DE102004047441A1 - Linear axle for industrial facilities has crank rocker mechanism with rotary electric motor powered by inverter, which provides motion for tools with constant speed with exemption of small area around reversal point of movement direction - Google Patents

Abstract

The linear axle has crank rocker mechanism drive whereby crank rocker mechanism has a rotary electric motor (S) powered by the inverter. A tool (1) is provided which is movable to and fro by means of crank rocker mechanism. The inverter is operated in such a manner that the to and fro motion takes place with constant speed with the exemption of small area around reversal point of movement direction. An independent claim is also included for the method for operation of electric motor.

Description

The The invention relates to a linear axis and a method.

In Production plants are so-called flying saws implemented in such a way that a rotary movement of an electric motor to a linear movement is implemented. The path on the linear axis is proportional the angle at the engine. At the end of the linear trajectory, the Direction of rotation of the drive can be reversed to the flying saw again to bring them into their original position.

1 shows an electric motor S, which drives a chain on the tool 2 is provided. This has a working direction perpendicular to the direction of movement and can therefore change the delivery of the tool in this direction to the workpiece, in particular drive the tool into the workpiece. Thus, the workpiece is machinable, for example sawed, cut off or drilled.

The workpiece itself is driven by a drive M in the direction of movement. The drive M and the electric motor S are operated synchronously, wherein the drive M is operated as a master and the electric motor as Slave tracked to the master.

Of the Invention is therefore based on the object, a linear axis and to develop a method using cost-effective mechanics should be and at least equal manufacturing quality achievable should be.

According to the invention Task with the linear axis according to claim 1 and in the method solved according to the features indicated in claim 8 or 9.

Essential features of the invention in the linear axis are that the linear axis comprises a crank arm drive,
wherein the rocker arm comprises a rotary electric motor S powered by an inverter,
wherein a tool is provided for reciprocating by means of the rocker arm,
wherein the inverter is operable to make the reciprocating motion at a constant speed except for small areas around the movement direction reversal points.

From The advantage here is that a rocker arm is used. These is that a cost-effective mechanical design compared to a chain drive that also works against pollution susceptible is, has a low life and high maintenance costs.

The fly according to the invention Saw, at the the slave axis over a rocker arm is driven, is mechanically simple and cost-effective produced. It has a non-linear traversing profile, resulting from the rocker arm function, and is due to the overlay an "electric" cam function Compensated in the frequency converter. This procedure is very simple technically fast and inexpensive executable.

• – Durch eine günstige Hebelstellung im Startpunkt kann vorteiligerweise mit geringem Motormoment aus der Ruhelage der Fliegenden Säge gestartet werden.
• – Die Drehrichtung muss zum Rückpositionieren der Fliegenden Säge nicht gedreht werden.
• – Das Trägheitsmoment der mechanischen Teile ist gering, insbesondere im Vergleich zum Stand der Technik.
• – Das lineare Verfahrprofil ist nicht proportional zum Winkel am Abtrieb!

The rocker arm offers the following differences with respect to the prior art:

• - By a favorable lever position in the starting point can advantageously be started with low engine torque from the rest position of the flying saw.
• - The direction of rotation does not have to be turned to reposition the flying saw.
• - The moment of inertia of the mechanical parts is low, especially compared to the prior art.
• - The linear travel profile is not proportional to the angle at the output!

Especially exists in the construction of the possibility to shorten the Repositioning, because of the plant geometry, depending on the design of a small Angle at the output the complete return path at the linear axis can correspond.

through The invention is a flying saw feasible because a synchronous drive between Master and Flying Saw is provided.

By the use of the fast and easy to enter electronic Cam in the frequency converter, which has an integrated positioning controller includes, non-proportionality is between Output angle and path on the linear axis can be compensated.

The Movement of the uncompensated linear axis is as a function of the angle determined at the output and thus an associated transfer function. The curve the electronic cam is such from its inverse function determinable that the proportionality of the web speed of the master and the slave drive can be produced.

The electronic cam is quick and easy from the regulation, also cost-effective workable, in particular by the use of a system bus for data exchange between the master and the slave drive.

at an advantageous embodiment cover the small areas less than 15% of the total linear motion range and are to Acceleration or braking of the tool provided. Advantageous is doing that the inverse transfer function no over the entire range of the linear axis must be used but in terms of simple control technology by means of predeterminable acceleration ramps limited starting distances are foreseeable, ie after reversing the direction of movement, nominal values, as target position with target speed, can be specified.

at According to an advantageous embodiment, a workpiece is parallel in a direction of movement movable to reciprocate the tool, wherein the workpiece of a electric drive M is driven. The advantage here is that the tool the workpiece in the same way as when both drives are at rest would. Especially the delivery of the tool to the workpiece is changed for processing.

