US20120047979A1

US20120047979A1 - Hydroforming die assembly and method for deforming a tube

Info

Publication number: US20120047979A1
Application number: US13/010,314
Authority: US
Inventors: Klaus Hertell; Prashant Soman
Original assignee: Schuler Inc
Current assignee: Schuler Inc
Priority date: 2010-08-25
Filing date: 2011-01-20
Publication date: 2012-03-01
Also published as: CA2746896A1; MX2011008887A

Abstract

A hydroforming die assembly for deforming a tube and a method for deforming the tube are provided.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 61/376,926, filed on Aug. 25, 2010, the entire contents of which are hereby incorporated by reference herein.

BACKGROUND

Hydroforming systems have been utilized to deform tubes. However, the hydroforming systems may at least partially crush pipes in the central regions of the pipes. Accordingly, the inventors herein have recognized a need for an improved hydro forming die assembly and method.

SUMMARY

A hydroforming die assembly for deforming a tube in accordance with an exemplary embodiment is provided. The hydroforming die assembly includes a lower die having a first cavity formed therein. The hydroforming die assembly further includes a vertically movable upper die disposed above the lower die. The vertically movable upper die has a second cavity formed therein. The hydro forming die assembly further includes a first sealing assembly disposed proximate to a first end of the lower die. The first sealing assembly has a first subplate, a first feed insert, a first axial cylinder, and a first seal cone. The first seal cone is coupled to the first axial cylinder. The first feed insert and the first axial cylinder are coupled to the first subplate. The first subplate is configured to move vertically. The hydroforming die assembly further includes a second sealing assembly disposed proximate to a second end of the lower die. The second sealing assembly has a second subplate, a second feed insert, a second axial cylinder, and a second seal cone. The second seal cone is coupled to the second axial cylinder. The second feed insert and the second axial cylinder are coupled to the second subplate. The second subplate is configured to move vertically. The first and second feed inserts are configured to initially support the tube above the lower die. The upper die is configured to move vertically downwardly to contact the tube when the tube is supported on the first and second feed inserts. The first and second axial cylinders are configured to move the first and second seal cones, respectively, toward first and second ends of the tube, respectively, to seal the first and second ends of the tube, respectively. The first and second seal cones are configured to increase a pressure of a fluid disposed in the tube to obtain pressurized fluid therein. The upper die is further configured to move further vertically downwardly against the tube while the tube has the pressurized fluid therein such that the first and second sealing assemblies are moved vertically downwardly and the tube is at least partially deformed into the first and second cavities.
A method for deforming a tube utilizing a hydroforming die assembly in accordance with another exemplary embodiment is provided. The hydroforming die assembly has a lower die with a first cavity formed therein, a vertically movable upper die with a second cavity formed therein, and first and second sealing assemblies. The first sealing assembly has a first subplate, a first feed insert, a first axial cylinder, and a first seal cone. The first feed insert and the first axial cylinder are coupled to the first subplate. The first subplate is configured to move vertically. The second sealing assembly has a second subplate, a second feed insert, a second axial cylinder, and a second seal cone. The second feed insert and the second axial cylinder are coupled to the second subplate. The second subplate is configured to move vertically. The method includes supporting the tube above the lower die utilizing the first and second feed inserts. The method further includes moving the upper die vertically downwardly to contact the tube when the tube is supported on the first and second feed inserts. The method further includes moving the first and second seal cones, respectively, toward first and second ends of the tube, respectively, to seal the first and second ends of the tube, respectively, utilizing the first and second axial cylinders, respectively. The method further includes increasing a pressure of a fluid disposed in the tube to obtain pressurized fluid therein utilizing the first and second seal cones. The method further includes moving the upper die further vertically downwardly against the tube while the tube has the pressurized fluid therein such that the first and second sealing assemblies are moved vertically downwardly and the tube is at least partially deformed into the first and second cavities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a hydroforming system in accordance with an exemplary embodiment;

FIG. 2 is an enlarged view of a portion of a hydroforming die assembly utilized in the hydroforming system of FIG. 1; and

