EP3583476A1

EP3583476A1 - Method for designing and machining a gear, and corresponding processing machine and software

Info

Publication number: EP3583476A1
Application number: EP18700653.1A
Authority: EP
Inventors: Vogel OLAF; Thomas Schenk
Original assignee: Klingelnberg AG
Current assignee: Klingelnberg AG
Priority date: 2017-02-16
Filing date: 2018-01-11
Publication date: 2019-12-25
Also published as: DE102017103115A1; WO2018149565A1; CN110300936B; CN110300936A; JP2020507485A; US20190391555A1

Abstract

The invention relates to a method (200) for designing and machining a gear, having the following steps: a) designing (S1) a gear to be produced in a software-based computer-aided manner in order to obtain a function-oriented geometry (fG) of the gear, b) using a software-based computer-aided method (S2) for ascertaining a theoretically producible gear geometry which corresponds to the function-oriented geometry (fG) or which is used as an approximation of the function-oriented geometry (fG), c) providing production data (PD) which represents the theoretically producible geometry, d) machining (S3) a gear using the production data (PD) in a CNC-controlled processing machine (50), e) measuring (S4) the gear in order to obtain an actual data set (ID), f) carrying out a comparison (S5) of the actual data set (ID) with the production data (PD) in order to ascertain at least one correction variable (ΔΡD), g) using (S6) the correction variable (ΔΡD) in order to ascertain corrected production data from the production data (PD) or in order to carry out a machining correction in the processing machine (50), and h) post-machining the gear using the machining correction or using the corrected production data in order to machine at least one additional gear in the processing machine (50).

Description

METHOD FOR EQUIPPING AND WORKING ON A GEAR WHEEL, AND CORRESPONDING MACHINE AND SOFTWARE

The invention relates to a method for the automated design and processing of gears. The invention also relates to a corresponding processing machine and software.

BACKGROUND OF THE INVENTION

There are numerous calculation, processing and documentation steps between the first design of a gear wheel or wheelset pair and the finished wheelset.

The production of a gear typically begins with the arithmetical interpretation, which is based on specifications such as a customer. There are a variety of approaches here, which ultimately make all a setpoint record or a neutral record available. This data record is then typically loaded into a processing machine. The processing machine converts the data record into machine data and the processing of a gear workpiece is based on the machine data. If the gear thus produced does not conform to the original design, corrections are made to the process and another gear is produced. Today's production and machining processes are becoming more complex and the requirements in terms of accuracy are increasing. In addition, especially for the single-part or small-lot production, the aim is to produce as little or no waste as possible.

It is an object of the invention to provide a robust method which makes it possible reliably and efficiently to design and manufacture a gearwheel or wheel set pair. The object is achieved by a method according to claim 1.

Advantageous embodiments are the subject of the dependent claims.

The invention also relates to software or software modules adapted to execute the method of the invention on a computer. Such a software module can, for. B. be part of a modular program system for a user-friendly application on the computer platform of the customer.

The method of the invention is designed as a software-based, computer-aided method that operates largely autonomously.

However, in preferred embodiments, the method may involve a user to the extent that this e.g. make inputs on a screen and / or influence a selection of tools.

The invention is based on a design method (also called dimensioning or design phase), which is suitable for specifying a function-oriented geometry of a gear to be produced, or a wheelset. In the following, only a single gear Z is always mentioned, whereby the invention can also be applied to wheelsets. The design method is preferably a purely theoretical, mathematical definition of the gear with or without modifications. Preferably, this design is done using customer specifications. In addition, the invention is based on a method for the definition of a theoretically producible geometry of the gear, this method starting from the function-oriented geometry or builds on the function-oriented geometry.

The definition of the theoretically producible geometry is preferably carried out in all embodiments, taking into account the available processing machines and / or the available tools or tool systems (e.g., cutter heads that can be equipped with different bar knives).

The invention is based quasi on a separate treatment of design-relevant (theoretical) aspects and production-relevant, kinematic (practical) aspects.

It then takes place according to the invention, the production (processing) of at least one gear on the basis of nominal or neutral data (here generally referred to as production data), which were passed to the machine. The desired data were previously derived or determined from the definition of the theoretically producible geometry of the gear.

