EP3814125A1

EP3814125A1 - Methods for operating a stamping press and stamping presses for being operated according to the methods

Info

Publication number: EP3814125A1
Application number: EP18743747.0A
Authority: EP
Inventors: Ugo De Santis; Herbert HÖGGER
Original assignee: Bruderer AG
Current assignee: Bruderer AG
Priority date: 2018-07-16
Filing date: 2018-07-16
Publication date: 2021-05-05
Anticipated expiration: 2038-07-16
Also published as: WO2020015815A1; SG11202100462QA; JP2021531170A; US20210291474A1; ES2939825T3; EP3814125B1

Abstract

The invention relates to methods for operating a stamping press (1), comprising a ram (2), which operates against a (in particular fixed) bolster plate (3) and the position of which can be set with respect to the bolster plate (3) during operation as intended, wherein the ram (2) bears a first die part (4) and the bolster plate (3) bears a second die part (5), wherein the two die parts (4, 5) provide stop faces (6a, 7a), which are assigned to one another and, when the die is completely closed, form one or more fixed stops for delimiting the closing clearance of the die (4, 5) internally within the die. According to a first method according to the invention, during operation of the stamping press (1) as intended, the distance (a, a1, a2, a3) of the two die parts (4, 5) from one another or a parameter (b1, b2, b3, c) representing this distance at a specific point (P1, P2, P3) of the ram movement at which the die (4, 5) is not completely closed is monitored and the position of the ram is changed in dependence on the result of the monitoring. According to a second method according to the invention, during operation of the stamping press as intended, at least one of the fixed stops is monitored for contact between the stops and the position of the ram is changed in dependence on the result of the monitoring. With the methods according to the invention, it is possible even in the case of dies (4, 5) with fixed stops and irrespective of the skill and experience of the operator for the process to be conducted energy-efficiently and with little wear.

Description

Method of operating a punch press and punch presses for operation according to the procedures

Technical field

The present invention relates to methods of operating a punch press, punch presses to operate according to the method and the use of such punch presses for generating embossments for predetermined separation points in sheet metal surfaces according to the preambles of the independent claims.

State of the art

Highly complex and precise parts are manufactured on today's high-speed punching machines. So that such parts can be manufactured with a high cadence, a high repeatability of the

Closing dimension of the tool required. A change in the closing dimension on the tool has negative effects on the part accuracy.

In the event that only punching and / or forming work is carried out, tools without stops are mostly used. With these tools, the closing dimension essentially depends on the position of the upper tool part at the bottom dead center of the crank mechanism (UT position). Important factors influencing a change in the bottom position are the speed of the crank drive, the oil temperature (heating of the machine), the ambient temperature (changes during the day) and the tool heating.

From EP 0 732 194 B1 it is known to measure the UT position in a non-stop tool and to keep it constant by changing the ram position. This allows the most important influencing variables to be compensated for in a relatively simple manner.

In the event that precise embossing is carried out, for example with follow-up cutting tools, the tools are usually with so-called fixed stops equipped. The function of these fixed stops is to limit the closing dimension under operating conditions. The press is inevitably clamped at bottom dead center to ensure that the fixed stops make contact. Due to the previously mentioned influencing factors of speed, oil temperature, ambient temperature and tool heating, the degree of clamping in operation can change significantly, with the result that the press is also subjected to high loads that are not involved in the actual process and apart from that they destroy energy unnecessarily and can lead to increased wear of the press.

The solution known from EP 0 732 194 B1 cannot be used here, since the closing dimension during operation is determined independently of the degree of tensioning via the fixed stops and is always the same.

Accordingly, the problem arises that automated process control is hardly possible with such tools with fixed stops and it is essentially left to the skill and experience of the operator to run the process as energy-efficiently and with little wear.

Presentation of the invention

It is therefore the task to provide a technical solution that can help here.

This object is achieved by the methods and stamping presses according to the independent patent claims.

According to these, a first aspect of the invention relates to a method for operating a punch press, in particular with a tool, with which embossings for predetermined separation points are produced in sheet metal surfaces.

The punch press comprises a ram that works against a preferably fixed platen. The ram position opposite the clamping plate, This means that the relative position of the up and down movement of the ram in relation to the clamping plate can be adjusted during normal operation. The ram carries a first part of the tool and the platen carries a second part of the tool. The two tool parts have mutually associated stop surfaces which, when the tool is completely closed, form one or more fixed stops for limiting the closing dimension of the tool within the tool.

According to the method according to the invention, in the intended operation of the punch press, the distance between the two tool parts from one another or a parameter representing this distance, i.e. monitors a parameter from which the distance between the two tool parts can be derived at a certain point in the ram movement at which the tool is not completely closed and then changes the ram position as a function of the monitoring result.

The tool is not completely closed in the sense of the claim if the closing dimension of the tool is not limited by the or one of the fixed stops, ie no assigned stop surfaces of the two tool parts are in stop contact. This is irrespective of whether the tool is in contact with the workpiece or not.

With the method according to the invention, even in the case of tools with fixed stops, an energy-efficient and low-wear process control is possible regardless of the skill and experience of the operator.

The distance between the two tool parts or the parameter representing this distance is preferably monitored at a point of the ram movement which is closer to bottom dead center than top dead center, preferably shortly before or shortly after bottom dead center. The closer this point is to the dead center, the more precisely the process can be managed.

In a first preferred variant of the method, the distance between the two tool parts to one another or the parameter representing this distance is monitored at a point of the ram movement at which the tool is not in deformation contact with the workpiece, that is to say does not act on the workpiece, so that the pestle does no work. This has the advantage that the monitoring cannot be disturbed by any effects caused by the punching blow.

In an alternative, second preferred variant of the method, the distance between the two tool parts to one another or the parameter representing this distance is monitored at a point of the ram movement at which the tool is in deformation contact with the workpiece, i.e. acts on the workpiece, so that the Pestle does work. This variant has the advantage that the monitoring takes place under operating conditions that are very similar to the conditions at bottom dead center. This enables particularly precise process control.

Depending on the punching process, one or the other variant may be more preferred.

The movement of the plunger is preferably generated via a crank or eccentric drive, in particular in such a way that a 360 ° rotation of a crank or eccentric shaft is converted into a complete downward movement and a complete upward movement of the plunger between an upper and a lower dead center of the plunger movement , Such ram drives have become established in high-speed punch presses.

Accordingly, in the case of such stamping presses, it is preferred to set the distance between the two tool parts to one another or the parameter representing this distance at a specific angular position of the crank or To monitor the eccentric drive on which the tool is not completely closed, and then to change the ram position depending on the monitoring result. The angular position can be determined exactly and is therefore particularly well suited to determining the point of the ram movement at which the distance between the two tool parts or the parameter representing this distance is monitored.

Monitoring is advantageously carried out at an angular position which lies in a range of plus / minus 35 ° around the bottom dead center. It has been shown that this angular position range is particularly suitable for monitoring the distance between the two tool parts or the parameter representing this distance.

In a preferred embodiment of the method according to the invention, the distance between the two tool parts to one another or the parameter representing this distance at the specific point of the plunger movement or at the specific angular position in the intended operation is set manually by adjusting the plunger position as a function of the monitoring result or kept constant automatically. This makes it possible to keep the degree of tension in the press at bottom dead center essentially constant over the entire operation, irrespective of the influencing factors speed, oil temperature, ambient temperature and tool heating, so that a uniform product quality can be ensured.