FIGS. 3-10 illustrate different operational positions of the hydroforming die assembly utilized in the hydroforming system of FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, a hydroforming system 10 for deforming a shape of a tube 12 utilizing fluid within the tube 12 in accordance with an exemplary embodiment is illustrated. The hydroforming system 10 includes a hydroforming die assembly 13, an actuator 14, a fluid supply system 15, and a controller 16. The tube 12 is constructed of a metal. For example, the tube 12 can be constructed from at least one of steel, aluminum, copper, and stainless steel.
The hydroforming die assembly 13 is configured to deform the tube 12 to a desired shape utilizing pressurized fluid within the tube 12. In one exemplary embodiment, the fluid is a water-based fluid. Of course, other types of fluids could be utilized. The hydroforming die assembly 13 includes a lower baseplate 20, an upper baseplate 22, a lower die 24, an upper die 26, a sealing assembly 30, a sealing assembly 32, and an ejector unit 33.
The lower baseplate 20 is configured to hold the lower die 24 and the sealing assembly 30 thereon. The lower baseplate 20 is constructed of steel and is substantially rectangular-shaped.
The upper baseplate 22 is configured to hold the upper die 26, and the upper feed inserts 52, 102 thereon. The upper baseplate 22 is operably coupled to the actuator 14. The actuator 14 is configured to move the upper baseplate 22 vertically, either upwardly or downwardly, relative to the lower baseplate 20 in response to control signal from the controller 16. The upper baseplate 22 is constructed of steel and is substantially rectangular-shaped.
Referring to FIGS. 1 and 3, the lower die 24 has a first cavity 35 formed therein for shaping at least a portion of the tube 12. The lower die 24 is constructed of a hardened steel and is fixedly coupled to the lower baseplate 20. In an alternative embodiment, the lower die 24 could have more than one cavity therein.
The upper die 26 has a second cavity 36 formed therein for shaping at least a portion of the tube 12. The upper die 26 is constructed of a hardened steel and is fixedly coupled to the upper baseplate 22. In an alternative embodiment, the upper die 26 could have more than one cavity therein.
Referring to FIG. 1, the sealing assemblies 30, 32 are configured to seal first and second ends, respectively, of the tube 12 and to fill the tube 12 with a fluid and to increase a pressure of the fluid within the tube 12. Further, the sealing assemblies 30, 32 are configured to move vertically relative to the baseplate 20.
Referring to FIGS. 1 and 2, the sealing assembly 30 includes a subplate 42, push bars 44, 46, a lower feed insert 50, an upper feed insert 52, a seal cone 60, and an axial cylinder 62. The subplate 42 is constructed of steel and is biased above the baseplate 20 utilizing springs 63, 64 that are disposed between the subplate 42 and the baseplate 20. The springs can be at least one of metal springs, plastic springs, and gas loaded springs. In an alternative embodiment, the springs can be replaced by a hydraulic cylinder operably coupled between the subplate 42 and the baseplate 20.
The push bars 44, 46 are disposed on the subplate 42 on opposite sides of an axial cylinder 62 disposed on the subplate 42. The push bars 44, 46 are constructed of steel. When the upper baseplate 22 is lowered towards the lower baseplate 20, the push bars 44, 46 contact a lower surface of the baseplate 22 to urge the subplate 42 downwardly against the biasing force of the springs thereof.
The lower feed insert 50 is coupled on the subplate 42 proximate to a first end of the tube 12. The upper feed insert 52 is coupled to the upper baseplate 22 directly above the lower feed insert 50. The lower feed insert 50 and the upper feed insert 52 are configured to clamp around an end portion of the tube 12 when the actuator 14 moves the upper baseplate 22 toward the lower baseplate 20.
The seal cone 60 is operably coupled to the axial cylinder 62. The axial cylinder 112 is configured to move the seal cone 60 axially, either toward the tube 12 or away from the tube 12, in response to control signals from the controller 16. When the axial cylinder 62 moves the seal cone 60 toward the tube 12, the seal cone 60 seals a first end of the tube 12. The seal cone 60 includes an aperture extending therethrough for allowing fluid to flow through the seal cone 60 into an interior region of the tube 12. The seal cone 60 is fluidly coupled to the fluid supply system 15 for receiving pressurized fluid from the system 15.
Referring to FIG. 1, the sealing assembly 32 includes a subplate 92, push bars 94, 96, a lower feed insert 100, an upper feed insert 102, a seal cone 110, and an axial cylinder 112. The subplate 92 is constructed of steel and is biased above the baseplate 20 utilizing springs 113, 114 disposed between the subplate 92 and the baseplate 20. The springs can be at least one of metal springs, plastic springs, and gas loaded springs. In an alternative embodiment, the springs can be replaced by a hydraulic cylinder operably coupled between the subplate 92 and the baseplate 20.
The push bars 94, 96 are disposed on the subplate 92 on opposite sides of an axial cylinder 112 disposed on the subplate 92. The push bars 94, 96 are constructed of steel. When the upper baseplate 22 is lowered towards the lower baseplate 20, the push bars 94, 96 contact a lower surface of the upper baseplate 22 to urge the subplate 92 downwardly against the biasing force of the springs thereof.