After the production of the at least one gear, a measurement of the gear is made, wherein actual data are determined, which are then compared with the desired data.

In this way, preferably at least one correction variable can be determined, which can then be used to intervene in the processing machine and / or to calculate adjusted production data. This adjusted production data may then be used, for example, for the production of another gear (e.g., a small series).

The invention thus relies on a method which comprises a plurality of process modules or processes which intermesh to build a robust process chain from design to production that enables the production of high quality gears. The invention sets in preferred embodiments to the targeted selection of a suitable tool and the definition of a suitable machine kinematics of a multi-axis, CNC-controlled machining machine for machining a gear. Preferably, the machine kinematics are determined as part of a computer-based manufacturing or processing simulation.

Preferably, the software-based, computer-aided method for determining a theoretically producible geometry of the gear is used so that it takes into account kinematic aspects of both a tool and a machine tool. That All kinematic relationships are preferably determined here.

The invention is in preferred embodiments to the use of existing tools, instead of using modified tools or even need to modify tools.

It is an advantage of the invention that largely existing tools can be used. In the case of dressable abrasive tools, another advantage of the invention lies in the fact that a standard dressing method can be used to dress existing tools. Unlike in the prior art, neither modified tools nor appropriately modified dressing methods are used here. The invention enables, inter alia, the production of gears with a tooth geometry and / or surface structure of the tooth flanks (in the sense of the topology of the tooth flanks), which largely corresponds to the original design. The method of the invention makes it possible to select a suitable tool for use in a suitable tool Machining machine to produce a gear with a Verzahnungsgeometrie and / or surface structure that comes as close as possible to the function-oriented geometry that was defined in the context of a design.

According to the invention, in the design, d .h. when determining a function-oriented geometry, also modifications of the tooth flanks (for example, flank crowning, final return, and the like) may be specified, e.g. B. may be necessary to pair the gear with another gear in the desired manner as Radsatzpaar. The method of the invention helps to provide the most efficient way to produce such a gear, but always a gear is produced, which is considered to be the best possible approximation of the theoretically given gear. This is because the theoretically manufacturable geometry of the gear used to provide the production data differs from the function-oriented geometry, and the actual data on the gear produced again deviates from the production data.

The invention makes it possible to find a method that allows robust and reliable production / processing of a gear that matches as possible within narrow tolerances with the function-oriented geometry.

The invention can be applied to CNC machines that have at least 5 CNC-controlled axes. In particular, the invention can be applied to milling (e.g., diagonal hobbing), peeling (e.g., skiving), or grinding (e.g., diagonal skiving) gears. The invention can be applied both to individual methods and to continuous sub-methods.

Preferably, within the scope of the invention, a CNC-controlled processing machine is used, which is designed as a neutral data machine. The invention may, for. B. in connection with a Wälzschleifmaschine according to EP3034221 AI, a Wälzschälmaschine according to EP2520390 AI or a universal machine according to WO2007012351 AI be used.

Preferably, the software and / or the computer on which the software is installed, for example, an interface to the processing machine, and / or the software can be installed on a processing machine.

In particular, a processing machine adapted for use of the invention is thereby adapted by the software according to the invention.

Preferably, the invention is used in a manufacturing environment which, in addition to the CNC-controlled processing machine and a precision measuring device, e.g. a tool station (possibly with Werkzeuginstellgerät) includes.

The invention enables the rapid and targeted development of gears or wheelsets, as well as the immediately following production.

The invention makes it possible to ensure a high level of quality and to keep the rejection rate low. In addition, the approach of the invention is robust and thus guarantees high process reliability.

DRAWINGS

Embodiments of the invention will be described in more detail below with reference to the drawings.

FIG. Fig. 1A shows a schematic view of the method of the invention; FIG. Figure 1B is a parallel schematic view of the flow diagram of the method of the invention; FIG. Figure 2 is a schematic view of a substep of the method of the invention;

FIG. 3A shows a schematic view of a further substep of FIG

Method of the invention;

FIG. FIG. 3B is a schematic view of another substep of FIG

Process of the invention.

