EP2378615A1 - Crimp press - Google Patents

Abstract

The press (1) has a crimping tool (13) moved relative to a crimping tool (11). A drive e.g. electric rotation motor or hydraulic linear motor, applies crimping force between the crimping tools during crimp production process. Prestressing units e.g. flexible elements (15, 18), apply an initial load between the crimping tools, which act in same direction as the force and are active before the crimp production process. A machine frame (2) is moved against the two crimping tools. The prestressing units apply the initial load between the frame and the tools.

Description

The invention relates to a crimping press comprising a first crimping tool, a second crimping tool movable relative to the first crimping tool, and a drive for applying a crimping force between first and second crimping tools during a crimping operation.

Crimping, which is a special way of crimping, is a joining process in which a wire or cable is connected by plastic deformation to a contact, often in the form of a plug. The resulting non-detachable connection between conductor and contact ensures high electrical and mechanical safety and thus represents an alternative to conventional connections such as soldering or welding. A very common field of application for crimping is therefore found in electrical engineering (eg HF electronics, telecommunications , Automotive electrical system).

The connection is created by pressure, whereby exactly on the connecting part and conductor cross-section matched crimping effect a precisely predetermined deformation of the connection element and conductor. This process is usually carried out with the help of a special crimping tool or a crimping press. While crimping tools are usually relatively simple, the construction of a crimping press is comparatively complex. Here is the still unfinished workpiece, so the wire or cable, usually inserted with already stripped strands, in the crimp claw of the contact in the press and the contact pressed on it in the tool of the crimping press with the wire or cable. In this case, a press ram presses against the tool and thus generates the pressure necessary for the crimping process.

In order to obtain an optimum crimp connection or to ensure the quality of several successively manufactured crimp connections, the force-displacement curve or the force-time profile during a crimping process is quite frequently determined. For this purpose, the force acting between the two crimping tools is recorded as a function of the distance between the two tools and analyzed with regard to various desired parameters. If the actual course differs significantly from a desired course, then the (faulty) crimp connection should be sorted out, or parameters of the crimp press should be readjusted so that proper crimp connections are produced again.

A disadvantage of known crimping presses is that the drive of a crimping press generally consists of a plurality of movable components, which are connected to one another via different bearings. For example, an eccentric press on a drive shaft with a drive shaft bearing, the drive shaft in turn comprises an eccentric, which is mounted in a connecting rod. This acts via a connecting rod bearing on the press carriage, which is mounted on both sides in a carriage guide.

All these bearings are - since the parts are movable with each other - playful. This then has adverse consequences for the determination of a representative force-displacement curve or force-time curve during the crimping process, when the measuring device operates with high sensitivity. As is easy to imagine, the individual bearing surfaces are pressed together by the forces acting during the crimping process. Unfortunately, this is more or less uncontrolled, if not chaotic. Because depending on the type of storage, the forces acting, the properties of any lubrication in the bearings, the tools used, the workpieces to be produced, etc., the bearing surfaces of the individual bearings are pressed together at different times, resulting in the force-displacement curve or force-time curve by flattening (variable path or variable time with the same force ) or even expressed by local minima and discontinuities. To make matters worse, that the circumstances change with increasing operating time of a crimping press, since the lubrication conditions in the camps change or pollute or wear occurs.

Due to this unpredictable, due to the crimping presses influences on the force-displacement curve / force-time curve of this can only conditionally statements about the quality of a manufactured crimp connection or can lead to statements that do not depend on the actual crimp , For the time being, it is not clear whether a certain force-displacement curve / force-time curve - even if only in sections - stems from the crimping press as such or the workpiece as such. This is as easy to see a very unsatisfactory condition.

According to the prior art, therefore, trying to produce the bearings of a crimping press by precise production of the relevant items as low as possible or adjust accordingly. These include e.g. Attractable spherical bearings or cone bearings or the like. Both options are technically complex and therefore time and cost intensive. In addition, you often increase the friction and thus ease of operation of the press.

