DE202013102487U1 - Punching machine with reduced dynamic deformation through optimized force application - Google Patents

Abstract

Punching machine (10) for separating and grooving sheet-like materials with two crucible parts (12, 13), wherein at least one crucible part (12) is moved in a punching stroke by means of at least two lifting devices (14, 14 ') in the direction of the other crucible part (13) in which the lifting devices (14, 14 ') act on the one crucible part (12, 12') on the side facing away from the other crucible part (13), characterized in that the lifting devices (14, 14 ') are arranged and configured that their force introduction lines (F) at the end of the punching stroke (16) extend at an angle α to a normal (N) to the crucible surface (11) of the one crucible part (12) facing the other crucible part (13), the force introduction lines ( F) cut their force introduction points (17) with respect to the lifting devices (14, 14 ') facing away.

Description

The invention relates to a punching machine with reduced dynamic deformation by optimized introduction of force according to the preamble of patent claim 1.

In punching machines, the requirement for the upper and lower punching dies in relation to the straightness or parallelism is very high. For example, parallelism in the hundredth range (mm) is often required, with different tonnages and punching forces of approx. 40 to more than 250 tonnes. When such enormous forces occur, there are always dynamic deformations in the punching die.

On the fixed side of the crucible you can counteract this momentum by much mass and choice of material. However, it is advantageous if the moving crucible is as light as possible because of the need to accelerate (up to) up to 12,000 strokes per hour.

The design of punching machines (stamping presses or punching dies) usually provides that a force is introduced into the movable punching / pressing pot via four points.

Typically, this introduction of force is accomplished in that in the punching machines in the prior art, inter alia, so-called toggle lever as in EP 0741001 B1 be used or, as in the EP 0 596 697 A1 in that control of the press pressure is accomplished by four hydraulic cylinders in the four corners of the press. These toggle or hydraulic cylinders are conventionally mounted below the moving crucible part and have their maximum force in the stretched state. The force introduction lines are aligned parallel with maximum force.

Since the introduction of force by the knee lever or a hydraulic usually takes place in the vicinity of the vertices of the moving crucible, this has the consequence that the punching the flat distributed cutting lines are punched at said points of attack first, since the deflection of the press pot in these areas minimal is. In the middle area, the deflection is stronger, so it may happen in this area that z. B. a cardboard sheet is not punched through, d. H. This results in so-called "holes", areas in which the material is not or at least not completely punched through.

However, depending on the quality requirement, this leads to a poor quality of the final product.

In the state of the art one goes today in a compromise u. a. with respect to the weight of the movable crucible part, d. H. the weight of the movable crucible is large enough to minimize dynamic deformation but low enough to save energy and achieve better dynamics since the mass of the crucible must be accelerated and decelerated with each stroke.

However, necessarily, this compromise always leads to dynamic deformation, i. H. it creates "holes".

To compensate for this disadvantage conventionally more punching pressure (force) is given. The disadvantage of this, however, is that then cut the edges indeed in the "holes" at the "high places", d. H. at the points where the dynamic deformation is not pronounced, but the cutting edges are destroyed.

Alternatively, in order to counteract the dynamic deformation, in the prior art, for each punching job, the center deflection, i. H. the dynamic deformation compensated by surface underlay of thin dressing paper.

The disadvantage of this, however, is that with every punching job that works with trimming paper (trimming sheets), there is a shorter set-up time and this set-up time is economically undesirable (additional time and material expenditure).

The present invention is therefore based on the object to provide a punching machine, which does not show the disadvantages mentioned above or to a lesser extent, d. H. to provide a punching machine ready, whose moving pot part shows little to no dynamic deformation and thus the above-mentioned, necessary in the prior art measures such. B. increased punching pressure, increased weight of the movable crucible part and / or use of trimming sheets obsolete or minimize them.

This object is achieved by a punching machine having the features of patent claim 1. Advantageous developments of the punching machine according to the invention are the subject of protection claims 2 to 5.

