EP1357561A1 - Flat ribbon cable manufacturing - Google Patents

Abstract

The method involves transporting the cable (1) with drive rollers that are driven at different tangential surface speeds. The cable passes from drive rollers (4'-6'') with a lower tangential surface speed to drive rollers with a higher tangential surface speed. The drive torque of at least one roller is lower than the frictional force between the surface of the roller and cable multiplied by the roller radius. AN Independent claim is also included for the following: an arrangement for implementing the inventive method.

Description

The invention relates to the manufacture and equipment of ribbon cables, in particular their movement in the course of their manufacture, processing and equipment. in the In particular, the invention relates to a method for transporting a flat conductor cable to, between and from processing stations by means of drive rollers, configurations this method and an apparatus for performing the method.

There are two types of ribbon cables, the laminated and the extruded, both can and will be manufactured continuously, either directly from their location Manufacture, or different from a drum on which they are temporarily stored Processing steps subjected to different, successive stations. These individual processing steps can include removing a piece of an insulating layer to be able to create a window, connecting with any electronic Elements or elements for handling or the like ..

It is important that when continuously running through several stations, between which are the drive rollers for the ribbon cable, the speed of the ribbon cable is different between the stations and is in Direction of movement increased. This leads to the formation of humps, loops, etc., to the occurrence of different conditions at the individual stations and finally for the shutdown of the system by the monitoring system.

This problem arises not only with a large number of consecutively arranged Stations, but always when a large length of a ribbon cable to be processed in one go. It then comes to two processing stations with a total of three drive stations on these problems. Also in the meantime Switching off and "tightening" only partially because knowing the exact location the processing steps already carried out on the ribbon cable are lost goes.

The object and aim of the invention is to solve these problems.

According to the invention, this goal is achieved in that the drive rollers with different Speed are driven and that between the roller parts, which contact the ribbon cable and the drive elements a slip clutch is provided. In this way, a measurable and reproducible movement of the Ribbon cable also over long distances and also over many processing stations achieved.

Depending on the surface condition of the respective drive roller and the ribbon cable, the contact pressure between the drive roller and the ribbon cable, possible contamination of the surfaces and other operating parameters the slip clutch must be adjusted so that it begins to slip before it Sliding friction between the drive roller and the ribbon cable comes. This Adjustment can be carried out by a person skilled in the art knowing the invention using the data sheets from Ribbon cable and possibly a few simple experiments easily done become.

die Fig. 1 eine schematische Darstellung einer Fertigungsstraße und

die Fig. 2 den prinzipiellen Aufbau einer Antriebsrolle.

The invention is explained in more detail below with reference to the drawing. It shows

1 is a schematic representation of a production line and

2 shows the basic structure of a drive roller.

1 shows purely schematically the movement of a flat cable 1 in the area of two Processing stations 2, 3. The movement of the flat cable 1 is carried out by three Drive stations 4, 5 and 6, wherein, viewed in the direction of movement of the flat cable, the drive station 4 is the first and the drive station 6 is the last to which the Flat cable arrives. Each drive station 4, 5, 6 consists essentially of two Rollers 4 ', 4 "; 5', 5" or 6 ', 6 ", of which always the lower roller as the drive roller 4 ', 5', 6 'is used and is therefore driven while the respective upper roller as Pinch roller 4 ", 5", 6 "is used.

In the exemplary embodiment shown, the last drive station 6 is operated directly by one Motor or a motor-gear unit 7 driven while the other two Drive stations 4 and 5 are driven by toothed belts 8 and 9.

Figures 2 and 3 show, based on a special embodiment, one of the lower drive rollers 4 'or 5': the outer surface 10 on which the flat cable (Fig. 1) rests with the drive unit (tooth lock washer or direct drive) 11 an (adjustable) slip clutch 12 connected. This ensures that only one preset and preferably controllable torque can be transmitted. This in turn means that only a predetermined "drag force" on the flat cable is transmitted.

