EP1632297B1 - Method and tool for punching and/or forming - Google Patents

Description

The invention relates to a method for punching and / or forming by means of a high-speed press, in particular high-speed forging press, for the production of parts with at least first and second perforations from blanks and a corresponding tool.

Parts that are produced in large numbers, for example for the automotive industry, are produced in economic production processes by stamping and / or forming or forging on fully automatic multi-stage rapid forging presses, for example, working at 70 strokes per minute. Such parts are z. As gears or gear wheels for transmission.

In the usual forging process, bar stock is first inductively heated and then sheared warm in the machine to make the blank. Subsequently, the actual setting and forming or forging of the blank takes place in the forging press. For the completion of the parts last made the production of perforations by punching or punching by means of suitable punching tools. For the completion of z. B. gear wheels while the central bore is knocked out.

This last step of punching or punching for the production of the perforated parts is particularly difficult for multi-perforated parts.

With simultaneous perforation of all auszulochenden areas of the parts, there is a risk of clogging of the ejection funnel or the press by the large amount of the perforated material.

Another problem is that the parts to be produced tend to deform during the simultaneous punching or punching of all auszulochenden areas. Also, the parts tend to puncture in the die of the press to twist or move, resulting in damage to the parts, such. B. the die-side engraving of the gear wheels leads.

Furthermore, no burrs may occur when punching or punching, as this would require a reworking of the parts.

These difficulties occur especially when parts z. B. to reduce weight and material savings are repeatedly punched, as z. B. in gear wheels by forming spokes.

The production of such multiply perforated parts could theoretically also be done by a subsequent machining or non-cutting machining, but this would be expensive and not economically viable for large numbers.

From the JP 1306028 a tool for punching blanks according to the preamble of claims 1 and 12 is known in which a plurality of circular punched on the outer circumference of a punch first piercing punch spoke holes and a second, centrally arranged Lochungsstempel punch a central shaft bore in a gear tooth blank. In this case, the first piercing punch and the second piercing punch are arranged offset in such a way that the spoke holes are punched in a first step and the shaft bore in the subsequent step. Since the Lochungsstempel are arranged against each other immovable with a short distance, on the one hand, the acting punching forces on the gear tooth blank are quite high, on the other hand, the material removal of the punched pieces in the tool is not sure ensured by the quite rapid successive punching operation.

The object of the invention is therefore to provide a method and a tool for punching and / or forming multi-perforated parts by means of a high-speed press, the automatic production of parts in large numbers without the above drawbacks, especially without burrs and without obstruction of the discharge funnel Press enabled.

This object is achieved by the method given in claim 1.

With the method according to the invention for punching and / or forming by means of a high-speed press, in particular rapid forging press, it is possible to produce multiply perforated parts without burrs and without blockage of the discharge hopper of the press automatically in large numbers, the parts do not warp.

This is achieved by dividing the punching step ii), in which the hole punching of the part takes place with at least one punching tool (L), in at least two working steps, wherein in each working step only a part of the total perforations to be executed is carried out, so that the finished perforated part only after Completion of the last step, wherein the part is held in position in the first piercing operation by the punching tool for the subsequent punching operation.

Thus, the amount of vented material to be dissipated per working step is reduced, so that the discharge hopper or jacks of the press do not clog. Furthermore, it is ensured by the positioning of the parts in the first step that they do not distort when punching and not move and also no burrs occur at the edges of the perforated areas. Thus, a post-processing of the parts is not necessary, despite the use of a conventional rapid forging press, the z. B. works with 70 strokes per minute, allowing the economic production of a large number of parts.

In particular, the method according to the invention allows circular parts, in particular gears, preferably gear wheels and most preferably gear wheels to produce spokes that are repeatedly perforated and otherwise prone to distortion during punching.

Such parts, in particular spoked gear wheels for the automotive industry to produce, is of great interest, since in addition to the weight reduction and material savings also results in a reduction in the flywheel, resulting in a better response of the transmission. So, in addition to the weight savings, the u. a. Saves fuel, also the structure of the transmission z. B. be simplified in the synchronization unit.

For this purpose, preferably in the first step (a), the pocketing of a central bore is performed. In the following step (b) then the spokes are punched out.

In the method according to the invention, the part is subjected to a force in the first punching operation by the punching tool for the subsequent punching operation, in particular by spring force, held in position.