The punching machine according to the invention for separating and grooving sheet-like materials consists of two crucible parts, wherein at least one crucible part is moved in a punching stroke by means of at least two lifting devices in the direction of the other crucible part. The lifting devices engage the one crucible part on the side facing away from the other crucible part. The invention is now based on the change in the force introduction lines F, ie the lifting devices are arranged and designed so that their force introduction lines at the end of the punching stroke at an angle α to a normal N to the other crucible part facing crucible surface of a crucible part, wherein the force introduction lines cut their force introduction points facing away from the lifting devices.

This introduced introduction of force can both in relation to the surface of the cuboid moving crucible part, d. H. the crucible surface in the longitudinal or x-direction and in the transverse or y-direction or at the same time in both directions.

With calculations using the "finite element method", it can be demonstrated that the deflection in the middle region changes in such a way by the introduction of force at an angle α that there is an optimal angular position for the introduction of force given the geometry of the crucible part and the force introduction points. in which the deflection in the middle reaches a minimum.

According to the invention therefore the lifting devices are arranged at an angle which counteracts the deflection in the center of the crucible. The relationships are to be aligned with one another such that the force vectors above the moving crucible surface undergo an intersection point under separate viewing in the x direction and in the y direction.

The punching machine according to the invention according to claim 1 results in a lower deflection in the central region of the crucible part with the same thickness and geometry of the crucible. Since most punching jobs occur in the area of the front and center of the crucible part, this procedure offers a set-up time saving when trimming the die.

A further advantage of the punching machine according to the invention is that the crucible can be reduced in mass to achieve the same deflection (as in the conventional procedure, that is to say with parallel application of force) in the center region of the crucible. This in turn leads to energy savings and better dynamics, since the mass of the moving crucible part has to be accelerated and decelerated with each stroke.

Another advantage of the punching machine according to the invention is that a targeted shift in the mass ratios in the crucible would entail a reduction in the center region and reinforcement in the outer region of the crucible. This would in turn lead to an optimal stress-strain behavior, which gives the entire system a maximum of parallelism.

According to the invention, the moving crucible part is pressed or pressed against at least two lifting devices against another crucible part. This other crucible part can be fixed. According to the invention, however, both crucible parts can also be movable. Thus, the same, but also different lifting devices can apply to the crucible parts.

Preferably, the angle of the force introduction lines F of the lifting devices is between greater than 0 ° and 30 °, more preferably between 10 ° and 20 °.

The realization of the lifting devices can be done in different ways, so u. a. by hydraulic cylinders, preferably the lifting devices are knee joints.

Preferably, a total of four lifting devices are mounted, which press the at least one movable crucible part against the other crucible part embodiments of the invention are explained below with reference to the accompanying drawings, wherein

1a) , a moving pot part of a punching machine according to the prior art with two knee joints in non-stretched (solid lines) and stretched state (dashed lines) with the associated force introduction lines,

1b) a moving crucible part according to the invention a punching machine with two knee joints in non-extended (solid lines) and stretched state (dashed lines) with the associated force introduction lines and

2 : shows a schematic plan view of the crucible surface of a moving crucible part according to the invention a punching machine with four knee joints in the stretched state and the schematically illustrated force introduction points (solid lines) and the schematically illustrated position of attachment of the lifting devices on the pressure shoes (dashed lines).

In addition to the 1a) and 1b) For better orientation, a three-dimensional Cartesian coordinate system is appropriate. In this coordinate system, the z-axis corresponds to the normal N to the crucible surface 11 the moving cuboid crucible part 12 , the x-axis runs parallel to the longitudinal side, the y-axis parallel to the transverse side of the crucible surface 11 the moving cuboid crucible part 12 ,

At the bottom of the in 1a) shown moving crucible part 12 According to the prior art grip two lifting devices 14 . 14 ' in the form of two knee joints on pressure shoes 18 stand, in the unstretched state 15 (solid lines) the middle segments of the knee joints point to each other. By stretching 16 of the knee joints 14 . 14 ' becomes the moving crucible part 12 pressed upwards and against the other crucible part 13 pressed. The position of the force application points 17 lies here at the bottom of the moving crucible part 12 , Both the force application points 17 as well as below the moving crucible part 12 lying attachment 19 the lifting devices 14 . 14 ' on the pressure shoes 18 lie on a parallel to the z-axis. As a result, the force introduction lines F (see arrows) in the extended state 16 at the end of the punching stroke 12 ie at maximum force, parallel and in the direction of a normal N to the crucible surface 11 of the moving crucible part 12 (corresponds to z-axis) aligned.