The object of the invention is therefore to provide an improved crimping press, in particular a crimping press, in which the impairment of a determined force-displacement curve or force-time course is reduced by bearing clearance.

According to the invention this object is achieved by a crimping press of the type mentioned, additionally comprising biasing means for applying a Vorkraft between the first and second crimping tool, which is rectified with the crimping force and already acts before the crimping process.

By means of the measures according to the invention it is achieved that the bearing surfaces of the individual bearings lie as far as possible against each other even before the crimping process and the force-displacement or force-time course during the actual crimping production process is little or in the best case not influenced by bearing clearance becomes. Abnormalities in the force-displacement or force-time curve can therefore be largely unambiguously assigned to the crimping process. The quality assurance of the novel crimping press is thus much more reliable than in known crimping presses. In addition, there is the surprising effect that in addition to the better and more meaningful measurement results, the actual crimping process is more harmonious and thus the quality of the Crimpablaufs is improved and thus the crimping is better. In addition, this results in not only an improvement for the crimp but also an increase in the life of the tools, bearings and all mechanical components, as these are thus spared. As an additional advantageous and synergistic effect, the generated noise volume of the press may decrease.

The increased reliability is achieved not with precision machined or better adjusted and expensive bearings, but with much cheaper biasing means. In addition, it must be noted that a play-free bearing in any case contradicts a free movement of the stored parts and thus more or less non-existent. A certain game in the camps must therefore be accepted. With the provision of more precise bearings and better adjusted bearings, a wrong path was thus taken in the prior art, since the problem according to the invention can in principle not be solved in this way, or only to a limited extent.

The benefit of the invention is therefore primarily to be able to build a press with machine elements of low precision and also to be able to save adjustment work without having to forego the detection of a meaningful force-displacement curve or force-time curve. Furthermore, the inventive problem is solved in principle, since even before the crimp manufacturing process adjacent bearing surfaces can not scatter any abnormalities in the determined force-displacement curve or force-time curve. By the measures according to the invention, therefore, a great effect is achieved with little effort. These are therefore not only cost effective but also efficient.

By extending a press to the novel biasing means existing presses, in particular game-related presses can be subsequently transformed into precisely working presses.

The inventive measures not only have a positive effect on the determination of a force-displacement curve or force-time curve, but also influence the production process of a crimp connection as such in an advantageous manner because of the reduced influence of bearing clearance.

The effectiveness of the invention is largely independent of the nature of the drive mechanism of the press. The invention is therefore equally applicable to e.g. Crank presses, presses with eccentric shaft and slide gate, spindle presses and toggle mechanisms can be used.

The term "drive" in the context of the invention designates not only a motor as such (that is, for example, an electric rotary motor or a hydraulic linear motor) but also the means for transmitting the motor power to the crimping tool or crimping tools. Thus, the drive also includes all types of shafts, pulleys, tenons, levers, connecting rods, carriages and the like located in the drive train.

Advantageous embodiments and modifications of the invention will become apparent from the dependent claims and from the description in conjunction with the figures of the drawing.

It is particularly advantageous if the preliminary force is dimensioned such that bearing surfaces of the drive lie against each other without play before the crimp-producing process. In this variant of the invention, all bearing clearances are "degraded" before the actual crimping process, so that the crimping process and in particular the determination of a force-displacement curve or a force-time curve during the crimping process are entirely uninfluenced by bearing clearance can.

• die Crimppresse einen Maschinenrahmen umfasst, gegenüber dem das erste und/oder zweite Crimp-Werkzeug bewegbar ist, und
• die Vorspann-Mittel zum Aufbringen der Vorkraft zwischen dem Maschinenrahmen und dem ersten und/oder zweiten Crimp-Werkzeug vorbereitet sind.