1. Welche Kräfte und Momente wirken auf das Flachkabel in den Antriebsstellen

2. Welche Beschleunigung und Geschwindigkeit erfährt das Kabel in den Berührungspunkten mit den Antriebsrollen

3. Wie verhält sich das Kabel zwischen zwei Rollen, bzw. unter Berücksichtigung des gesamten kinematischen Strangs

4 Welcher Einfluss hat die Lage des Weggebers auf die Fertigungsgenauigkeit

To determine the machining accuracy, which is dominated in the direction of movement by the kinematics of the drive train and the forces acting on the flat cable, one has to find an answer to the following questions:

1. What forces and moments act on the flat cable in the drive points

2. What acceleration and speed does the cable experience at the points of contact with the drive rollers

3. How does the cable behave between two rollers, or taking into account the entire kinematic strand

4 What influence does the position of the encoder have on the manufacturing accuracy

For a controlled feed of the flat cable, two drive rollers are required for each application - before and after the production unit. If the production units are not separated from each other by buffers, the number of drive rollers is n + 1 , where n indicates the number of individual processes.

Model of the drive

The drive is implemented in such a way that the last lower roller is spikl-free in the transport direction is driven. The previous rolls from the bottom row are by timing belts also driven. The upper rollers are slightly pretensioned on the lower ones that a contact path is created in the contact points.

Due to the manufacturing tolerances, both the toothed lock washers and the cable drive rollers have different outside diameters. In contrast to gear pairs, with a toothed belt drive you have to use the outer diameter of the toothed pulleys to determine the actual gear ratio within the backlash (the theoretical gear ratio can of course be calculated from the effective diameter or the number of teeth). This inevitably results in different circumferential speeds on the cable drive rollers, as long as there is play in the corresponding direction. Depending on which of the two following rollers has the greater peripheral speed, either a pulling or an upsetting zone is formed in the area between the rollers. It is obvious that cable transport with the formation of compression tins is not permitted. Therefore, the condition for a proper cable feed can be formulated as follows: (1) V 1 <V 2 <.... <V n V i - peripheral speed of the driven roller

D_i

Außendurchmesser der i. Kabelantriebsrolle

ω _i

Winkelgeschwindigkeit der i.
Kabelantriebsrolle

ω _M

Winkelgeschwindigkeit des Motors

i_G

Getriebeübersetzung

Außendurchmesser der Zahnscheibe

oder allgemein:

The flat cable must always be slightly tense! Based on the angular speed of the motor, the following expressions can be derived for the peripheral speeds on the cable drive rollers: (2) V n = D n 2 ω n = D n 2 ω M i G = R n ω M i G V 2 = D 2 2 ω 2 = D 2 2 ω n i n 2 = D 2 2 ω n d 2 d n = D 2 2 d n d 2 ω M i G = R 2 d n d 2 ω M i G

D _i

Outside diameter of the i . Cable driving roll

ω _i

Angular velocity of the i.
Cable driving roll

ω _M

Angular speed of the motor

i _G

gear ratio

Outside diameter of the toothed disc

or in general:

und dem Zahnscheibendurchmesser

. It can be seen from the above formulas that condition (1) can be satisfied by varying 2 parameters, namely the roll diameter

and the pulley diameter

,

However, the manufacturing processes do not take place in the immediate environment of a role instead, but usually in the middle between 2 rolls. That is why it is necessary that To know the distribution of the flat cable speed between the roles, if necessary the To be able to synchronize the speed of the process with that of the cable.

Let us consider the movement of the flat cable only between 2 rolls i and i-1 . The speed of the cable in the reels is known or can be determined from (2).

According to condition (1), the speed between the rollers increases continuously. For the speed of the cable at any point between the reels you can write down:

kann man (3) nur als Funktion von

ausdrucken:

l

Abstand zwischen den Rollen

t₁

Zeit für die Bewegung eines Punktes des Kabels von Rolle i-1 zu r Rolle i

∼V

Durchschnittsgeschwindigkeit eines Punktes des Kabels von n i-1 nach i

S

Flächenmaß des Dreiecks V_i-l P V_i

Keeping in mind that

can only be (3) as a function of

print:

l

Distance between the roles

t ₁

Time to move a point of the cable from roll i-1 to r roll i

∼ V

Average speed of a point on the cable from n i-1 to i

S

Area of the triangle V _il PV _i

The differential form of (3b) - dx / dt = (.....) t -, integrated in the interval l ₀ -l provides the law of motion of a point of the cable as it moves from point il to i :

1. Geschwindigkeit des Kabels in den Rollen und der Einfluss des Rollen- und Zahnscheibendurchmessers auf diese Geschwindigkeit

2. Verteilung der Kabelgeschwindigkeit zwischen 2 Rollen

3. Bewegungsgesetz des Kabels zwischen 2 Rollen

As a resume, what has been determined so far should be recorded:

1. Speed of the cable in the rollers and the influence of the roller and pulley diameter on this speed

2. Distribution of the cable speed between 2 rolls

3. Law of movement of the cable between 2 rolls

Now you can find an answer to the question of what performance for locomotion the cable is necessary, or by what contact pressure normal operation is guaranteed.

