EP3187276A1 - Forming tool - Google Patents

Abstract

The invention relates to a forming tool (1) for forming a metal sheet (2) with a first tool part (3), which has a tool top part (5), a die (6) and a hold-down device (7) which bears against the tool top part (5 ) via a first pressure means (8), with a second tool part (4) having a tool lower part (9), a with the die (6) for forming the metal sheet (2) cooperating punch (10) and a blank holder (11) , which is supported against the tool lower part (9) via a second pressure means (12), and with a between sheet holder (11) and hold-down (7) provided locking means (13) having a spacer element (14), which spacer element (14 ) is movably mounted in dependence upon a relative movement resulting from the closing of the forming tool (1) from a rest position (15) to a working position (16) which, upon opening the forming tool (1), moves the distance between blank holder (11) and hold down he (7) determines. In order to provide a particularly stable forming tool (1), it is proposed that the locking device (13) has a wedge drive (17) with slide (18) and driver (19), wherein the slide (18) having the spacer element (14) Dependence of the sheet metal holder (11) and the upper part of the tool (5) during closing of the forming tool (1) resulting relative movement, under contact with the driver (19), is slidably mounted to move the spacer element (14) in its working position (16).

Description

The invention relates to a forming tool having a first tool part, which has a tool upper part and a die with a movably inserted hold-down, which is supported against the upper part of the tool via a first pressure medium, with a second tool part, the lower tool part, a cooperating with the die for forming Stamp and a movable plate holder, which is supported against the lower tool part via a second pressure means, and provided with a blank holder and hold-down locking device having at least one spacer, which spacer depending on a resulting upon closing of the forming relative movement from a rest position in a working position is movably mounted, which defines the distance between the blank holder and blank holder when opening the forming tool.

In order to lock each other when opening a forming tool hold-down and sheet metal holder or set their distance from each other, it is known from the prior art to provide a locking device which pivots when closing the forming a designed as a rocker spacer between hold and sheet holder. By this measure of locking, it is possible to compensate for a difference in the pressure force of the two pressure means, such as gas springs, in some ways - to try to prevent unwanted relative movement between hold and sheet holder when opening the forming tool. In this regard, a deterioration of the forming quality can therefore be reduced. The disadvantage of this solution requires the locking device, inter alia, that due to the leverage on Rocker arm a comparatively massive design is required, which is why such locking devices for tools with relatively high loads are unsuitable. In addition, such locking devices of the prior art in their control and structural design are relatively expensive - and thus costly in production and maintenance.

The invention has therefore based on the forming of the described prior art, the task to simplify this in terms of design effort and to ensure high stability. In addition, this design should also be suitable for heavy loads.

The invention achieves the stated object in that the locking device has at least one wedge drive with slide and driver, wherein the slide having the spacer element is displaceably mounted in contact with the driver as a function of the relative movement resulting between the blank holder and the tool top when closing the forming tool. to move the spacer into its working position.

If the locking device has at least one wedge drive with slider and driver, that function of the force deflection known by wedge drives can be used to simply actuate the locking device if the slide having the spacer element depends on the relative movement between blank holder and tool top when closing the forming tool, is slidably mounted under contact with the driver to move the spacer into its working position. In addition, a wedge drive compared to an axle-mounted rocker arm of the prior art be made relatively robust, so that even high loads can be safely removed. In this way, it may for example also be possible to use gas springs as pressure medium. The wedge drive can firmly fix the distance between the blank holder and blank holder on the locking device according to the invention. According to the invention, it is therefore a forming tool provided that can be used even at high loads and always allows a high forming quality.

In general, it is mentioned that the forming tool can be a deep-drawing tool for tensile-compression-forming according to DIN 8584. Further, it is generally mentioned that a metal sheet, a sheet metal blank (sheet metal blank) or a tailored blank sheet (Tailored Blank) can be formed with this forming tool.

In order to determine the distance between blank holder and hold-down safely, it can be provided that the spacer element forms a stop for the blank holder and / or blank holder in its working position. In addition, this comparatively mechanically robust solution can further improve the stability of the forming tool.

If the holding-down device has a shoulder protruding radially from the die, which forms a counterstop for the abutment of the spacer element, the construction of the forming tool can be further simplified. In addition, so that the locking device can be provided outside of cooperating for forming tool parts - with which a relief in the structure reachable and possible interference contours on the forming tool can be avoided.

The loads on the movable tool parts or on the upper tool part can be reduced if the driver is attached to the upper tool and the slider is slidably mounted on the blank holder.

If the slide is slidably mounted in contact with the driver against the action of a first spring, the slider can be returned to its free rest position after opening the forming tool - structurally simple solved.