It is advantageous if the biasing means for applying the pre-load are prepared directly on the first and second crimping tool. In this variant, the pre-load is applied directly to both crimping tools, which ensures that all bearings lying in the course of the drive are influenced by the pre-load. It is also beneficial if:

• the crimping press comprises a machine frame, opposite which the first and / or second crimping tool is movable, and
• the biasing means are provided for applying the pre-load between the machine frame and the first and / or second crimping tool.

In this variant of the invention, a preliminary force is applied between a crimping tool and the machine frame. This may be easier to accomplish than applying the pre-load directly to both crimping tools. If one of the two crimping tools is stationary with respect to the machine frame, the application of the crimping tool, which is movable relative to the machine frame, is generally sufficient. If both crimping tools are movable, then advantageously both are subjected to a pre-load.

It is advantageous if the biasing means are formed by at least one spring, in particular a helical spring, an evolute spring, a leaf spring, a plate spring, a gas spring, an elastomer spring and / or a spring made of a fiber composite material. The said springs are known per se and represent proven means for applying a force. The biasing means can thus be implemented in a particularly simple technical way in practice. The said springs have different spring characteristics and can therefore be particularly well adapted to the inventive requirements, in particular by combining different springs and spring types. Depending on the design of the press namely different spring characteristics are advantageous. Springs are also divided into compression, torsion, bending, tension and gas springs. All types can be used in principle for solving the task according to the invention, with pressure, tension and gas springs offering themselves in particular because of the generally linear movement of the tools. The latter can also be adapted particularly well to a required spring force by the gas spring is subjected to more or less pressure. Elastomeric springs, in turn, offer excellent damping properties as well as high mechanical strength and good resistance to many chemicals and oils. Due to the generally smooth surface, they are also less susceptible to contamination or easy to clean. It should also be noted at this point that in the context of the invention the term "elastomer springs" also means springs made of silicone.

It is also advantageous if the biasing means are formed by at least one actuator, in particular by a pneumatic cylinder, a hydraulic cylinder or a PiezoElement. Instead of a spring or in addition to a Vorkraft can in principle be used up by an actuator, for example by a pneumatic cylinder. This is applied before the crimp manufacturing process with appropriate pressure. Since a gas spring can also be subjected to variable pressure, the boundaries between gas springs and pneumatic cylinders are fluid. Advantageously, actuators can also be completely relieved if necessary, which can be particularly advantageous when changing tools or other maintenance on the crimping press.

It is advantageous if the biasing means are designed to be adjustable, in particular manually or automatically adjustable. In this way, the header means be optimally adapted to the crimping process. In particular, aging effects on the crimping press (eg soiled bearings, changed viscosity of lubricating grease) as well as temperature influences can thus be well compensated. It is conceivable, in particular, that the adjustment takes place automatically. For example, the biasing force can be adjusted depending on an ambient temperature.

• Mittel zur Detektion, ob Lagerflächen des Antriebs während des Crimp-Herstellvorgangs spielfrei aneinander liegen, und
• Mittel zum Einstellen der Vorspann-Mittel bei negativem Ausgang der Überprüfung derart, dass die genannten Lagerflächen während des Crimp-Herstellvorgangs spielfrei aneinander zu liegen kommen.

Bei dieser Variante der Erfindung wird durch die Detektionsmittel und die Einstellmittel eine Regelschleife aufgebaut. Wird festgestellt, dass die Vorkraft nicht ausreicht, um das Lagerspiel in gewünschter Weise abzubauen, so wird diese entsprechend erhöht. Gleichermassen kann die Vorspann-Kraft gesenkt werden, wenn festgestellt wird, dass auch eine geringere Vorspann-Kraft ausreicht, um das Lagerspiel in gewünschter Weise zu reduzieren. Auf diese Weise kann insbesondere erreicht werden, dass die Crimppresse, insbesondere deren Antrieb, nicht durch eine unnötig hohe Vorkraft belastet wird. Zur Messung, ob die Lagerflächen aneinander liegen, können im Bereich der Lager entsprechende Drucksensoren oder Dehnmessstreifen vorgesehen werden, die eine Kraftübertragung über die aneinander liegenden Lagerflächen anzeigen.In addition, a crimping press, which additionally comprises:

• Means for detecting whether bearing surfaces of the drive are free of play during the crimping process, and
• Means for adjusting the biasing means at negative output of the review such that the said bearing surfaces come to rest without play during the crimping manufacturing process.

