The invention relates to a drive method for moving a first and a second forming means for processing a web-like material (referred to as a “material web”) arranged between the same. The invention relates in particular to corrugated-type forming of a web of paperboard or cardboard, for example, for which purpose the forming means and optionally the material web are brought into a force-fitting and/or form-fitting engagement in between.
Furthermore, the invention relates to a drive arrangement which is suitable in particular for performing the aforementioned method and has two forming means that can be brought together into a force-fitting and/or a form-fitting engagement and are arranged in such a way that a material web to be processed can find room between them.
DE 195 35 602 A1 discloses a method and a device for producing honeycomb material from webs of an embossable material, such as cardboard, plastic or a lightweight metal. A material web is guided through a roller pair with profiling like a gear wheel to create a half honeycomb web. Furthermore, the web is pretreated by means of a pair of embossing rotors.
DE 10 2005 052 691 B3 describes a method and a device for producing a honeycomb structure, wherein corresponding strips of material are profiled by means of profiling rollers. To do so, the strips of material are passed between two opposing profile rollers, which have protrusions along their circumference, intermeshing with one another in a form-fitting manner. The material web is embossed with a periodic profile, for example, a regular trapezoidal profile, corresponding to these gear wheel-type protrusions.
The invention is based on the object of creating a drive structure for the forming means, so that the efficiency of a material web-forming operation can be increased. To solve this problem, the drive method defined in claim 1 and the drive arrangement, as defined in the other independent claim, are proposed. Expedient optional embodiments are derived from the dependent claims.
Since the forming means are each actively driven with their own dedicated drive means, these can be controlled and coordinated with one another, so that, in the wake of profiling and/or shaping the material web, the pressing of the material web between the forming means can also be accomplished at the same time in a manner that is both time-saving and component-saving and can always be adapted to the respective boundary conditions and requirements in a flexible manner. With the assignment of an independently activatable drive means to each of the forming means, their shaping torques can be varied in a targeted manner in the sense of a constant surface pressure, in particular in forming a honeycomb shape, if the drive means mesh with one another in a force-fitting and/or form-fitting manner. In particular the slave drive operates with a selected force or torque, such that the two forming means exert a predefinable pressing force on the material web passing between them. In particular the force and/or torque exerted by the slave drive on the forming means is/are selected, so that the pressing force creates a constant surface pressure on the material.
In many cases the web material can be processed with a certain water resistance. This is obtained due to the fact that the web material is impregnated with resin but is not saturated. With adequate pressure on the web material by means of the invention, the quality of special water resistance is not yet required in the finished product. Thus, for example, in the case of a honeycomb made of paper/paperboard, a moisture resistance can be created, such as that which could previously be achieved only with high-quality materials such as plastic, metal or CFRP (carbon fiber-reinforced plastics). The torque exerted by the slave drive on the forming means is selected so that the pressing force creates a constant surface pressure on the material.
With this invention, the material web can be shaped as well as pressed into a corrugated shape or any other shape between intermeshing forming means in one working step, so that its water uptake capacity is reduced. To do so, according to one embodiment of the invention, it is expedient for the drives of the forming means to be activated in such a way that the latter are braced against one another, optionally with the material web in between, to create the pressing force (cf. claim 2). In other words, the drives are activated in such a way that they press the forming means that are in force-fitting and/or form-fitting connection against one another. The forming means are driven in such a way that one drives the other or one brakes the other.
To effectively coordinate the forces or torques applied to the forming means by the drives, in particular to achieve a constant surface pressure on the material web, according to one optional embodiment of the invention, it is proposed that, of the drives, a first one is used as the master drive connected to the first forming means and a second one is used as the slave drive connected to the second forming means. In doing so, the slave drive is activated or operated as a function of or under the influence of a position value of the master drive and/or of the first forming means (hereinafter referred to as the “master position value”) (cf. claim 3). Thus, a respective torque setpoint value is preselected for the slave drive in relation to the position of the master drive and/or of the forming means activated by it. The slave drive thus generates its force or torque as a function of the (rotational) position (master position value) of the master drive and/or of the (first) forming means connected to it. In that the activation of the slave drive is linked to the master position value through this master/slave configuration, a correlation and/or a relationship of the forces or torques exerted by the slave drive can be implemented with the respective position of the master drive or of the (first) forming means thereby driven. It is thus possible to take into account specific locally varying shaping profiles between the forming means in implementation of a constant surface pressure.
