EP3012038B1 - Adjustment device for a sheet-metal forming tool and sheet-metal forming tool with an adjustment device - Google Patents

Description

The invention relates to an adjusting device for a sheet metal forming tool with which a desired sheet metal holder distance between a sheet holder and a counter plate holder of Blechumformwerkzeugs can be ensured, and provided with such an adjusting sheet metal forming tool

Out DE 10 2012 002 213 A1 is a sheet metal forming known with at least one adjusting device for ensuring a desired blank holder distance between a blank holder and a counter plate holder of Blechumformwerkzeugs. In detail, this Blechumformwerkzeug two mutually relatively movable tool parts for the intermediate forming a sheet material and a blank holder and a counter plate holder. The blank holder and the counter plate holder are mutually relatively movable parallel to the tool parts to clamp during forming an edge portion of the sheet material between each other with a certain Blechhaltekraft. The blank holder and the counter plate holder have mutually opposite respective support portions, between which the at least one adjusting device is mounted to set a desired Blechhaltekraft between blank holder and counter plate holder or surface pressure for the sheet material by generating a sheet holding force counteracting force. For this purpose, the at least one adjusting device has an actuator and an electrically controllable drive unit in a multi-part housing. The actuator is height adjustable to provide the actuating force. The drive unit is connected to the actuator to drive the actuator.

For the control of the sheet holding force or surface pressure process sizes are e.g. detected by sensors. The process variables are evaluated by a control device (control unit) connected to the drive unit and the sensors, in order to calculate the possibly required actuating force of the actuating device based thereon, to generate an actuating signal on the basis of the calculated actuating force, and the drive unit with the actuating signal for generating the actuating force head for.

Out DE 103 31 939 A1 is a sheet metal forming known with an adjusting device to ensure a desired blank holder distance between a blank holder and a Counter plate holder of the sheet metal forming tool. More specifically, this sheet metal forming tool has two tool parts relatively movable relative to each other for forming a sheet material therebetween, and a sheet holder and a counter sheet holder. The blank holder and the counter plate holder are mutually relatively movable parallel to the tool parts to clamp during forming an edge portion of the sheet material between each other with a certain Blechhaltekraft. The blank holder and the counter plate holder have mutually opposite respective support portions between which a plurality of adjustable in their respective height dimension spacers of the actuator are mounted on the spacers and on this Aufsitzen the support sections to ensure a desired respective blank holder distance between blank holder and counter plate holder ,

Each of the spacers is connected to an electrically controllable drive unit of the actuating device in order to drive a height adjustment of the spacer. In each spacer, a force measuring sensor is provided, which may be arranged in a power transmission path of the respective spacer between the support sections and which is adapted to detect a physical quantity from which a compressive force acting on the spacer on the spacer can be derived.

The adjusting device further comprises a control device, which is connected to the drive units and the sensors and which is configured to determine the pressure force acting on the spacer for each pair of drive unit and sensor from the detected physical quantity, based on the pressure force an actual pressure force determine to compare the Istdruckkraft with an individual for this pair of desired pressure force to determine a difference between them, based on the difference to generate a control signal to compensate for the difference and to control the respective drive unit with the control signal for adjusting the respective actuator.

The control device of this known adjusting device is arranged outside of the two tool parts of Blechumformwerkzeugs and connected via a plurality of connecting lines with the individual pairs of drive unit and sensor, so that a central control of the respective height dimensions of the spacers and thus the respective blank holder distances is guaranteed. However, such a central control of blank holder distances requires a tuned to the sheet metal forming control, which must be trained or calculated in advance. If further blankholder distances are to be integrated into such a coordinated control system, then the control must be adapted consuming. However, such an adaptation can only be carried out by specially trained specialist personnel or experts and goes well beyond the qualification of, for example, a plant operator of a forming press driving the sheet metal forming tool.

The invention has for its object to provide an adjusting device as mentioned above to ensure a desired blank holder distance in a sheet metal forming tool so that it can be easily integrated into the sheet metal forming tool. The invention is also based on the object to provide a provided with such an adjusting sheet metal forming tool.