In this variant of the invention, a control loop is established by the detection means and the adjusting means. If it is determined that the pre-load is not sufficient to reduce the bearing clearance in the desired manner, it will be increased accordingly. Similarly, the biasing force can be reduced if it is determined that a lower biasing force is sufficient to reduce the bearing clearance in the desired manner. In this way it can be achieved, in particular, that the crimping press, in particular its drive, is not loaded by an unnecessarily high pre-load. In order to measure whether the bearing surfaces lie against one another, appropriate pressure sensors or strain gauges can be provided in the region of the bearings, which indicate a force transmission via the abutting bearing surfaces.

• die Crimppresse Mittel zum Erfassen der zwischen erstem und zweitem Crimp-Werkzeug aufgebrachten Kraft in Abhängigkeit von a) der Distanz zwischen erstem und zweitem Crimp-Werkzeug und/oder b) von der Zeit umfasst und
• die Detektionsmittel zur Untersuchung eines während des Crimp-Herstellvorgangs aufgenommenen Kraft-Weg-Verlaufs und/oder Kraft-Zeit-Verlaufs auf einen Verlauf hin, welcher von einem Lagerspiel im Antrieb herrührt, ausgebildet sind. Bei dieser Variante der Erfindung wird direkt der Kraft-Weg-Verlauf oder Kraft-Zeit-Verlauf während des Crimp-Herstellungsvorgangs zur Detektion einer Anomalität, welche von einem unzureichend beseitigten Lagerspiel herrührt, herangezogen. Beispielsweise sind dies Abflachungen oder Unstetigkeiten im Kraft-Weg-Verlauf oder Kraft-Zeit-Verlauf. Bei dieser Variante werden also Mittel zur Detektion eines Lagerspiels ausgenützt, welche zumeist ohnehin in einer Crimppresse vorhanden sind, nämlich der Kraft-Weg-Verlauf oder Kraft-Zeit-Verlauf zur Qualitätsbestimmung einer Crimp-Verbindung. Der ermittelte Kraft-Weg-Verlauf oder Kraft-Zeit-Verlauf kann somit einen Doppelnutzen erfüllen.

It is also particularly advantageous if:

• the crimping press comprises means for detecting the force applied between the first and second crimping tools as a function of a) the distance between the first and second crimping tools and / or b) of the time and
• the detection means for examining a recorded during the crimping process force-displacement curve and / or force-time curve on a course, which results from a bearing clearance in the drive, are formed. In this variant of the invention, the force-displacement curve or force-time curve during the crimping production process for the detection of an abnormality, which results from an insufficiently eliminated bearing clearance, is used directly. For example, these are flattening or discontinuities in the force-displacement curve or force-time curve. In this variant, means for detecting a bearing clearance are thus utilized, which are usually present anyway in a crimping press, namely the force-displacement curve or force-time curve for determining the quality of a crimp connection. The determined force-distance curve or force-time curve can thus fulfill a double benefit.

• Mittel zum Erfassen der zwischen erstem und zweitem Crimp-Werkzeug aufgebrachten Kraft und
• Mittel zum Senken der Vorkraft während des Crimp-Herstellvorgangs umfasst.