DETAILED DESCRIPTION In the context of the present specification, terms are used which are also used in relevant publications and patents. It should be noted, however, that the use of these terms is for the convenience of understanding only. The inventive idea and the scope of the claims should not be limited by the specific choice of the terms in the interpretation. The invention can be readily applied to other conceptual systems and / or fields. In other fields the terms are to be applied mutatis mutandis.

This is a method for laying out and processing or producing a gear Z, which comprises a plurality of intermeshing substeps or processes. Basic aspects of the invention will first be described in connection with FIGS. 1A and 1B. Fig. 1A shows a schematic diagram for machining a gear Z. To be specific, the method starts from a blank or a gear workpiece. In the following, however, there is always talk of a gear Z, so as not to complicate the description. FIG. 1B shows in a parallel representation a highly schematized flow diagram which shows the essential steps in the form of individual (procedural) blocks. In a first step Sl, the software-based, computer-aided design of a gear Z to be produced takes place. The aim of step S1 is to provide a function-oriented geometry fG of the gear Z. In FIG. 1A is indicated that step Sl z. B. by software SW1 can be executed or supported, which is installed and executed, for example, in a computer 10.1 with screen 12.1.

In FIG. 1A is symbolized by an arrow 201 that the function-oriented geometry fG is passed to the next step S2 (eg to a software SW2).

In a second step S2, the software-based, computer-aided determination of a theoretically producible geometry THG of this gear Z. The second step S2 is based on the provided function-oriented geometry fG.

The aim of step S2 is to provide a geometry thG which corresponds to the function-oriented geometry fG or which is to be regarded as an approximation of the function-oriented geometry fG. In general, there will always be a difference between the function-oriented geometry fG and the theoretically producible geometry thG. In Fig. 1A, it is indicated that step S2, e.g. can be executed or supported by software SW2, e.g. is installed in a computer 10.2 with screen 12.2 and is executed.

The steps S1 and S2 can be performed in all embodiments but also on the same computer 10, in a computer network and / or with one and the same software SW. Preferably, the software SW in this case comprises two correspondingly designed software modules SW1 and SW2.

As a result of the second step S2, production data PD may be provided and e.g. B. be transferred to a processing machine 50, as shown in FIG. 1A symbolized by an arrow 202. These production data PD represent the theoretically producible geometry thG. That is, the theoretically producible geometry thG is included in these production data PD or is mapped by the production data PD. The production data PD can in all embodiments in addition to the theoretically producible geometry thG still include:

- the tool data,

- the machine kinematics (incl. required dressing kinematics),

- the target measurement data.

The term "production data PD" is used here to take account of the fact that, depending on the provider of the software, manufacturers of the processing machine 50 and, depending on the user, different data sets and / or standards are used for communication purposes [0045] In a further step S3, the actual machining of a toothed wheel now takes place in the processing machine 50. As a result, the processing machine 50 provides a toothed wheel, which is designated here by the reference symbol Z *, since there are always deviations between the gear Z, which was originally intended to be produced, and the currently produced gear Z * (eg due to production inaccuracies), a CNC-controlled processing machine 50 is preferably used in this step.

In a further step S4, the toothed wheel Z * is then subjected to a measurement which is carried out in the processing machine 50 or e.g. is performed in a separate measuring machine 20. In Fig. 1A, such a separate measuring machine 20 is shown by way of example. The transfer of the toothed wheel Z * is symbolized in FIG. 1A by an arrow 203. The aim of the measurement of the gear Z * is the provision of an actual record ID.

In a further step S5, the production data PD is set in relation to the actual data record ID. Preferably, a comparison is made individual production data PD with individual data of the actual data record ID to detect deviations and to determine at least one correction value ΔΡϋ. In FIG. 1A, the production data PD relating to the actual data ID is set by a software SW3. For this purpose, the production data PD (see arrow 204) and the actual data record ID (see arrow 205) are transferred to this software SW3. In a further step S6, the correction quantity / n ΔΡϋ is either used to intervene in the processing machine 50 (see arrow 206) or to determine corrected production data kPD (see arrow 207). The intervention in the processing machine 50 may, for. For example, in such a way that the processing machine 50 can make corrections during reworking of the same toothed wheel Z *, or that during the processing of a subsequent further toothed wheel, the machining takes place from the start in a corrected form.