at An advantageous embodiment is by means of a control device the electric motor S as slave the state values of the electric Tracked drive M, So the speed values and / or the position values. From The advantage here is that a quick and easy to implement Rule structure is applied.

at According to an advantageous embodiment, the workpiece is a strand, such as for example Clay strand, metal strand or plastic strand, and the tool includes at least one cutting edge, a knife and / or a drill. The advantage here is that the invention in extrusion machines and machines that produce a strand of material can be used. So the invention is also applicable to continuous casting machines.

at An advantageous embodiment is the regulation of the electric motor S in the housing the electric motor is integrated and is connected to the electric Drive M connected to the data exchange, in particular via a Bus system, such as firmware bus, system bus or the like. Is an advantage doing that, the transferable Data rate and thus the quality the regulation is very highly predictable.

Essential features of the invention in the method for operating an electric motor are that a mechanism for generating a linear movement is provided,
wherein at constant speed of the electric motor, the linear velocity is not constant,
wherein the rotational speed of the electric motor S is controlled such that the linear movement has constant velocity in at least one region.

basics Features of the invention in the corresponding method of operation an electric motor for a rocker arm drive are that the rocker arm to the drive a linear axis is provided, wherein the rotational speed of the electric motor S is controlled such that the linear movement a reciprocating motion with constant speed is except for small areas around the movement direction reversal points.

From The advantage here is that by means of controllable drives, in particular From a converter controllable drives, functions are considered, which correspond to a mechanical cam and fast and easily taken into account by the regulation and are workable.

at an advantageous embodiment is an inverse motion profile used in the rules. The advantage here is that mechanically generated transfer functions can be compensated by functions in the electronic control, so no complicated but simple and inexpensive mechanics is usable, their undesirable Behavior of the regulation is electronically wegregelbar.

at an advantageous embodiment of the electric motor as a slave a drive for a workpiece, provided as master, tracked, especially both Drives are connected for data exchange. It is advantageous that at speed fluctuations of the master drive, so too of the workpiece, the tool is still synchronously moved in parallel and similar, both web speeds are thus operated synchronously. Important So it's not the constant speed of the tool the speed in sync with the speed of the workpiece.

• – der Geschwindigkeitsverlauf als Funktion der Zeit oder des Ortes bestimmt unter der Voraussetzung, dass die Drehzahl des Elektromotors S konstant ist,
• – dann wird die Umkehrfunktion dieses Verlaufs bestimmt,
• – der Sollwert der Drehzahl des Elektromotors S wird gemäß der Umkehrfunktion vorgegeben.

In an advantageous embodiment is

• The speed profile as a function of time or location is determined on condition that the speed of the electric motor S is constant,
• - then the inverse function of this course is determined,
• - The target value of the rotational speed of the electric motor S is specified according to the inverse function.

In an advantageous embodiment, setpoint values for time or location are supplied by the drive M for the workpiece and the inverse function determined as a function of these predetermined setpoint values for determining the setpoints for the speed specification for the electric motor S. It is advantageous that the embodiment by means of an inverter easy and fast realization with integrated positioning control bar is.

Further Advantages emerge from the subclaims.

1

workpiece

2

Tool

M

Master drive

S

slave drive

In the plant according to the invention is a workpiece 1 driven by a master drive M on a first trajectory.

The tool 2 is driven by a slave drive S on a second trajectory, which is uniformly shaped to the first, is provided in particular displaced parallel.

If now the tool 2 synchronous to the workpiece 1 is traversed on its trajectory, the workpiece is machined as if both drives would rest.

through working in progress is a greater material flow and higher Rationalization and productivity the plant accessible.

The slave drive S comprises a rotary electric motor which can be produced inexpensively. To generate the trajectory movement, a mechanical device is provided. However, in the case of the invention, this is embodied such that, given a constant speed of the electric motor, a non-constant path speed of the tool 2 is generated on its trajectory.

to Generation of a synchronous movement speed, ie constant Web speed, the electric motor of the slave drive S of an inverter supplied with electrical power such that the rotational speed of the electric motor is changed in a suitable manner. This change is according to a Function specified, which determines as the inverse function of that transfer function which turns out to be the velocity course, if the electric motor would be operated at a constant speed.

When Default in the rules are the information provided by the master drive about speed, Time and / or space coordinates of the master drive taken into account.

For example is from the position of the master drive by means of the inverse function a preset speed value determined.

Instead of The mentioned speed curves is also a transfer function usable, which the positions of the master drive the positions assigns the slave drive accordingly, so again driving through the trajectory of the slave drive can be reached at a constant speed is.

example for one Such mechanical device is a rocker arm or a Cyclo disk, so not centric driven by the electric motor Disk on whose circumference the tool is attached, or a chain drive, wherein the sprocket driven by the electric motor is non-circular. Even drives with cams are possible here.