Auf diese Weise kann vermieden werden, dass die Crimppresse, insbesondere deren Antrieb, durch die Vorkraft übermässig belastet wird. Erhöht sich nämlich die zwischen dem ersten und zweiten Werkzeug aufgebrachte Kraft aufgrund des Crimp-Herstellvorgangs (d.h. wenn der Crimp-Kontakt auf einen Draht oder ein Kabel aufgepresst wird), dann wird die Vorkraft gesenkt, um die Gesamtbelastung auf die Presse zu reduzieren. Vorteilhaft wird die Gesamtkraft wenigstens abschnittsweise im Wesentlichen konstant gehalten. Durch Subtraktion der Vorkraft von der Gesamtkraft kann auf die eigentliche Crimp-Kraft zurückgerechnet werden. Für die Einstellung der Vorkraft eignen sich alle einstellbaren Aktoren, beispielsweise ein Pneumatik- oder Hydraulikzylinder mit einstellbarem Druck.Finally, it is particularly advantageous if the crimping press:

• Means for detecting the force applied between the first and second crimping tools and
• Means for lowering the Vorkraft during the crimping process comprises.

In this way it can be avoided that the crimping press, in particular its drive, is excessively loaded by the pre-load. Namely, when the force applied between the first and second tools increases due to the crimping process (ie, crimping the crimp contact onto a wire or cable), the pre-load is lowered to reduce the overall load on the press. Advantageously, the total force is at least partially kept substantially constant. By subtracting the Vorkraft of the total force can be calculated back to the actual crimping force. All adjustable actuators, for example a pneumatic or hydraulic cylinder with adjustable pressure, are suitable for setting the pre-load.

The above embodiments and developments of the invention can be combined in any manner.

Fig. 1

einen Kraft-Zeit-Verlauf beim Crimpen nach dem Stand der Technik;

Fig. 2

einen Kraft-Zeit-Verlauf beim Crimpen mit überlagerter Vorkraft durch eine Feder mit linearer Kennlinie;

Fig. 3

einen Kraft-Zeit-Verlauf beim Crimpen mit überlagerter Vorkraft durch eine Feder mit degressiver Kennlinie;

Fig. 4

einen Kraft-Zeit-Verlauf beim Crimpen mit überlagerter Vorkraft durch einen Aktuator und

Fig. 5

eine beispielhafte erfindungsgemässe Crimppresse.

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawing. It shows:

Fig. 1

a force-time course during crimping according to the prior art;

Fig. 2

a force-time curve during crimping with superposed pre-load by a spring with a linear characteristic;

Fig. 3

a force-time curve during crimping with superimposed pre-load by a spring with degressive characteristic;

Fig. 4

a force-time course during crimping with superimposed Vorkraft by an actuator and

Fig. 5

an exemplary crimping press according to the invention.

In the figures of the drawing are identical and functionally identical elements and features - unless otherwise stated - provided with the same reference numerals.

Fig. 1 shows a first exemplary force-time curve during a crimping process. In the illustrated diagram, the force F acting between the two crimping tools is plotted against time t, which elapses as the first crimping tool moves relative to the second crimping tool.

Good to see that the force F increases relatively sharply from a certain point, namely, when both crimping tools abut the workpiece. After a maximum force, however, the force F drops again sharply, namely, when the crimping tools move away from each other again. This is a typical force-time curve during a crimping process. Of course, the force-time curve in practice significantly differ, for example, when different types of contacts are pressed onto a wire.

In the illustrated force-time curve, a flattening A and a local minimum B can be seen. Both result from the fact that the bearing surfaces of two bearings come to rest at different times, that is, at different forces F. In area A, this is done with constant force, in area B even with decreasing force F. In area B, the bearing surfaces "snap" to each other, so to speak.

As a rule, only the middle section of the force-time curve is used to assess the crimping process. This is because the forces scatter strongly at the beginning and end of the crimping process, and thus represent only a small value for judging the quality of a crimped connection. In the present example, this section is denoted by the reference symbol D.

