Press with two drive motors

Patent metadata

Field	Value
Publication number	US-9868264-B2
Application number	US-201313837831-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Mar 23, 2012
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A press with a press drive for moving a plunger in stroke direction (H). The press drive comprises two electric drive motors which are controllable independently of each other. The two drive motors are connected to the plunger via a drive unit. A control arrangement is provided for controlling the two drive motors. The control arrangement includes a characteristic plunger curve (K) which determines the plunger positions and/or the plunger movement and/or the plunger force dependent on time or dependent on a so-called virtual press angle. In addition, the control arrangement includes an additional condition which is independent of the characteristic plunger curve (K). Via the additional condition the operation of the press drive, for example, in an optimum operating range and/or a low-wear lubrication state of the support bearings of the drive unit can be ensured.

First claim

What is claimed is:

1. Press ( 10 ) comprising:
a plunger ( 21 ) which is movable by a press drive ( 25 ) in a stroke direction H;
wherein the press drive ( 25 ) includes a first drive motor ( 26 ) and a second drive motor ( 27 ) which are connected to the plunger ( 21 ) via a drive unit ( 33 );
wherein the drive unit ( 33 ) includes a first eccentric ( 34 ) connected to the first drive motor ( 26 ) and a second eccentric ( 36 ) connected to the second drive motor ( 27 );
wherein the first eccentric ( 34 ) operatively connected to a main connecting rod ( 35 ) and the second eccentric ( 36 ) is operatively connected to a control connecting rod ( 37 );
wherein drive unit ( 33 ) further comprises a multi-arm lever ( 38 ) operatively connected via a first pivot bearing ( 39 ) to the main connecting rod ( 35 ) and via a second pivot bearing ( 40 ) to the control connecting rod ( 37 ) and via a third pivot bearing ( 41 ) to the plunger ( 21 );
a control arrangement ( 28 ) for controlling at least the first drive motor ( 26 ) and the second drive motor ( 27 ) for moving the plunger ( 21 ) and applying a plunger force thereto in accordance with a predetermined characteristic plunger curve (K);
wherein the two drive motors ( 26 , 27 ) are controlled in accordance with the characteristic plunger curve (K) in such a way that at least one additional condition (Z) which is independent of a change of plunger position (P) as predetermined by the characteristic plunger curve (K) and/or the plunger force (F) is fulfilled; and,
wherein each of the first pivot bearing ( 39 ) and the second pivot bearing ( 40 ) and the third pivot bearing ( 41 ) include in each case two drive components (G 1 , G 2 ) supported to be movable relative to each other and wherein a first additional condition of the at least one additional condition (Z) is fulfilled when the two drive components (G 1 , G 2 ) in each of the first pivot bearing ( 39 ) and the second pivot bearing ( 40 ) and the third pivot bearing ( 41 ) have a predetermined relative movement between the two drive components (G 1 , G 2 ) for maintaining a predetermined minimum thickness of a lubricant film therebetween independent of whether the position (P) of the plunger ( 21 ) changes or whether the plunger ( 21 ) is moving or is stopped.

2. Press ( 10 ) according to claim 1 , wherein the predetermined relative movement is present when a relative speed (co) between the two drive components (G 1 , G 2 ) of each of the first pivot bearing ( 39 ) and the second pivot bearing ( 40 ) and the third pivot bearing ( 41 ) corresponds at least to a predetermined threshold relative speed value (ωg).

3. Press ( 10 ) according to claim 1 , wherein a second additional condition of the at least one additional condition (Z) is fulfilled when one of the two drive motors ( 26 , 27 ) is operated in a predetermined operating state.

4. Press ( 10 ) according to claim 1 , wherein the first eccentric ( 34 ) and the second eccentric ( 36 ) are arranged along a common axis (A).

5. Press ( 10 ) according to claim 4 , wherein a relative angle (α) describing a relative position between the first eccentric ( 34 ) and the second eccentric ( 36 ) is predetermined fixed or variable.

6. Press ( 10 ) according to claim 1 , wherein the force provided to the plunger ( 21 ) by the first drive motor ( 26 ) and/or the first eccentric ( 34 ) is greater than the force provided by the second drive motor ( 27 ) and/or the second eccentric ( 36 ).