By in position or holding the part twisting or offset during punching is prevented. This relates in particular to a rotation or an offset of the gear gear in the hole die when punching the center hole through the hole tool. Twisting or misalignment could e.g. damage to the die-side gear gear engraving result.

Thus, it can be ensured that no burrs when poking the spokes and the center hole arise and a deformation or change in position of the part is excluded when punching.

According to the invention meets the punching tool after completion of the first punching step after overcoming the force on a stop and thus triggers the subsequent punching step.

One and the same piercing tool is used in the first piercing operation and subsequent piercing operation, which comprises two piercing punches, so that the piercing tool pierces the part in the first piercing operation by means of a first piercing punch and in the subsequent piercing operation by means of a second piercing punch.

The first piercing punch overcomes when punching a force acting on the second Lochungsstempel force with which this holds the part in position.

The Lochungsstempel were given for simplicity in the singular. It will be understood, however, that a plurality of punch punches (of any type) may be provided as required by the design of the part without departing from the invention. Furthermore, all regularly or asymmetrically formed parts can be produced by the method according to the invention, if several holes must be introduced into the part.

The invention also includes a corresponding tool for punching and / or forming by means of a high-speed press, in particular high-speed forging press, for the production of parts from blanks, in particular according to a method one of claims 1 to 11, according to claim 12.

According to the invention, the second piercing punch has an elastic force element acting in the pressing direction, in particular a spring force element, which acts on the piercing punch in order to hold the part in position in the first working step.

The first piercing punch is conveniently fixed to the piercing punch holder, and the piercing punch holder has a bore for receiving the second piercing punch, in which it is displaceably mounted in the pressing direction.

The second piercing punch protrudes longer in the pressing direction out of the perforation punch holder in the direction of the part to be punched than the first piercing punch, starting from the idle state of the tool.

Advantageously, the first piercing punch overcomes the force acting on the second piercing punch during punching and the force is so great that the piercing punch punches the part before it is completely overcome.

The Lochungsstempel is biased in the bore by means of the elastic force element in the pressing direction against a stop.

The tool may further be configured such that the second piercing punch defines the part in the first step when the tool is driven down by abutment, the trailing first piercing punch at least partially overcomes the force, then after completely overcoming the force, the second piercing punch is passed through Stop is set and then the part is punching.

When manufacturing geared gear wheels, the method according to the invention runs as follows using the tool just described: First, the spring-loaded spoke punch punches strike the gearwheel when the press is lowered and hold it in position by the applied spring force. Then there is the pocketing of the center hole through the trailing Lochungsstempel. When the center hole is punched and the center hole is removed, the spring force is overcome and the spoke punch punches hit a fixed stop, pushing them down and punching the spokes.

Fig. 1

ein mittels des erfindungsgemäßen Verfahrens und Werkzeugs hergestelltes gespeichtes Gangzahnrad in einer perspektivischen Ansicht von schräg oben und

Fig. 2

eine perspektivische Ansicht eines erfindungsgemäßen Werkzeugs von schräg oben, wobei der Lochstempelhalter transparent (gestrichelt) abgebildet ist.

Further features, properties and advantages of the invention will become apparent from the following description with reference to the drawing. In the drawing show:

Fig. 1

a stored gear produced by the method and tool according to the invention in a perspective view obliquely from above and

Fig. 2

a perspective view of a tool according to the invention obliquely from above, wherein the punch holder is shown transparent (dashed).

FIG. 1 shows a spoked gear produced by the method and tool according to the invention in a perspective view obliquely from above, which is designated as a whole by 1.

The gear 1 has two different types of perforations, namely a central bore 2 and six spokes 8 generating holes 3. The central bore 2 is surrounded by a circumferential collar 4 cylindrical shape, which rises from a concentrically arranged around the central bore 2 surface 6. Around the surface 6 around a circumferential edge 5 is arranged, are provided at the circumferential end face of the teeth of the gear 1, not shown. The surface 6 is offset from the edge 5, so that they are in the in Fig. 1 shown lower view.

The six spokes 8 producing perforations 3 have an oval shape and are arranged concentrically around the central bore 2 in the area 6 between the collar 4 and the edge 5 evenly spaced. In this case, two perforations 3 are combined into pairs, so that in the surface 6 three areas arise, which are separated by webs 7 from each other. The three webs 7 extend radially from the edge 5 in the direction of the central bore 2 and go over into the collar 4.