The lower feed insert 100 is coupled on the subplate 92 proximate to a second end of the tube 12. The upper feed insert 102 is coupled to the upper baseplate 22 directly above the lower feed insert 100. The lower feed insert 100 and the upper feed insert 102 are configured to clamp around an end portion of the tube 12 when the actuator 14 moves the upper baseplate 22 toward the lower baseplate 20.
The seal cone 110 is operably coupled to the axial cylinder 112. The axial cylinder 112 is configured to move the seal cone 110 axially, either toward the tube 12 or away from the tube 12, in response to control signals from the controller 16. When the axial cylinder 112 moves the seal cone 110 toward the tube 12, the seal cone 110 seals a second end of the tube 12. The seal cone 110 includes an aperture extending therethrough for allowing fluid to flow through the seal cone 110 into an interior region of the tube 12. The seal cone 110 is fluidly coupled to the fluid supply system 15 for receiving pressurized fluid from the system 15.
The ejector unit 33 is coupled to the lower die 24 and is configured to hold the tube 12 above the lower die 24, along with the lower feed inserts 50, 100, before closing the upper die 26 against the lower die 24.
The controller 16 is configured to generate control signals to control operation of the axial cylinder 62, 112, and the actuator 14. In one exemplary embodiment, the controller 16 is a computer. In another exemplary embodiment, the controller 16 is a programmable logic unit.
Referring to FIGS. 3-10, a method for deforming the tube 12 utilizing the hydroforming system 10 in accordance with an exemplary embodiment will now be explained.
Referring to FIG. 3, initially, the actuator 14 moves the upper baseplate 22 to a full upward position such that a relatively large gap is present between the lower die 24 and the upper die 26, in response to a control signal from the controller 16.
Next, referring to FIG. 4, the tube 12 is placed on the feed insert 50, 100 such that the feed inserts 50, 100 support the tube 12 above the lower die 24.
Next, referring to FIG. 5, the actuator 14 moves the baseplate 22 and the upper die 26 vertically downwardly such that the upper die 26 contacts the tube 12 when the tube 12 is supported on the feed inserts 50, 100. In one exemplary embodiment, the upper die 26 applies at least 50 tons of force against the tube 12. Of course, other amounts of force could be utilized based on the desired tube deformation and tube material type.
Next, referring to FIG. 6, the axial cylinders 62, 112 move the seal cones 60, 110 toward the first and second ends, respectively, of the tube 12 such that the seal cones 60, 110 seal the first and second ends, respectively, of the tube 12. Further, the seal cones 60, 110 route pressurized fluid from the fluid supply system 15 into an interior region of the tube 12 to fill the tube 12 with the pressurized fluid.
Next, referring to FIG. 7, the actuator 14 moves the upper die 26 further vertically downwardly against the tube 12 while the tube 12 has at least some pressurized fluid therein such that the sealing assemblies 30, 32 are also moved vertically downwardly (by the upper die 26 contacting the push bars) and the tube 12 is at least partially deformed into the cavities 35, 36. In one exemplary embodiment, the upper die 26 applies a force of at least 5,000 tons on the tube 12. Of course, other amounts of force could be utilized based on the desired tube deformation and tube material type.
Next, referring to FIG. 8, optionally the axial cylinders 62, 112 move the seal cones 60, 110 further inwardly into the tube 12. Further, the seal cones 60, 110 route pressurized fluid into the tube 12 to increase a pressure level of the pressurized fluid within the tube 12 to deform the tube 12 into the cavities 35, 36. In one exemplary embodiment, the seal cones 60, 110 route pressurized fluid into the tube 12 having a pressure greater than a yield point pressure level (i.e., Pi_max) of the tube 12 to deform the tube 12 into the cavities 35, 36. The yield point pressure level may be in a range of 8,000-20,000 psi for example. Of course, other amounts of yield point pressure levels could be utilized based on the tube material type.
Next, referring to FIG. 9, optionally the axial cylinders 62, 112 may maintain the pressurized fluid in the tube 12 for 1-2 seconds for example. Of course, other amounts of time could be utilized based on the tube material type and a shape of the cavities.
Next, referring to FIG. 10, the axial cylinders 62, 112 move the seal cones 60, 110, respectively, out of the first and second ends, respectively, of the tube 12 and the pressurized fluid within the deformed tube 12 exits the deformed tube 12.
In an alternative embodiment of the above method, the method steps illustrated in FIGS. 8 and 9 can be removed. For example, in an alternative method, after performing the method steps of FIGS. 3-7, the system 10 can immediately perform the method step shown in FIG. 10 and obtain a deformed tube having a desired shape.
An advantage of utilizing the hydroforming system 10 is that the system 10 can deform tubes without crushing central regions of the tubes.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description.