The dynamic analysis of the drive flat cable system provides information about the external forces acting on the flat cable and their influence on the position, or machining accuracy and about the boundary conditions for a slip-free Movement of the cable. First you have to drive the flat cable determine. This force is colinear to the x-axis of the model. For this it is necessary to determine the equivalent mass reduced to the x-axis. Then the necessary pressing forces on the flat cable taking into account the by the Machining and friction-induced resistance forces defined. It goes can be seen from the following from Fig. 2 apparent design of the roles from (the reason for the approach follows in the description):

l_i

Abstand zwischen den Rollen i und i+l

∼V

Durchschnittsgeschwindigkeit eines Punktes des Kabels von n i nach i+l

m_FFC

Masse des FFC in kg/m

The equivalent mass can be determined by equating the kinetic energies of the model and the real system. We will conditionally divide the dynamic system into two - subsystem FFC and subsystem drive. Accordingly, one can write down both subsystems for the kinetic energy:

l _i

Distance between the roles i and i + l

~V

Average speed of a point on the cable from n i to i + l

m _FFC

Mass of the FFC in kg / m

und

(6.1) EM = 12 JM ω2 M (6.2) EG = 12 JG ω2 M

E_M

Kinetische Energie des Motors

E_G

KE des Getriebes

Eo_R

KE der oberen Rolle

Eu_R

KE der unteren Rolle

E_SR

KE der Spannrolle

E_ZR

KE des Zahnriemens

For the sake of simplicity, we use (5) instead of ∼V -> V _i , so:

and

(6.1) e M = 1 2 J M ω 2 M (6.2) e G = 1 2 J G ω 2 M

E _M

Motor kinetic energy

E _G

KE of the transmission

Eo _R

KE of the upper role

Eu _R

KE of the lower role

E _SR

KE of the tension pulley

E _ZR

KE of the timing belt

Indices: D - Deckel, GS - Gleitscheibe, ZS - Zahnscheibe, AXL - Axiallager

wo:

VZR = dn ω M iG

ρ -

Materialdichte

l_i ―

Abstand zwischen zwei Rollen

The index L stands for bearings, R _RUi and R _ROi are the outer radius of the lower and upper roller, r _n and r _i mean the radius of the corresponding toothed disc.

Indices: D - cover, GS - sliding washer, ZS - toothed washer, AXL - axial bearing

Where:

V ZR = d n ω M i G

ρ -

material density

l _i -

Distance between two roles

Unter der Berücksichtigung der Formel (2) und der Vernachlässigung der geringfügigen Unterschiede der kinematischen Parameter der Rollen und der Zahnscheiben ( alle Antriebsrollen in einer Reihe sowie alle Zahnscheiben und Spannrollen haben ideale Maße, sprich jeweils gleiche Außendurchmesser), d.h. ω RU = ω M iG , ω RO = RRU ω M RRO iG ,   Vi = Vn kann man die äquivalente Masse folgendermaßen umschreiben:

Now one can write for the equivalent mass M _ä , reduced to the x-axis:

Taking into account the formula (2) and neglecting the slight differences in the kinematic parameters of the rollers and the lock washers (all drive rollers in a row as well as all lock washers and tension rollers have ideal dimensions, i.e. the same outer diameter), ie ω RU = ω M i G , ω RO = RR U ω M R RO i G . V i = V n the equivalent mass can be described as follows:

The system is thus reduced to the following model, with the entire mass being "concentrated" in the FFC

   wo F_A ―resultierende Antriebskraft
F_P ― resultierende Prozesskraft
β dx / dt = F_R ― resultierende Reibungskraft
η - Wirkungsgrad des GesamtantriebsThe system's differential equation is therefore:

where F _A ― resulting driving force
F _P - resulting process force
β dx / dt = F _R - resulting frictional force
η - efficiency of the overall drive

The run-up time of the system can be determined from the equations of motion:

The feed constant K _{V of} the system is given by:

For the sake of completeness, it is also shown which drive forces arise on the respective drive rollers. These forces can be roughly calculated by dividing the drive torque by the number of rollers and the radius of the drive roller.

