EP4305368A1

EP4305368A1 - Method for the heat treatment of metal workpieces

Info

Publication number: EP4305368A1
Application number: EP22721361.8A
Authority: EP
Inventors: Steffen Frank; Heike Liebe
Original assignee: Aerospace Transmission Technologies GmbH
Current assignee: Aerospace Transmission Technologies GmbH
Priority date: 2021-04-16
Filing date: 2022-04-08
Publication date: 2024-01-17
Also published as: WO2022218829A9; DE102022108510A1; WO2022218829A1

Abstract

The invention relates to a method for the heat treatment of metal workpieces (WB), in particular transmission components, wherein preferably carburized metal workpieces (WB) are introduced into a means (TK) for heating workpieces and are heated therein, wherein the means (TK) for heating workpieces is in the form of a continuous furnace and wherein workpieces (WB) are introduced into the continuous furnace through a first opening apparatus (1) and into a heating portion (TKH) of the continuous furnace for heating, wherein workpieces (WB), after being heated, are transferred to an outlet portion (TKO) which can be sealed off from the heating portion (TKH) and are kept warm therein at a defined temperature, wherein workpieces (WB), after being kept warm, are discharged from the continuous furnace through a second opening apparatus (2) which is different from the first opening apparatus (1), wherein workpieces (WB), after being discharged, are introduced into a means (PQ) for hardening.

Description

Process for the heat treatment of metallic workpieces

The invention relates to a method for the heat treatment of metallic workpieces.

The heat treatment of metallic workpieces is known from the prior art. The well-known basic principle of heat treatment is that metallic workpieces are heated and then hardened.

It is of great interest, particularly in the heat treatment of numerous workpieces, for example in series production, etc., to obtain a consistent quality of the heat-treated workpieces, and consequently a high degree of reproduction accuracy.

The invention is therefore based on the object of creating solutions by means of which a high level of reproduction accuracy can be ensured within the framework of a heat treatment that can be carried out advantageously in terms of the process technology with regard to the microstructure and the geometry of correspondingly heat-treated workpieces.

To solve this problem, a method for

Heat treatment of metallic workpieces, in particular

Proposed transmission components, preferably carburized metallic workpieces are introduced into a means for heating workpieces and heated therein, wherein the means for heating workpieces as

Continuous furnace is designed and with workpieces in the

Continuous furnace through a first opening device in one

Heating section of the continuous furnace are introduced for heating, wherein workpieces after heating in one of the

Heating section foreclosureable output section are transferred and kept warm therein at a specified temperature wherein workpieces, after being held warm, are removed from the continuous furnace through a second opening means different from the first opening means, wherein after removal, workpieces are introduced into a means for hardening for hardening.

The method according to the invention makes it possible to control temperature profiles or temperatures of heated workpieces or workpieces to be heated, in particular after the heating in the furnace has ended, but before the workpieces leave the furnace in order to be subsequently hardened. The sequential steps of heating and hardening can be matched to one another by keeping the workpieces warm while they are still in the furnace, which means that a consistent quality of the correspondingly heat-treated workpieces and thus a high degree of reproduction accuracy can be achieved.

The heating zone or section or the like can be conceived and described as a chamber for heating workpieces that is present in the continuous furnace.

An exit section can also be understood and referred to as a chamber for keeping workpieces warm or as an exit chamber or the like.

In an advantageous further development of the invention, provision can be made for a partitioning means to be arranged between the heating section and the outlet section, with the partitioning means being opened in a first step after the workpiece has been heated in the continuous furnace, preferably the heating section, in such a way that the heating section and outlet section form a reservoir. wherein in a subsequent second step workpieces are transferred from the heating section to the exit section, wherein in a third step the sealing means is closed in such a way that communication between the heating section and Output section is at least partially, preferably completely interrupted, wherein in a fourth step workpieces are kept warm in the output section and workpieces are removed from the output section through the second opening from the continuous furnace after being kept warm.

In this way it can be made possible to control the temperature profiles of heated workpieces, in particular in the continuous furnace. This can make a significant contribution to the consistent quality of workpieces that are subjected to heat treatment.

In a moreover advantageous development of the invention, it can be provided that workpieces in the continuous furnace, preferably in the heating section, are heated at least at a negative pressure and/or workpieces are kept warm in a vacuum in the exit section.

Negative pressure and vacuum can be understood as equivalent terms.

Heating or keeping warm in a vacuum or at low pressure can have a beneficial effect on the heat treatment of workpieces.

If heating is to take place at atmospheric pressure, a further advantageous embodiment of the invention can provide that workpieces in the continuous furnace, preferably in the heating section, are heated at atmospheric pressure and/or workpieces are kept warm at atmospheric pressure in the output section.

In a particularly advantageous embodiment, it can therefore be provided that workpieces are in the output section be kept warm. As a result, the temperature or a temperature profile of the workpieces can be maintained in a controlled manner before further transport to a hardening press, as a result of which a consistently high quality of heat-treated workpieces with high reproducibility can be achieved. It is irrelevant whether the food is kept warm in a vacuum or at atmospheric pressure.

It can be provided within the scope of the invention that at least one workpiece is heated in the heating section, while at least one workpiece is kept warm in the exit area. As a result, the number of workpieces to be subjected to heat treatment can be significantly increased.

A particularly advantageous embodiment of the invention can provide for pressures and/or temperatures in the heating section and in the outlet section to be regulated individually, preferably by means of a control unit.

This can make it possible to create specific and individual conditions in the heating section or in the exit section. This can also be understood in such a way that chamber-specific environmental conditions can be created. This can also make it possible to expose workpieces to different conditions within the continuous furnace, with these conditions taking place in a controlled form. This can result in high reproduction accuracy.

In a particularly preferred embodiment, the

Invention provide that workpieces are transported from the output area to the hardening means, in particular via a means for heating and means for hardening arranged storage means for workpieces, wherein the transport is accomplished in such a way that workpieces neither exceed nor fall below a defined temperature range when introduced into the means for hardening.

Such controlled temperatures or temperature stresses or similar temperature conditions of heated workpieces can make a significant contribution to a heat treatment process that enables high reproducibility under very controlled conditions.

In a development of the invention, it can be provided that the transport takes place in a vacuum or at atmospheric pressure.

A controlled transport can thus also take place, as a result of which a constant quality of the workpieces to be treated or treated can be achieved.

In an alternative development of the invention, it may be possible for workpieces to be quenched by means of fluid, preferably oil, in the medium for hardening.

Hardening can thus take place very evenly through fluid supply, which can have a positive effect on the workpiece quality.

Advantageously, the invention can provide that workpieces are quenched by means of gas during the hardening process.

Gas quenching can eliminate or at least reduce any downstream washing operations.

A further, very advantageous embodiment of the invention can provide that workpieces are substantially transverse to a Be transported longitudinally of the second opening to the means for hardening.

From this, a particularly fast transport can be made possible with a compact design. This can have a positive effect on maintaining specified temperature profiles or

Workpiece temperatures also affect during transport or before hardening. This can then also affect a high level of reproducibility in order to achieve consistent workpiece qualities.

In an alternative embodiment of the invention, it may be possible for workpieces to be transported essentially parallel to a longitudinal direction of the second opening to the means for hardening.

It can also be possible for workpieces to be transported to the hardening means essentially along a longitudinal direction of the second opening.

In addition, a very advantageous embodiment of the invention can provide that, after hardening, workpieces are transported from the hardening means to a washing means and are washed in the washing means, with the means for heating, the means for hardening and the means for Washing are arranged in an enclosed space in such a way that workpieces are transported in the space from the means for heating via the means for hardening to the means for washing, preferably in an automated manner, with workpieces being transported after washing either to a means for tempering workpieces, to finish the heat treatment after tempering and to transport finished workpieces from an exit outside the room, or through a discharge area different from the exit, to be ejected from the room and to be metrologically examined outside the room.

A hardening agent can also be referred to as a quenching agent. A quenching agent may also be referred to as a hardening agent.