The o.g. Tasks are achieved with an adjusting device according to claim 1 and a sheet metal forming tool according to claim 9. Preferred developments of the adjusting device according to the invention are defined in the dependent claims.

According to the invention, an adjusting device for a sheet metal forming tool is provided. The sheet metal forming tool has two mutually relatively movable tool parts for the intermediate forming a sheet material, a sheet holder and a counter plate holder, which are relatively movable parallel to the tool parts to each other to clamp during forming an edge portion of the sheet material between each other with a certain sheet holding force. The blank holder and the counter plate holder have mutually opposite respective support portions, between which the adjusting device is mounted to let by sitting on the actuator seating of the support portions to ensure a desired blank holder distance between the blank holder and counter plate holder. The adjusting device according to the invention has an actuator, an electrically controllable drive unit, a sensor and a control device. The actuator is adjustable to change a height dimension of the actuator and thereby adjust the guaranteed blank holder distance. The drive unit is connected to the actuator to drive the actuator for adjusting it. The sensor is set up to detect a physical quantity from which a pressure force, which acts on the adjusting device when the support sections are seated on the actuating device, can be derived.

The control device is connected to the drive unit and the sensor and is configured to determine from the detected physical quantity the pressing force acting on the setting device when the support sections are seated, to determine an actual pressure force on the basis of the pressure force, to compare the actual pressure force with a desired pressure force a difference to determine between them, based on the difference to generate a control signal to compensate for the difference and to drive the drive unit with the control signal for adjusting the actuator. The control device is set up to generate only the actuating signal for the one drive unit.

Characterized in that the control device is arranged to generate only the control signal for the particular single drive unit of the adjusting device and thus to regulate the adjustment of the particular single actuator of the adjusting device only a single blank holder distance, the adjusting device according to the invention provides an autonomously regulating blank holder distance, which without coordination with integrated in a central control other plate holder distances and thus easy to integrate into a sheet metal forming tool.

According to the invention, the actual pressure force can be equal to the determined pressure force, so that the actual pressure force corresponds to a force component of a sheet metal holder side force flow actually received via the adjusting device between the one tool part and the other tool part. In this case, the desired pressure force then corresponds to a desired force component of the sheet-metal-side power flow between the tool parts, which is to be absorbed via the adjusting device.

Alternatively, according to the invention, the actual pressing force may be determined by subtracting the determined pressing force from a total sheet holding force that would act in the forming process between the blank holder and the counter plate holder if no blank holder distance were to act between the first and second support sections. The determination of the total sheet holder force can eg in advance as in DE 10 2011 120 789 A1 described by means of a Leerhubes (without sheet material) are performed.

In this case, the actual pressure force then corresponds to a force component of the sheet-metal-side power flow between the tool parts that actually acts as a sheet-holding force on the edge portion of the sheet material. The desired pressure force then corresponds to a desired force acting as sheet holding force on the edge portion of the sheet material force component of the sheet holder-side power flow between the tool parts.

Preferably, the sensor is designed as a force measuring sensor (eg on a piezoelectric basis) or as a strain gauge sensor (eg as a strain gauge). The detected by the sensor physical size can be eg a voltage change or a resistance change.

According to the invention, at least the actuator, the drive unit and the control device are integrated in a common housing of the adjusting device. Thus, these components of the actuator form a compact unit, which can be easily placed in the sheet metal forming, assemble and replace as needed.

According to one embodiment of the invention, the sensor is also integrated in the housing, so that the compactness of the adjusting device is further increased.

According to yet another embodiment of the invention, the adjusting device also has a spacer plate for mounting on one of the support sections of the sheet metal forming tool, so that the spacer plate is located between the respective support section and the housing of the actuating device. By the spacer plate can advantageously be realized a height compensation, so that the adjusting device does not need to be made unnecessarily large in their height dimension and a control range of the actuator.

According to yet another embodiment of the invention, the sensor is arranged on the spacer plate, as an alternative to integration in the housing.