The The invention refers to trajectories that are straight or curved Curves are or include both components mixed.

The Invention will now be explained in more detail with reference to figures for a specific example, whose Generalization for the expert is obvious:

2 shows an electric motor S, which drives a circular disc, at the periphery of a rod is fixed, which is the tool 2 drives, which is guided on a predetermined path forced. This has a working direction perpendicular to the direction of movement and can therefore change the delivery of the tool in this direction to the workpiece, in particular drive the tool into the workpiece. Thus, the workpiece is machinable, for example, be cut off or drilled.

The workpiece itself is driven by a drive M in the direction of movement. The drive M and the electric motor S are to be operated in such a way that during operation of the drive M as the master of the slave electric motor a constant speed of the tool relative to the workpiece achievable is.

To the slave drive is controlled by the control included in the inverter tracked to the master, using an inverted transfer function becomes.

The transfer function itself represents the relationship between coordinates of the slave drive, so the Linear axis, and coordinates of the master drive.

During operation, it is sufficient that the Mas terantrieb the coordinates are transmitted to the slave drive and provided by the inverter for determining the desired coordinates for the slave drive, wherein the inverse transfer function is applied.

Instead of the coordinate-dependent Control can also speed-dependent control in other embodiments of the invention be used. The transfer function of the constant Rotational speed of the slave drive in the speed of the Tool and then the inverse transfer function, ie inverse function, certainly. This is then applied again by the regulation.

at of course, a reciprocating motion will be in acceleration and deceleration areas around the movement direction reversal points from the aforementioned regulatory principles, in particular the use an inverse transfer function, departed.

at Use of angle encoders connected to the electric motors is the regulation with very high quality executable.

at further embodiments of the invention At least one of the drives has no encoder. Nevertheless, it is the inventive method feasible because in the control of the corresponding inverter from the measured motor currents and corresponding to at least one measured voltage value of the drive Angle values can be determined. The regulation indicates appropriate Software on. Thus, encoderless drives can be used without size losses at control quality.

Claims (13)

Linear axis, which comprises a crank arm drive, wherein the rocker arm comprises a supplied by means of inverter, rotary electric motor S, wherein by means of the rocker arm, a tool is provided linearly reciprocable, characterized in that the inverter is operable so that the reciprocating motion with constant speed occurs with the exception of small areas around the movement direction reversal points. Linear axis after at least one of the preceding ones Claims, characterized in that the small areas are less than 15 Cover% of the total linear motion path and for acceleration or braking of the tool are provided. Linear axis after at least one of the preceding ones Claims, characterized in that a workpiece is parallel in a direction of movement is movable for reciprocation of the tool, wherein the workpiece is driven by an electric drive M. Linear axis after at least one of the preceding ones Claims, characterized in that by means of a control device of Electric motor S as a slave to the state values of the electric drive M tracked , ie the speed values and / or the position values. Linear axis after at least one of the preceding ones Claims, characterized in that for machining the workpiece of the Distance of the tool to the workpiece variable is. Linear axis after at least one of the preceding ones Claims, characterized in that the workpiece is a strand, such as clay strand, Metal strand or plastic strand, and the tool is at least a cutting edge, a knife and / or a drill includes. Linear axis after at least one of the preceding ones Claims, characterized in that the control of the electric motor S in the housing the electric motor is integrated and with the electric Drive M is connected to the data exchange, in particular via a Bus system, such as firmware bus, system bus or the like. Method for operating an electric motor, the provided by means of a mechanism for generating a linear movement is wherein at constant speed of the electric motor, the linear Speed is not constant, characterized, that the speed of the electric motor S is controlled in such a way that the linear movement in at least one area constant speed having. Method for operating an electric motor for a Rocker arms drive, wherein the rocker arm is a linear axis operates, characterized in that the speed of the Electric motor S is controlled such that the linear motion a Float with constant speed is except for small areas around the movement direction reversal points. Method according to at least one of the preceding Claims, characterized in that an inverse motion profile in the rules is used. Method according to at least one of the preceding gone claims, characterized in that the electric motor is a slave as a drive for a workpiece, which is provided as a master, tracked, in particular so both drives are connected for data exchange. Method according to at least one of the preceding Claims, characterized in that - the speed course is determined as a function of time or place, provided that that the rotational speed of the electric motor S is constant, - then Reverse function of this course is determined - the setpoint the speed of the electric motor S according to the inversion function specified becomes. Method according to at least one of the preceding Claims, characterized in that the setpoint for time or location of the drive M for that workpiece be delivered and the inverse function as a function of this predetermined Setpoint values are determined for determining the setpoint values for the speed specification for the Electric motor S.