In order to check the quality of workpieces, in particular after heating and press hardening and preferably after washing and before annealing the workpieces, it is particularly advantageous for workpieces to be able to be ejected from a room in this way.

It can be provided that the enclosed space comprises walls. Preferably the enclosed space comprises four walls. In a very particularly preferred manner, it can be provided that the four walls are arranged in the manner of a rectangle. The enclosed space thus has two long sides and two broad sides.

In particular, it can also be provided that workpieces are transported after hardening from the means for quenching to a means for washing and are washed in the means for washing, the means for heating, the means for hardening and the means for washing in one enclosed space are arranged in such a way that workpieces are transported in the space from the means for heating via the means for hardening to the means for washing, preferably automatically, with workpieces after washing and before tempering the workpieces in a means for tempering through an ejection area be discharged from the room and be metrologically examined outside the room.

The means for hardening can also be referred to as a hardening press. The hardening agent can also be used as a quenching press be designated. The heating means can also be referred to as a curing oven.

In order to enable constant treatment conditions for the workpieces and thus be able to provide a method with high reproduction accuracy, it can be provided that the workpieces are brought into the hardening furnace via a handling system and the heating of the workpieces as they pass through the hardening furnace is recorded by measurement .

The method according to the invention is preferably carried out in such a way that at least one workpiece is heated in the heating section while at least one workpiece is kept warm in the exit area. As a result, the number of workpieces that are treated can be increased.

To achieve the object, the disclosure also relates to a method for the heat treatment of metallic workpieces, in particular transmission components, in which carburized metallic workpieces are introduced into a means for heating workpieces and heated therein, the means for heating workpieces being designed as a continuous furnace and wherein workpieces are introduced into the continuous furnace through a first opening device and are removed from the continuous furnace through a second opening device spaced apart from the first opening device, wherein after removal, workpieces are introduced into a means for hardening for hardening.

In a particularly advantageous development of the method for the heat treatment of metallic workpieces, the following steps can be provided: - picking up the workpieces in a furnace exit area located in the vicinity of the second opening device by means of a handling system,

- Insertion of the workpieces in the hardening press

- management of the quenching process and

- Removal of the workpieces from the hardening press,

- The transfer of the workpieces into the hardening press by the handling system and the implementation of the quenching process by the hardening press form a process step group that is processed in a program-technically defined time frame.

This processing in a time frame defined by the program can enable a particularly high reproduction accuracy, ie also a constant quality of the workpieces.

A particularly high level of reproduction accuracy can also be made possible by operating the handling system in such a way that a programmatically secured temporal temperature profile of the workpiece results for the transfer of the workpiece from the output device into the hardening press.

A high degree of reproduction accuracy can also be possible if the handling system is operated in such a way that the workpiece is brought into contact with gas in a programmed manner for the transfer of the workpiece from the output device into the hardening press.

Provision can be made for the workpieces to be transported from the furnace exit area into the hardening press by a

Handling system is accomplished in one

Intermediate area between the output device and the

Hardening press is arranged. This allows a fixed Distance for transporting the workpieces from the heating means to the hardening means can be determined. This can have an advantageous effect on the consistent quality of treated workpieces and thus on high reproduction accuracy.

It may be possible that the transfer process is activated with a ready signal from the hardening press. As a result, the workpieces can be moved in a controlled manner, which can have an advantageous effect on high reproduction accuracy.

A transfer or transfer process can also be understood as transport or transport process and can be designated accordingly.

It can be provided that the transfer process can only be initiated when the hardening press is in a ready state.

It can thus be avoided that workpieces are brought to the means for hardening, although this is not ready for operation. In this respect, it is possible to prevent individual workpieces from cooling down, in particular while they are being transported and waiting for the agent to be ready for hardening. A transfer process can therefore only enable a constant quality of all workpieces when the hardening press is in a state of readiness.

It may be possible that a signal confirming the completion of the transfer process

Press hardening process starts. This means that hardening can be started under controlled conditions and the treated workpieces can be of consistent quality.

It may be possible that the gripping of the workpiece in the

Exit area of the hardening furnace takes place once the workpiece has reached a defined thermal state. Such a defined thermal state can be attainable for all workpieces that are treated and thus make a significant contribution to the high reproduction accuracy of the method.

It can also be provided that, as part of the quenching process, the workpiece is exposed to a quenching medium in a way that is defined in terms of programming and coordinated by adjusting means. Such controlled quenching conditions can be another essential component for a high reproducibility of the process.

The task is according to a further aspect of the present

Invention solved by a device for heat treatment of metallic workpieces, in particular

Transmission components, the device at least one

Means for heating workpieces, wherein the

Device further at least one means for curing

Workpieces includes, wherein the at least one means for

Heating of workpieces as a continuous furnace with a

Flow direction is formed and comprises at least one chamber for heating workpieces, the continuous furnace comprising at least one further chamber, the at least one further chamber being a heatable chamber for keeping warm in the at least one chamber for heating Workpieces is present, the at least one further chamber being connectable or connected to the at least one chamber for heating.

The device according to the invention makes it possible to control and maintain temperature profiles of heated workpieces and, in particular, to harden workpieces with controlled temperatures after heating. In this respect, the sequential steps of heating and hardening can be coordinated with one another, as a result of which a consistent quality of the correspondingly heat-treated workpieces and thus high reproduction accuracy can be achieved.

The at least one chamber for heating workpieces can also be understood as a heating zone or heating section or the like, which is present in the continuous furnace. The at least one further chamber for keeping workpieces warm can also be understood as an exit section or exit chamber or the like.

Thus, according to the invention, the continuous furnace comprises a heating section and an exit section that can be separated therefrom. It is essential that the exit section is present as a heatable exit section, in particular as a chamber-like exit section.

In an advantageous development of the invention, it can be provided that the at least one further chamber can be detachably connected or is connected to the at least one chamber for heating.

It is thus possible to easily change or exchange the at least one further chamber or the chamber for heating. It can also be advantageous that the means for heating is present as a modular means for heating.

Modules can be chambers that are present for heating workpieces and chambers that are for keeping workpieces warm. Modules can also be chambers for inserting workpieces. Modules can also be chambers for removing workpieces. Modules can also be combinations of the above lists.

In a further advantageous development of the invention, it can be provided that the at least one further chamber can be sealed off from the at least one chamber for heating workpieces by means of at least one sealing means.

A means of sealing off can be present, for example, in the form of a door or the like.

In this way, different states can be generated or are generated in the different chambers. Such states can be, for example, pressure, temperature, humidity, etc.

In a particularly advantageous embodiment of the invention, it may be possible for isolation or isolation to be achieved reversibly.

The invention can also provide that at least the at least one chamber for heating workpieces and/or the at least one further chamber can be acted upon with a negative pressure. In this way, workpieces can be heated in a vacuum.

In a further very advantageous embodiment, it can be provided that at least one control device is included, the at least one control device being such is configured such that temperatures in the at least one further chamber and in the at least one chamber for heating workpieces can be regulated in a chamber-specific manner.

In this way it can be made possible to control temperature profiles of heated workpieces even more and thus to be able to subject improved workpieces with controlled temperatures to post-heating curing. In this respect, the sequential steps of heating and hardening can be better coordinated with one another, as a result of which a consistent quality of the correspondingly heat-treated workpieces and thus high reproduction accuracy can be achieved.

In order to be able to coordinate the sequential steps of heating and hardening in an improved manner and to be able to achieve a consistent quality of the correspondingly heat-treated workpieces, and thus increased reproduction accuracy, it can be provided in an advantageous development of the invention that the at least one control device is also configured in such a way that the at least one sealing means for sealing off the at least one chamber for heating workpieces from the at least one further chamber can be regulated, preferably as a function of the chamber-specific regulation of the temperatures.

In a further advantageous development of the invention it can be provided that the at least one

Control device is designed such that negative pressures in the at least one further chamber and in the at least one chamber for heating workpieces are chamber-specific controllable.

