DE10227088B4 - press drive - Google Patents

Abstract

Drive of mechanical presses with a plunger which is drivable by means of eccentric and steering gear, characterized
in that the double lever (10) of the steering-lever transmission (6) is mounted on an outer eccentric (17) and this on an inner eccentric (16) mounted rotatably on the axle (14),
wherein the inner eccentric (16) to the outer eccentric (17) is rotatably adjustable by a predetermined angle through the press drive by means of a drive wheel (4) connected to the inner eccentric (16).

Description

The Invention relates to the drive of cutting and forming presses, in which a steering gear by means of connecting rods connected to a press ram is and drives this and moves vertically and in particular on the possibility a stroke adjustment and a variable speed profile for press ram.

In diverse Way, it is known to achieve favorable forming and transfer conditions the ram speed optimally adapt this. A simple eccentric or crank drive has a solid, sinusoidal Movement course, the current requirements of fully automated presses and various embodiments the reshaped components usually does not suffice. Also the transformation of materials with very different strengths and forming behavior require highly flexible press drives.

Already Some time ago, drive concepts were developed for modification the course of movement and speed.

This is detailed in the DE 14 52 772 C described. The change in the sinusoidal shape was achieved through the use of lever and joint drives.

adversely in this approach is the rigid, uniquely defined, speed profile. changes are only by change the lever lengths possible, However, what failed in practice so far at high cost.

Recent solutions suggest the use of a second drive with the goal of motion overlay. So will in the DE 198 10 406 A1 proposed for a eccentric press a main drive and an additional servo drive. Via gear stages, the main drive drives the eccentric shaft. The connecting rod connected to the press ram is pivotally mounted on a further, additional eccentric device. This second eccentric device is in operative connection with a servo drive. By the servo drive, the additional eccentric is selectively rotated or pivoted against the eccentric shaft during operation of the press. Due to the relative eccentric movement relative to the eccentric shaft, the path-time profile of the plunger movement can be influenced. A movement profile deviating from the sinusoidal shape in relation to time is possible in certain areas.

adversely in the proposed concept is the large construction effort. In particular in addition to the main drive still a second drive required. to functionality the further drive belongs a loop of dependence generated by the rotational movement of the main drive a controlled variable, for targeted adjustment of the second eccentric. Because the entire torque support during the Forming of the other eccentric is added Also, the dimensioning of the components must be correspondingly large.

• – Verstellung des Lenkhebels mittels Hydraulikzylinder
• – am ortsfesten Gestellpunkt Verwendung eines zusätzlichen Hilfsexzenter der durch einen Hydromotor betätigt wird zur Veränderung der Lage des Koppelhebels.

In detail, the kinematics of the plunger in the VDI Progress Report No. 516, "Multi-tappet transfer presses", VDI Verlag, Dusseldorf 1999 treated. On page 60, two alternatives for changing the ram kinematics are presented.

• - Adjustment of the steering lever by means of hydraulic cylinders
• - At the fixed frame point use of an additional auxiliary eccentric is actuated by a hydraulic motor to change the position of the coupling lever.

The author points out that both proposals can only be realized with a high level of technical control. Another disadvantage is the use of soft hydraulic elements in the power flow of the transmission called. From the DE 195 47 671 C2 and to take these suggestions as well. The intellectual property right covers presses with an eccentric drive and on presses with a variable stroke in position and size. As a further disadvantage of this solution, there is the undesirable effect that with a long stroke, the ram speed is lowered below the value for smaller strokes. For a practice-oriented press operation this change of the speed behavior makes little sense.

For the forming process is ideally the absolute minimum speed at the beginning of the forming process. Particularly advantageous is the low Impact hit, causing the press is loaded only with a low vibration energy and thereby only a small sound development occurs.

Task and Advantage of the invention

Of the Invention is based on the object with simple, inexpensive Means a steering gear for Cutting and forming presses to be designed so that in a wide Range of different lifting and speed profiles feasible for press ram are and that at the beginning of the forming a significantly reduced ram speed is reachable.

These Task is based on the drive of an eccentric press the preamble of claim 1 by the characterizing features of Claim 1 solved.

In the dependent claims are advantageous and expedient developments the drive system according to the invention specified.

The Invention uses the known use of double eccentrics for stroke adjustment of eccentric presses and proposes these in the fulcrum to integrate the double lever of a steering gear. Both Double eccentrics is additional to the eccentric required to drive another eccentric arranged for stroke adjustment. The two eccentrics are designed that while the production phase these are lockable with each other and thus constitute a firm and rigid composite. The setting of the Stroke size takes place after unlocking exclusively through the press drive during the setup phase.

The Active connection of the adjustable eccentrics with the steering gear gives the possibility a change the stroke size and one Influencing the velocity profile. It is in the area greater Lift one achieved pronounced steering-arm kinematics, while at small strokes the kinematics approach that of an eccentric. Thus, with large strokes a desired reduction the impact speed is reached, the smaller it gets Strokes sensitively on is lowerable. Analog behaves the return stroke speed, the one at a big one Hub is correspondingly high.

One Another advantage of these movement curves is the achievable good freedom of movement for the automated transport of workpieces between two processing stages or for inserting or removing the workpieces.