In refinement of this embodiment of the invention, a force or torque setpoint value is assigned to the master position values, as a function of which or influenced by which the slave drive is triggered or operated (cf. claim 4). Therefore, if the master drive is in a rotationally fixed or motion-fixed connection to the first forming means assigned thereto, for example, in the manner of a direct drive, the position-variable deformation profile can be mapped on the forming means for the corresponding generation of a torque setpoint value for the slave drive and utilized. In this sense, a special embodiment of the invention consists of making the allocation between the master position values and the force or torque setpoint values according to a deformation profile, an external contour or some other geometry or topography of the forming means and/or in accordance with the pressing force to be generated per specification (cf. claim 5). In another embodiment of the invention, the force or torque setpoint values to be generated are predetermined for the slave drive, in particular its current regulator, as a control variable or command variable within the context of a control chain (open) or as the setpoint value within the context of a (closed) control loop (cf. claim 6).
The torque control value or setpoint value is usually applied to the slave drive and thus to the (second) forming means via a corresponding motor current flow. However, there are often mechanical transmission links, in particular gears or the like, between the drive and the forming means, which are installed between the electric drive and the forming means (for example, gear-type shaping wheels). Mechanical friction losses unavoidably occur in this process. As a remedy, according to an optional embodiment of the invention, it is proposed that the force or torque setpoint value should be linked to, precontrolled by or acted upon by an additional force and/or an additional torque, for example, added up, said force or torque setpoint being obtained by weighting or filtering a position value and/or a speed value of the drive master drive or of the first forming means (assigned to it) (referred to as the “master speed value”) with a predefined linear or nonlinear characteristic or function table (cf. claim 7). The profile of the characteristic line or the function table can be determined empirically, for example, on the basis of a measurement series, or approximated theoretically for compensation of the aforementioned friction losses or other losses in the mechanical transmission.
According to another variant of the invention, the slave drive is operated with the force or torque setpoint value as a guide variable in force or torque regulation, wherein the force or torque setpoint value is subject to a comparison with a force or torque actual value, measured on preferably at least one of the forming means (cf. claim 8). This achieves the advantage that loss moments caused by mechanical friction, for example, can be regulated out directly. Pilot control with an additional force and/or an additional torque is no longer absolutely necessary. Use of a PI regulator (proportional/integral regulator) is expedient to rule out the regulating difference; this regulator is subjected to a pilot control with the force or torque setpoint value as the basic setpoint value (cf. claim 9). The PI regulator need then only smooth out minor control deviations. The control dynamics can thus be improved through this pilot control.
According to another variant of the invention, the slave drive is operated in speed control and/or position control at a dynamic limit and/or torque limit that is preselected as a function of or influenced by the master position value and/or force or torque setpoint value (cf. claim 10). In electrical drive technology, it is known that a “torque and current limitation” function block can be assigned mainly to the speed control and/or rpm control, which serves to provide device protection, among other things. The slave drive, which is expediently a servo drive, regularly has a cruise control and/or rpm regulator with an integrating component. If there is constantly a deviation in the rotational speed, the cruise control and/or rpm regulator is driven to its dynamic limit (saturation) by means of its integrating component. This dynamic limit can be influenced and can be preselected. Within the context of the present invention, the variable dynamic limit and/or the adjustable saturation amount is expediently (also) set by means of the torque setpoint value. In a refinement of this idea, the rpm setpoint value and/or position setpoint value for the slave drive is generated as a function of the plus or minus sign or the direction of the force or torque setpoint value, such that the rpm and/or position setpoint value for the slave drive is greater than or less than the rpm and/or position setpoint value for the master drive (cf. claim 11). There is therefore always an rpm deviation beyond which the dynamic limit is reached. As already indicated above, it is within the scope of expedient design according to the invention to use a regulator in the speed drive, in particular a cruise control with an integrating component (I component) in such a way that the regulator is run to its torque limit (cf. claim 12). In the case of forming means that can be operated rotationally in particular, one variant of the invention, in which the master drive and/or the slave drive is/are operated alternately in generator mode or in motor mode, basically so they are complementary to one another, depending on their instantaneous (rotational) position, with the forming means brought into engagement. This is true pending any friction losses. The transition from motor operation to generator operation does not take place obligatorily but instead depends on whether the force resultant on the slave wheel as the forming means, acting against the direction of rotation is greater or smaller than the pressing force required in the process technology. It may thus happen that the slave wheel operates as a motor for a complete cycle because of the friction conditions.