   wobei:

η _i - Wirkungsgrad in der jeweiligen Übersetzungsstufe

r_i - Radius der jeweiligen Zahnscheibe

The exact value is given by the expression:

in which:

η _i - efficiency in the respective gear ratio

r _i - radius of the respective toothed disc

From the previous explanation it has become clear that a continuous operation with predictable behavior of the flat cable is only guaranteed if it is between two drive rollers are subjected to a certain train. This creates in a non-linearly increasing elastic force in this area. The maximum value of this However, tractive effort must be limited, otherwise the FFC may be in plastic Area stretched, narrow FFCs may even be destroyed. This value can be restricted in two ways: you set the contact pressure between the rollers such that when a traction limit is reached the FFC switches to the corresponding one The drive roller for sliding begins or you can see a slip clutch on everyone Drive roller ahead with the exception of the roller that is driven directly by the motor.

This slip clutch enables the drive torque transferred to the roller be limited. When a predefined elastic stretch is reached (i.e. more elastic Force) between two roles, one (or both) begins with one to rotate another angular velocity with respect to the driving toothed pulley. The slip thus occurs in the slip clutch and not between the drive roller and Electric wire. This creates a defined position of the cable with respect to the surface of everyone Drive role and thus ensured in the room what processing individual allows predetermined areas of the cable with high accuracy.

ƒ

Reibungskoeffizient bei Rollen

µ₀

Reibungskoeffizient bei Gleiten

r

Radius der Rolle

R

Reaktionskraft = F_n

The conditions for slip-free operation in the vicinity of a roller can be defined as follows, based on the drive model: (12) ΣF X ≤ µ 0 R - Condition for slip-free power transmission to the FFC (13) Σ F X ≥ ƒ r R - Condition for rollers of the drive and pressure roller and on the FFC where (without slip clutch):

ƒ

Coefficient of friction for rollers

µ ₀

Friction coefficient when gliding

r

Radius of the roll

R

Reaction force = F _n

At ΣF _X > 0 and Σ F X ≥ µ 0 R we have forward sliding, or at Σ F _X <0 and ΣF X ≥ µ 0 R - slide backwards.

wo: t_H - Hochlaufzeit und

By installing the slip clutch, you gain a parameter with which you can always achieve (12) and (13). The equation of the forces on x changes as follows:

where: t _H - ramp-up time and

The clutch closing force F _Cyl is given by:

In order to be able to correctly set the drive of the flat cable by the machine, be aware of the elastic properties of the cable. It is particularly too determine whether all with a constant setting of the limit value of the elongation Cable widths can be edited, or whether depending on the composition of the Cable cross-section an individual setting for slip-free operation in the Harness is necessary. Because the elasticity of the cable is dominated by the copper only this material is used for clarity in the following considerations considered.

E

Elastizitätsmodul

S

Querschnittfläche

l

Länge des Leiters

The spring constant c of a flat copper conductor is given by: (14) c = IT l With

e

modulus of elasticity

S

Cross-sectional area

l

Length of the conductor

mit

h

Höhe des Leiters

b_j

Breite des Leiters

i

Anzahl Leiter mit gleicher Breite

The spring constant of a flat cable is therefore given with the general formula:

With

H

Height of the ladder

b _j

Width of the ladder

i

Number of conductors with the same width

δx

Verschiebung des Berührungspunktes der Räder

Δx

Absolute Dehnung des Kabels

ε

Relative Dehnung des Kabels

e_S

Spezifische Dehnung des Kabels

l_FFC

Ungedehnte Länge des Kabels

l

Abstand zwischen den Rollen

The elastic force that arises between two rollers depends on the path x , i.e. on the time t. The process of creating the elastic force is illustrated by the image below:

Ax

Shift of the contact point of the wheels

Ax

Absolute extension of the cable

ε

Relative elongation of the cable

e _p

Specific elongation of the cable

l _FFC

Unstretched length of the cable

l

Distance between the roles

According to condition (1), V _{i + 1 is} always greater than V _i , that is to say that the outgoing cable end, i.e. the point of contact between the rolls i + 1 , moves faster than the incoming end, ie the point of contact between the rolls i . This speed difference results in the creation of a mechanical stretch in the cable harness, which causes a smaller or greater elastic force depending on the elastic constant of the cable, which in turn depends on the effective length of the cable. This force does not increase linearly due to the conditions of the drive.

Looking at the condition of the wire harness at any time t _j . The cable has the following elastic parameters: Δx ^j , ej / i, ε j / i , and l ^j _FFC . The part of the cable in front of the rolls i has a relative (specific) elongation ε ^j _{i- l} ( e ^j _{i- l} ) and the strand after the rolls i + 1 - a relative (specific) elongation ε ^j _{i + l ( e} j _i) .

In an infinitely small interval dt the left end of the cable moves by δx ^{j + l} _{i + l} and the right by δx ^{j + l} _i according to formula (2), and thus the parameters change as follows:

Thus one can define the elastic force for every infinitely small time interval as:

Summary of what has been achieved so far:

When transporting the flat cable through more than one reel, there is no slip given the idealization of the components of the kinematic chain theoretically, in practice, however, due to their manufacturing tolerances and elastic properties the cable cannot be implemented without additional measures. Therefore, at constructive implementation of the machine concept are looking for solutions that eliminate the cable slip in the rollers and thereby the kinematic behavior make the cable predictable.

The invention provides such a solution. In the kinematic according to the invention Solution of the feed drive, the flat cable moves through all without slipping Roll. The speeds of the respective pairs of rollers are reasonable Selection of their outer diameter and that of the toothed pulleys chosen such that the last driven roller in the transport direction has the highest peripheral speed has and each previously attached ever lower. The frictional forces on the FFC only make sense at the level of the driving forces and are caused by the contact pressure certainly.

The different peripheral speeds cause in the range between two rolls each uneven displacements of the cable. These shifts cause the creation of elastic forces in the respective cable harness. they climb nonlinear as long as it has the lower frictional force between either one Roll pairs do not exceed or if the difference of the products from the Peripheral speeds of the rollers with the specific elongations in the upstream areas goes to zero. When the first occurs, the flat cable should slip on the corresponding drive roller and thereby compensate for the elastic Forces take place from both sides of the role. Because this slipping for the cable and the manufacturing accuracy is unfavorable in all drive rollers except for the last one Slip clutches installed.

The like Adjustment of the elastic forces takes place in the couplings, what prevents the relative movement between cable and reel and prevents slippage Operation guaranteed. The forces reduced to the x-axis by the Frictional moments in the clutches are said to accelerate the system as Resistance forces and when braking are considered as active forces.

The last roll is the only one without a slip clutch and directly from the engine is driven. The transmission moments in the slip clutches are on one Value between the mass torque and the proportional drive torque on the roller set. This peculiarity of the drive guarantees a continuity of the movement of the flat cable and good deterministic properties of the entire system, which in addition to the correction of the position of the cable or the processing units by the Control also allow a good estimate of the machining tolerances of the FFC.

The invention is not based on the illustrated and described embodiment limited, but can be modified in various ways. Instead of the drive belt (Toothed belt) the use of chains or gears or friction wheels is conceivable, which may also take over the function of the slip clutches can.

It is also possible to have each drive roller on its own at the predetermined speed to drive, the slip clutch can be mechanical, as described in the above Case, or electrically, be designed as a control of the drive torque.

It is always spoken in the description and the claims of speed, this strictly applies only to drive rollers with the same diameter, strictly one would have to take the tangential surface speed as a comparison parameter use what is known to the expert.

Claims (8)

Method for transporting a flat conductor cable to, between and from processing stations by means of drive rollers, characterized in that the drive rollers are driven with different tangential surface speeds. A method according to claim 1, characterized in that the flat conductor cable passes from drive rollers with a lower tangential surface speed to drive rollers with a higher surface speed. A method according to claim 1 or 2, characterized in that the drive torque of at least one drive roller is less than the frictional force between the surface of the drive roller and the ribbon cable, multiplied by the radius of the drive roller. Device for carrying out a method according to one of the preceding claims, with drive rollers which set a ribbon cable in motion, characterized in that the drive rollers are driven at different tangential surface speeds. Apparatus according to claim 4, characterized in that a slip clutch is provided in at least one drive roller between the surface and the drive. Apparatus according to claim 5, characterized in that the slip clutch is designed mechanically, pneumatically or electrically. Device according to one of claims 4 to 6, characterized in that at least two drive rollers are driven with different torque. Apparatus according to claim 7 and 5, characterized in that the different torques are ensured by differently designed or adjusted slip clutches.

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