PRESS SHUTHEIGHT ADJUSTMENT USING BOLSTER HYDRAULIC TIE ROD ASSEMBLIES

• US 20040159140A1
• Filed: 02/13/2003
• Published: 08/19/2004
• Est. Priority Date: 02/13/2003
• Status: Active Grant

• Current Assignee: The Minster Machine Company (Nidec Corporation)
• Original Assignee: The Minster Machine Company (Nidec Corporation)
• Inventors: Daniel, Edward A., Brewer, W. Craig
• Granted Patent: US 6,772,682 B1
• Time in Patent Office: Days
• US Class Current: 72/455
• CPC Class Codes: B30B 15/0041 Control arrangements therefor

Abstract

A shutheight adjustment system incorporating tie rods and accompanying hydraulic tie rod nut assemblies in connecting a bed to a bolster of a mechanical press for dynamically altering the tensioning of the tie rods. Each hydraulic tie rod nut assembly includes a cylinder with an inner sliding piston threadably engaging the tie rod. A pressurizing mechanism injects pressurized fluid within a chamber formed by the piston and cylinder. By increasing pressure within the chamber of the hydraulic tie rod nut assembly, compression between the press bed and press bolster may be increased, thereby increasing the press shutheight.

Claims

1. A press comprising:

a crown and a bed attached together by a frame, said bed having a bolster attached thereto;

a slide attached to said crown for reciprocating movement in opposed relation to said bed;

a plurality of tie rods connecting between said bolster and said bed;

a plurality of pressure-activated tie rod nut assemblies attached to at least two said tie rods adjacent one of said bolster and said bed so that when activated, said tie rod nut assemblies force said bolster toward said bed;

a shutheight measuring means for measuring the shutheight of said press, said shutheight measuring means associated with said press; and

feedback means connected to said shutheight measuring means and said tie rod nut assemblies for comparing a predetermined desired shutheight to the shutheight measured by said measuring means and pressure activating said tie rod nut assemblies when the measured shutheight deviates from the predetermined shutheight, whereby shutheight is controlled.

2. The press of claim 1 in which a tie rod nut assembly comprises:

a cylinder block having a cylinder bore fit about said tie rod;

a piston threadedly engaged about said tie rod and slidably disposed within said cylinder bore, thereby forming an inner chamber, said inner chamber pressurized with a liquid; and

a tie rod nut threadably engaged about said tie rod and engaging said piston.

3. The press of claim 2 in which said inner chamber is further defined by seals between said piston and said cylinder block.

4. The press of claim 2 in which said liquid comprises oil.

5. The press of claim 2 in which said tie rod nut assembly includes a spacer interfit between said nut and said cylinder block to maintain a desired preload on said bolster without said tie rod nut assemblies being pressurized.

6. The press of claim 2 having at least two said tie rod nuts assemblies in which said inner chambers of said tie rod nut assemblies are connected together by a manifold.

7. The press of claim 2 in which said feedback means controls the shutheight of the press by altering the pressure within said inner chamber.

8. The press of claim 1 in which said feedback means comprises:

a pump connected to said tie rod nut assemblies and activated by a control signal for changing the pressure of liquid communicated to said tie rod assemblies; and

comparator means having input lines for a measured shutheight from said shutheight measuring means and a predetermined desired shutheight, said comparator means including a signal output line connected to said pump, said comparator means causing a control signal to be formed on said output line on the basis of a comparison between a measured shutheight and a predetermined desired shutheight.

9. A press comprising:

a crown and a bed attached together by a frame, said bed having a bolster attached thereto;

a slide attached to said crown for reciprocating movement in opposed relation to said bed;

a plurality of tie rods connecting between said bolster and said bed;

a plurality of pressure-activated tie rod nut assemblies, at least two said tie rods having at least one tie rod nut assembly mounted thereto adjacent one of said bolster and said bed, each said tie rod nut assembly including a cylinder block having a cylinder bore fit about said tie rod, a piston threadedly engaged about said tie rod and slidably disposed within said cylinder bore, thereby forming an inner chamber, said inner chamber pressurized with a liquid, and a tie rod nut threadably engaged about said tie rod and engaging said piston so that an increase in pressure within said inner chamber forces said tie rod nut away from said cylinder block;

a shutheight measuring means for measuring the shutheight of said press, said measuring means operatively associated with said press; and

feedback means connected to said shutheight measuring means and to said tie rod nut assemblies for comparing a predetermined desired shutheight to the shutheight measured by said measuring means and altering the pressure within each said inner chamber when the measured shutheight deviates from the predetermined shutheight, whereby shutheight is controlled.

10. The press of claim 9 in which said feedback means includes a pump to pressurize said liquid, said pump controlled by said feedback means.

11. The press of claim 9 in which said feedback means includes a manifold connected to said inner chambers of said tie rod nut assemblies.

12. The press of claim 9 in which said feedback means controls the pressure within each tie rod nut assembly individually.

13. The press of claim 9 in which said liquid is pressurized to between 1200 p.s.i. and 3500 p.s.i.

14. The press of claim 9 in which said tie rod nut assembly includes a spacer interfit between said tie rod nut and said cylinder block to maintain a desired preload on said bolster without said tie rod nut assemblies being pressurized.

15. The press of claim 9 in which said inner chambers of said plurality of said tie rod nut assemblies are connected together by a manifold.

16. The press of claim 9 in which said feedback means comprises:

a pump connected to said inner chambers of said plurality of tie rod nut assemblies and activated by a control signal for changing the pressure of said liquid communicated to said inner chambers of said plurality of said tie rod assemblies; and

comparator means having input lines for a measured shutheight from said shutheight measuring means and a predetermined desired shutheight, said comparator means including a signal output line connected to said pump, said comparator means causing a control signal to be formed on said output line on the basis of a comparison between a measured shutheight and a predetermined desired shutheight.

17. A press comprising:

a crown and a bed attached together by a frame;

a bolster attached to said bed at a position intermediate said bed and said crown;

a slide attached to said crown for reciprocating movement in opposed relation to said bolster, said slide and said bolster having a shutheight associated therewith;

a plurality of tie rods connecting said bolster to said bed; and

a plurality of pressure-activated tie rod nut assemblies, at least two said tie rods having at least one tie rod assembly mounted thereto adjacent one of said bolster and said bed, each said tie rod nut assembly being configured for selectively adjusting at least one of tolerance and compression between said bed and said bolster to thereby effect a proportional change in the shutheight.

18. The press of claim 17, further comprising a quick access adjustment mechanism for adjusting a relative bolster height of said bolster, said quick access adjustment mechanism being operatively positioned between said bed and said bolster, said quick access adjustment mechanism being hydraulically activated.

19. The press of claim 18, further comprising at least one limit stop associated with one of said bed and said bolster, each said limit stop limiting a degree of relative bolster height adjustment that can be made using said quick access adjustment mechanism.

20. The press of claim 18, wherein said quick access adjustment mechanism and said plurality of tie rod nut assemblies are capable of being used conjunctively to effect the shutheight.