7. Press ( 10 ) according to claim 1 , wherein the control arrangement ( 28 ) includes a wireless interface ( 47 ) via which control data including the characteristic plunger curve (K) and the at least one additional condition (Z) can be received from an external device ( 48 ) and/or transmitted to an external device ( 48 ).

8. Press ( 10 ) according to claim 1 , wherein the press drive ( 25 ) further includes a third drive motor ( 73 ) which is connected to the plunger ( 21 ) via the drive unit ( 33 ) which includes a third eccentric ( 55 ) connected to the third drive motor ( 73 ).

9. Press ( 10 ) according to claim 8 , wherein the third drive motor ( 73 ) is controlled by the control arrangement ( 28 ) in such a way that a tilt tendency of the plunger ( 21 ) by a non-symmetric plunger force (F) is at least partially compensated for.

10. Method for operating a press ( 10 ), the press ( 10 ) comprising:
a plunger ( 21 ) which is movable by a press drive ( 25 ) in a stroke direction H;
wherein the press drive ( 25 ) includes a first drive motor ( 26 ) and a second drive motor ( 27 ) which are connected to the plunger ( 21 ) via a drive unit ( 33 );
wherein the drive unit ( 33 ) includes a first eccentric ( 34 ) connected to the first drive motor ( 26 ) and a second eccentric ( 36 ) connected to the second drive motor ( 27 );
wherein the first eccentric ( 34 ) is operatively connected to main connecting rod ( 35 ) and the second eccentric ( 36 ) is operatively connected to a control connecting rod ( 37 );
wherein drive unit ( 33 ) further comprises a multi-arm lever ( 38 ) operatively connected via a first pivot bearing ( 39 ) to the main connecting rod ( 35 ) and via a second pivot bearing ( 40 ) to the control connecting rod ( 37 ) and via a third pivot bearing ( 41 ) to the plunger ( 21 );
a control arrangement ( 28 ) for controlling at least the first drive motor ( 26 ) and the second drive motor ( 27 ) for moving the plunger ( 21 ) and applying a plunger force thereto in accordance with a predetermined characteristic plunger curve (K);
wherein the two drive motors ( 26 , 27 ) are controlled in accordance with the characteristic plunger curve (K) in such a way that at least one additional condition (Z) which is independent of a change of plunger position (P) as predetermined by the characteristic plunger curve (K) and/or the plunger force (F) is fulfilled; and,
wherein each of the first pivot bearing ( 39 ) and the second pivot bearing ( 40 ) and the third pivot bearing ( 41 ) include in each case two drive components (G 1 , G 2 ) supported to be movable relative to each other and wherein a first additional condition of the at least one additional condition (Z) is fulfilled when the two drive components (G 1 , G 2 ) in each of the first pivot bearing ( 39 ) and the second pivot bearing ( 40 ) and the third pivot bearing ( 41 ) have a predetermined relative movement between the two drive components (G 1 , G 2 ) for maintaining a predetermined minimum thickness of a lubricant film therebetween independent of whether the plunger ( 21 ) changes the plunger position (P) or whether the plunger ( 21 ) is moving or is stopped, said method comprising the following steps:
providing a change in the plunger position (P) and/or the plunger force (F) directive via the characteristic plunger curve (K);
providing the at least one additional condition (Z) which is independent of the change in the plunger position (P) and/or the plunger force (F) provided by the characteristic plunger curve (K);
operating the first drive motor ( 26 ) and the second drive motor ( 27 ) in such a way that the change in the plunger position (P) and/or the plunger force (F) corresponds to the characteristic plunger curve (K) and, additionally the first additional condition of the at least one additional condition (Z) is fulfilled.

11. Press ( 10 ) according to claim 1 , wherein the predetermined minimum lubricant film thickness between the two drive components (G 1 , G 2 ) exceeds that of any dirt particles contained in the lubricant film.

Assignees

• Fahrenbach Juergen
• Schuler Pressen Gmbh

Inventors

• Fahrenbach Juergen

Classifications

• B30B1/14

  operated by cams, eccentrics, or cranks · CPC title

• B30B1/06

  operated by cams, eccentrics, or cranks · CPC title

• B30B1/266

  Drive systems for the cam, eccentric or crank axis · CPC title

• B30B1/268

  using a toggle connection between driveshaft and press ram · CPC title

• B30B15/148 Primary

  Electrical control arrangements · CPC title