The section D of the force-time curve, which is actually intended to determine the quality of a crimp connection, but in this example has two sections A, B, which caused not by the crimp manufacturing process as such, but by bearing clearance become. As can easily be seen, this greatly impedes the assessment of the quality of a crimp connection. Under certain circumstances, the bearing clearance could even lead so far that the force-time curve in the areas A and B leaves an allowable tolerance band and the crimp connection is therefore erroneously qualified as unusable.

Fig. 2 shows the same situation as in Fig. 1 , except that in this example according to the invention a pre-load between the first and second crimping tool is applied, which is rectified with the crimping force F and already acts before the crimping process. In the present case this is caused by a spring with linear spring characteristic C (Note: Since the crimping tools move away from the maximum force F again from each other, the spring characteristic C falls again from this point).

It can clearly be seen that the discontinuities in the force-time curve in areas A and B are well ahead of the actual crimping process. This means in particular the bearing surfaces of the bearing, which cause the flattening A, come together long before the crimping process. Section D of the force-time curve, which characterizes the crimping process, is now unaffected by bearing play and can thus be used directly to assess the quality of a crimp connection.

Like from the Fig. 2 can be seen, it is often sufficient to keep the section D free of abnormalities, which of Bearing game originate. It is not absolutely necessary to keep clear of the entire crimping process of abnormalities caused by bearing play.

Fig. 3 shows a similar situation as in Fig. 2 , but with a modified spring characteristic C. This first increases strongly and then continues horizontally in this example. For example, such a spring characteristic C can be realized with a gas pressure spring, which has a pressure relief valve. The pressure in the interior of the gas pressure spring and thus the external force increase first strong, but remain at a constant level when the pressure relief valve opens. By setting an appropriate opening pressure, the spring characteristic C can be well adapted to various requirements. Of course, however, other types of springs with a degressive spring characteristic can be used equally.

As can easily be seen, the bearing surfaces now come to rest even earlier, so that the areas A and B are even further to the left in the diagram shown. The section D of the force-time curve, which characterizes the crimping process, is now completely unaffected by bearing play. An assessment of the quality of a crimp connection is now even better possible.

Fig. 4 shows a similar situation as in Fig. 3 , however, the pre-load is actively influenced by an actuator in this example. The force F increases as in Fig. 3 first strong and then remains constant. Unlike the in Fig. 3 However, it remains constant even at the beginning of the crimping process (see dashed curve). This is achieved by measuring the force F and reducing the pre-load to such an extent that the total force F remains at a constant level. The force F is thus regulated. If it increases because of the beginning of the crimping process, the pre-load is correspondingly reduced.

Where the force F is higher than the pre-power due to the crimping process, the force F - because a further lowering of the pre-power is no longer possible - no longer be kept constant and increases as in the above examples (it because, the actuator for applying the Vorkraft can apply this in the opposite direction). The force-time curve therefore compensates for the force-time curve in this area Fig. 1 , However, if the force F drops below the set level for the pre-load again, then the pre-load is successively increased again, so that at the end of the crimping process, there is again a horizontal section in the force-time curve.

By measuring the currently applied Vorkraft this can from the im Fig. 4 drawn force-time curve can be subtracted so that the force-time curve can be reconstructed without a preliminary force. The resulting force-time curve during the crimping process (shown here in dashed lines) therefore resembles that in FIG Fig. 1 Course shown, but without the resulting game from the bearing areas A and B, which are still very far left in the diagram and thus far before the crimp manufacturing process.

The advantage of this variant of the invention is that the maximum force in the force-time curve despite applying a Vorkraft not above the in Fig. 1 level without pre-power. The crimping press is controlled by the pre-load unlike the ones in the Figures 2 and 3 illustrated cases - not claimed.

As actuators for in Fig. 4 illustrated variant of the invention are, for example, pneumatic or hydraulic cylinders into consideration, the pressure can be actively controlled. Of course, other actuators, which are suitable for applying an adjustable Vorkraft be used.