If the distance between the two tool parts to one another or the parameter representing this distance at the specific point of the ram movement or at the specific angular position is set to a specific value, in particular to an empirically determined value at which a desired production result is achieved, and then kept constant at this value by adjusting the ram position as a function of the monitoring result high efficiency achieve optimal production results with minimal mechanical stress on the press.

According to a preferred variant, it is also provided to monitor the distance between the two tool parts to one another or a parameter representing this distance at several points of the ram movement, e.g. both shortly before and shortly after bottom dead center, and then to change the ram position depending on this monitoring result.

A second aspect of the invention relates to a further method for operating a punch press, in particular with a tool, with which embossings for predetermined separation points are produced in sheet metal surfaces.

The punch press comprises a plunger that works against a preferably fixed platen and the plunger position of which can be adjusted relative to the platen during normal operation.

The ram carries a first part of the tool and the platen carries a second part of the tool.

The two tool parts have mutually associated striking surfaces which, when the tool is completely closed, form one or more fixed stops for internal limitation of the closing dimension of the tool.

According to this procedure, at least one of the fixed stops is monitored for stop contact during the intended operation of the punch press and the pushing position is changed depending on the monitoring result.

This second method according to the invention also makes it possible to implement energy-efficient and low-wear process control for tools with fixed stops, regardless of the skill and experience of the operator.

With this method, monitoring for stop contact can be carried out directly or indirectly, i.e.

by recording effects caused by the tact are caused (directly) or by parameters that suggest a contact or

represent this (indirectly).

Thus, according to a preferred embodiment of the second method, an electrical contact is produced or closed by the contact of the respective stop surfaces, which generates a contact signal that is used for monitoring.

For this purpose, in a first variant, at least one of the fixed stops advantageously has one of the stop surfaces with two contacts, which are short-circuited by the other stop surface for generating the contact signal in the event of stop contact.

In another preferred variant, in at least one of the fixed stops, the two stop faces form a contact pair which is closed when the contact signal is generated in order to generate the contact signal.

These direct monitoring variants by means of stop surfaces which simultaneously represent electrical contacts can be implemented in a simple manner and are robust and reliable.

In a further preferred embodiment of the second method, a deformation of a physicality of the tool or of a tool area which occurs under the stop pressure and which provides one of the contact surfaces of a fixed stop is detected for monitoring the fixed stop for stop contact, e.g. using strain gauges and / or piezo elements.

In yet another preferred embodiment of the second method, a parameter representing the stop contact is monitored.

According to a preferred variant, this is done in such a way that physicalities formed by or carried by the two tool parts are preferably monitored in a contactless manner for a relative position to one another which represents the stop contact, For example, to a reference dimension, which is only reached when the stop contact is made.

In a further preferred variant, one or more reference stops are monitored for stop contact, each of which is formed by mutually associated stop faces of the two tool parts and at the stop contact of which or the monitored fixed stops also have stop contact. This is done e.g. such that, as described above, an electrical contact is produced or closed by the contact of the stop surfaces of the respective reference stop, which generates a contact signal, or a deformation of a physical body taking place under the stop pressure, which provides one of the contact surfaces of the respective reference stop, is detected.

In the second method according to the invention, the movement of the tappet is preferably generated via a crank or eccentric drive, in particular in such a way that a 360 ° rotation of a crank or

Eccentric shaft is converted into a complete downward movement and a subsequent complete upward movement of the plunger between an upper and a lower dead center of the plunger movement. Such ram drives have become established in high-speed punch presses.

In yet another preferred embodiment of the second method, the movement course of the first tool part or the plunger is monitored with respect to the fixed press structure, with respect to the clamping plate or with respect to the second tool part in the region of the bottom dead center of the plunger movement and the plunger position is dependent changed by the monitoring result.

In a preferred variant, this is done in such a way that the time or the angle of rotation of the crank or eccentric drive is monitored, during which or which the first tool part or the ram in the loading Rich the bottom dead center of the ram movement no relative movement with respect to the fixed press structure, with respect to the platen or with respect to the second tool part, and the ram position is changed depending on this time or this angle of rotation. In this way, relatively simple and precise monitoring is possible.

In yet another preferred embodiment of the second method, the drive torque curve or the power consumption curve of the press drive is monitored in the region of the bottom dead center of the ram movement and the ram position is changed as a function of the monitoring result.

According to a preferred variant, this is done in such a way that the time or the angle of rotation of the crank or eccentric drive is monitored, during which or which the drive torque or the power consumption in the area of the bottom dead center of the tappet movement has a certain course or a certain threshold len value exceeds, and the ram position is changed depending on this time or this angle of rotation.

In another variant, the maximum value is what the drive torque or the Power Con- would take in the region of bottom dead center of Stösselbewe supply achieved monitored and the ram location Depending ^¬ ness is changed from the monitoring result.

Such variants based on the drive torque curve or the power consumption curve of the press drive have the advantage that no sensors are required in the actual working space of the punch press, which is why they are very reliable.

In yet another preferred embodiment of the second method, the duration of the stop contact of one or more fixed stops is adjusted manually or automatically by setting the ram position depending on the Monitoring result kept constant. This makes it possible to keep the degree of tension in the press at bottom dead center essentially constant over the entire operation, regardless of influencing factors such as speed, oil temperature, ambient temperature and tool heating, so that uniform product quality and efficient and low-wear operation are guaranteed can be.

It is preferred that the plunger position is set in dependence on the monitoring result in such a way that a certain stop contact duration results, preferably the shortest possible stop contact duration. In this way, optimal production results can be achieved with a high degree of efficiency with minimal mechanical stress on the press.

In yet another preferred embodiment of the second method, the punch press tool has several monitored fixed stops. In the intended operation, a certain constellation from these monitored fixed stops is preferably brought into stop contact automatically by adjusting the ram position, depending on the monitoring result, with each working stroke.

The plunger position is preferably set as a function of the monitoring result in such a way that a fixed stop of the constellation that comes last into stop contact is as short as possible in stop contact. In this way too, optimal production results with minimal mechanical stress on the press can be achieved with such tools with high efficiency.

In the method according to the invention in accordance with the first and the second aspect of the invention, embossments for predetermined separation points in sheet metal surfaces are advantageously produced with the tool, preferably predetermined separation points in sheet metal surfaces for container lids with tear-open or press-in tabs. In such applications the advantages of the method according to the invention are particularly evident.

A third aspect of the invention relates to a first punch press for operation according to the method according to the first aspect of the invention.

The punch press comprises a preferably fixed platen and a ram that works against the platen. The ram position of the ram in relation to the clamping plate can be adjusted during normal operation. The ram carries a first tool part and the platen carries a second tool part. The two tool parts provide mutually assigned stop surfaces which, when the tool is completely closed, provide one or more fixed stops for limiting the tool inside

Form the closing dimension of the tool. Such punching tools are typically used when high-precision embossing has to be produced, e.g. Deselection points in can lid blanks.

The punch press has devices for controlling the ram position, with which, during the intended operation of the punch press, the distance between the two tool parts to one another or a parameter representing this distance at a certain point in the ram movement, at which the tool is not completely free is closed, can be monitored as described in the first aspect of the invention and the ram position can be changed depending on the monitoring result.