Further Advantages and details of the invention will become apparent from the description an embodiment. The associated Figures show:

1 Two-point drive of a press with steering lever gear and double eccentric

2 Cut along the line AA in 1

3a Eccentric position at max. stroke

3b Eccentric position with a small stroke

4 Diagram of plunger movement and speed

Description of an embodiment

In 1 is the innovative part of the drive chain 1 illustrated by the example of a 2-point press. In the press head piece 2 the drive is stored. Not shown is the drive motor with belt drive, flywheel and clutch / brake combination in operative connection with pinion shaft 3 stand. pinion shaft 3 drives the drive wheel 4 directly or via intermediate wheel 5 at. The steering gear 6 consists of the paddock 7 with fixed bearing point 8th in the head piece 2 , The other end of the paddock 7 is as a storage point 9 with the double lever 10 connected.

In the camp point 11 of the double lever 10 is the connecting rod 12 stored, which via connection point 13 connected to the pressure point and thus with the press ram. The double lever 10 is pivotable on the in 2 and 3 stored and driven eccentrics shown. It shows the illustration in 2 a section along the line AA in 1 , The axis 14 is in the head piece 2 attached. On this axis 14 the drive wheel rotates 4 , which exemplifies a takedown connection 15 with the inner eccentric 16 connected is. This inner eccentric 16 is also rotatable on the axis 14 stored and is provided on its largest diameter with an external toothing. An outer toothing with the same geometry also has the outer eccentric 17 , By means of a locking ring 18 with corresponding internal teeth are the two eccentrics 16 . 17 during the production phase positively connected with each other, as shown.

A change in Hubgröße done in the Einrichtungsphase in that the locking ring 18 through pressurized cylinders 19 in the direction of the arrow 20 is moved. The toothing of the inner eccentric 16 with the locking ring 18 comes out of engagement while holding the locking ring 18 over fitting 21 the double lever 10 , About locking ring 18 and fitting piece 21 is the outer eccentric 17 with the double lever 10 connected.

By a rotation, by a defined angle, of the drive wheel 4 with inner eccentric 16 the new, desired stroke is set. This change in the position of the eccentric to each other is off 3a and 3b refer to. 3a shows the arrangement of the inner eccentric 16 to the outer eccentric 17 at maximum stroke. The eccentricity E1 and E2 lie on the vertical axis and add up to the maximum stroke H1.

In 3b is the inner eccentric 16 to the outer eccentric 17 twisted and a small effective mer stroke H2 set. After Hubveränderung the cylinders 19 reversed and the positive connection of the eccentric 16 . 17 through locking ring 18 is restored.

Out The procedure described is clearly visible that with low Effort and the use of a known and proven technology a hub and speed change the ram is executable.

The graphical representation of the relationships is the diagram in 4 refer to. Over the angular range of one revolution, ie 360 °, the stroke of the plunger (full line) and the associated speed (dash-dotted line) are shown. At the maximum lift Hmax, the maximum speed Vmax is obtained and the minimum lift Hmin is driven at the minimum speed Vmin.

Well recognizable is the reduced speed for all stroke variants during the Hit or the beginning of the forming process. Thus becomes the task fully fulfilled.

The invention is not limited to the example described and illustrated. It also includes all professional training in the context of the inventive idea. Thus, the invention also applies without limitation for single-point or four-point presses. Likewise, instead of a positive connection in the eccentric locking and a frictional, z. B. by means of cones, as by the applicant in the DE 43 07 535 A1 described, be selected. In a non-positive connection, a stepless adjustment is achievable.

1

drive chain

2

headpiece

3

pinion shaft

4

drive wheel

5

idler

6

Steering lever mechanism

7

paddock

8th

bearing point

9

bearing point

10

double lever

11

bearing point

12

pleuel

13

connection point

14

axis

15

driving connection

16

internal eccentric

17

outer eccentric

18

locking ring

19

cylinder

20

arrow

21

Pass-piece

Claims (5)

Drive of mechanical presses with a plunger which is drivable by means of eccentric and steering gear mechanism, characterized in that the double lever ( 10 ) of the steering gear ( 6 ) on an outer eccentric ( 17 ) and this on a rotatable on the axis ( 14 ) mounted inner eccentric ( 16 ), wherein the inner eccentric ( 16 ) to the outer eccentric ( 17 ) by a predetermined angle through the press drive by means of a with the inner eccentric ( 16 ) connected drive wheel ( 4 ) is rotationally adjustable. Drive according to claim 1, characterized in that during production of the inner eccentric ( 16 ) and the outer eccentric ( 17 ) are positively or non-positively locked together. Drive according to claim 1 or 2, characterized in that the eccentric ( 16 . 17 ) have an external toothing and via a locking ring ( 18 ) are locked with internal teeth. Drive according to one or more of the preceding claims, characterized in that the outer eccentric ( 17 ) by means of locking ring ( 18 ) and fitting ( 21 ) with the double lever ( 10 ) is connectable. Drive according to claim 4, characterized in that the locking ring ( 18 ) by cylinder ( 19 ) is displaceable.