It can thereby be made possible chamber-specific

to create environmental conditions. This can also be possible be to expose workpieces to different conditions within the continuous furnace, these conditions occurring in a controlled manner. This can result in high reproduction accuracy.

In a further advantageous development of the invention, it can also be provided that at least one control device is included, with the at least one control device being designed in such a way that temperatures in the at least one additional chamber and in the at least one chamber for heating workpieces can be regulated in a chamber-specific manner and that the at least one partitioning means for sealing off the at least one chamber for heating workpieces from the at least one additional chamber can be regulated, preferably depending on the chamber-specific control of the temperatures, and that negative pressures in the at least one additional chamber and in the at least one chamber for heating workpieces can be regulated chamber-specifically.

This can make it possible to create chamber-specific environmental conditions. This can also make it possible to expose workpieces to different conditions within the continuous furnace, with these conditions taking place in a controlled manner. This can result in high reproduction accuracy.

A further advantageous embodiment of the invention can provide that the means for heating and the means for hardening are arranged in an enclosed space, the space comprising at least one exit area for outputting finished heat-treated workpieces and the space also comprising at least one discharge area, which is is different from the at least one exit area, wherein workpieces can be removed and inserted from the room for metrological investigations. It can be provided that the enclosed space comprises walls. Preferably the enclosed space comprises four walls. In a very particularly preferred manner, it can be provided that the four walls are arranged in the manner of a rectangle. The enclosed space thus has two long sides and two broad sides.

A further advantageous embodiment of the invention can provide that the continuous furnace is designed as a vacuum continuous furnace, with a negative pressure being able to be applied at least in the first chamber and/or in the second chamber and/or in the at least one further chamber, with the negative pressure being preferred can be regulated chamber-specifically.

It can be provided within the scope of the invention that at least one means for interrupting a communication, in particular for closing at least one section between the at least first chamber and the at least second chamber and/or between the at least first chamber and the at least one further chamber and/or is present between the at least one further chamber and the second chamber.

A particularly advantageous embodiment of the invention can provide that at least one means for adjusting at least one temperature of the continuous furnace, in particular a control unit, is present by means of which or the temperatures are chamber-specific individually, preferably in the at least first chamber and in the at least second chamber are individually adjustable.

In a development of the invention, it can be provided that workpieces can be introduced into the at least one means for hardening workpieces and can be quenched by means of fluid, preferably oil.

In an alternative development of the invention, it can be possible for workpieces to be introduced into the at least one means for hardening workpieces and quenched by means of gas.

The invention can advantageously provide that at least one handling device is included, by means of which workpieces can be transferred from the continuous furnace, preferably from the at least second chamber or from a storage device downstream of the at least second chamber, into the at least one means for hardening workpieces.

Furthermore, the invention also relates to a press hardening system, in which the means for heating the workpieces mentioned at the outset is designed as a hardening furnace for heating a workpiece to a defined target temperature. This press-hardening system includes a hardening press for carrying out a quenching procedure under tension on the workpiece and also a control device for controlling the press-hardening system.

According to a further aspect of the invention, the object is also achieved by providing a device for the heat treatment of metallic workpieces, in particular transmission components, wherein: the device comprises at least one means for heating workpieces, the device further comprises at least one means for hardening workpieces, the at least one means for heating workpieces is designed as a continuous furnace through which the workpieces can be conveyed in a continuous direction, the continuous furnace has an input section, a heating section and an output section, the workpieces via a first opening device can be introduced into the input section, the workpieces can be removed from the output section via a second opening device, the output section comprises an output chamber and the output chamber can be closed in a controlled manner with respect to the heating section and the means for hardening the workpiece.

This advantageously makes it possible to decouple the transfer of the workpieces into the quenching device from the introduction of the workpieces into the furnace and the furnace-internal transfer of the workpieces into the exit section and to coordinate them with the opening of the second opening device. In addition, the furnace acts as a transport system through which the components are heated as part of their transport to the entry area of the quenching agent. In a particularly advantageous manner, this results in a local offset of a cold zone in front of the furnace, which is used for the introduction of the workpiece, from a hot zone facing the means for hardening. This results in an elongation of an overall system formed including the device according to the invention.

The device according to the invention thus makes it possible

Coordinate sequential steps of heating and hardening, resulting in a consistent quality of the heat-treated workpieces and thus a high

Reproduction accuracy can be achievable. The continuous furnace is preferably designed in such a way that it comprises at least one entry chamber, which forms the entry section. The input chamber and the output chamber are coupled to each other by a work transport path passing through the heating section.

The workpieces are preferably conveyed through the continuous furnace in connection with workpiece carriers. The workpieces can be brought into the input chamber through the first opening device, preferably in conjunction with an associated workpiece carrier. The workpieces are preferably conveyed on the workpiece transport path by a transport mechanism. This transport mechanism can be designed in such a way that it conveys the workpieces in connection with the workpiece carriers. The workpieces can be removed from the output chamber through the second opening device. The workpiece carriers are preferably conveyed back to the input section. The heating section is preferably dimensioned in such a way that a number of workpieces can be arranged in successive stations in this heating section. The workpieces can be conveyed through the heating section by successively advancing the workpiece carriers.

The input chamber and the output chamber are preferably designed in such a way that they each receive only one workpiece or a workpiece carrier with one or more workpieces arranged on it. The workpiece carriers can in particular be made of a ceramic or heat-resistant metallic material. After leaving the output chamber, the material carriers are handled automatically. As part of this handling, the same is cleaned in the form of blowing off, brushing and/or

ablution. It is possible the workpiece carrier in tempered condition to the entrance area of the continuous furnace and to bring about the introduction of the workpieces or the workpiece into the continuous furnace in connection with a defined preheated workpiece carrier.

At least one further chamber is preferably provided. This further chamber preferably forms the heating section.

The communication of the further chamber with the input chamber and/or with the output chamber can be established and interrupted in a switchable manner. For this purpose, doors, flaps or slide structures are preferably provided, which switchably separate the heating section from the input chamber upstream in the workpiece transport direction and the output chamber downstream in the workpiece transport direction.

According to a particular aspect of the present invention, the continuous furnace is preferably designed as a vacuum continuous furnace, with a vacuum being able to be applied at least in the input chamber and/or in the output chamber and/or in the at least one further chamber, with the vacuum being preferably chamber-specifically controllable.

Advantageously, at least one means is provided for interrupting communication, in particular for closing at least one section between the input chamber and output chamber and/or between the input chamber and the at least one additional chamber and/or between the at least one additional chamber and the output chamber. This means for interrupting the communication can be designed in particular as a flap, door, slider or bulkhead that can be brought selectively into a release position and into a closed position. The position of this means can be changed in an advantageous manner by electronically controlled actuating means. According to a further aspect of the present invention, at least one means for setting at least one temperature of the continuous furnace, in particular a control unit, is preferably provided, by means of which the temperatures can be individually set chamber-specifically, preferably in the input chamber and in the output chamber.

The dispensing chamber can advantageously be provided with a heating device. This heating device is preferably operated via a control or regulating device. The output chamber can advantageously be operated in a controlled or regulated manner in such a way that it enables the workpiece located therein to be kept warm in a vacuum, preferably temperature-controlled. Furthermore, the dispensing chamber can be operated in such a way that it is kept warm at ambient pressure or reduced vacuum. Furthermore, the workpiece transfer from the output chamber to the hardening press can be handled in such a way that it takes place either in an atmospheric environment or in a vacuum.

The output chamber forms a lock system through which

Workpieces can be removed from the heating section without the vacuum prevailing in the heating section having to be terminated for this purpose. The output chamber also acts as a

Holding section in which the workpieces can continue to be kept at a specified temperature level.