As already mentioned, the tool is not completely closed in the appropriate sense if the closing dimension of the tool is not limited by the or one of the fixed stops, i.e. none of the associated stop surfaces of the two tool parts are in stop contact. This is irrespective of whether the tool is in deformation contact with the workpiece or not. With the punch press according to the invention, even with tools with fixed stops, energy-efficient and low-wear production is possible regardless of the skill and experience of the operator.

In a preferred embodiment of the punch press, its devices for controlling the ram position are designed such that the distance between the two tool parts to one another or the parameter representing this distance can be monitored at a point of the ram movement which is closer to the bottom dead center of the ram movement than their top dead center. This point is preferably shortly before or shortly after the bottom dead center. The closer this point is to the bottom dead center, the more precisely the process can be conducted.

In a first variant, the devices for controlling the ram position are designed in such a way that the distance between the two tool parts to one another or the parameter representing this distance can be monitored at a point of the ram movement at which the tool is not in deformation contact with the workpiece, So do not act on the workpiece so that the ram does no work. This has the advantage that a disturbance in the monitoring can be prevented by any effects caused by the work of the plunger.

In an alternative second variant of the device, the devices for controlling the ram position are designed in such a way that the distance between the two tool parts to one another or the parameter representing this distance can be monitored at a point of the ram movement at which the tool is in deformation contact with the workpiece , so acts on the workpiece so that the ram does work. This variant offers the advantage that the moni ^¬ monitoring can take place under operating conditions that the Conditions at bottom dead center are very similar, which enables particularly precise process control.

Depending on the punching process carried out on the punch press, one or the other variant may be more preferred.

According to a preferred variant of the punch press, the devices for controlling the ram position are designed such that the distance between the two tool parts to one another or a parameter representative of this distance can be monitored both before and after the bottom dead center of the ram movement and then the ram position can be changed depending on these monitoring results.

The punch press preferably has a crank or eccentric drive for generating the ram movement. A 360 ° rotation of a crank or eccentric shaft is converted into a complete downward movement and a complete upward movement of the ram between an upper and a lower dead center of the ram movement. Such stamping presses have become established for the production of stamped parts with a high cadence.

Accordingly, in the case of punching presses of this type, it is preferred to monitor the distance between the two tool parts from one another or the parameter representing this distance at a specific angular position of the crank or eccentric drive at which the tool is not completely closed, and then the plunger position as a function of to change the monitoring result. The angular position can be determined exactly and is therefore particularly well suited to determining the point of the ram movement at which the distance between the two tool parts or the parameter representing this distance is monitored.

The devices for controlling the ram position are advantageously designed such that they monitor the distance between the two tool parts to each other or this distance can represent the parameter at an angular position which is in a range of plus / minus 35 ° around the bottom dead center. It has been shown that this angular position range is particularly suitable for monitoring the distance between the two tool parts from one another or for a parameter representing this distance.

In yet another preferred embodiment of the first punch press, the devices for controlling the ram position are designed such that the distance between the two tool parts to one another or the parameter representing this distance at the particular point of the ram movement or at the particular winch position in the intended operation by adjustment the ram position can be kept constant depending on the monitoring result. This makes it possible to keep the degree of tension in the press at bottom dead center essentially constant over the entire operation, regardless of influencing factors such as speed, oil temperature, ambient temperature and tool heating, so that uniform product quality and efficient, low-wear operation can be ensured.

The devices for controlling the ram position are advantageously designed such that the distance between the two tool parts to one another or the parameter representing this distance can be set to a specific value, preferably to a value, at the specific point of the plunger movement or at the specific angle empirically determined value at which a desired production result is achieved and then can be kept constant automatically at this value automatically by adjusting the ram position depending on the monitoring result. With such punching presses according to the invention, optimal production results can be achieved with high efficiency with minimal mechanical stress on the press. A fourth aspect of the invention relates to a further punch press for operation according to the method according to the second aspect of the invention.

This second punch press also includes a preferably fixed platen and a ram that works against the platen. The ram position of the ram in relation to the clamping plate can also be adjusted during normal operation. The ram carries a first tool part and the platen carries a second tool part. The two tool parts provide mutually associated stop surfaces which, when the tool is completely closed, form one or more fixed stops for limiting the closing dimension of the tool inside the tool.

The punch press has devices for control of the ram position, with which at least one of the fixed stops of the tool can be monitored for stop contact during the intended operation of the punch press and who can change the ram position depending on the monitoring result.

As already mentioned, the tool is not completely closed in the appropriate sense if the closing dimension of the tool is not limited by the or one of the fixed stops, i.e. no assigned stop surfaces of the two tool parts are in stop contact. This is irrespective of whether the tool is in deformation contact with the workpiece or not.

With the second punch press according to the invention, energy-efficient and low-wear production is also possible with tools with fixed stops, regardless of the skill and experience of the operator.

In a preferred embodiment of the second punch press, the tool is designed such that an electrical contact is made or closed by the contact of the respective stop surfaces. which generates a contact signal for monitoring the devices for controlling the plunger position.

Advantageously, in a first variant, for at least one of the fixed stops, one of the stop surfaces has two contacts which are short-circuited by the other stop surface for the generation of the contact signal upon stop contact.

In another preferred variant, in at least one of the fixed stops of the tool, the two stop surfaces form a contact pair which is closed when the contact signal is generated in order to generate the contact signal.

In a further preferred embodiment of the second punch press, the tool and the devices for controlling the ram position are designed in such a way that a deformation of a physicality of the tool or a tool area, which provides one of the contact surfaces of a fixed stop, takes place under the stop pressure. to monitor the fixed stop on stop contact can be detected, in particular by means of strain gauges and / - or piezo elements, and depending on this the ram position can be changed.

In yet another preferred embodiment of the second punch press, the devices for controlling the ram position are designed such that a parameter representing the stop contact can be monitored.

In a preferred variant, the devices for controlling the plunger position are designed in such a way that physicalities formed by or carried by the two tool parts can preferably be monitored contactlessly for a relative position to one another which represents the stop contact, for example to a reference dimension which is only available at Stop contact is reached. In a further preferred variant of the second punch press, the tool and the devices for controlling the ram position are formed in such a way that one or more reference stops formed by respectively assigned stop surfaces of the two tool parts, at the stop contact of which the monitored fixed stop or stops have stop contact, can be monitored for stop contact, preferably in such a way that an electrical contact is produced or closed by the contact of the stop surfaces of the respective reference stop, which generates a contact signal, or that a physical body deformation taking place under the stop pressure affects one of the contact surfaces of the respective reference stop provides, can be detected.

The second punch press also preferably has a crank or eccentric drive for generating the plunger movement, with which a 360 ° rotation of a crank or eccentric shaft in a fully continuous downward movement and a complete upward movement of the plunger between an upper and a lower one Dead center of the ram movement is converted.

As already mentioned, such stamping presses have become established for the production of stamped parts with a high cadence.

In yet another preferred embodiment of the second punch press, the devices for controlling the ram position are designed such that the course of movement of the first tool part or the ram with respect to the fixed press structure, with respect to the clamping plate or with respect to the second tool part in the area of the bottom dead center Plunger movement can be monitored and the plunger position can be changed depending on the monitoring result.

In a preferred variant, the devices for controlling the plunger position are of this type formed that the time or the angle of rotation of the crank or eccentric drive can be monitored during which or which the first tool part or the plunger in the region of the bottom dead center of the plunger movement no relative movement with respect to the fixed press structure, with respect to the clamping plate or with respect to the second tool part performed, and the ram position can be changed depending on this time or this angle of rotation. This enables relatively simple and precise monitoring.