According to one embodiment of the invention, the control device has an input unit, via which the desired pressure force is manually adjustable. Preferably, the input unit comprises a switch for stepwise manually increasing and decreasing the target pressure force and / or a keypad for value-inputting the target pressure force. With the keyboard, a desired value for the target pressure force can be entered easily and quickly. With the switch can be a once entered value for the target pressure force easily and quickly correct.

According to another embodiment of the invention, the control device has a display screen and is configured to display the target pressure force and the actual pressure force on the display screen, respectively, so that an operator of the sheet metal forming tool (such as an operator of the forming press driving the sheet metal forming tool) particularly from outside the case from the target pressure force and the actual pressure force can read on the display screen.

According to a further embodiment of the invention, only one power supply connection is provided on the adjusting device as external connection. That is, in the sheet metal forming tool, no expensive laying of signal lines and various power supply lines needs to be realized, and the entire adjusting device is preferably supplied with power via the single power supply terminal as an external terminal. This makes the actuator even more compact and even easier to integrate into a sheet metal forming tool.

According to the invention, there is also provided a sheet metal forming tool comprising two tool parts relatively movable relative to each other for forming therebetween a sheet metal material, a sheet holder and a counter plate holder and an adjusting device according to one, several or all embodiments of the invention described above in any conceivable combination.

The blank holder and the counter plate holder are mutually relatively movable parallel to the tool parts to clamp during forming an edge portion of the sheet material between each other with a certain Blechhaltekraft. In addition, the blank holder and the counter plate holder on each opposite respective support sections, between which the adjusting device according to the invention is mounted to let by sitting on the actuator seating the support sections to ensure a desired blank holder distance between blank holder and counter plate holder.

Fig. 1

zeigt in schematischer Schnittansicht einen Teil eines Blechumformwerkzeugs gemäß einer Ausführungsform der Erfindung.

Fig. 2

zeigt eine schematische Schnittansicht einer Stelleinrichtung des Blechumformwerkzeugs von Fig. 1.

In the following, the invention will be described with reference to preferred embodiments and with reference to the accompanying figures.

Fig. 1

shows a schematic sectional view of a part of a Blechumformwerkzeugs according to an embodiment of the invention.

Fig. 2

shows a schematic sectional view of an adjusting device of the Blechumformwerkzeugs of Fig. 1 ,

The following are with reference to the FIGS. 1 and 2 a sheet metal forming tool 1 and an integrated therein adjusting device 10 according to an embodiment of the invention will be described.

How out Fig. 1 it can be seen, the here a deep drawing stage realizing sheet metal forming tool 1 a lower tool part 2 and an upper tool part 5, which in a vertical direction in Fig. 1 relative to each other are relatively movable and between which a sheet material B is added in order to transform this by mutual process of the two tool parts 2, 5 in a deep-drawing process.

The lower tool part 2 comprises for forming the sheet material B a deep-drawing die 3, which is fixedly mounted on a base plate (not shown), and an annular die holder 4 surrounding the deep-drawing die 3. The upper die part 5 comprises for forming the sheet material B on a press ram a forming press (both not shown) to be mounted thermoforming die 6, on which an annular counter-plate holder 6.1 is formed as a section of the thermoforming die 6.

In the forming process, a relative movement of thermoforming punch 3 and thermoforming die 6 is effected by vertical movement of the press ram and thus of the thermoforming die 6, whereby the sheet material B is pressed by the thermoforming die 3 into the thermoforming die 6. The blank holder 4 is received on a hydraulically vertically movable lifting table (not shown) of the forming press and is for the forming process prior to the method of Deep-drawing die 6 moved vertically upwards, so that between the plate holder 4 and the opposite counter-plate holder 6.1 directed parallel to the relative movement of thermoforming dies 3 and thermoforming die 6 relative movement is effected to form a peripheral portion of the sheet material B between sheet holder 4 and counter plate holder 6.1 during forming to clamp a certain plate holding force. When after vertically down process the thermoforming die 6 then the sheet holder 4 is pressed under defined counterforce of the lift table, which generates the sheet holding force from the counter plate holder 6.1 down vertically.