The pressure in the dispensing chamber is preferably also low

Measure of a control device adjustable. The dispensing chamber is separable from the heating section by a closure device. This locking device and the

Opening devices are operated at different times. in the

Normal operation is the locking device closed, it will preferably only temporarily opened for moving a workpiece from the heating section into the discharge chamber. The opening device is also primarily closed and is only opened temporarily for the removal of a workpiece from the removal chamber. During regular operation of the hardening device, the opening device is only opened when the closing device is closed and the interior of the dispensing chamber is thus sealed off from the interior of the heating section. In the course of keeping the workpiece warm in the discharge chamber, the closing device pointing to the heating section and the opening device pointing outward are closed. In the open position, the closing device pointing towards the heating section releases a workpiece passageway between the heating section and the output chamber. In the closed position, the closing device blocks this workpiece passageway. The closure device atmospherically seals the heating section and the dispensing chamber from one another.

It is possible to set a negative pressure in the dispensing chamber for as long as possible and to equalize the pressure only shortly before the opening device is opened. This makes it possible to avoid the action of any non-inert gases on the workpiece and, in particular, avoid scaling.

The at least one means for hardening the workpieces is preferably designed in such a way that the workpieces introduced into it can be quenched by means of a fluid, preferably oil.

As an alternative to the measure mentioned above or in combination with this, the at least one means for hardening the workpieces can also be designed in such a way that the introduced workpieces are quenched by means of a gaseous medium.

According to a particular aspect of the present invention, the means for hardening is designed as a device in which the fluid provided for quenching the workpiece is actively brought to the workpiece. In this case, a channel system is created in the device in interaction with the workpiece and a structure enclosing it and/or dipping into it, and the quenching medium actively flows through this channel system. The flow is controlled in such a way that there is a defined heat dissipation from the zones of the workpiece that are flushed. The workpiece is preferably clamped and/or supported in the quenching device. Insofar as the workpiece is clamped, the workpiece is loaded in a state in which it assumes a desired geometry with the introduction of compressive forces.

The application of the quenching medium can be controlled in such a way that a defined energy discharge from the workpiece takes place, in which case the workpiece assumes a defined thermal expansion state. In this defined thermal state, the workpiece can be relieved or, in particular, mandrel structures can be moved out of the workpiece. After this change in the workpiece fixing, the quenching process can be continued in the quenching device, which can also be referred to as a means for hardening, or the workpiece can already be removed in this state from the hardening device, which can also be referred to as a means for hardening or quenching device and fed to another device, in which a further heat discharge from the workpiece takes place, which is defined in terms of its temporal characteristics. The workpiece can be quenched in a clamped state at intervals. These intervals can be tailored to provide sequential reheating of selected and already quenched zones of the workpiece. The quenching medium can then be applied again to these reheated zones.

Different quenching media can be actively applied to the workpiece in chronological sequence or coordinated for different workpiece zones. It is thus possible, as part of a first quenching step, to apply a reactive quenching medium to the workpiece, which causes oxide removal or a layer-forming reaction with the workpiece. In a subsequent step, a quenching or reaction medium that differs in terms of its composition can then be applied to the workpiece.

The quenching device is designed so that in this individual workpieces or groups of workpieces

be subjected to quenching treatment. The workpieces or the workpiece are held in a defined position in the quenching device. This position can be determined by receiving structures and/or by inserting the workpiece into the quenching device.

It is possible, in addition to the automated introduction of the

Workpieces in the quenching also any in the

Device to be used matrices, fixtures, mandrels,

Enclosure bells or valve devices also be used automatically in the quenching device. The automated loading of the quenching device with these

Auxiliary facilities and the automated movement of the

Workpiece in the quench allows the Processing of the heat treatment of a single workpiece while ensuring a required microstructure.

The system, ie the device according to the invention, comprising means for hardening and means for heating workpieces, is therefore suitable for the treatment of different workpieces in different batches, including batch 1 in a chronological sequence. The device according to the invention can thus also enable a particularly high degree of flexibility with regard to the number of workpieces to be treated and workpiece geometries.

The quenching device is designed in particular as a hardening press. The stamps provided for building up the pressing stress are preferably moved in the vertical direction. During the quenching process, the workpiece is preferably at or above the level at which it passed through the heating section of the continuous furnace or at which it was tapped from the discharge chamber. The quenching medium is thus brought to the fixed workpiece and not the workpiece to the quenching medium.

The device according to the invention preferably also comprises at least one handling device, by means of which workpieces can be transferred from the continuous furnace, preferably from the output chamber or from a storage device downstream of the output chamber, into the at least one means for hardening workpieces.

The device according to the invention forms part of an assembly which functions as a hardening cell. The hardening cell is preferably constructed in such a way that it covers those process steps that are necessary for hardening the components. These hardening process steps are austenitizing, quenching (preferably in oil), washing, deep freezing and tempering. The combination of austenitizing in vacuum and quenching in oil is accomplished within the hardening cell with the integration of an airlock acting as a holding chamber, which can be understood and referred to as a discharge chamber, a handling system and a hardening press.

Austenitizing is done by heating and holding in a vacuum. In this way, it is achieved in an advantageous manner that the process takes place with reduced release of particles and the workpiece surface is exposed to a reduced extent to reaction events. The workpieces are heated by passing them through a furnace designed as a continuous furnace, which is located between two lock devices. The workpieces are thus transported from an entry lock area through the furnace along a flow direction to an exit lock area. The opening of the sluice devices towards the inside of the furnace takes place only after a sufficient reduction in pressure in the respective sluice chamber.

The inventive concept makes it possible

To subject individual parts or very small batches to hardening treatment efficiently in a short time sequence. Due to the process management according to the invention, the transfer times incurred for moving the workpiece from the austenitizing furnace to the start of quenching can be maintained in a reproducible manner with high accuracy and can also be kept very short.

According to the inventive concept, the

Ausschleusebereich forming output chamber at the end of the furnace, in which a pressure equalization to the ambient pressure takes place as a heatable chamber, in which the Heating can be continued in order to maintain the workpiece temperature reached in the continuous furnace or to set it in a defined manner.

It can also be possible that the dispensing chamber is designed as a heatable dispensing chamber that can be operated both at atmospheric pressure and in a vacuum.

By keeping the heated workpiece ready in a discharge chamber that is sealed off from the vacuum area of the continuous furnace, it is possible to coordinate the timing of the quenching process with the exit time of the workpiece from the discharge or pressure equalization chamber. The quenching process, which is monitored with regard to its timing, begins when the door of the output chamber, which acts as a pressure equalization chamber, is opened.

The workpiece transfer between the

Continuous austenitizing furnace and the hardening press is automated according to a particular aspect of the present invention. As a result, a program-technically defined and reproducible workpiece transfer between the continuous furnace and the press with regard to the workpiece transfer path and the temporal dynamics of the workpiece transfer can be ensured. The flaps, doors and bulkheads and/or locks at the beginning, at the end and inside the continuous furnace are opened in conjunction with a control device. The workpieces are heated in such a way that a defined heating over time in the furnace and in the exit area, i.e. the ejection or output chamber, results in high temperature stability. This can have a particularly advantageous effect on the consistent quality of heat-treated workpieces.

The deterrent is preferably as

Oil quenching device, in particular in the form of a Mandrel hardening press designed for oil quenching. This advantageously ensures a controlled distortion behavior. As an alternative to this, or also in combination with this measure, quenching in gas can also take place. The system according to the invention can be designed in such a way that it enables a combination of vacuum austenitizing with a gas quenching process in the hardening press.

Gas quenching can be carried out with or without support. In particular, it is possible to carry out targeted gas quenching in the hardening press using numerically controlled nozzles.

The workpiece is preferably clamped in the hardening press by inserting the workpiece into the press and driving a mandrel, preferably from below, into an oversized hole in the workpiece. The workpiece or component can be covered from above. For example, it may be possible for a hood to be lowered over the component from above. Subsequently, oil is again preferably pressed through this arrangement from below.

It may be possible for the oil flow to be controlled in such a way that all areas of the component or workpiece cool down evenly despite the different thicknesses. For this purpose, the press can advantageously control several, in particular two, different oil inflows. The hardening press offers channels that allow different fluid throughputs and these channels for supplying the quenching medium can be opened or closed individually in a time-controlled manner.