In yet another preferred embodiment of the second punch press, the devices for controlling the ram position are designed such that the drive torque curve or the power consumption curve of the crank or eccentric drive can be monitored in the region of the bottom dead center of the ram movement and the ram position as a function of it can be changed from the monitoring result.

For this purpose, the devices are constructed in such a way to control the ram position, that the time or the angle of rotation of the treatment ^¬ Bel or eccentric drive can be monitored during which or which the driving torque or the power in the region of bottom dead center of the ram movement of a according to a preferred variant has a certain course or exceeds a certain threshold and the plunger position can be changed depending on the monitoring result.

It is also preferred that the devices for controlling the plunger position are designed such that the maximum value which the drive torque or the power consumption reaches in the region of the bottom dead center of the plunger movement can be monitored and the plunger position can be changed as a function of the monitoring result.

Such on the drive torque curve or the power consumption curve of the press drive based monitoring devices have the advantage that they do not require any sensors in the actual working space of the punch press, which is why they are very reliable.

In yet another preferred embodiment of the second punch press, the devices for controlling the ram position are designed in such a way that the duration of the stop contact of one or more fixed stops can preferably be kept constant in an automated manner by adjusting the ram position depending on the monitoring result. This makes it possible to keep the degree of tension in the press at bottom dead center essentially constant over the entire operation, regardless of influencing factors such as speed, oil temperature, ambient temperature and tool heating, so that uniform product quality can be ensured.

It is preferred that the devices for controlling the plunger position are designed such that the plunger position can be set as a function of the monitoring result in such a way that a certain stop contact duration results, and preferably the shortest possible stop contact duration. In this way, optimal production results can be achieved with a high degree of efficiency with minimal mechanical stress on the press.

In yet another preferred embodiment of the second punch press, the punch press tool has several monitored fixed stops and the devices for controlling the ram position are designed in such a way that, during normal operation, a certain constellation of these monitored fixed stops is preferably automated by adjusting the ram position in dependence can be brought into stop contact by the monitoring result at every working stroke. The devices for controlling the plunger position are preferably designed such that the plunger position can be set in such a way as a function of the monitoring result that a fixed stop of the constellation that comes last into stop contact is as short as possible in stop contact. In this way too, optimum production results can be achieved with a high degree of efficiency with minimal mechanical stress on the press.

A fifth aspect of the invention relates to the use of the punch presses according to the third and fourth aspects of the invention for producing embossments for predetermined separation points in sheet metal surfaces, preferably for predetermined separation points in sheet metal surfaces for container lids with tear-open or press-in tabs. With such uses, the advantages of the invention become particularly apparent.

Brief description of the drawings

Further preferred embodiments of the invention result from the dependent claims and from the description that follows with reference to the figures. Show:

Fig. 1 shows a punch press according to the invention with a punch tool with fixed stops in the

Front view; and

FIGS. 2 to 10 each show the detail X from FIG. 1 with an associated ram movement curve in various embodiments and modes of operation of the punch press according to the invention.

Ways of Carrying Out the Invention

Fig. 1 shows a highly abstracted inventive fast-running stamping press 1 for the manufacture of stamped parts with high-precision embossing for predetermined separation points in sheet metal surfaces, such as blanks for Front view of container lid with tear-open or press-in tab.

As can be seen, the press 1 has a fixed platen 3 and a plunger 2 which works against the platen 3. The plunger position, ie the relative position of the upward and downward movement of the plunger 2 relative to the clamping plate 3, can be set in the intended operation.

The plunger 2 carries an upper tool part 4 (first tool part according to the claims), which has a stamp 9 with a punching mandrel 10 and a punching mandrel 10 surrounding the punching punch 10.

The platen 3 carries a lower tool part 5 (according to the second tool part), which forms a support surface for the material to be machined mialial 13 and a die 12 for the punch 10 of the upper tool part 4. The two tool parts 4 and 5 together form the punching and embossing tool 4, 5 of the press 1. They each have stop bodies 6, 7, which provide mutually associated stop surfaces 6a, 7a, which, when the tool 4, 5 are fully closed, provide fixed stops for internal tool limitation the closing asses of the tool 4, 5 form.

The punch press 1 has a crank mechanism 8 for generating the tappet movement (symbolically represented by dashed lines), which provides 360 ° rotation of a crankshaft in a complete downward movement and a subsequent complete upward movement of the tappet 2 between an upper dead center and a lower dead center UT the ram movement converts.

By means of a belt feed (not shown), the material band 13 to be processed is intermittently pushed through the press 1 from right to left when the punch press 1 is operating as intended.

Furthermore, the press 1 has a press control (not shown) with devices for controlling the ram position. In Figures 2 to 10 are each based on the detail X from FIG. 1 and an associated ram movement curve 15 for an angle of rotation range of the crank drive from about 35 ° before bottom dead center UT to about 35 ° thereafter various operating modes and embodiments of the punch press according to the invention 1 explained.

The distances, the thickness of the strip material 13 and in particular also the height of the embossing projection 11 are shown clearly enlarged for the sake of better visibility.

In the first embodiment of the punch press 1 according to the invention illustrated in FIGS. 2 to 4 and in the second embodiment of the punch press 1 according to the invention illustrated in FIG. 5, the press control is designed according to the invention in such a way that, during the intended operation of the punch press 1, the distance a, al, a2, a3 of the two tool parts 4, 5 to one another or a parameter bl, b2, b3, c representing this distance at a specific point Pl, P2, P3 of the ram movement at which the tool 4, 5 is not completely closed, can be monitored and the ram position can be changed depending on the monitoring result, preferably such that constant closing conditions of the tool 4, 5 are present at the bottom dead center of the ram movement over the entire production operation.

In this way it is possible the influence of the closing dimension influencing variables such as work zeug- and compensate for heating of the machine, ambient temperature and speed of the crankshaft drive and make largely over the entire operating substantially identical Werkzeugschliessbedingungen at bottom dead center sicherzu ^¬.

In the first embodiment of the punch press 1 according to FIGS. 2-4, the lower stop body 7 has a contactless distance sensor 14 at its center, set back from the stop surface 7a Intended operation of the press 1 serves to determine the distance to the stop surface 6 a of the associated impact body 6 of the upper tool half 4. In the present case, this sensor 14 is an inductive position sensor or a laser distance sensor.

As can be seen from the representation according to FIG. 2 in a view with the associated ram movement curve 15 shown next to it, the press ram 2 is in the situation shown here - shortly after the punching and embossing process - in the upward movement in a position which is an angle of rotation position PI of the crank mechanism of 35 ° after the UT (+ 35 °) corresponds. In this position, the abutment surfaces 6a, 7a of the abutment bodies 6, 7 shown have a position from one another. In this situation, the tool 4, 5 is not in deformation contact with the material band 13, and consequently does no work.

In the first mode of operation according to the invention of the punch press 1 illustrated here according to the invention, the press control uses the sensor 14 to determine the distance a1 between the stop faces 6a with each ram stroke or at certain intervals in the illustrated rotational angle position PI (35 ° after UT) , 7a or a reference distance, e.g. the distance bl between the sensor 14 and the stop surface 6a of the upper stop body 6, and compares this with a target value.

