitudinal direction (L) of the fed strand of wire.
9. Device according to claim 7, characterized in that the forming pin (9) is mounted to a rotating mechanism (8) which is mounted to the holding table (18), by means of which rotating mechanism the pin is additionally displaceable in a circular movement (b).
10. Device according to any one of claims 6 to 9, characterized in that the gripping jaw (7) of the gripping tongs (5) is that gripping jaw which, when seizing the wire portion (4), is located on that side thereof on which the spring body (2) is formed.

Images