At the bottom of the in 1b) shown moving crucible part according to the invention 12 grab two lifting devices 14 . 14 ' in the form of two knee joints on pressure shoes 18 stand, although here in the unstretched state 15 (solid lines) the middle segments of the knee joints point to each other. In this embodiment, the lifting devices 14 . 14 ' at the bottom of the moving, here lower crucible part 12 appropriate. By stretching 16 of the knee joints 14 . 14 ' becomes the moving crucible part 12 pressed upwards and against the other crucible part 13 pressed. The position of the force application points 17 also lies here at the bottom of the moving crucible part 12 , but the position of the force application points 17 in terms of attachment 19 the lifting devices 14 . 14 ' on the pressure shoes 18 respectively in the direction of the center of the crucible part 12 moved on the x-axis. As a result, the force introduction lines F (see arrows) in the extended state 16 at the end of the punching stroke, ie at maximum force, according to the invention at an angle α from here 18 ° to a normal N to the crucible surface 11 of the moving crucible part 12 (corresponds to z axis, dashed arrows) aligned. The force introduction lines F intersect at the, the force introduction points 17 opposite side of the moving crucible part 12 , ie above the crucible surface 11 ,

In the 2 shown top view of a moving crucible part according to the invention 12 ie the crucible surface 11 , schematically shows the position of the attachment 19 the pressure shoes 18 below the moving crucible 12 (see dashed circles) and the position of the force application 17 below the moving crucible 12 (Closed circles), as well as the course of the lifting devices below the moving crucible 12 (dashed lines between the circles).

Out 2 becomes clear that the force application points 17 concerning the position of the fixture 19 the lifting device 14 . 14 ' on the pressure shoes 18 both in the x-direction, ie parallel to the longitudinal side of the crucible surface 11 as well as in the y-direction, ie parallel to the transverse side of the crucible surface 11 can take place (see adjacent axis system).

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0741001 B1 [0005]
• EP 0596697 A1 [0005]

Claims (5)

Punching machine ( 10 ) for separating and grooving sheet-like materials with two crucible parts ( 12 . 13 ), wherein at least one crucible part ( 12 ) in a punching stroke by means of at least two lifting devices ( 14 . 14 ' ) in the direction of the other crucible part ( 13 ) is moved, wherein the lifting devices ( 14 . 14 ' ) on the one crucible part ( 12 . 12 ' ) on the other crucible part ( 13 attack) side facing away, characterized in that the lifting devices ( 14 . 14 ' ) are arranged and designed so that their force introduction lines (F) at the end of the punching stroke ( 16 ) at an angle α to a normal (N) to that of the other crucible part ( 13 ) facing the crucible surface ( 11 ) of a crucible part ( 12 ), wherein the force introduction lines (F) their force application points ( 17 ) with regard to the lifting devices ( 14 . 14 ' ) cut away. Punching machine ( 10 ) according to claim 1, characterized in that the angle of the force introduction lines (F) to the normal (N) to that of the other crucible part ( 13 ) facing the crucible surface ( 11 ) of a crucible part ( 12 ) is greater than 0 ° and not more than 30 °. Punching machine ( 10 ) according to claim 2, characterized in that the angle is 10 ° to 20 °. Punching machine ( 10 ) according to one of the preceding claims, characterized in that the lifting devices ( 14 . 14 ' ) are formed by knee joint devices. Punching machine ( 10 ) according to one of the preceding claims, characterized in that four lifting devices ( 14 . 14 ' ) on the one crucible part ( 12 attack).

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