If corrected production data kPD are to be determined, this can be done in all embodiments, for. B. by the (re) use of the software SW2, as Fig. 1A indicated. In this case, the corrected production data kPD are transferred via the connection 202 to the processing machine 50 and processing of at least one additional gear wheel takes place there.

In the following, further details of the method of the invention will now be described and further embodiments will be explained.

The invention sets in step Sl on a design method that is suitable to specify a function-oriented geometry fG of a gear Z to be produced, or a wheelset. In all embodiments, this is preferably a purely theoretical, mathematical definition of the gear Z with or without modifications (such modifications are sometimes referred to as corrections, although this term is not precise). Preferably, this interpretation is carried out in step Sl using input variables, such. For example, the number of teeth, diameter and tooth width, spiral and pressure angle, tooth height and tooth head height, tooth thickness, choice of tooth system, axis angle and misalignment for installation of the gears of a wheelset, specifications for power transmission of the wheelset to be produced, information on the translation, efficiency, noise behavior.

The input quantities can be e.g. in the form of customer specifications KV (eg in the form of a requirement profile for a wheel set). The use of customer specifications KV is shown in FIG. 2 represented by an input arrow pointing in the direction of the box Sl.

Instead of starting from customer specifications KV, or as a supplement to the customer specifications KV, step S1 can also be fed with the loading of a data set DS (for example, from another development environment). In Fig. 2, therefore, another optional input arrow DS is shown.

Alternatively or additionally, however, the required input variables can also be input to the system, as shown in FIG. 2 indicated by a keyboard 13.1. In connection with the design, for example, already existing software can be used in step S1, changes and extensions having to be made in order to adapt this software to the steps of the invention. Starting from input variables, a function-oriented geometry fG of the toothed wheel Z or of the wheelset is determined in step S1. For this purpose formulas F1 may be deposited in the software (see Fig. 2), or the formulas or a formula set may be loaded. One or more of the following partial steps can be carried out in the context of this design:

- Computational strength analysis (M l);

- determination of tolerances for production (M2);

- static and / or dynamic consideration (M3);

- mathematical optimization of the microgeometry (eg by edge modification) (M4);

- Zahnkontaktanalyse the two gears of the pair of wheels (M5);

- EaseOff synthesis (M6).

Preferably, in all embodiments, corresponding software modules M1 to M6 can be used in step S1, as shown in FIG. 2 indicated. The step Sl can be the function-oriented geometry fG z. B. passed directly to the subsequent step S2, as shown by the arrow 201, or the function-oriented geometry fG can be (intermediate) stored in a (central) database. In step S2, the invention is based on a method for defining a theoretically producible geometry thG of the gear Z, this method starting from the function-oriented geometry fG or building on the function-oriented geometry fG. The aim of this method is the provision of target data or neutral data (here generally referred to as production data PD), which can be transferred directly or indirectly (for example via a (central) database) to the processing machine 50.

Starting from the function-oriented geometry fG, the theoretically producible geometry thG of the toothed wheel Z or of the wheel set is determined in step S2. For this purpose, formulas F2 may be stored in the software (see FIG. 3A), or the formulas or a formula set may be loaded. The theoretically producible geometry thG can be determined, for example, by means of a numerical optimization method in which the Deviations between the theoretically producible geometry thG and the function-oriented geometry fG are minimized or that is applied in such a way that the deviations of the theoretically producible geometry thG from the function-oriented geometry fG lie within tolerances).

In FIG. 3B is indicated that in the context of step S2 tool data WD z. B. can be loaded from a database 11. This substep is optional. Preferably, in all embodiments, corresponding software modules M7 to Mx are used in step S2, as indicated in FIG. 3A.

Additionally, manual input of data or selection may be required in step S2, as indicated by a keyboard 13.2 in FIG. 3A.

Preferably, in step S2 in all embodiments for determining the theoretically producible geometry thG of the gear Z, a computer-based machining simulation, preferably in the form of an average simulation, is used.