This in Fig. 1 illustrated gear tooth 1 is by the method according to the invention by a in Fig. 2 illustrated tool 10 made in a press, not shown, in which the tool 10 can be centrally positioned over the gear gear 1 and its finished forged blank and can be driven down to this.

The tool 10 comprises a Lochungsstempelhalter 11 approximately rectangular cross-section which in Fig. 2 is shown transparently for better visibility and consists of an upper part I and a lower part II, which are releasably connected by means of suitable measures, however, firmly connected.

The tool 10 further comprises perforation punches 12 and 13 arranged on the punch holder 11.

The Lochungsstempel 12 is used to punch out the central bore 2 and is therefore viewed in cross-section circular and centered on the underside of the upper part I of Lochungsstempelhalters 11 there via a thread 16 and passes through the lower part II of Lochungsstempelhalters 11 in a corresponding hole 19 round section.

The perforation punches 13 are arranged concentrically and evenly spaced around the perforation punch 12 on the perforation punch holder 11 and serve to produce the spokes 8 by punching out the spoke-forming holes 3.

Correspondingly, six perforation punches 13 are provided, which have an approximately oval shape in cross-section, which corresponds to the shape of the perforations 3.

The perforation punches 13 are respectively arranged in corresponding bores 17 and 20, which pass through the lower part II and the upper part I of the Lochungsstempelhalters 11 in the longitudinal direction or pressing direction P.

The holes 17 in the lower part II of Lochungsstempelhalters 11 have a Lochungsstempeln 13 corresponding oval cross-section.

In contrast, the holes 20 in the upper part I of Lochungsstempelhalters 11 has a circular cross-section. In addition, they each have a stop 14 arranged on the side facing away from the upper or the gear wheel 1. The stops 14 are determined by means of suitable measures, such as thread, in the respective holes 20.

In the holes 20 between the stops 14 and the Lochungsstempeln 13 each have a spring 15 is provided. At the upper end, the spring 15 is fixed to the respective stop 14 and at the lower end via a ring 18 in the bore 20 and connected to the corresponding Lochungsstempel 13. Thus are the Lochungsstempel 13 in the bores 20 and 17 in the pressing direction P to the extent of the spring 15 movably mounted. The Lochungsstempel 13 are thus guided by the oval lower holes 17, while the springs 15 are arranged for the bias in the round holes 20, where they are compressible during operation of the tool.

This particular design of Lochungsstempelhalters 11 and the holes 17 and 20 allows to use conventional springs with a circular cross-section, although the Lochungsstempel 13 have an oval contour. Further, the springs can not escape in the pressing direction P down because they do not fit into the oval bore 17 of smaller diameter. In contrast, however, the piercing punches 13 can be pushed up into the holes 20, whereby the springs 15 are compressed. So that the piercing punches 13 do not "drop out" through the bores 17, they are widened by means of the circular ring 18 at their upper end and thus fixed.

Due to the division of the Lochungsstempelhalters 11, it can be easily manufactured and adapted to different circumstances.

The press is knocked down for punching until the tool 10 rests against the gear toothed wheel 1 only with the punching punches 13 which project further from the punching punch holder 11 in the pressing direction P onto the gear toothed wheel 1. This is virtually the initial state of the process or of the tool when the press is lowered. Here Niederfahren refers to the closing movement of the press. It goes without saying that the position of the press can be both horizontal and vertical, that the gear 1 can be arranged above or below the tool 10, and that either the gear 1 and / or the tool 10 is moved during the pressing process.

Now, if the press is driven down further in the direction of the gear, the Lochungsstempel 13 against the spring force of the spring 15 are each partially inserted into the holes 20 until the central Lochungsstempel 12 on the gear gear is applied, wherein the Lochungsstempel 13 are guided in the holes 17.

In this state, the spring-biased spoke punch 13 holds the gear 1 in its position in the die not shown.

Then, the press is further driven down in the direction of the gear gear and there is the pocketing of the central bore 2 by the trailing Lochungsstempel 12, wherein the Lochungsstempel 13 are further inserted against the spring force of the springs 15 in the holes 20.

If the center hole 2 is perforated and the center hole is removed, the springs 15 are completely compressed, d. H. the Lochungsstempel 13 maximum inserted into the holes 20 and meet each on the fixed stop 14 and on the maximum compressed springs 15 so that they are now pressed together with the tool 10 and Lochungsstempelhalter 11 in the pressing direction P down and the perforation of Spokes 8 and the spokes producing perforations 3 takes place.