This determination of the distance a1 or the reference distance b1 and comparison of the same with a target value corresponds to the monitoring of the distance between the two tool parts to one another or a parameter representing this distance (reference distance).

If a deviation from the target value is determined, the press control changes the ram position, in the present case in such a way that when the monitoring, the deviation from the setpoint is reduced or eliminated.

3 illustrates a second mode of operation according to the invention of the first embodiment of the punch press 1. As can be seen in conjunction with the associated ram movement curve 15, the press ram 2 is in the situation shown in the downward movement - shortly before the punching and Embossing process - in a position which corresponds to a rotation angle position P2 of the crank mechanism of 20 ° before the OT (-20 °). In this position, the stop surfaces 6a, 7a of the illustrated stop bodies 6, 7 are at a distance a2 from one another or the sensor 14 is at a distance b2 from the stop surface 6a of the upper stop body 6. In this situation, the tool 4, 5 is not in contact with the material strip 13 and consequently does not perform any work. The second operating mode of the punch press 1 illustrated here differs from that illustrated in FIG. 2 only in that the distance a2 between the stop surfaces 6a, 7a and the reference distance b2 are each in the angular position P2 of the crank mechanism (20 ° before UT) it is averaged and compared with a corresponding setpoint. Monitoring the distance a2 of the two tool parts 4, 5 to one another or a reference distance b2 representing this distance at the rotational angle position P2 shortly before the punch mandrel 10 and the embossing protrusion 11 hit the material strip 13 has the part before that on the system acting acceleration forces are very similar to those at bottom dead center, but there are still no system vibrations excited by the punch that could interfere with the measurement. Accordingly, very reliable and precise monitoring is possible in this way.

4 illustrates a third mode of operation according to the invention of the first embodiment of the punch press 1. As viewed in conjunction with the associated pushing Sel movement curve 15 can be seen, the press ram 2 is in the situation shown in Fig. 4 in the downward movement during the punching and embossing process in a position which corresponds to a rotational angle position P3 of the crank mechanism of 10 ° before the OT (-10 °) , In this position, the stop surfaces 6a, 7a of the illustrated stop bodies 6, 7 are at a distance a3 from one another or the sensor 14 is at a distance b3 from the stop surface 6a of the upper stop body 6. The punching mandrel 10 has already continuously penetrated the material strip 13 and is inserted into the die 12, and the embossing projection 11 has just begun to penetrate the material strip 13. Accordingly, the tool is in deformation contact with the material band 13 in this situation and performs deformation work (embossing).

The third operation of the punch press according to the invention illustrated here differs from that illustrated in FIG. 3 only in that here the distance a3 between the stop surfaces 6a, 7a or the reference distance b3 in each case in the rotational angle position P3 of the crank mechanism (10 ° before UT) is determined and compared with a corresponding setpoint. Monitoring the distance a3 between the two tool parts 4, 5 or a reference distance b3 representing this distance at the rotational angle position P3 after the punching mandrel 10 has passed through the material strip 13 and during the penetration of the embossing projection 11 into the material strip 13 has the advantage that the total forces acting on the system are very similar to those that occur in ideal operation at bottom dead center. Correspondingly, a particularly reliable and precise monitoring is possible with this mode of operation.

The second embodiment of the punch press 1 according to FIG. 5 differs from the first embodiment according to FIGS. 2, 3 and 4 in that the distance sensor 14 is not located in the lower stop body 7. is arranged, but on an auxiliary carrier 16, and that the distance c between the sensor 14 and a reference surface 21 on the underside of the upper tool half 4 is determined with it. This reference distance c, like the reference distances bl, b2, b3 in the first embodiment of the punch press 1, is a parameter representing the distance between the stop surfaces 6a and 7a of the stop bodies 6, 7. The remaining structure of the punch press 1 is identical to that according to the first embodiment and the sensor 14 is also an inductive distance sensor or a laser distance sensor in the present case.

As can be seen from the representation according to FIG. 5 in a summary with the associated ram movement curve 15 shown next to it, the press ram 2 is in the situation shown here (as already in the situation shown in FIG. 2) shortly after the stamping and embossing process has taken place in the upward movement in a position which corresponds to a rotational angle position Pl of the crank mechanism of 35 ° after the UT (+ 35 °). In this position 7 have the abutment surfaces 6a, 7a of the stop body 6 shown, a distance a zuein ^¬ on the other. In this situation, the tool is not in deformation contact with the material band 13 and consequently does no work.

In the operation of the second embodiment of the punch press 1 illustrated here according to the invention, the press control uses the sensor 14 to determine the distance a between the stop surfaces 6a with each ram stroke or at certain intervals, in each case in the illustrated rotational angle position Pl (35 ° according to UT).

7a or a reference distance, for example the distance c between the sensor 14 and the reference surface 21 on the ^{underside of} the upper tool half 4 and compares this with a target value.

This determining the distance a or the reference distance c and comparing the same with one The setpoint corresponds to the monitoring of the distance between the two tool parts to one another or a parameter representing this distance (reference distance).

If a deviation from the setpoint is determined, the press control changes the ram position, in the present case in such a way that the deviation from the setpoint is reduced or eliminated when monitoring continues.

In the various embodiments of the punch press 1 illustrated in FIGS. 6 to 11, the press control is designed in accordance with the invention in such a way that it can be used to monitor at least one of the fixed stops for stop contact during the intended operation of the punch press 1 and the plunger position depending on the monitoring result can be changed, preferably in such a way that constant closing conditions of the tool 4, 5 are present at the bottom dead center of the ram movement over the entire production operation.

In this way, it is also possible to largely compensate for the influence of the variables influencing the closing dimension, such as tool and machine heating, ambient temperature and speed of the crank mechanism, and to ensure essentially identical tool closing conditions at bottom dead center UT over the entire operation.

As can be seen in conjunction with the associated ram movement curves 15, the press ram 2 is in the situations shown in FIGS. 6 to 11 in each case at the bottom dead center UT of its movement. In this position, the abutment surfaces 6a, 7a of the abutment bodies 6, 7 shown abut one another and thus form a fixed stop which limits the tool closing dimension.

As can further be seen from the associated plunger movement curves 15, the point Pkl is in the situations shown in FIGS. 6 to 11 which the stop contact occurs between the two stop surfaces 6a, 7a, in each case at 5 ° before UT (-5 °) and the point Pk2, at which the stop contact is canceled again, in each case at 5 ° after UT (+ 5 °). Correspondingly, there is stop contact within a rotation angle range of 10 ° (plus / minus 5 ° around UT). At the present speed of the crank mechanism 8 of the press 1 of 1000 rpm, there is a stop contact for a time period t of 1.6 ms.

The third embodiment of the punch press 1 illustrated in FIG. 6 differs from the first embodiment according to FIGS. 2 to 4 only in that it has a press control which implements a different mode of operation of the press according to the invention. In this embodiment, the press controller does not determine the distance between the stop surfaces 6a, 7a or a reference distance at a specific rotational angle position PI, P2 or P3, but instead uses the sensor 14 to determine the rotational angle positions Pkl and Pk2 or the rotational angle range or the contactlessly Period t, between which or within which there is no longer a distance between the stop surfaces 6a, 7a (stop contact) or between which surfaces or within which a certain minimum distance between the stop surfaces 6a, 7a has fallen below or has been reached. For this purpose, the press control evaluates the reference distance d between the sensor 14 and the stop surface 6a of the upper stop body 6, which represents the stop contact of the stop surfaces 6a and 7a or the determined minimum distance.