At the end of the method for defining a theoretically producible geometry thG, production data PD are provided and stored and / or transferred to a processing machine 50, as symbolized by the arrow 202.

Optionally, at the end of the method for defining a theoretically producible geometry thG, a graphical representation can also be made (for example, as a scoring page) in order to inform the user of deviations of the theoretically producible geometry thG from the function-oriented geometry fG.

According to the invention, production-relevant details (eg the question of whether a single-part method or a continuous partial method is used is to be discussed) in the definition of theoretically producible geometry thG, since it is in this process step, among other things, kinematic aspects. These production-relevant details can z. B. in the form of individual software modules M7 to Mx or processed.

Preferably, all embodiments comprise at least one CNC-controlled processing machine 50 for machining the gear Z. Such a processing machine 50 may, for. B. implement the production data PD in suitable machine data, so that in the processing machine 50, the processing steps and axis movements run coordinated in time and space. The machining of the gear is summarized in FIG. 1B as step S3.

At the end of step S3, a gear Z * is transferred directly or indirectly (eg via an intermediate storage) to a measuring device 20 within the processing machine 50 or to a separate measuring machine 20, as shown in FIG. 1A. This transfer can be done manually, semi-automatically or fully automatically in all embodiments.

The measuring device 20 or measuring machine 20 is incorporated in the overall concept of the invention. All embodiments may be a fully automated or semi-automatic measuring device 20 or measuring machine 20.

From a database (e.g., a central production database), production data PD for measurement S4 (eg, for a topography measurement) is read. The actual data ID of the toothed wheel Z * resulting from the measurement S4 can be stored in an associated data record.

The method of the invention preferably performs a target / actual adjustment in all embodiments in step S5. Under use suitable parameters (eg tolerances previously defined in the context of the design Sl) can be transmitted to the processing machine 50 directly or indirectly (eg via a database or via the software SW2) the correction variables ΔΡϋ determined therefrom.

In practice, an individual data record is preferably maintained for each customer order in order to be able to handle the design, definition, processing and measurement process in a production-oriented manner that is free of any confusion. At the same time a complete documentation of all relevant process steps Sl - S6 is guaranteed.

For example, in all embodiments, two databases may be used, one using the databases for the development data (eg, fG and thG) and the other for the production data PD. The development data database may or may not be associated with the processing engine 50. The database of production data PD (i.e., target data and / or neutral data) is typically connected to the processing machine 50. The mentioned databases can all, or only partially, be reachable via a network.

With reference to FIG. 1A, further embodiments will be described. Between the two computers 10.1 and 10.2, or between the software SW1 and SW2, an optional feedback or interaction arrow Ww is shown. This arrow Ww indicates that under certain circumstances there may be a kind of iteration between steps S1 and S2. This will be illustrated by a simple example.

In step S1, a purely theoretical, mathematical consideration is made. Only the step S2 creates the reference to the practice. It is therefore entirely conceivable that in step Sl a function-oriented Geometry fG is developed, which turns out in step S2 as not at all or not economically viable to produce.

The step S2 can now offer the best possible approximation for the planned production. However, if this approximation does not meet expectations, e.g. corresponds to the customer, such an approximation must be discarded. In this case, the method of the invention may branch back to step S1 to allow the user to make corrections to the function-oriented geometry fG.

Also, the method of step S2, which is used to determine the theoretically producible geometry thG of the gear Z, may be designed as an iterative method to allow a user to select a first tool (eg from the tool database 11 in FIG 3B) and the theoretically producible geometry thG of the gear Z based on tool data WD of this first tool, and if the theoretically producible geometry thG is not suitable, allow the user to select a second tool and the theoretically producible geometry thG of Gear Z based on tool data WD to determine this second tool.