Advantageously, it can be possible that the mandrel is also designed in such a way that it includes oil channels. After completion of the quenching process in the hardening press, the workpieces can be removed from the hardening press after sufficient cooling and subjected to a preferably multi-stage washing treatment.

It is also possible to carry out a first washing step inside the hardening press, in that a washing medium is passed through the channels for supplying the quenching medium by channel switching. This washing medium can be subjected to a separation treatment, by which washed-off quenching medium is separated. This pre-cleaning, which is carried out within the hardening press, can also be carried out in connection with a gaseous medium.

The washed workpieces are preferably automatically transported to a preferably combined freezer/oven. The transformation of martensite is driven further by deep-freezing and the structure is strengthened. Subsequent tempering then removes residual internal stresses. After this thermal post-treatment, the workpiece treatment in this system is complete and the component can be output.

The hardening system according to the invention is preferably designed in the manner of a sealed, enclosed cell with a preferably elongated rectangular cross section. In one embodiment of the invention, the continuous furnace used according to the invention can extend in the longitudinal direction of this cell. The hardening press can be located in a longitudinal end area of this cell. The workpiece store can be located in the area of the longitudinal end area of the cell opposite the hardening press. A very compact cell can be provided in a particularly advantageous manner. An embodiment of the invention can provide that within the cell a workpiece carrier circuit takes place through the furnace and outside of the furnace back along it.

It is also possible to arrange the means for heating and the means for hardening in one cell in such a way that a longitudinal extent of the output region of the means for heating, which is preferably designed as a continuous furnace, is arranged approximately parallel to a longitudinal extent of an insertion device of the means for heating. A very compact unit consisting of means for hardening and means for heating workpieces can thus be provided as part of a device for heat-treating workpieces.

A system can also be taken from the present disclosure, which comprises at least two, preferably several devices for the heat treatment of workpieces, in particular at least two, preferably several means for heating and means for hardening workpieces.

The heat treatment of the workpiece can be carried out as a so-called batch process. This batch process enables heat treatment as part of a single workpiece treatment as well as subsequent treatment of different single workpieces. In the hardening press, different quenching procedures specifically defined for the respective workpiece can be processed in direct succession.

According to another aspect of the present invention is the

Hardening system designed in such a way that workpiece transport, especially through the austenitizing furnace, is largely independent of component size and geometry.

For this purpose, the workpieces are preferably guided through the continuous furnace on trays or are accordingly passable. In this way, several and even relatively small workpieces can be grouped and fed through the hardening plant, which is designed as a cell, for the processing of external orders.

The automated conveyance of the workpieces through the continuous furnace in connection with workpiece transport pallets or trays can be handled in such a way that the pallets or trays are transported back within the system from the exit area of the continuous furnace to the entrance area of the same. For this purpose, the hardening system according to the invention preferably comprises a circulatory conveyor system for returning the pallets, trays or workpiece carriers. A wide variety of workpiece carriers can be stored in a carrier store.

It is also possible to bring the workpieces into the hardening plant in connection with workpiece carriers. It is also possible, after the workpieces have left the washing station, to put the workpieces back into the workpiece carriers intended for introduction into the continuous furnace, or to insert the workpiece carriers intended for the workpiece output. Workpiece handling within the system designed as a processing cell is preferably automated in all stations, monitored and documented by handling systems.

The invention further relates to the use of a device according to the invention for the heat treatment of preferably carburized workpieces.

In particular, it is provided here that the device according to the invention comprises at least one means for heating and at least one means for hardening. According to the above statements, it is particularly advantageous here that heat-treated workpieces can be obtained with consistent quality.

The device according to the invention, comprising at least one means for heating and at least one means for hardening, has the further advantage that it saves a lot of space, ie is compact.

It is thus possible to arrange at least two, preferably several, devices according to the invention. Such an arrangement can be understood and referred to as a system of at least two devices according to the invention.

Thus, the invention also provides a system comprising at least two devices according to the invention.

A resulting compact system can enable a significantly increased number of workpieces to be heat-treated, with the quality of the workpieces being able to be kept constant.

In particular, it can also be provided that the system comprises at least two means for heating and at least two means for hardening. It may be possible for the means for heating and/or the means for hardening to be regulated or controllable or to be controlled or regulated by means of a common control device or the like.

Within the scope of the invention, workpieces can be all metallic workpieces or the like

Objects that are exposed to at least one heat treatment in a hardening oven as part of heat treatments. Workpieces are preferably used as gear components designed. Transmission components can preferably be designed as gears.

By definition, the at least one further chamber can be referred to as a dispensing chamber within the scope of the invention and disclosure. A dispensing chamber may be referred to as the at least one other chamber.

By definition, the at least one chamber for heating workpieces can be referred to as a heating section within the scope of the invention and disclosure. The heating section can be referred to as a chamber for heating workpieces.

By definition, the at least one further chamber for keeping workpieces warm within the scope of the invention and disclosure can be referred to as the exit section. The exit section can be described as another chamber for holding workpieces.

By definition, within the scope of the present disclosure and invention, the hardening furnace can be referred to as a means for heating workpieces. The means of heating workpieces can be referred to as a hardening furnace.

By definition, within the scope of the invention and disclosure, a means of interrupting a communication may be referred to as an isolation means. A means of sealing off can be referred to as a means of interrupting a communication.

Further details and features of the invention result from the following description of the invention in conjunction with the drawing. It shows:

Figure 1 is a schematic representation to illustrate the Structure of a device according to the invention for the heat treatment of workpieces using a continuous furnace and a hardening press;

FIG. 2 shows a further schematic illustration to illustrate the structure of a hardening system according to the invention constructed as a hardening cell;

FIG. 3 shows a flowchart to illustrate the sequence according to the invention for the heat treatment of workpieces in the device according to FIG.

FIG. 4 shows a schematic representation to explain the embedding of the furnace designed as a continuous furnace between an inlet lock chamber and an outlet lock chamber and between two workpiece transfer systems.

The disclosed method according to the invention for the heat treatment of metallic workpieces WB, in particular transmission components, can be inferred from FIGS. 1 and 2 in particular, with preferably carburized metallic

Workpieces in a medium TK for heating workpieces

(See Figure 1) are introduced and heated therein, the means TK for heating workpieces as

Continuous furnace is designed and with workpieces WB in the

Continuous furnace through a first opening device 1 in one

Heating section TKH of the continuous furnace are introduced for heating, with workpieces WB after heating in one of the

Heating section TKH foreclosureable output section TKO are transferred and are kept warm therein at a specified temperature, wherein workpieces WB after being kept warm through a second opening device 2, from the first

Opening device 1 is different from the continuous furnace are discharged, with workpieces WB being introduced into a medium PQ for hardening after being discharged for hardening.

Furthermore, a disclosed method according to the invention for the heat treatment of metal workpieces WB, in particular transmission components, can be seen, in which preferably carburized metal workpieces WB are introduced into a means for heating workpieces TK and are heated therein, with the means for heating workpieces TK as is configured as a continuous furnace and wherein workpieces WB are introduced into the continuous furnace TK through a first opening device 1 and are removed from the continuous furnace TK through a second opening device 2 spaced apart from the first opening device, wherein workpieces WB after being removed for hardening are placed in a hardening agent PQ be introduced. In a particularly advantageous development of the method for the heat treatment of metallic workpieces, the following steps can be provided:

- picking up the workpieces WB in a furnace exit area located in the vicinity of the second opening device 2 by means of a handling system TS,

- Insertion of the workpieces WB in the hardening press PQ

- management of the quenching process and

- Removal of the workpieces WB from the hardening press PQ,

- The transfer of the workpieces WB into the hardening press PQ by the handling system TS and the accomplishment of the quenching process by the hardening press PQ form a process step group Q1, Q2, Q3, Q4 (Q1 to Q4), which is processed in a time frame defined by the program ( see also Figure 3).