The determined rotation angle positions Pkl,

Pk2, rotation angle ranges and / or time periods t are compared with setpoints. If the press control detects a deviation from the setpoint, it changes the ram position in such a way that the deviation from the setpoint is reduced or eliminated with continuous monitoring. The fourth embodiment of the punch press 1 according to FIG. 7 differs from the second embodiment according to FIG. 5 in that it does not have a distance sensor 14 for determining a reference distance representing the distance between the stop surfaces 6a, 7a, but two strain gauges 17 or piezo elements , with which a deformation D of the lower impactor 7 can be determined when pressing the upper stopper 6 with its stop surface 6a against the stopper surface 7a of the lower stopper 7. It also has a press control which implements a different mode of operation of the press 1 according to the invention.

In the present case, the press control uses the strain gauges 17 or piezo elements to determine the rotation angle positions Pkl and Pk2 or the rotation angle range or the period t between which or within which stop contact there is between the stop surfaces 6a, 7a. The determined rotation angle positions Pkl, Pk2, rotation angle ranges and / or time periods t are compared with target values. If the press control detects a deviation from the setpoint, it changes the ram position in such a way that the deviation from the setpoint is reduced or canceled as monitoring continues.

The fifth embodiment of the punch press 1 according to FIG. 8 differs from the second embodiment according to FIG. 5 in that it does not have strain gauges 17 or piezo elements for determining a stop contact between the stop surfaces 6a, 7a, but these stop surfaces 6a, 7a are formed by electrical contact bodies 18a and 18b, which together form a pair of contacts 18a, 18b, which is closed for the generation of a contact signal KS with stop contact. It also has a press control which implements a different mode of operation of the press according to the invention. In this embodiment, the press controller uses the contact pair 18a, 18b to determine the rotation angle positions Pkl and Pk2 or the rotation angle range or the period t between which or within which contact contact between the stop surfaces 6a, 7a. The determined rotation angle positions Pkl, Pk2, rotation angle ranges and / or time periods t are compared with target values. If the press control detects a deviation from the setpoint, it changes the ram position in such a way that the deviation from the setpoint is reduced or eliminated with continuous monitoring.

The sixth embodiment of the punch press 1 according to FIG. 9 differs from the fifth embodiment according to FIG. 8 in that the stop surface 7a of the lower stop body 7 is formed by two separate electrical contact bodies 19a and 19b, while the stop surface 6a of the upper stop body 6 is formed by a single contiguous contact body 20. The contact bodies 19a and 19b form two contacts 19a, 19b, which are short-circuited by the contact body 20 in the event of a stop contact and thereby generate a contact signal KS.

The press control is identical to that of the fifth embodiment of the punch press described above. With the help of the contacts 19a,

19b, the rotation angle positions Pkl and Pk2 or the rotation angle range or the period t, between which or within which stop contact between the stop surfaces 6a, 7a. The determined rotation angle positions Pkl, Pk2, rotation angle ranges and / or time periods t are compared with target values. If the press control system detects a deviation from the setpoint, it changes the ram position in such a way that the deviation from the setpoint is reduced or eliminated with continuous monitoring. The seventh embodiment of the punch press 1 illustrated in FIG. 10 differs from the second embodiment according to FIG. 5 only in that it has a press control which implements a different mode of operation of the press according to the invention. In this embodiment, the press control with the aid of the sensor 14 does not determine the distance between the stop surfaces 6a, 7a or a reference distance at a specific angle of rotation position, but rather determines it with the aid of the sensor 14 and the reference surface 21 on the underside of the upper tool half 4 without contact, the rotation angle positions Pkl and Pk2 or the rotation angle range or the period t, between which or within which the upper tool half 4 does not perform any vertical movement due to a stop contact of the stop surfaces 6a, 7a (movement stop). For this purpose, the press controller evaluates the change in the reference distance c between the sensor 14 and the reference surface 21 in the area around the bottom dead center UT.

The determined rotation angle positions Pkl,

Pk2, rotation angle ranges and / or time periods t are compared with setpoints. If the press control detects a deviation from the setpoint, it changes the ram position in such a way that the deviation from the setpoint is reduced or eliminated with continuous monitoring.

While preferred embodiments of the invention have been described in the present application, it should be clearly pointed out that the invention is not limited to these and can also be carried out in other ways within the scope of the following claims. In particular, it should also be explicitly mentioned here that various combinations of the previously described modes of operation are also provided, insofar as this is technically sensible.

Claims

claims

1. Method for operating a punch press (1) with a plunger (2), which works against a fixed platen (3) in particular and whose plunger position relative to the platen (3) can be adjusted during normal operation, the plunger (2 ) carries a first tool part (4) and the clamping plate (3) carries a second tool part (5), the two tool parts (4, 5) providing mutually assigned stop surfaces (6a, 7a) which, when the tool is completely closed ( 4, 5) one or more fixed stops to limit the tool internal

Form the closing dimension of the tool (4, 5),

characterized in that during the intended operation of the punch press (1) the distance (a, al, a2, a3) of the two tool parts (4, 5) to one another or a parameter (bl, b2, b3, c) representing this distance a certain point (PI, P2, P3) of the plunger movement, at which the tool (4, 5) is not completely closed, is monitored and the plunger position is changed depending on the monitoring result.

2. The method according to claim 1, wherein the distance (a, al, a2, a3) of the two tool parts (4, 5) to one another or the distance representing this

Parameter (bl, b2, b3, c) is monitored at a point (PI, P2, P3) of the ram movement which corresponds to the lower one

Dead center (UT) of the ram movement is closer than the top dead center of the ram movement, in particular shortly before or shortly after the bottom dead center (ÜT).

3. The method according to claim 2, wherein the distance (a, al, a2) of the two tool parts (4, 5)

to each other or the one representing this distance Parameter (bl, b2, c) is monitored at a point (Pl, P2) of the ram movement at which the tool (4, 5) is not in deformation contact with the workpiece (13).

4. The method according to claim 2, wherein the distance (a3) of the two tool parts (4, 5) to one another or the parameter (b3) representing this distance is monitored at a point (P3) of the ram movement at which the tool (4, 5) is in deformation contact with the workpiece (13).

5. The method according to any one of the preceding claims, wherein the ram movement is generated via a crank or eccentric drive (8).

6. The method according to claim 5, wherein the distance (a, al, a2, a3) of the two tool parts (4, 5) to one another or the parameter (bl, b2, b3, c) representing this distance at a specific angular position (Pl, P2, P3) of the crank or eccentric drive (8), in which the tool (4, 5) is not completely closed, is monitored and the ram position is changed as a function of the monitoring result.

7. The method according to claim 6, wherein the Win kelpposition (Pl, P2, P3) is in a range of plus / minus 35 ° around the bottom dead center (UT).

8. The method according to any one of the preceding claims, wherein the distance (a, al, a2, a3) of the two tool parts (4, 5) to one another or the parameter representing this distance (bl, b2, b3, c) on the be ^¬ correct point (Pl, P2, P3) of the plunger movement or at the specific angular position (Pl, P2, P3) in the operation required for the intended purpose by setting the plunger position as a function of the monitoring result.