On the blank holder 4 of the lower tool part 2 also a not included in the clamping of the sheet material B graded annular portion is provided, which defines a first support section 4.1. In addition, a not included in the clamping of the sheet material B annular portion is provided on the counter plate holder 6.1 of the thermoforming die 6, which is opposite to the first support section 4.1 and which defines a second support section 6.2.

In an annular space formed between the first and second support sections 4.1, 6.2, the adjusting device 10 according to the invention is mounted and can assume such a height dimension that during the forming process, when blank holder 4 and counter plate holder 6.1 are moved together for clamping the edge portion of the sheet material B, the first and second Support sections 4.1, 6.2 on the actuator 10 or sit on this. Thus, the actuator 10 acts as a spacer to ensure a desired blank holder distance between plate holder 4 and counter plate holder 6.1. Preferably, the adjusting device 10 is mounted on the first support section 4.1.

In the annular space formed between the first and second support sections 4.1, 6.2 also not shown in their respective height dimension adjustable spacers to ensure further respective sheet holder distances between plate holder 4 and counter plate holder 6.1 are provided, the spacers, for example, as in DE 103 31 939 A1 are arranged and are controlled via a central control (not shown) or adjusted in height.

The adjusting device 10 according to the invention is used in the exemplary embodiment as an example to be able to integrate in the coordinated control system of the height-adjustable spacers a further blank holder distance.

As in Fig. 2 1, the adjusting device 10 according to the invention has an actuator 15, an electrically controllable drive unit 20, a sensor 30, a spacer plate 35 and a control device 40. The actuator 15, the drive unit 20 and the control device 40 are integrated into a common housing 11 of the actuator 10, so that these components of the actuator 10 form a compact unit.

The columnar actuator 15 is adjustable (as indicated by the double arrow in FIG Fig. 2 indicated) in order to be able to change a height dimension of the adjusting device 10 between a minimum height dimension H1 and a maximum height dimension H2 and thereby to be able to adjust the guaranteed blank holder distance.

The drive unit 20 is connected to the actuator 15 to drive the actuator 15 for adjusting it. The drive unit 20 may be e.g. provide an electric drive, a pneumatic drive or a hydraulic drive (not shown in detail) to drive the actuator 15 for height adjustment. In the present embodiment, the actuator 15 is exemplified as a reciprocating piston of a piston-cylinder unit and is moved by the drive unit 20 electrically and / or pneumatically in the cylinder (not shown separately) of the piston-cylinder unit. The actuator 15 is e.g. is mechanically connected to the housing 11 via the cylinder of the piston-cylinder unit, so that a compressive force acting on the actuator 15 via the second support section 6.2 can be transmitted to the housing 11.

The spacer plate 35 is mounted on the first support section 4.1 of the Blechumformwerkzeugs 1, so that the spacer plate 35 between the first support section 4.1 and the housing 11 of the adjusting device 10 is located.

The sensor 30 is arranged on the spacer plate 35 and is adapted to detect a physical quantity from which a compressive force acting on the adjusting device 10 when the support sections 4.1, 6.2 act on the actuating device 10 can be derived. According to the present embodiment, the sensor 30 may be e.g. be designed as a force measuring sensor (for example on a piezoelectric basis) or as a strain gauge sensor (for example as strain gauges).

According to an embodiment, not shown, the spacer plate 35 could also be omitted and the sensor 30 could be integrated into the housing 11.

The control device 40 has a computer unit 45, an input unit 50 and a display screen 55. The computer unit 45 is connected to the drive unit 20, the input unit 50 and the display screen 55 via electrical leads (not separately referred to) running in the housing 11. In addition, the computer unit 45 is connected to the sensor 30 via an electrical lead (not separately indicated) led out of the housing 11. Finally, the computer unit 45 is connected via a further extending in the housing 11 electrical line (not separately designated) to a power supply terminal 12 through which the actuator 10 is supplied with electric power. In this case, the computer unit 45 supplies all the other components of the setting device 10 which are connected thereto with electrical current via the respective electrical lines as required. Thus, only the power supply terminal 12 is provided on the adjusting device 10 as an external connection.

Various algorithms for realizing a control and a corresponding control of the drive unit 20 are stored in the computer unit 45. More specifically, at least one algorithm for determining a compressive force level and an algorithm for controlling the compressive force level are stored in the computer unit 45.