If the spacer element on the slide is displaceably mounted against the action of a second spring whose direction of action opposes the direction of action of the first spring, the spacer element can be moved under pretension into its working position - which can increase the reliable operation of the locking device. In addition, so that the spacer element can be shifted in time offset from the movement of the slide in its working position, which can facilitate the vote of the wedge guide on the relative movement between blank holder and upper tool. The construction of the forming tool can be further simplified in this way.

The handling of the forming tool - both when loading with a sheet and when removing the formed sheet / the formed board - is advantageously unimpaired by the locking device, when the slider is slidably mounted so that it in the working position of the spacer element to the die next situated position. Slide velvet spacer are namely with open forming tool from the insertion or removal area between the two tool parts further away, whereby the locking device can not form any interference contours on the forming tool. In addition, so that the locking device can be protected in a structurally simple way from damage caused by the loading / unloading of the sheet - which can contribute to further increase the stability of the forming tool.

Constructive simplicity of the forming tool can be achieved when first and second pressure medium are designed as gas springs.

Fig. 1

eine aufgerissene Seitenansicht auf ein offenes Umformwerkzeug mit einer eingelegten Blechplatine,

Fig. 2

das Umformwerkzeug in einer teilweise geschlossener Stellung,

Fig. 3

das Umformwerkzeug in einer geschlossener Stellung und

Fig. 4

das Umformwerkzeug bei seiner Rückführung in die offene Stellung,

In the figures, for example, the subject invention is illustrated in more detail with reference to a variant embodiment. Show it

Fig. 1

a torn-open side view of an open forming tool with an inserted sheet metal blank,

Fig. 2

the forming tool in a partially closed position,

Fig. 3

the forming tool in a closed position and

Fig. 4

the forming tool in its return to the open position,

That in the FIGS. 1 to 4 For example, shown as a single-acting press forming tool 1 is used for deep drawing a sheet, a sheet metal blank (sheet metal blank) and / or a custom sheet metal blank (Tailored Blank). In Fig. 1 is this forming tool 1 in its open position, in which open position the reshaping flat board 2 is already inserted. In this open position of the forming tool 1, the two tool parts 3, 4 of the forming tool 1 can be seen.

The first, upper tool part 3 includes a tool upper part 5, a die 6 and a hold-down 7. The hold-7 is supported against the upper tool 5 via a first pressure medium 8, which is executed in the embodiment as the first gas spring 108 - see the latter Fig. 3 , The die 6 is rigidly connected to the upper tool 5.

The second lower tool part 4 includes a lower tool part 9, a punch 10 and a sheet holder 11. The sheet holder 11 is supported against the lower tool part 9 via a second pressure means 12, which is designed as a second gas spring 112 - see the latter Fig. 3 , The forming tool 1 according to the invention therefore requires no under-air. The punch 10 of the lower tool part 4 is attached to the lower tool part 9 and cooperates with the die 6 of the upper tool part 3 for forming the board 2 together.

The forming tool 1 also has a locking device 13 which is provided between plate holder 11 and hold-down 7. The locking device 13 comprises a spacer element 14, with which the distance between the sheet holder 11 and hold-down 7 can be set. This is necessary for the opening of the forming tool 1, in spite of possibly different pressure forces of the first and second pressure means 8, 12 a high quality, eg. B. at the deformed board 2, to ensure. This locking device 13 is actuated by the closing movement of the forming tool 1, as shown in FIG Fig. 2 can be seen. In synopsis of FIGS. 1 to 4 It can be seen that the spacer element 14 is movably mounted in response to a relative movement resulting upon closing of the forming tool 1 - namely from a free rest position 15 when the forming tool 1 is open Fig. 1 in a working position 16 after Fig. 3 , which defines the distance between blank holder 11 and hold-down 7 when opening the forming tool 1.

According to the invention, this movement of the spacer element 14 is converted by a wedge drive 17, which belongs to the locking device 13. For this purpose, the wedge drive 17 has a slide 18 and a driver 19, which form corresponding guide surfaces 20 on the wedge drive 17.

The slide 18 has the spacer element 14 and is displaceably mounted - namely in the embodiment of the sheet holder 11. Depending on the relative between sheet holder 11 and 5 tool upper part relative movement of the slider 18 is now - under contact with the driver 19, which in the embodiment on the upper tool 5 is fixed - moved and thus moves the spacer element 14 under the hold-down 7, whereby the hold-7 abuts the spacer element 14 and thus to the blank holder 11. For this purpose, the spacer element 14 forms a stop 24 for the hold-7. Thus, the distance between the sheet holder 11 and hold-down 7 is fixed - in the embodiment over the height of the spacer element 14 and its height offset to the sheet holder 11, which height offset results from the position of the spacer element 14 on the slide 18.