Advantageously, it is also detected whether bearing surfaces of the drive lie against each other without play during the crimping process. If this is not the case, because, for example, anomalies, such as flats A and local minima B, were detected in the force-time curve, the biasing means or the pre-load are adjusted so that the bearing surfaces play each other without play during the crimping process lie down and thus no more anomalies occur. The pre-load is advantageously dimensioned so that no anomalies can be detected.

Fig. 5 The crimping press 1 comprises a machine frame 2, a drive shaft 4 mounted in a drive shaft bearing 3, an eccentric 5 connected to the drive shaft 4 and a connecting rod 6 connected to the eccentric 5, which has a connecting rod bearing 7 a press carriage 8 is connected. The press carriage 8 is displaceably mounted in the slide guides 9a and 9b.

Furthermore, a crimping apparatus 10, which comprises a first crimping tool 11, is connected to the machine frame 2. In this example, this is the first crimping tool 11 fixed relative to the machine frame 2. This is by no means a mandatory condition. Rather, the first crimping tool 11 can also be movably mounted relative to the machine frame 2.

Via a bending beam, on which a crimp force sensor 12 is arranged, the press slide 8 is also connected to a second crimping tool 13, which in such a way is movable relative to the machine frame 2.

Finally, the crimping press 1 comprises a carriage-side mount 14, a frame-fixed mount 16 and an elastic element 15 arranged between the carriage-side mount 14 and the frame-fixed mount 16.

• Über die Antriebswelle 4 wird der Exzenter 5 in Bewegung versetzt, welche die Antriebskraft über das Pleuel 6 auf den Pressenschlitten 8 überträgt. Beim Crimp-Herstellvorgang bewegt sich der Pressenschlitten 8 nach unten, sodass sich die beiden Crimp-Werkzeuge 11 und 13 einander annähern. Mit Hilfe des Crimpkraftsensors 12 wird dabei laufend die zwischen den Crimp-Werkzeugen 11 und 13 herrschende Kraft gemessen.

The function of in the Fig. 5 shown crimping press 1 is now as follows:

• About the drive shaft 4, the eccentric 5 is set in motion, which transmits the driving force via the connecting rod 6 on the press carriage 8. In the crimping process, the press slide 8 moves down so that the two crimping tools 11 and 13 approach each other. With the help of the Crimpkraftsensors 12 while the ruling between the crimping tools 11 and 13 force is continuously measured.

By the elastic element 15, a pre-force between the first and second crimping tool 11 and 13 is now applied, which already acts before the crimping process. This pre-load causes the bearing surfaces of the bearings in the drive train to come to rest against each other. This concerns in the present case, for example, the storage between the eccentric 5 and the connecting rod 6, and between the connecting rod 6 and press carriage. 8

If the second crimping tool 13 finally strikes a workpiece (not shown) when the press carriage 8 is moved down, then the bearing clearances are already degraded to such an extent that they affect the force measurement only slightly or not at all during the actual crimping process.

As an alternative or in addition to the pressure-loaded elastic element 15, an elastic element 18 can also be provided, which is arranged between a frame-fixed holder 17 and the carriage-side holder 14 and is subjected to tension.

As elastic element 15 or 18, for example, a coil spring, an Evolutfeder, a leaf spring, a plate spring, a gas spring, an elastomeric spring or a spring may be provided from a fiber composite material to effect a force-time curve, as he, for example, in Fig. 2 and 3 is shown.

Instead of the elastic elements 15 or 18 (or in addition thereto) may also be provided actuators. For example, between the carriage-side bracket 14 and the frame-fixed bracket 16, a pneumatic cylinder may be provided, the pressure of which can be actively controlled, so as to effect a force-time curve, as he, for example, in Fig. 4 is shown.