The computer unit 45 of the control device 40 is set up by means of the respective algorithms to determine from the physical quantity (for example a change in an electrical voltage or an electrical resistance) detected by the sensor 30 the pressure force acting on the setting device 10 when the support sections 4.1, 6.2 are seated. to determine an Istdruckkraft based on the pressure force to compare the Istdruckkraft with a desired pressure force to determine a difference between them, based on the difference to generate a control signal to compensate for the difference and the drive unit 20 with the control signal for adjusting the actuator 15 to control ,

In this case, the actual pressure force may be equal to the predetermined compressive force, so that the actual pressure force corresponds to a force component of a sheet-metal-side force flow between the lower tool part 2 and the upper tool part 5 that is actually received via the adjusting device 10. In this case, the desired pressure force then corresponds to a desired force component of the sheet-metal-side power flow to be absorbed via the adjusting device 10 between the lower tool part 2 and the upper tool part 5.

Alternatively, the actual pressure force can be determined by subtracting the determined pressure force from a total plate holder force which is applied during the forming process between the Sheet metal holder 4 and the counter plate holder 6.1 would act if no plate holder distances between the first and second support sections 4.1, 6.2 would act. The determination of the total sheet holder force can eg in advance as in DE 10 2011 120 789 A1 described by means of a Leerhubes (without sheet material B) are performed.

In this case, the actual pressure force then corresponds to a force component of the sheet metal holder force flow between the lower tool part 2 and the upper tool part 5, which actually acts as a sheet holding force on the sheet material B. The set pressure force then corresponds to a desired force component of the sheet material B acting as a sheet holding force sheet holder-side power flow between the lower tool part 2 and the upper tool part. 5

The computer unit 45 of the control device 40 is configured to display the target pressure force and the actual pressure force on the display screen 55 respectively, so that an operator of the sheet metal forming tool 1 (such as an operator of the sheet metal forming tool 1 driving forming press) from outside the housing 11 of the target pressure and can read the actual pressure force on the display screen 55.

The input unit 50 of the control device 40 is also set up, so that the operator can set the desired pressure force manually via the input unit 50 or change it if necessary. For this purpose, the input unit 50 has a switch (not shown) for stepwise manually increasing and decreasing the target pressure force and a keypad (not shown) for inputting the target pressure force by value. Both the switch and the keypad are operable from outside the housing 11.

As can be seen from the above explanations, the control device 40 is thus configured to generate only an actuating signal for the integrated into the housing 11 drive unit 20 of the actuator 10 and thus to control only a single blank holder distance. The adjusting device 10 according to the invention thus provides an autonomously regulating blank holder distance which can be integrated without coordination with the spacers integrated in the central control and thus simply into the sheet metal forming tool 1.

Of course, if necessary, it would also be possible for the display / adjustment of the pressure force levels of the blank holder distance according to the invention to take place, for example, centrally on a press control desk. Then, however, would have, for example, appropriate communication lines from Sheet metal forming tool 1 are moved to the press control panel and the actuator 10 are extended by a corresponding communication component.

In summary, according to the invention in the forming process with the sensor 30, the physical quantity is detected, from which the pressure force which acts on the adjusting device 10 when the support sections 4.1, 6.2 act on the adjusting device 10, can be derived. The detected physical quantity is transmitted to the computer unit 45 as a signal. From this signal, a respective press stroke is detected by means of the algorithm stored in the computer unit 45 for determining the pressure force level, and the corresponding part of the signal is evaluated. The display screen 55 displays the actual pressing force of the last press stroke and the target pressing force set by the operator. The stored in the computer unit 45 algorithm for controlling the pressure force level compares setpoint and Istdruckkraft and then controls the drive unit 20 for distance adjustment (adjustment of the actuator 15). The target pressure force can be adjusted by the operator via the input unit 50 (Kraftniveauverstelleinheit) if necessary.