The representation of Figure 1 illustrates the structure of an embodiment of a device according to the invention Heat treatment of metallic workpieces, especially transmission components.

The device according to the invention comprises at least one means TK for heating workpieces WP. In addition, the device also comprises at least one means PQ for hardening workpieces, the at least one means TK for heating workpieces WP being designed as a continuous furnace through which the workpieces WP travel in a continuous direction DTK, the continuous furnace having an input section TKI, a heating section TKH and an outlet section TKO, the workpieces being able to be introduced into the inlet section TKI via a first opening device 1, the workpieces being able to be removed from the outlet section TKO via a second opening device 2 and both the inlet section TKI and the outlet section TKO opposite the heating section TKH can be temporarily isolated.

This structure makes it possible to heat the components WP as part of their transfer to the

quenching device PQ, whereby the transfer of the workpieces WP to the quenching device PQ is decoupled in time from the introduction of the workpieces WP into the heating section TKH and the furnace-internal transfer of the workpieces WP into the output section TKO and can be coordinated with the opening of the second opening device 2.

The continuous furnace TK is designed here such that it includes at least one input chamber CI, the

Forms input section TKI, and at least one output chamber

C2 includes, which forms the output section TKO, these two chambers CI, C2 connected to each other by a through

Workpiece transport path running through heating section TKH

W are coupled. The workpieces WP are in the

Input chamber CI through the first opening device 1 recoverable. Furthermore, the workpieces WP can be removed from the output chamber C2 through the second opening device 2 .

The at least one chamber for heating workpieces can be understood and referred to as a heating section TKH. This also applies vice versa.

The at least one further chamber for keeping workpieces warm can be understood and referred to as the exit section TKO. This also applies vice versa.

In this exemplary embodiment, at least one further chamber C3 is provided, with this further chamber C3 forming the heating section TKH here, through which the input chamber CI communicates with the output chamber C2.

In the exemplary embodiment shown, the continuous furnace TK is designed as a vacuum continuous furnace, with a negative pressure being able to be applied at least in the input chamber CI and/or in the output chamber C2 and/or in the at least one further chamber C3. This negative pressure can be regulated chamber-specifically and is set to ambient pressure before the openings 1, 2 are opened.

In the device according to the invention is a means 3 for

Interruption of a communication, in particular for

Closing at least a portion between the first

Chamber CI and the heating section TKH provided. Furthermore, a means 4 between the second chamber C2 and the

Heating section TKH provided. This means 3.4 to

Interruption of communication with the chamber C3 can be designed in particular as a flap, door, slider or bulkhead that in a release position and in a

Closing position can be brought. The change of position this

Means 3, 4 can advantageously by electronically controlled actuators and / or actuators are accomplished.

In the device shown, there is at least one means 5 for setting at least one temperature of the continuous furnace TK, in particular a control unit CPU, by means of which the temperatures TI, T2, T3 are individually chamber-specific, preferably in the output chamber C2 and in the at least third chamber C3 are individually adjustable.

The at least one means PQ for hardening the workpieces WP is designed here in such a way that the workpieces WP introduced into it can be quenched by means of a fluid, preferably oil or gas.

The device according to the invention comprises a handling device TS by means of the workpieces WP from the continuous furnace TK, i.e. from the output chamber C2 or from a storage device downstream of the output chamber C2, into which at least one means PQ for hardening the workpieces WP can be transferred. The handling device TS can be formed by a robot arm or a portal system.

The control device CPU is used to control a heat treatment process of preferably metallic workpieces. As part of this heat treatment process, carburized workpieces are preferably introduced through a first opening device 1 into chambers CI, C2, C3 of a means TK for heating workpieces to a predetermined temperature and heated there.

After heating, the workpieces WP are discharged from a discharge chamber C2 through a second opening device 2 different from the first opening device 1 and transported to and quenched by a means for hardening workpieces.

The controller also controls the pressures in chambers CI, C2, C3. The process sequence controlled by the control device CPU is explained further in connection with FIG.

The continuous furnace TK provides several heating zones ZI, Z2, Z3, AK.

The continuous furnace TK provides several heating zones ZI, ZTK, AK. The heating zone of the heating section ZTK is subdivided into further zones Z2, Z3.

The temperature in these zones can be controlled according to the control unit CPU. The heating section TKH is constructed in such a way that it defines a number of heating zones Z2, Z3 in which different temperatures and heating outputs can be set to a sufficient extent. Both the input area TKI, the heating section TKH and the output area TKO are designed in such a way that these measuring points TUS provide for recording, monitoring and documenting the workpiece heating.

The pressures in chambers CI, C2, C3 are also measured and recorded.

The pressures in these chambers can be lowered to below ambient pressure via a vacuum pump VP. The chambers CI, C2, C3 are coupled to one another via a line system and electrically controllable valves provided therein. About the

Management system, the chambers CI, C2, C3 can communicate with each other temporarily, so that within a

Partial ventilation of a chamber CI, C2 a correspondingly antiphase partial venting of the other chamber C2, CI can be accomplished.

The representation according to FIG. 2 shows a press-hardening system constructed including the device according to FIG. 1 and designed as a cell. This press hardening system includes a hardening furnace TK, an output lock TKO for the output of workpieces WP from the hardening furnace TK and a hardening press PQ for clamping a workpiece WP and for accomplishing a quenching process of the workpiece WP in the clamped state.

In the press hardening system shown, a handling system TS is provided in an intermediate area between the discharge chamber TKO, which functions as an output lock, and the hardening press PQ. This handling system TS is operated in such a way that a programmatically secured temporal temperature profile of the workpiece WP results for the movement of the workpiece WP from the output lock into the hardening press PQ.

The hardening oven TK is also in this embodiment as

Running vacuum furnace for heating a workpiece WP in a low-oxygen environment. Furthermore, the TK hardening furnace is designed as a continuous furnace. The workpiece handling between the hardening furnace TK and the hardening press PQ is accomplished here in such a way that the workpiece WP after the exit from the opening device 2 of the output lock TKO transverse to

Flow direction DTK through the hardening furnace TK in the

Hardening press PQ is guided. The hardening furnace TK and the

The PQ hardening presses are linked across the corner by the TS transfer system with regard to workpiece movement. Of the

Transfer process of the workpieces from WP from the

Output sluice TKO of the hardening furnace TK to the hardening press PQ and the quenching process in the hardening press PQ are technically time-coupled. The spending of Workpiece from the output chamber TKO into the hardening press PQ is handled as a thermally relevant sub-step of the quenching process.

In the press hardening system shown, a workpiece transfer system WPH1, WPH2 is provided, which extends along the hardening furnace TK between an output area of the hardening press PQ and an entry opening 1 of the entry lock TK1 of the hardening furnace TK. The workpiece transfer system WPH1, WPH2 includes several linked conveyor modules. About a first module of the

Workpiece transfer system WPH1, an after-cooling station 6, a washing station 7 and/or a test station 8 can be loaded with workpieces. A second module of the workpiece transfer system can be used to return the respective workpiece to the input area of the cell CW. From there, the hardened and washed workpieces can be taken to the cooling cells 10, 11, 12, 13. The press hardening system is designed in such a way that workpieces WP located in the area of the test station 8 can be removed from the press hardening system.

The press hardening system can be designed so that the

Press hardening of the workpieces using a

Die set-up takes place. This die device is used to hold the workpiece and to provide it

Workpiece supporting wall sections. In the hardening press

PQ can be the quenching medium in combination with the

Die device controlled by valve devices are performed on the workpiece. If the workpiece is supported using a core or mandrel, it is possible to carry out the quenching process in such a way that the workpiece is not completely cooled. After this partial cooling, the supporting structures such as mandrels, Cores or matrices are subtracted. Then there is further cooling. This can also take place outside of the hardening press, for example in a bath.