Alternatively, it is also conceivable that elastic elements or actuators are arranged elsewhere than shown. For example, these can be arranged directly between the first and the second crimping tool 11 and 13. Of course, a plurality of biasing means may be arranged on the press 1, for example, between the connecting rod 6 and eccentric 5 and between the connecting rod 6 and press carriage 8. Here many constructive embodiments of the inventive principle are conceivable, but their finding is within the skill of the art.

In conclusion, it is noted that instead of force-time courses, as in the FIGS. 1 to 4 are shown, equally force-displacement curves can be used for the invention. The presented variants of the crimping press 1 according to the invention also represent only a part of the many possibilities and must not be used to limit the scope of the invention. Of course, the variants shown can be arbitrarily combined and modified. For example, the doctrine of the Figures 2 and 4 combined by combining a spring with an actuator. In addition, it should be understood that portions of the devices illustrated in the figures may also form the basis of independent inventions.

LIST OF REFERENCE NUMBERS

A

flattening

B

local minimum

C

Spring characteristic

D

Quality Assessment Section

F

force

t

Time

1

Crimping Press

2

machine frame

3

Drive shaft bearing

4

drive shaft

5

eccentric

6

pleuel

7

connecting rod bearing

8th

press slide

9a, 9b

carriage guide

10

A crimping apparatus

11

first crimping tool

12

Crimpkraftsensor

13

second crimping tool

14

carriage-side bracket

15

elastic element for pressure arrangement

16

frame-fixed bracket for pressure assembly

17

frame-fixed bracket for train assembly

18

elastic element for tension arrangement

Claims (10)

Crimping press (1), comprising a first crimping tool (11), a second crimping tool (13) movable relative to the first crimping tool (11), a drive (3..8) for applying a crimping force between first and second crimping tools (11, 13) during a crimping process (D),
marked by
Biasing means (15, 18) for applying a pre-load between the first and second crimping tool (11, 13), which is rectified with the crimping force and already acts before the crimping process (D). Crimping press (1) according to claim 1, characterized in that the pre-load is dimensioned such that bearing surfaces of the drive (3..8) prior to the crimping process (D) without play abut each other. Crimping press (1) according to claim 1 or 2, characterized in that the biasing means (15, 18) for applying the pre-load directly to the first and second crimping tool (11, 13) are prepared. Crimping press (1) according to claim 1 or 2, characterized in that - This comprises a machine frame (2) against which the first and / or second crimping tool (11, 13) is movable, and - The biasing means (15, 18) for applying the Vorkraft between the machine frame (2) and the first and / or second crimping tool (11, 13) are prepared. Crimping press (1) according to one of claims 1 to 4, characterized in that the biasing means (15, 18) by at least one spring, in particular a coil spring, an evolute spring, a leaf spring, a plate spring, a gas spring, an elastomeric spring and / or a spring made of a fiber composite material are formed. Crimping press (1) according to one of claims 1 to 5, characterized in that the biasing means (15, 18) are formed by at least one actuator. Crimping press (1) according to one of claims 1 to 6, characterized in that the biasing means (15, 18) are made adjustable. Crimping press (1) according to one of claims 1 to 7, characterized by - Means for detecting whether bearing surfaces of the drive (3..8) during the crimping process (D) without play abut each other, and - means for adjusting the biasing means (3..8) in the negative outcome of the review such that the said bearing surfaces come to rest without play during the crimping process (D). Crimping press (1) according to claim 8, characterized in that - This means for detecting the force applied between the first and second crimping tool (11, 13) (F) as a function of a) the distance between the first and second crimping tool (11, 13) and / or b) the time ( t) and - The detection means for examining a recorded during the crimping process (D) force-displacement curve and / or force-time course on a course (A, B), which is derived from a bearing clearance in the drive (3..8) are formed. Crimping press (1) according to one of claims 1 to 9, characterized by - means for detecting the force applied between the first and second crimping tools (11, 13) (F) and - means for lowering the Vorkraft during the crimping process (D).

Images