The now finished gear gear 1 is ejected from the ramping press and the next gear gear blank used for punching.

Claims (16)

1. Method of stamping and forming by means of a high-speed press, in particular a high-speed forging press, for producing parts having at least first and second perforations from blanks, comprising the steps:

   i) forming the part (1) from the blank, and

   ii) perforating the part (1) with at least one perforating tool (10),

   characterized in that the perforating in step ii) being split up into at least two operations (a, b), and only some of the total number of perforations (2, 3) to be made being made during each operation (a, b), so that the ready perforated part is not present until the last operation (b) has been completed, characterized in that the part (1) is held in position during the first perforating operation (a) by the perforating tool (10) for the subsequent perforating operation (b).
2. Method according to Claim 1, characterized in that the part is held in position during the first perforating operation (a) by force, in particular spring force, being applied to it by the perforating tool (10) for the subsequent perforating operation (b).
3. Method according to Claim 2, characterized in that the perforating tool (10), after completion of the first perforating operation (a), strikes a stop (14) after overcoming the force and thus initiates the subsequent perforating operation (b).
4. Method according to one of the preceding claims, characterized in that one and the same perforating tool (10) is used during the first perforating operation (a) and the subsequent perforating operation (b).
5. Method according to one of Claims 1 to 4, characterized in that the perforating tool (10) perforates the part (1) by means of a first perforating punch (12) during the first perforating operation (a) and by means of a second perforating punch (13) during the subsequent perforating operation (b).
6. Method according to Claim 3, 4 or 5, characterized in that the first perforating punch (12), during the perforating, overcomes a force which acts on the second perforating punch (13) and with which the latter holds the part (1) in position.
7. Method according to one of the preceding claims, characterized in that circular parts (1) are produced.
8. Method according to Claim 7, characterized in that gears (1), in particular speed gears, are produced.
9. Method according to Claim 8, characterized in that the speed gears (1) are produced with spokes (3, 8).
10. Method according to one of the preceding claims, characterized in that a center hole (2) is punched out during the first operation (a).
11. Method according to either of Claims 9 and 10, characterized in that spokes (3, 8) are punched out during the subsequent operation (b).
12. Tool (10) for stamping and/or forming by means of a high-speed press, in particular a high-speed forging press, for producing parts from blanks, in particular according to a method according to one of Claims 1 to 11, having
    at least one first perforating punch (12) for producing first perforations (2) in the part (1), and at least one second perforating punch (13) for producing second perforations (3) in the part (1), which
    are arranged on a perforating-punch holder (11), characterized in that the perforating-punch holder (11) being designed in such a way that the first perforating punch (12) perforates the part (1) during a first operation (a) and the second perforating punch (13) perforates the part (1) during a subsequent operation (b), characterized in that the second perforating punch (13) bears against the part (1) and holds it in position during the first operation (a), the second perforating punch (13) having an elastic force element (15), in particular a spring-force element, which acts in the pressing direction (P) and on the perforating punch (13) in order to hold the part (1) in position during the first operation (a), the first perforating punch (12) is secured to the perforating-punch holder (11), and the perforating-punch holder (11) has a hole (17, 20) for accommodating the second perforating punch (13), in which the latter is displaceably mounted in the pressing direction (P), and the second perforating punch (13) projects from the perforating-punch holder (11) in the pressing direction (P) toward the part (1) to be perforated to a greater extent than the first perforating punch (12).
13. Tool according to Claim 12, characterized in that it is designed in such a way that the first perforating punch (12), during the perforating, overcomes the force acting on the second perforating punch (13), and the force is so great that the perforating punch (12) perforates the part (1) before it has completely overcome said force.
14. Tool according to Claim 12 or 13, characterized in that the second perforating punch (13) is preloaded in the hole (20) in the pressing direction (P) against a stop (14) by means of the elastic force element (15).
15. Tool according to one of Claims 12 to 14, characterized in that it is designed in such a way that the second perforating punch (13) secures the part during the first operation (a) during the lowering of the tool (10) by being acted upon by force in such a way as to bear against said part, the trailing first perforating punch (12) perforates the part while at least partly overcoming the force, the second perforating punch (13) is subsequently secured by the stop (14) after completely overcoming the force and then perforates the part (1).
16. Tool according to one of the preceding Claims 12 to 15, characterized in that the perforating-punch holder (11) consists of two parts (I, II).

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