In this way, a particularly robust locking device 13 is provided, which can set the specified distance between blank holder 11 and hold-7 safely even at high loads. The forming tool 1 according to the invention thus has a particularly high stability.

Again Fig. 1 can be seen further, the slider 18 is slidably mounted against an action of a first spring 21, which is designed as a third gas spring. This spring 21 acts between slide 18 and plate holder 11 and presses the slider 18 along its first linear guide 22 on the blank holder 11 of the die 6 away. As a result, the slider 18 comes in the working position 16 of the spacer element 14 of the die 6 closest, which position 23 of the slider in the Fig. 3 can be seen. In the rest position 15 of the spacer element 14, slide 18 is arranged furthest away from the die 6. In order for this resulting interference contours are prevented when loading the forming tool 1.

Of the Fig. 1 In addition, it can be seen that the hold-down device 7 forms a shoulder 25 radially projecting the die 6, which forms a counter-abutment 26 for the stop 24 of the spacer element 14. This counter-abutment 26 is provided on the axially projecting portion 27 of the radially projecting shoulder 25, whereby the spacer element 14 can be made demensprechend reduced in height.

Advantageously, the spacer 14 is slidably mounted on the slider 18 against the action of a second spring 28. This designed as a fourth gas spring spring 21 acts between the spacer element 14 and slide 18 and loads the spacer element 14 along its second linear guide 31 on the slider 18 with a direction of action 29, which is opposite to the direction of action 30 of the first spring 21. As a result, the spacer 14 can be brought under bias in its working position 16, which bias in Fig. 2 can be seen against the action of the second spring 28 on the basis of the displacement of the spacer element 14.

In addition, in the FIGS. 1 to 4 to recognize that the first and second linear guides 22 and 31 are parallel.

In general, it is mentioned - but not shown - that the slide 18 also movably mounted on the upper tool part 5 and the driver can be attached to the blank holder 11. In this case, then also the spacer element forms a stop 24 for the blank holder 11 to determine the distance between blank holder 11 and hold-7. It is also conceivable that the spacer element 14 each forms a stop 24 for blank holder 11 and hold-down 7 - this is also not shown.

Claims (8)

Forming tool with a first tool part (3) having a tool top part (5) and a die (6) with a movably inserted downholder (7), which is supported against the upper tool part (5) via a first pressure means (8), with a second tool part (4), which has a tool lower part (9), a punch (10) cooperating with the die (6) for forming, and a movable sheet holder (11), which bears against the tool lower part (9) via a second pressure means (12 ), and with a between sheet holder (11) and hold-down (7) provided locking means (13) having at least one spacer element (14), which spacer element (14) in response to a closing of the forming tool (1) resulting relative movement of a rest position (15) is movably mounted in a working position (16), which defines the distance between blank holder (11) and hold-down (7) when opening the forming tool (1), characterized gekennz eichnet that the locking device (13) at least one wedge drive (17) with slide (18) and driver (19), wherein the spacer element (14) having slide (18) in dependence of itself between sheet holder (11) and upper tool ( 5) during the closing of the forming tool (1) resulting relative movement, is slidably mounted under contact with the driver (19) to move the spacer element (14) in its working position (16). Forming tool according to claim 1, characterized in that the spacer element (14) in its working position (16) forms a stop (24) for the hold-down (7) and / or blank holder (11) to the distance between blank holder (11) and hold-down (7). Forming tool according to claim 2, characterized in that the holding-down device (7) has a shoulder (25) which protrudes radially from the die (6) and forms a counter-abutment (26) for the abutment (24) of the spacer element (14). Forming tool according to claim 1, 2 or 3, characterized in that the driver (19) on the upper tool part (5) is fixed and the slide (18) on the blank holder (11) is displaceably mounted. Forming tool according to one of claims 1 to 4, characterized in that the slide (18) in contact with the driver (19) against the action of a first spring (21) is displaceably mounted. Forming tool according to claim 5, characterized in that the spacer element (14) on the slide (18) against the action of a second spring (28) is displaceably mounted, the direction of action (29) of the direction of action (30) of the first spring (21) is opposite , Forming tool according to one of claims 1 to 6, characterized in that the slide (18) is mounted so displaceable that it occupies in the working position (16) of the spacer element (14) to the die (6) closest position (23) , Forming tool according to one of claims 1 to 7, characterized in that first and second pressure means (8, 12) are designed as gas pressure springs (108, 112).

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