9. The method according to claim 8, wherein the distance (a, al, a2, a3) of the two tool parts (4, 5) to one another or the parameter representing this distance (bl, b2, b3, c) at the determined point (PI , P2, P3) of the ram movement or at the specific angular position (PI, P2, P3) to a specific value

is set, in particular to an empirically determined value, and then automated by

Adjustment of the ram position depending on the

Monitoring result is kept constant at this value.

10. Method for operating a punch press (1) with a plunger (2), which works against a fixed platen (3) in particular and whose plunger position relative to the platen (3) can be adjusted during normal operation, the plunger (2 ) carries a first tool part (4) and the clamping plate (3) carries a second tool part (5), the two tool parts (4, 5) providing mutually assigned stop surfaces (6a, 7a) which, when the tool (4 , 5) one or more fixed stops to limit the tool internal

Form the closing dimension of the tool (4, 5),

characterized in that during the intended operation of the punch press (1) at least one of the fixed stops is monitored for stop contact and the ram position is changed depending on the monitoring result.

11. The method according to claim 10, wherein the contact of the respective stop surfaces (6a, 7a) produces or closes an electrical contact (18a, 18b; 19a, 19b, 20) which generates a contact signal for monitoring.

12. The method according to claim 11, wherein in at least one of the fixed stops one of the stop surfaces (7 a) has two contacts (19 a, 19 b), which contact for the generation of the contact signal (KS) on stop by the other stop surface 6 a, 20) be closed.

13. The method according to any one of claims 11 to

12, with at least one of the fixed stops the two stop surfaces (6a, 7a) forming a pair of contacts (18a, 18b) which is closed for generating the contact signal (KS) when the stop contact is made.

14. The method according to any one of claims 10 to

13, wherein a deformation (D) of a physical body (7) taking place under the stop pressure, which one of the contact surfaces (7a) of a fixed stop provides, is detected for monitoring the fixed stop for stop contact.

15. The method according to claim 14, wherein the detection is carried out by means of strain gauges (17) and / or piezo elements.

16. The method according to any one of claims 10 to 15, wherein a parameter representing the stop contact (c, d, v, M, P) is monitored.

17. The method according to claim 16, wherein from the two tool parts (4, 5) formed or carried by these physicalities (6, 6a, 14; 4, 14, 21), in particular contactless to a relative position representing the stop contact (c; d ) are monitored to each other.

18. The method according to any one of claims 16 to 17, wherein one or more of each assigned Beats of the two tool parts formed reference stops, at the stop contact of which or the monitored fixed stops have stop contact, are monitored for impact contact, in particular in such a way that an electrical contact is produced or closed by the contact of the stop faces of the respective reference stop, which generates a contact signal , or that a deformation of a physical body taking place under the stop pressure, which provides one of the contact surfaces of the respective reference stop, is detected.

19. The method according to any one of claims 10 to 18, wherein the ram movement of the punch press (1) via a crank or eccentric drive (8) is generated.

20. The method according to any one of claims 10 to 19, wherein the relative movement course (v) of the first tool part (4) or the plunger (2) relative to the fixed press structure, the platen (3) or the second tool part (5) in the area of the bottom dead center (UT) of the ram movement is monitored and the ram position is changed as a function of the monitoring result.

21. The method according to claim 20, wherein the time (t) or the angle of rotation of the crank or eccentric drive (8) is monitored, during which or which the first tool part (4) or the plunger (2) in the area of bottom dead center (UT) of the ram movement no relative movement with respect to the fixed press structure, the platen (3) or the second tool part (5), and the ram position is changed depending on the monitoring result.

22. The method according to any one of claims 10 to 21, wherein the drive torque curve (M) or the Leis tion recording course (P) of the press drive (8) in the area of the bottom dead center (UT) of the ram movement is monitored and the ram position is changed depending on the monitoring result.

23. The method according to claim 22, wherein the time (t) or the angle of rotation of the crank or eccentric drive (8) is monitored, during which or which the drive torque (M) or the power consumption (P) in the region of the bottom dead center Ram movement has a certain course or exceeds a certain threshold and the ram position is changed depending on the monitoring result.

24. The method according to any one of claims 22 to

23, the maximum value (Mpeak, Ppeak), which the drive torque (M) or the power consumption (P) reaches in the region of the bottom dead center (UT) of the ram movement, is monitored and the ram position is changed as a function of the monitoring result ,

25. The method according to any one of claims 10 to 24, wherein in the intended operation, the duration (t) of the stop contact of one or more fixed stops, in particular automated, is kept constant by adjusting the plunger position as a function of the monitoring result.

26. The method according to claim 25, wherein the plunger position is set as a function of the monitoring result in such a way that a specific stop contact duration (t) results, in particular the shortest possible stop contact duration.

27. The method according to any one of claims 10 to

26, wherein the punch press tool has several monitored fixed stops and in the intended operation a specific constellation from these monitored fixed stops is brought into stop contact in each automated stroke, in particular automatically, by adjusting the ram position depending on the monitoring result.

28. The method according to claim 27, wherein the ram position is set as a function of the monitoring result in such a way that a fixed stop of the constellation that comes last in contact with the stop is as short as possible in contact with the stop.

29. The method according to any one of the preceding claims, wherein the tool (4, 5) embossings for predetermined separation points in sheet metal surfaces are generated, in particular predetermined separation points in sheet metal surfaces for container lids with tear-open or press-in tab.

30. punch press (1) for operation according to the method according to any one of claims 1 to 9, comprising a particularly fixed platen (3) and a plunger (2) which works against the platen (3) and the plunger position relative to the platen ( 3) can be set in the intended operation, the plunger (2) carrying a first tool part (4) and the clamping plate (3) carrying a second tool part (5), the two tool parts (4, 5) being assigned stop surfaces (6a , 7a) which, when the tool (4, 5) is completely closed, form one or more fixed stops for limiting the closing dimension of the tool (4, 5) within the tool,

characterized in that the punch press (1) has devices for controlling the ram position, with which the distance (a, al, a2, a3) of the two tool parts (4, 5) to one another or this distance when the punch press (1) is operating as intended represent- the parameter (bl, b2, b3, c) at a certain point (PI, P2, P3) of the plunger movement, at which the tool (4, 5) is not completely closed, can be monitored and the plunger position depending on the Monitoring result can be changed.

31. punch press (1) according to claim 30, wherein the devices for controlling the ram position are designed such that the distance (a, al, a2, a3) of the two tool parts (4, 5) to each other or the parameter representing this distance (bl , b2, b3, c) can be monitored at a point (Pl, P2, P3) of the tappet movement, which is the bottom dead center (UT) of the

Tappet movement is closer than the top dead center of the tappet movement, in particular shortly before or shortly after bottom dead center (UT).

32. Punching press (1) according to claim 31, wherein the devices for controlling the ram position are designed such that the distance (a, al, a2) of the two tool parts (4, 5) to one another or the parameter (bl, b2) representing this distance , c) can be monitored at a point (P1, P2) of the ram movement at which the tool (4, 5) is not in deformation contact with the workpiece (13).

33. punch press (1) according to claim 31, wherein the devices for controlling the ram position are designed such that the distance (a3) of the two

Tool parts (4, 5) to one another or the parameter (b3) representing this distance can be monitored at a point (P3) of the ram movement at which the tool (4, 5) is in deformation contact with the workpiece (13).

34. punch press (1) according to any one of claims 30 to 33, wherein the punch press (1) a crank or Eccentric drive (8) has movement to generate the ram.