To generate the aforementioned tension between the forming means, they and/or the master drive and slave drive operate more or less “against one another.” What this means for the slave drive, for example, is, firstly, that it operates as a motor drive, i.e., it provides more drives than the master drive. Secondly, after rolling along half a gearing period of rotational forming means with a gear wheel-type shaping profile, the slave drive decelerates the master drive, which results in generator operation for the slave drive. This is true similarly of other types of shaping profiles of other types (not of the gear wheel type) but nevertheless periodic in the case of forming means that can be operated rotationally and/or translationally. From this standpoint, one expedient variant of the invention consists of activating the drives with different and/or opposing or directed torque-position setpoint values and/or speed setpoint values (cf. claim 14), so that the forming means that are in engagement exert forces and/or torques against one another. The aforementioned tension can be achieved, for example, by the fact that one of the drives can always be allowed to run somewhat faster or further in terms of position than the other, which is adjustable by means of oppositely directed setpoint values, with the possible consequence that setpoint values that cannot be achieved are preselected for the slave drive.
According to an embodiment of the invention, as mentioned above, the defined torque is made as a function of the “master position” so the goal is for this master position to be always available in a functional and targeted manner. This is taken into account in one embodiment of the invention such that the drive(s) is/are designed and/or operated so that the master drive always achieves its stipulation with respect to position, speed, force and/or torque despite the tension on the forming means (cf. claim 15). This requires a master drive that is capable of retaining its position or speed even when the slave drive acts with a driving or decelerating force against the master drive.
According to one embodiment of the invention, the economic aspect of the production and storage when the same types of motors with the same power rating are used for both the master drive and the slave drive. Thus, drives of the same maximum power, force and/or torque potential are used, but without limiting and/or exhausting the maximum power, force and/or torque potential of the slave drive in the control technology with respect to or in comparison with those of the master drive (cf. claim 16). On the other hand, it is also within the scope of the invention for the slave-forming means, i.e., the following forming means, to select a smaller (slave) drive if both the master drive and the slave drive are to be utilized 100%. The master drive is expediently operated, so that it can develop its torque 100%. The torque developed by the slave drive must then be smaller in order not to impair the generation of a functionally correct master position value. A corresponding adjustment and/or limitation for the slave drive can be achieved by scaling a characteristic line link/an electronic cam for conversion of the master position value into a force and/or torque setpoint value (see below) for the slave drive. However, full utilization of the slave drive to generate a maximum force and/or its maximum torque can be prevented not only by means of a direct force or a default torque but also by means of a force or torque limitation (see above). In the sense of the embodiment of the invention, this predetermination of the force and/or torque setpoint characteristic either acts on the force or torque limitation or acts directly as a torque setpoint value for the slave drive (omitting a speed control/rpm regulator and position regulator).
A drive configuration suitable for performing the drive method according to the invention in particular, wherein this configuration is equipped with two forming means that are arranged in such a way that they can be brought into a force-fitting and/or form-fitting engagement with one another, is characterized by the following: The forming means can each be controlled and coordinated with its own electric servo drive or some other electric drive; the aforementioned servo drives or electric drive can be controlled and coordinated by a (higher level) control or guiding device; the control device is equipped and designed in terms of the circuitry and/or programming to activate the electric drives to apply tension to the forming means against one another (cf. claim 17). This configuration implies that the forming means are arranged with a predetermined distance between them, depending on the thickness of the material web to be processed, to form opposing contact surfaces and pressing surfaces and/or a passage gap for the material web arranged in between.