A handling system TS is provided in the device according to FIG. 1 and in the press hardening system according to FIG. This handling system TS is arranged in an intermediate area between the output chamber TKO and the hardening press PQ. This handling system TS is operated in such a way that, for the transfer of the workpiece WP from the output chamber TKO into the hardening press PQ, there is a program-technically secured time sequence of movements for the transfer of the workpiece WP.

The handling system is configured in connection with a corresponding control device in such a way that the delivery process and the quenching process are linked in terms of time. The transfer process can be activated with a ready signal from the hardening press PQ or can only be initiated in a ready state PQ of the hardening press. Furthermore, a signal confirming the completion of the transfer process of the workpiece WP into the press PQ can start the press hardening process. The TS handling system is located in a CW hardening cell, which houses the TK hardening furnace and the PQ hardening press. The hardening cell CW is designed as a rectangular cuboid structure, the oven extends in the longitudinal direction of this cuboid structure.

The hardening press is located in a longitudinal end area.

The workpiece transfer process handled by the TS handling system is monitored and documented with regard to its timing. For this purpose, in particular the thermal time profile of the workpiece can be measured and recorded. The illustration according to FIG

TS workpiece handling system for transporting the workpieces from the TK hardening furnace to the PQ hardening press. The hardening cell CW includes a workpiece return system WPH for moving the workpieces WP from the hardening press PQ to an input and output area 9, 9a. The TK hardening furnace is designed as a continuous furnace. The WPH workpiece return system runs parallel to the TK hardening furnace. The workpiece washing device 7 is arranged in an intermediate area between the workpiece output area 9a and the hardening press PQ and can be loaded via the workpiece return system WPH.

A means for washing may be referred to as a workpiece washer. A workpiece washing device can be referred to as a means for washing.

The hardening furnace TK has an input lock TKI and a

Exit gate TKO open. A loading system LS is provided in a zone upstream of the entry lock TKI.

About the workpiece return system WPH1, WPH2 is a

Workpiece transfer between the PQ press and the

Feeding system LS feasible. in a dem

entrance area or the entrance lock TKI of the hardening furnace

TK adjacent area of hardness cell CW is a

Workpiece storage WPB1, WPB2 provided. Furthermore, in an entry area TKI of the hardening furnace TK is adjacent

A first cooling cell 10 is provided in the area of the hardening cell CW.

In an area of the hardening cell CW adjacent to the entrance area TKI of the hardening furnace TK, there are further cooling cells

11, 12, 13 provided. The workpiece storage WPB1, WPB2 and/or the cooling cells 10, 11, 12, 13 are via the

Feeding system LS accessible, so from these modules

Workpieces WP can be removed by the loading system and in these modules can be introduced. The cooling cells 10, 11, 12, 13 can also be equipped with heating devices, so that a tempering process can also be carried out via these cells.

The hardening cell CW is enclosed by a cell wall CW2.

The workpiece return system WPH is connected to an output lock 8 . A workpiece discharge from the hardening cell CW can be accomplished via this output lock 8 in order to carry out a workpiece inspection. Checked workpieces WP can also be returned to the system via the output lock, for example to be used in the cooling cell modules 10, 11, 12, 13.

It can be provided that the enclosed space comprises walls. Preferably the enclosed space comprises four walls. These four walls can be formed by the cell wall CW2.

Accordingly, the cell wall CW2 can enclose the space. An enclosed space can thus be enclosed by the cell wall CW2.

The operation of the hardening cell is controlled by a control device CPU (see Fig. 1), which is subdivided here by way of example into two modules CE, CP1 coupled with signals, with the module CE being used primarily for workpiece handling in the entrance area of the hardening furnace TK and the module CP1 controls the workpiece flow in the TK hardening furnace, the TS transfer system and the PQ hardening press.

All control tasks relevant to the handling of the workpiece WP from entry into the hardening furnace TK to the end of the hardening process, including the temperature control of the hardening furnace TK, are thus coordinated by the control module CP1. The control module CP1 thus takes over the "hot handling" and the control module CE the "cold handling". The processes in "hot handling" are documented specifically for each workpiece. For "cold handling", documentation is only provided with regard to the trouble-free handling process.

The cold handling control processed via the CE module also includes the workpiece handling after exit from the PQ hardening press.

Any data on thermal workpiece post-treatment, in particular cooling and renewed tempering, can be fed back to module CP1.

The illustration according to FIG. 3 shows a control device CPU and a flow chart of a process processed by this control device.

The control device CPU controls the sequence of the method according to the invention for carrying out a press hardening process, in which workpieces are heated in a hardening furnace as part of a tempering step and quenched in a hardening press as part of a quenching step. The control device CPU is coupled here, for example, via a bus system with the switching elements of the controlled components of the hardening system.

In the context of the present description, the term control used here also includes regulation; the control device can represent a control device in this respect, and adjust manipulated variables taking into account returned signals, in particular with regard to pressure, temperature, workpiece position and dynamically. According to the system operating method handled by the configuration of the control device CPU by this, a workpiece WP is in step S1 by the

Handling device picked up from the workpiece storage WPB1 and placed in an area upstream of the first opening device 1 . In step S2, the pressure in the chamber CI is adjusted to the ambient pressure in a system state in which the barrier wall 3 is closed. In step S3, the opening device 1 is opened. In step S4, the workpiece WP is introduced into the input chamber CI. In step S5, the opening device 1 is closed.

In step S6, the pressure in the chamber CI is lowered to the internal pressure in the third chamber C3. In step S7, the barrier wall 3 is opened. In step S8, the workpiece is conveyed into the third chamber C3 in the throughput direction of the furnace TK. In step S9, the barrier wall 3 is closed.

In steps S10 to S15, the workpiece is conveyed through zones or stations of the furnace TK that follow in the throughput direction DTK and is heated in a defined manner in these zones.

A defined negative pressure prevails in chamber C3, which is set and maintained via a control routine that is not described further here.

As soon as the workpiece WP is in a required thermal

State in the last zone upstream of the barrier wall 4

Chamber C3 is located in step S16 in the discharge chamber

C2 the pressure is lowered to the internal pressure of the chamber C3. in the

In step S17, the barrier wall 4 is opened and the workpiece WP is brought into the output chamber C2 forming the discharge section TKO. The barrier wall 4 is closed in step S18. in the

Step S19 increases the pressure in the chamber C2

Ambient pressure level increased. The pressure increase can be accomplished by equalizing the pressure by feeding of an inert gas into chamber C2. In step S20, the temperature in the discharge chamber C2 is adjusted to a workpiece holding temperature. In step S21 it is queried whether the transfer system TS and the hardening press PQ are in a ready state suitable for processing the quenching process.

In step S22, the quenching process is activated. For this purpose, the opening device 2 is opened in step Q1. In step Q2, the transfer system TS picks up the workpiece WP from the chamber C2 and transfers it to the hardening press PQ on a defined path with a defined speed profile. In step Q3, the hardening press PQ clamps the workpiece used. In step Q4, the clamped workpiece is subjected to a quenching medium.

Steps Q1 to Q4 form a process step group that is processed in a time frame defined by the program. The release of the workpiece WP in the chamber C2 and the process of transferring the workpiece WP into the hardening press PQ form part of the quenching process, which is carried out in a parameterized manner specific to the workpiece. The handling system TS is operated in such a way that for the transfer of the workpiece WP from the output device TKO into the hardening press PQ, a program-technically secured temporal temperature profile of the workpiece WP as well as a program-technically secured temporal gas contacting of the workpiece WP results.

The transfer process beginning with the opening of the opening device 2 can only be carried out in conjunction with a ready signal from the hardening press. In this respect, there is no waiting time or lengthening of the process time outside of the defined process. Following the sequence of press hardening steps Q1 to Q4, the hardening press PQ is opened in step S23 and the workpiece is removed from the hardening press PQ in step S24.

In step S25, the workpiece is inserted into a workpiece carrier and fed to a washing station in step S26.