LIST OF REFERENCE NUMBERS

1

sheet-metal forming

2

tool part

3

Ironing punch

4

blankholder

4.1

support section

5

tool part

6

deep drawing mold

6.1

Against Blankholder

6.2

support section

10

setting device

11

casing

12

Power connector

15

actuator

20

drive unit

30

sensor

35

spacer plate

40

control device

45

computer unit

50

input unit

55

display screen

B

sheet material

H1

minimum height dimension

H2

maximum height dimension

Claims (9)

1. Adjustment device (10) for a sheet-metal forming tool (1) comprising two tool parts (2, 5), which are relatively movable in relation to one another and are intended for the forming of a sheet-metal material (B) between them, a sheet holder (4) and a counter sheet holder (6.1), which are relatively movable in relation to one another parallel to the tool parts (2, 5), in order during the forming to clamp an edge portion of the sheet-metal material (B) between one another with a certain sheet holding force, and which have respective supporting portions (4.1, 6.2), which lie opposite one another and between which the adjustment device (10) can be mounted, in order to ensure by placement of the supporting portions (4.1, 6.2) on the adjustment device (10) a desired sheet holder spacing between the sheet holder (4) and the counter sheet holder (6.1), the adjustment device (10) having:

   an adjustment element (15), which is adjustable to change a height dimension (H1, H2) of the adjustment device (10) and thereby adjust the ensured sheet holder spacing,

   an electrically activatable drive unit (20), which is connected to the adjustment element (15) in order to drive the adjustment element (15) for adjusting the same,

   a sensor (30), which is designed to sense a physical variable, from which a compressive force that acts on the adjustment device (10) during the placement of the supporting portions (4.1, 6.2) on the adjustment device (10) can be derived, and a control device (40), which is connected to the drive unit (20) and the sensor (30) and is designed to determine from the sensed physical variable the compressive force acting on the adjustment device (10), to determine on the basis of the compressive force an actual compressive force, to compare the actual compressive force with a setpoint compressive force, to ascertain a difference between these, to generate on the basis of the difference an adjustment signal to compensate for the difference and to activate the drive unit (20) with the adjustment signal for adjusting the adjustment element (15),

   the control device (40) being designed to generate exclusively the adjustment signal for the one drive unit (20), and

   at least the adjustment element (15), the drive unit (20) and the control device (40) being integrated in a common housing (11).
2. Adjustment device (10) according to Claim 1, the sensor (30) being integrated in the housing (11).
3. Adjustment device (10) according to Claim 1, also comprising a spacer plate (35) for mounting on one of the supporting portions (4.1, 6.2) of the sheet-metal forming tool (1), so that the spacer plate (35) is located between the supporting portion (4.1, 6.2) concerned and the housing (11) of the adjustment device (10), the sensor (30) being arranged on the spacer plate (35).
4. Adjustment device (10) according to one of Claims 1-3, the control device (40) having an input unit (50), by way of which the setpoint compressive force can be set manually.
5. Adjustment device (10) according to Claim 4, the input unit (50) having a switch for manually increasing and reducing the setpoint compressive force stage by stage.
6. Adjustment device (10) according to Claim 4 or 5, the input unit (50) having a keypad for entering values for the setpoint compressive force.
7. Adjustment device (10) according to one of Claims 1-6, the control device (40) having a display screen (55) and being designed to display values for the setpoint compressive force and values for the actual compressive force on the display screen (55).
8. Adjustment device (10) according to one of Claims 1-7, only a power supply connection (12) being provided on the adjustment device (10) as an external connection.
9. Sheet-metal forming tool (1) comprising two tool parts (2, 5), which are relatively movable in relation to one another and are intended for the forming of a sheet-metal material (B) between them, a sheet holder (4) and a counter sheet holder (6.1), which are relatively movable in relation to one another parallel to the tool parts (2, 5), in order during the forming to clamp an edge portion of the sheet-metal material (B) between one another with a certain sheet holding force, and which have respective supporting portions (4.1, 6.2), which lie opposite one another and between which an adjustment device (10) according to one of Claims 1-8 is mounted, in order to ensure by placement of the supporting portions (4.1, 6.2) on the adjustment device (10) a desired sheet holder spacing between the sheet holder (4) and the counter sheet holder (6.1).

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