The step S2 may also offer in all embodiments the calculation of optimal tool data WD of a tool as an option. These optimal tool data WD describe a tool that would be optimal for machining (step S 3) of the gear Z based on the production data PD in the processing machine 50. The user can now assemble a tool based on the optimal tool data WD (eg by grinding bar knives and fitting a knife head with these bar knives, or dressing a grinding wheel or selecting a dressing tool), or he can, for example, a corresponding tool at a tool manufacturer in Give order. reference numeral

Computer / Computer / Processor 10.1, 10.2

Database / storage medium 11

Screen / Display 12.1, 12.2

Keyboard 13.1, 13.2

Measuring machine / measuring device 20

Processing machine 50

Method 200

Arrow 201, 202, 203, 204, 205

Correction variable APD

Record DS

Formulas Fl, F2

function-oriented geometry fG

Actual data record / actual data ID

corrected production data kPD

Customer specifications KV

Software modules Ml - M6, M7 - Mx

Production data PD

Method steps S1, S2, S3, S4, S5, S6, S7

Target data record (also neutral data) / SD

production data

Software SW1, SW2, SW3 theoretically producible geometry thG

Tool data WD

Interaction Ww

Gear Z, Z *

Claims

claims

A method (200) for laying out and machining a gear, comprising the steps of:

a) software-based, computer-aided design (Sl) of a

producing gear (Z) to obtain a function oriented geometry (fG) of the gear (Z),

b) applying a software-based, computer-assisted method (S2) for determining a theoretically producible geometry (thG) of the toothed wheel (Z), which corresponds to the function-oriented geometry (fG) or which serves as an approximation of the function-oriented geometry (fG), c) Provision of production data (PD), which theoretically

represent producible geometry (thG),

d) processing (S3) a gear (Z *) based on the production data (PD) in a CNC-controlled processing machine (50),

e) measuring (S4) the gear (Z *) to obtain an actual data set (ID),

f) performing a comparison (S5) of the actual data record (ID) with the production data (PD) in order to determine at least one correction variable (ΔΡϋ),

g) applying (S6) the correction quantity (APD) to the

Production data (PD) corrected production data (kPD) to determine or to make a machining correction in the processing machine (50),

h) reworking the gear (Z *) with the machining correction or applying the corrected production data (kPD) for machining at least one further gear in the processing machine (50).

2. Method (200) according to claim 1, with the following additional step:

- Providing tool data (WD) to this in step b) in the

Determining the theoretically producible geometry (THG) of the gear (Z) to consider. Method (200) according to claim 1, wherein the method in step b) for determining the theoretically producible geometry (thG) of the toothed wheel (Z) is designed as an iterative method to enable a user to select a first tool and the theoretically producible one

Geometry (thG) of the gear (Z) based on tool data to determine this first tool, and if the theoretically producible

Geometry (thG) is not suitable to allow the user to select a second tool and the theoretically producible geometry (thG) of the gear (Z) based on tool data of the second

Tool to determine.

Method (200) according to claim 1, with the following additional step:

Calculating optimal tool data (WD) of a tool that would be optimal for machining the gear (Z) based on the production data in the processing machine (50).

Method (200) according to claim 4, with the following additional step:

- Select a tool that matches the optimal tool data

corresponds or has comparable tool data.

Method (200) according to any one of claims 1-5, characterized in that in step b) for determining the theoretically producible geometry (thG) of the gear (Z), a computer-based machining simulation, preferably in the form of an average simulation is performed.

Method (200) according to any one of claims 1-5, characterized in that between steps b) and a) there is an interaction (Ww) which allows a user to at least partially re-run step a) to obtain an adapted one to obtain function-oriented geometry of the gear (Z).

Method (200) according to claim 7, characterized in that it is specially designed to determine the production data (PD) using an existing tool and an existing processing machine (50).

9. Method (200) according to claim 8, characterized in that the production data (PD) a practical machining strategy for the machining of the gear in step d) in the CNC-controlled

Specify processing machine (50).

10. Processing machine (50), which comprises a computer or with a computer (10.1, 10.2) or a computer network is connectable to perform the method (200) according to one of claims 1 to 9.

11. Software that is designed to be installed in a computer (10.1, 10.2) or a computer network that is connectable to a manufacturing environment, the at least one processing machine (50) for machining a gear (Z) and a

Precision measuring device (20), wherein the software, when executed, the steps of the method (200) according to one of claims 1 to 9 carries out.