JPH04228229A - Drawing device in press - Google Patents

Abstract

PURPOSE: To make the distance between a ram 2 and a pressing head 8 constant during the time of deformation (drawing phase) and to act respective sheet holding cylinders 10 directly on a sheet holding body 13 with a drawing apparatus, which is the drawing apparatus of a press having a ram vertically movable within the press and a press bench installed fixed in order to house a tool or made carriable out and has the pressing head subjected to a pressing action by at least one pressing cylinder for the purpose of a drawing process and the sheet holding cylinder for adjusting sheet holding force via a drawing pin. CONSTITUTION: The purposes described above are achieved by disposing a spacing bolt 14 between the ram 2 and the pressing head 8, maintaining the pressing head 8 at a specified distance to the ram 2 by receiving the reaction of the drawing apparatus 7 during the drawing process of the entire part, disposing the sheet holding cylinder 10, fixing the same to the pressing head 8 and making the force thereof adjustable to the drawing state via a pressure control means 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squeezing device in a press.

0002

2. Description of the Prior Art Up to now, in known drawing devices of this type, it has been necessary to compensate not only the drawing force but also the drawing distance of the deformation phase or drawing phase by means of the thin plate holding cylinder.

[0003] Therefore, the Federal Republic of Germany Patent Publication No. 24
No. 07 864 discloses that a pressing bolt is provided on a pressing cushion on the side of a press table. This pressing bolt is supported by a pressing head. The pressure head can be raised and lowered by means of a pressure cylinder, so that it takes on the one hand the drawing distance for the sheet metal to be deformed and, on the other hand, applies the required holding force for the edge region of the sheet metal during the drawing. The distance of the pressing head is thereby determined by the distance between the apertures, the tool, the sheet metal deformation and the aperture pin.

Furthermore, European Patent No. 0 173 75
No. 5 discloses a drawing device in a press, in which the force of the sheet-holding cylinders can be adjusted individually by active or passive control means. Here too, the means for deforming the lamella could be completely compensated by the lamella holding cylinder.

[0005]

On the other hand, it is an object of the present invention to maintain the distance between the ram and the pressing head or between the tool upper part and the pressing head constant during the deformation (drawing phase). .

[0006]

This object is achieved by the features of claim 1 of the patent claims. The features of the subsequent claims represent particularly advantageous embodiments and partially inventive developments according to claim 1.

In this case, there is the particular advantage of carefully adjusting the force of each individual sheet-holding cylinder in a constricted state in the affected edge region of the sheet. The laminar holding cylinder is constructed with a short stroke, which makes it possible to keep the amount of displaced pressure medium low. A further essential advantage of the invention is that, when the bottom dead center of the ram is reached, unloading the lamella holding cylinder directly unloads the laminate holder. The sheet metal holder itself can therefore also be formed from individual parts. Direct force measurement is possible by using a force measuring device between the slat holding cylinder and the slat holding means, such as an aperture pin.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

The partial region of the press corresponds to FIG. 1 and has a press stand 1 on which a ram 2 can be raised and lowered by the press drive. A tool upper part 4 is fixed to the ram. The press furthermore has a press stand 3, which can also be a sliding stand which can be removed from the press in order to change tools or tool sets and transport means. A press rod 7 is attached to the press or this press stand.
A throttling device characterized by is installed. Possible embodiments of such a diaphragm device are known from the publications cited above. The squeezing device acts on a press head 8 that is supported on a press table so as to be movable up and down. A sheet-retaining cylinder 10 is integrated into the press head, the piston rod 11 of which acts on the throttle pin 9. The aperture pin rests from below on a sheet metal holder 13, which can also be made from individual parts. A sheet metal holder divided into individual parts is disclosed in DE 38 07 683 A1. The sheet metal holder has a lower tool part 5, such as a drawing punch part, for example.

Corresponding to FIG. 1, a spacing bolt 14 is provided between the ram 2 and the pressure head 8. According to FIG. 4, these bolts act between the tool upper part 4 and the pressure head 8.

FIG. 2, which is drawn in the same way as FIG.
1) are joined together at 16 at spacing bolts 14. From this point on, the pressure head 8 moves downwards with a further descent of the ram 2 against the forces on the throttling device, in this embodiment against the forces on the pressure head 7.