According to one variant of the invention, the electric drives are configured as master drives and as slave drives following the former and/or dominated by the former. The control unit therefore comprises a source for making available a master position value, and a linear or nonlinear characteristic line member connected to the source for converting the master position value into a torque setpoint value. The latter can be supplied to control means of the slave drive for processing and implementation (cf. claim 18). The characteristic line member may be stored, for example, in a memory region of the control unit, for example, as a function table in which the respective torque setpoint values are assigned to master position values. In a further embodiment of this variant of the invention, the characteristic line member is designed with a function curve and/or as an allocation table and/or as an electronic cam disk, which corresponds to a shaping profile, optionally with curves or some other geometry or topography of the forming means (cf. claim 19). In this embodiment, in the case of shaping means that resemble gear wheels or are otherwise rotationally symmetrical the resulting periodicity of the shaping profile at the circumference can expediently be imaged in the manner of a cam disk. A change in the pair of forming means can be taken into account by replacing the electronic cam disk and/or the characteristic line member.
For compensation of friction losses, as already mentioned above, it is expedient to have a pilot control for the torque setpoint value accordingly. This is served in particular by the design according to the invention, in which the control unit comprises a summation member upstream from the control means of the slave drive and which is connected to the output of the torque setpoint value characteristic line member and the output of another torque characteristic line member, which serves in particular to compensate for the friction losses between the forming means (cf. claim 20).
In another design according to the invention, the control unit comprises a regulating member and a setpoint/actual value comparator upstream from the input of the control member. The setpoint/actual value comparator is connected at the input end to the torque setpoint characteristic line member and to a torque actual value source. The control member output is sent to the control means of the slave drive (cf. claim 21). The torque actual value can be measured on the forming means connected to the master drive or the slave drive. In this design, measures or means for friction compensation are no longer necessary because any friction losses can be detected and regulated out by taking into account the actual value of the torque. However, the complexity of a torque measurement must be taken into account.
According to another embodiment of the invention, the control unit comprises a direction detector downstream from the torque setpoint value characteristic line member, additionally comprising more or less a plus or minus sign filter and a setpoint value generator for the position and/or speed of the slave drive. The setpoint value generator is connected at the input to the aforementioned master position value source and to the output of the direction detector (plus or minus sign filter) and is adjusted or designed through the program and/or circuitry to generate a speed and/or position setpoint value for the slave drive as a function of the input variables, wherein the slave drive is larger than or smaller than the master drive (cf. claim 22). In this design, it is advantageous that the usual control structure can continue to be used with no change in the preferred design of the slave drive as a servo drive, with the limiting member with the position, rpm and current regulators, optionally with the rpm and current regulators connected in between.
Additional details, features, combinations of figures, effects and advantages based on the invention are derived from the following description of preferred exemplary embodiments and the drawings, in which:
a-h show axial views of individual shots of the torque curve during one tooth pitch.
According to
According to the drive method variant illustrated in
The resulting torque on the tooth flanks of the forming wheels 1, 2 can be falsified in some cases due to friction (e.g., in a gear between the drive wheel and the forming wheel) in the drive train of the slave wheel 2, especially since the torque of the slave wheel 2 acts in the direction of rotation 5 or opposite that direction depending on its tooth flank, which is currently applying pressure. The driving torque would be reduced by the amount of the friction losses and the decelerating torque would be increased accordingly. Therefore according to
As an expedient and to increase the function accuracy, a torque actual value feedback is implemented in the exemplary embodiment according to
According to
The following explanation is given for the mechanism of action of the present invention on the basis of the torque curve during one tooth pitch p according to
According to
According to
According to
e through 5h illustrate how the surface pressure and/or tension is applied. Oppositely directed normal forces FN occur on the opposing tooth flanks of the master wheel 1 and the slave wheel 2, such that the material web 3 can be pressed between them. As in
It is advantageous if the tooth flanks 6 are provided with convex curvatures so that the contact surface and the required pressing force and/or tension can be minimized. There is therefore a dynamic range, which is not too large for the torque setpoint value stipulation and/or the torque limit. Actual saturation limits can be taken into account.
Because of the additional method of manufacturing the corrugated material web 3 and honeycomb structures, reference is made to the older patent application PCT/EP2012/062241 by the same applicant, which was published subsequently.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2012/073612 | 11/26/2012 | WO | 00 |