After the system operation initiated according to the invention by the control device CPU, the opening device 2 is opened and the workpiece is picked up in the output area TKO of the hardening furnace when the workpiece has reached a defined thermal state and the transfer system and the hardening press in one

are ready. The process step group Q1 to Q4 (Q1, Q2, Q3, Q4) takes its course when the opening device 2 is opened.

An exit area may be referred to as an exit section. An exit section can be referred to as an exit area.

As part of the application of the medium to the workpiece WP in the hardening press PQ, in step Q4 the workpiece is exposed to a quenching medium in a way that is defined by the program and coordinated by means of adjusting means.

The heating of the workpieces as part of the passage through the hardening furnace AND is measured and recorded and documented for each workpiece.

The illustration according to FIG. 4 shows a press hardening system with a hardening furnace TK, which is designed as a continuous furnace and has a furnace inlet TKI and a furnace outlet TKO. the

Press hardening plant also includes a hardening press PQ, for

Clamping a workpiece and accomplishing a quenching process of the workpiece in the clamped state. A handling system TS is provided in an intermediate area between the furnace outlet TKO and the hardening press PQ. Furthermore, a workpiece loading system LS is provided in an area adjacent to the furnace entrance TKI. The handling system TS and the workpiece loading system LS are connected to one another via a workpiece carrier conveyor path DTR, which runs past the continuous furnace TK.

The workpiece carriers are returned to the entrance area of the continuous furnace TK via the workpiece carrier conveyor path. The workpiece carriers move through zones both in the input area of the continuous furnace TK and in the output area of the continuous furnace TK, in which a workpiece handling by transfer systems, which are formed in particular by a robot arm or a portal robot, takes place. The workpiece carrier conveyor path runs parallel to the continuous furnace. The workpiece conveyor path WPH described in connection with FIG. 2 again runs parallel to this workpiece carrier conveyor path from the exit from the hardening press PQ back to the cooling cells 10 . . . 13.

This makes it possible to use the TS handling system to pick up the workpiece carriers that have been brought out of the furnace outlet and bring them to the entrance of the hardening furnace TK.

An opening device can be referred to as an opening. An opening may be referred to as an opening device.

Also disclosed is an inventive means for heating workpieces in the course of heat treatments will be affected, the means for heating as a continuous furnace with a

Flow direction is formed and comprises at least one chamber for heating workpieces, wherein the continuous furnace comprises at least one further chamber, wherein the at least a further chamber is present as a heatable chamber for keeping workpieces heated in the at least one chamber for heating warm, the at least one further chamber being connectable or connected to the at least one chamber for heating.

This heating means according to the invention can make it possible to control temperature profiles of heated workpieces. This can have a very positive effect on the consistent quality of the workpieces.

In addition, the use of such a means for heating workpieces during heat treatments is disclosed.

Also disclosed is a means for heating according to the invention, with the at least one means for heating workpieces being designed as a continuous furnace, through which the workpieces can be conveyed in a direction of flow, with the continuous furnace having an input section, a heating section and an output section, with the workpieces a first opening device can be introduced into the input section, with the workpieces being able to be removed from the output section via a second opening device, with the output section comprising an output chamber provided for taking over the workpiece from the heating section and the output chamber being able to be closed in a controlled manner with respect to the heating section and the means for hardening the workpiece .

This heating means according to the invention can make it possible to control temperature profiles of heated workpieces. This can have a very positive effect on the consistent quality of the workpieces. The use of such a means for heating workpieces during heat treatments is also disclosed.

It should be understood that the foregoing detailed description and drawings, while representing certain exemplary embodiments of the invention, are intended for purposes of illustration only and should not be construed as limiting the scope of the invention. Various modifications of the configurations described are possible without departing from the scope of the following claims and their range of equivalence. In particular, features of the exemplary embodiments that are not mentioned in the claims also emerge from this description and the figures. Such features may also occur in combinations other than those specifically disclosed herein. The fact that several such features are mentioned in the same sentence or in some other type of textual context does not therefore justify the conclusion that they can only occur in the specifically disclosed combination. Instead, it is generally to be assumed that several such features can also be omitted or modified individually, provided this does not call into question the functionality of the invention.

Device features can also be considered and formulated as process features. Process features can be considered and formulated as device features.

Claims

Patent claims :

1. A method for the heat treatment of metallic workpieces (WB), in particular transmission components, with preferably carburized metallic workpieces being introduced into a means (TK) for heating workpieces and being heated therein, the means (TK) for heating workpieces being designed as a continuous furnace and wherein workpieces (WB) are introduced into the continuous furnace through a first opening device (1) into a heating section (TKH) of the continuous furnace for heating, wherein workpieces (WB) after heating are fed into an exit section (TKO ) are transferred and kept warm therein at a specified temperature, wherein workpieces (WB) after being kept warm are discharged from the continuous furnace through a second opening device (2) which is different from the first opening device (1), wherein workpieces (WB ) are introduced into a curing agent (PQ) after application for curing.

2. The method according to claim 1, wherein between the heating section (TKH) and the output section (TKO) a partition is arranged, wherein in a first step the partition after heating the workpiece (WP) in the continuous furnace, preferably the heating section (TKH), is opened in such a way that the heating section (TKH) and the exit section (TKO) form a reservoir, with workpieces (WB) being transferred from the heating section (TKH) into the exit section (TKO) in a subsequent second step, with the sealing means being closed in a third step, such that communication between the heating section (TKH) and the output section (TKO) is at least partially, preferably completely interrupted, in a fourth step Workpieces (WB) are kept warm in the output section (TKO) and wherein workpieces (WB) are removed from the continuous furnace through the second opening device (2) after being kept warm from the output section (TKO).

3. The method according to claim 1 or 2, wherein workpieces (WB) in the continuous furnace, preferably in the heating section (TKH) are heated at least at a negative pressure and / or wherein workpieces (WB) in the output section (TKO) are kept warm in a vacuum.

4. The method according to claim 1 or 2, wherein workpieces (WB) in the continuous furnace, preferably in the heating section (TKH) are heated at atmospheric pressure and / or wherein workpieces (WB) in the output section (TKO) are kept warm at atmospheric pressure.

5. The method according to any one of the preceding claims, wherein at least one workpiece (WB) is heated in the heating section (TKH), while at least one workpiece (WB) is kept warm in the output area (TKO).

6. The method according to any one of the preceding claims, wherein pressures and / or temperatures in the heating section (TKH) and in the output section (TKO) are preferably controlled individually by means of a control unit (CPU).

7. The method according to any one of the preceding claims, wherein workpieces (WB) are transported from the output area (TKO) to the means (PQ) for hardening, in particular via a storage means for workpieces arranged between means (TK) for heating and means (PQ) for hardening be carried out in such a way that the workpieces (WB) neither exceed nor fall below a defined temperature range when they are introduced into the means (PQ) for hardening.

8. The method according to claim 7, wherein the transport takes place in a vacuum or at atmospheric pressure.

9. The method according to any one of the preceding claims 1 to 8, wherein workpieces (WB) are quenched in the medium (PQ) for hardening by means of fluid, preferably oil.

10. The method according to any one of the preceding claims 1 to 8, wherein workpieces (WB) are quenched in means (PQ) for hardening by means of gas.

11. The method according to claim 7 or 8, wherein workpieces (WB) are transported substantially transversely to a longitudinal direction of the second opening (2) to the means (PQ) for hardening.

12. The method according to any one of the preceding claims 1 to 11, wherein workpieces (WB) are transported after hardening from the means for hardening (PQ) to a means (7) for washing and are washed in the means (7) for washing, wherein the means (TK) for heating, the means (PQ) for hardening and the means (7) for washing are arranged in an enclosed space such that workpieces (WB) in the space from the means (TK) for heating via the Means (PQ) for hardening are transported to the means (7) for washing, preferably automatically, with workpieces (WB) after washing being transported either to a means for tempering workpieces to end the heat treatment after tempering and finished workpieces (WB) to be transported out of an exit from the room, or to be removed from the room from a rejection area that is different from the exit and to be metrologically examined outside the room.