35. punch press (1) according to claim 34, wherein the devices for controlling the ram position are designed such that the distance (a, al, a2, a3) of the two tool parts (4, 5) to each other or the parameter representing this distance (bl , b2, b3, c) at a certain angular position (PI, P2, P3) of the crank or eccentric drive (8), at which the tool (4, 5) is not completely closed, can be monitored and the plunger position depending can be changed from the monitoring result.

36. punch press (1) according to claim 35, wherein the devices for controlling the ram position are designed such that the monitoring at an angular position (Pl, P2, P3) in a range of plus / minus 35 ° around the bottom dead center (UT) can be done around.

37. punch press (1) according to any one of claims 30 to 36, wherein the means for controlling the ram position are designed such that the distance (a, al, a2, a3) of the two tool parts (4, 5) to each other or these Parameters representing distance (bl, b2, b3, c) at the specific point (Pl, P2, P3) of the ram movement or at the specific angular position (Pl,

P2, P3) can be kept constant during operation according to the intended purpose by adjusting the ram position depending on the monitoring result.

38. Punching press (1) according to claim 37, wherein the devices for controlling the ram position are designed such that the distance (a, al, a2, a3) of the two tool parts (4, 5) to one another or to these

Parameters representing distance (bl, b2, b3, c) at the specific point (Pl, P2, P3) of the ram movement or on the determined angular position (PI, P2, P3) can be set to a specific value, in particular to an empirically determined value, and can then be kept constant automatically at this value by adjusting the plunger position depending on the monitoring result.

39. Punching press for operation according to the United method according to one of claims 10 to 29, comprising a particularly fixed platen (3) and a plunger (2) which works against the platen (3) and its plunger position relative to the platen (3) in intended operation is adjustable, the plunger (2) carrying a first tool part (4) and the clamping plate (3) carrying a second tool part (5), the two tool parts (4, 5) being assigned to each other stop surfaces (6a, 7a ) which, when the tool (4, 5) is completely closed, form one or more fixed stops for limiting the closing dimension of the tool (4, 5) within the tool,

characterized in that the punch press (1) has devices for controlling the ram position, with which at least one of the fixed stops can be monitored for stop contact during the intended operation of the punch press (1) and the ram position can be changed depending on the monitoring result.

40. punch press (1) according to claim 39, wherein the tool (4, 5) is designed such that one or more fixed stops one or more electrical contacts (18a, 18b; 19a,) by the contact of the stop surfaces (6a, 7a) 19b, 20) are produced or closed, which generate a monitoring signal (KS).

41. Punching press (1) according to claim 40, wherein at least one of the fixed stops one of the stop surfaces (7a) has two contacts (19a, 19b), which are short-circuited by the other stop surface (6a) in the case of stop contact.

42. Punching press (1) according to one of claims 40 to 41, wherein in at least one of the fixed stops the two stop surfaces (6a, 7a) form a contact pair (18a, 18b) which is closed when the stop contact is made.

43. Punching press (1) according to one of claims 39 to 42, wherein the tool (4, 5) is designed in such a way that a deformation (D) of a physical body (7) taking place under the stop pressure, which one of the contact surfaces (7a ) of a fixed stop, can be detected for monitoring the fixed stop for stop contact, in particular by means of strain gauges (17) and / or piezo elements.

44. Punching press (1) according to one of claims 39 to 43, the devices for controlling the ram position being designed in such a way that a parameter (c, d, v, M, P) representing the impact contact can be monitored.

45. Punching press (1) according to claim 44, wherein the devices for controlling the ram position are designed such that the two tool parts (4,

5) physicalities (6, 6a, 14; 4, 14, 21) formed or carried by them, in particular contactlessly, can be monitored for a relative position (c; d) representing the stop contact.

46. Punching press according to one of claims 44 to 45, the devices for controlling the pusher Selling are designed in such a way that one or more reference stops formed by respectively assigned stop surfaces of the two tool parts, at the stop contact of which the monitored fixed stop or stops have stop contact, can be monitored for stop contact, in particular in such a way that the contact of the respective stop surfaces Reference stop an electrical contact is made or closed, which generates a contact signal, or that a deformation of a physical body taking place under the stop pressure, which provides one of the contact surfaces of the respective reference stop, can be detected.

47. punch press (1) according to any one of claims 39 to 46, wherein the punch press (1) a crank or

Eccentric drive (8) has movement to generate the ram.

48. punch press (1) according to any one of claims 39 to 47, wherein the means for controlling the

The plunger position is designed such that the relative movement profile (v) of the first tool part (4) or of the plunger (2) compared to the fixed press structure, the platen (3) or the second tool part (5) in the area of bottom dead center (UT) of the ram movement can be monitored and the ram position can be changed depending on the monitoring result.

49. punch press (1) according to claim 48, wherein the devices for controlling the ram position are designed such that the time (t) or the angle of rotation of the crank or eccentric drive (8) can be monitored, during which or which the first tool part (4) or the plunger (2) in the region of the lower Totpunk ^¬ tes (ÜT), the plunger movement there is no relative movement against fixed to the press structure, the Aufspannplat- te (3) or the second tool part (5), and the ram position can be changed depending on the monitoring result.

50. punch press (1) according to any one of claims 39 to 49, wherein the devices for controlling the ram position are designed such that the drive torque curve (M) or the power consumption curve (P) of the crank or eccentric drive ( 8) in the area of the bottom dead center (UT) of the ram movement can be monitored and the ram position can be changed depending on the monitoring result.

51. Punching press (1) according to claim 50, wherein the devices for controlling the ram position are designed such that the time (t) or the angle of rotation of the crank or eccentric drive (8) can be monitored, during which or which the drive torque ( M) or the power consumption (P) in the area of the bottom dead center (UT) of the ram movement has a certain course or exceeds a certain threshold value and the ram position can be changed as a function of the monitoring result.

52. punch press (1) according to any one of claims 50 to 51, wherein the devices for controlling the ram position are designed such that the maximum value (Mpeak, Ppeak), which the drive torque (M) or the power consumption (P) in the range reached bottom dead center (UT) of the ram movement, who can be monitored and the ram position can be changed depending on the monitoring result.

53. Punching press (1) according to one of claims 39 to 52, the devices for controlling the ram position being designed such that the duration (t) of the stop contact in the intended operation one or more fixed stops, in particular automated, can be kept constant by adjusting the ram position as a function of the monitoring result.

54. Punching press (1) according to claim 53, wherein the devices for controlling the ram position are designed such that the ram position can be set as a function of the monitoring result in such a way that a certain stop contact duration (t) results, in particular the shortest possible stop contact duration.

55. Punching press according to one of claims 39 to 54, wherein the punch press tool has several monitored fixed stops and the devices for controlling the ram position are designed in such a way that, during normal operation, a certain constellation of these monitored fixed stops is automated in particular by adjusting the ram position can be brought into stop contact with each working stroke depending on the monitoring result.

56. Punching press according to claim 55, wherein the devices for controlling the ram position are designed such that the ram position can be set as a function of the monitoring result in such a way that a fixed stop of the constellation that comes last in contact with the stop is as short as possible in stop contact.

57. Use of the punch press (1) according to one of claims 30 to 56 for generating embossments for predetermined separation points in sheet metal surfaces, in particular for predetermined separation points in sheet metal surfaces for container lids with tear-open or press-in tabs.