Claims

We claim:

1. A hydroforming die assembly for deforming a tube, comprising:

a lower die having a first cavity formed therein;

a vertically movable upper die disposed above the lower die, the vertically movable upper die having a second cavity formed therein;

a first sealing assembly disposed proximate to a first end of the lower die, the first sealing assembly having a first subplate, a first feed insert, a first axial cylinder, and a first seal cone, the first seal cone coupled to the first axial cylinder, the first feed insert and the first axial cylinder coupled to the first subplate, the first subplate configured to move vertically;

a second sealing assembly disposed proximate to a second end of the lower die, the second sealing assembly having a second subplate, a second feed insert, a second axial cylinder, and a second seal cone, the second seal cone coupled to the second axial cylinder, the second feed insert and the second axial cylinder coupled to the second subplate, the second subplate configured to move vertically;

the first and second feed inserts configured to initially support the tube above the lower die;

the upper die being configured to move vertically downwardly to contact the tube when the tube is supported on the first and second feed inserts;

the first and second axial cylinders configured to move the first and second seal cones, respectively, toward first and second ends of the tube, respectively, to seal the first and second ends of the tube, respectively, the first and second seal cones configured to increase a pressure of a fluid disposed in the tube to obtain pressurized fluid therein; and

the upper die being further configured to move further vertically downwardly against the tube while the tube has the pressurized fluid therein such that the first and second sealing assemblies are moved vertically downwardly and the tube is at least partially deformed into the first and second cavities.

2. The hydroforming die assembly of claim 1, further comprising:

the first and second axial cylinders further configured to move the first and second seal cones, respectively, further inwardly into the first and second ends of the tube, respectively, the first and second seal cones further configured to further increase the pressure of the fluid in the tube to deform the tube into the first and second cavities.

3. A method for deforming a tube utilizing a hydroforming die assembly, the hydroforming die assembly having a lower die with a first cavity formed therein, a vertically movable upper die with a second cavity formed therein, and first and second sealing assemblies, the first sealing assembly having a first subplate, a first feed insert, a first axial cylinder, and a first seal cone, the first feed insert and the first axial cylinder coupled to the first subplate, the first subplate configured to move vertically, the second sealing assembly having a second subplate, a second feed insert, a second axial cylinder, and a second seal cone, the second feed insert and the second axial cylinder coupled to the second subplate, the second subplate configured to move vertically, the method comprising:

supporting the tube above the lower die utilizing the first and second feed inserts;

moving the upper die being vertically downwardly to contact the tube when the tube is supported on the first and second feed inserts;

moving the first and second seal cones, respectively, toward first and second ends of the tube, respectively, to seal the first and second ends of the tube, respectively, utilizing the first and second axial cylinders, respectively;

increasing a pressure of a fluid disposed in the tube to obtain pressurized fluid therein utilizing the first and second seal cones; and

moving the upper die further vertically downwardly against the tube while the tube has the pressurized fluid therein such that the first and second sealing assemblies are moved vertically downwardly and the tube is at least partially deformed into the first and second cavities.

4. The method of claim 3, further comprising:

moving the first and second seal cones, respectively, further inwardly into the first and second ends of the tube, respectively, utilizing the first and second axial cylinders, respectively; and

increasing the pressure of the fluid in the tube to deform the tube into the first and second cavities utilizing the first and second seal cones.