When the laminate holding cylinder 10 is controlled and thus the laminate holder 13 is acted upon, the distance between the laminate holder or the lamella 6 and the tool upper part 4 decreases, which increases the distance between the ram 2 and the tool. Even though the distance between the upper part 4 and the pressing head 8 remains constant, it is reduced. The control of the sheet holding cylinder 10 takes place via a pressure control 12 or a corresponding pressure regulator. In order to prevent the spacing bolts 14 from losing their mutual contact during the deformation and drawing process, the force of the drawing device is generally set higher than the overall force of the sheet holding cylinder.

FIG. 3 shows the means known from FIGS. 1 and 2 of the press in the final phase of deformation. When the ram 2 reaches its bottom dead center, the lamella holding cylinder 10 can be controlled without pressure. The piston rod 11 receives its own weight and reaches its lower position by switching control of pressure control. When the ram returns to top dead center, the sheet 6 thus formed is lifted out of the lower part 5 of the tool behind the ram's upward movement.

FIG. 4 differs from the previous figures in that a spacer bolt 14 is arranged between the tool upper part 4 and the pressure head 8, the upper spacer bolt It can be integrated with the upper part.

[0015]

Effects of the Invention The present invention provides a spacing bolt between the ram and the pressing head, so that during the entire throttling process, the pressing head is kept at a constant distance from the ram under the reaction force of the throttling device. and fix the thin plate holding cylinder to the pressing head,
Since the force can be controlled or adjusted to the throttle state through the pressure control means, the distance between the ram and the press head or the upper part of the tool and the press head, which was a problem in the prior art, can be reduced during deformation. , can be kept constant, which is a remarkable effect.

[Brief explanation of the drawing]

1 shows an open tool space of a press with a thin plate inserted therein; FIG.

FIG. 2 shows the lowered ram of the press at the moment when the spacing bolts are joined;

3 shows the ram with the upper part of the tool and the drawing device with the lower part of the tool and the sheet metal holder during deformation; FIG.

4 shows a ram and throttling device corresponding to FIG. 3 with a spacing bolt between the pressing head and the upper part of the tool; FIG.

[Explanation of symbols]

1 Press stand 2
Ram 3 Press stand 4
Upper part of tool 5
Tool lower part 6
thin plate

Claims (6)

[Claims] 1. A ram that moves up and down in a press and a stationary or removable press stand for accommodating tools, the drawing device having at least one pressure cylinder for the drawing process. In a drawing device in a press, the ram (2) and the press are equipped with a pressing head which is acted upon by a ram (2) and a plurality of sheet holding cylinders which adjust the sheet holding force in individual areas via drawing pins during the drawing process. A spacing bolt (14) is provided between the head (8), so that the pressing head (8) remains constant relative to the ram (2) during the entire throttling process under the reaction force of the throttling device (7). furthermore, the thin plate holding cylinder (10) is fixed to the pressing head (8), the force of which can be controlled or adjusted to the throttled state via the pressure control means (12). A squeezing device. 2. Characterized in that the spacing bolt (14) is constructed in two parts, with a spacing bolt (14) of the pressing head (8) opposing each spacing bolt (14) of the ram (2). The aperture device according to claim 1. 3. Restriction device according to claim 1, characterized in that the sheet-retaining cylinder (10) is combined with the piston rod (11) into a pressure head (8). 4. The length of the spacing bolt (14) is adjusted to a constant distance from the ram (2) and the pressing head (8) during the drawing phase, and a laminate retainer with an interposed laminate (6) is provided. Immediately before setting the tool upper member (4) on the body (13),
2. Throttling device according to claim 1, characterized in that a mutual connection (16) of the spacer bolts is achieved. 5. Claim characterized in that the adjusted maximum overall force of the sheet-holding cylinder (10) is smaller than the force acting on the pressing head (8) of the throttling device via the pressing rod (7). 1. The aperture device according to 1. 6. The spacing bolt (14) is constructed in two parts, with the spacing bolt (8) of the pressing head (8) opposing each spacing bolt (14) of the tool upper part (4). The aperture device according to claim 1, characterized in that: