Devices and method for shaping a tubular hollow element

An arrangement for forming a tubular hollow body (1) having a hollow body wall (2) made of a plastically deformable material and a hollow body axis (3) extending in the longitudinal direction of the hollow body (1), comprising:

• a first forming device (7) and a second forming device (8), the second forming device (8) being arranged downstream of the first forming device (7) in a forming process,
• wherein the first forming device (7) is designed to produce a preform (32) of a finished formed hollow body from the hollow body (1) in an initial state, wherein the preform (32) is designed as a tubular hollow body having a preform wall (38) made of a plastically deformable material and having a preform axis (37) coinciding with the hollow body axis (3), and
• wherein the second forming device (8) is designed to produce a subsequent form of from the preform (32), which has a subsequent form wall, wherein the subsequent form is the fully formed hollow body,
• wherein
• the first forming device (7) comprises:
• a first forming die (26) designed to be arranged on an outer side of the hollow body (1) and provided with a first die opening (28) designed for receiving the hollow body (1),
• a first mandrel (27) designed to be arranged in an interior of the hollow body (1) and provided on a circumference with a first shape-imparting mandrel profile (29) having first mandrel profile projections (30) and first mandrel profile intermediate spaces (31) formed between the first mandrel profile projections (30), with the first mandrel profile projections (30) and the first mandrel profile intermediate spaces (31) extending along the hollow body axis (3) on the first mandrel (27) arranged in the interior of the hollow body (1), and the first mandrel profile intermediate spaces (31) opening towards an axially parallel inner side of the hollow body wall (2), and
• a first forming drive (34) with a first die drive (33), by means of which the first forming die (26) is movable with an axial die movement along the hollow body axis (3) relative to the hollow body (1) and thereby along the first mandrel (27) arranged in the interior of the hollow body (1), wherein material of the hollow body wall (2) flows into the first mandrel profile intermediate spaces (31) of the first mandrel (27) due to an axial die movement of the first forming die (26) and an associated exceeding of a flow limit of the material of the hollow body wall (2), forming an inner profile (39) of the preform wall (38), and
• wherein the second forming device comprises:
• a second forming die (40) designed to be arranged on an outer side of the preform (32) and having a second die opening (42) designed for receiving the preform (32),
• a second mandrel (41) designed to be arranged in an interior of the preform (32) and provided on a circumference with a second shape-imparting mandrel profile (46) having second mandrel profile projections (47) and second mandrel profile intermediate spaces (48) formed between the second mandrel profile projections (47), with the second mandrel profile projections (47) and the second mandrel profile intermediate spaces (48) extending along a preform axis (37) on the second mandrel (41) arranged in the interior of the preform (32), and the second mandrel profile intermediate spaces (48) opening towards an axially parallel inner side of the preform wall (38) and receiving the an inner profile (39) of the preform wall (38), and
• a second forming drive (50) with a second die drive (49), by means of which the second forming die (40) is movable with an axial die movement along the preform axis (37) relative to the preform (32) and thereby along the second mandrel (41) arranged in the interior of the preform (32), wherein material of the preform (32) flows into the second mandrel profile intermediate spaces (48) of the second mandrel (41) due to the axial die movement of the second forming die (40) and an associated exceeding of a flow limit of the material of the preform wall (38), forming an inner profile (53) of the subsequent form wall,
• wherein the second forming die (40) is provided at the second die opening (42) with a shape-imparting die profile (43) having die profile projections (44) and die profile intermediate spaces (45) formed between the die profile projections (44), and wherein, when the second forming die (40) is moved with the axial die movement,
• the die profile projections (44) and the die profile intermediate spaces (45) of the second forming die (40) extend along the preform axis (37) and the die profile intermediate spaces (45) open towards an axially parallel outer side of the preform wall (38) and
• die profile projections (44) arranged on the axially parallel outer side of the preform wall (38) and second mandrel profile intermediate spaces (48) arranged on the axially parallel inner side of the preform wall (38) as well as die profile intermediate spaces (45) arranged on the axially parallel outer side of the preform wall (38) and second mandrel profile projections (47) arranged on the axially parallel inner side of the preform wall (38) in each case lie opposite to each other on the preform wall (38) in a radial direction of the preform axis (37), with the die profile projections (44) impinging material of the preform wall (38) in a direction of the second mandrel profile intermediate spaces (48) opposite the die profile projections (44), forming the inner profile (53) of the subsequent form wall,
• and wherein:
• at least one of the first or second forming drives (34, 50) has a mandrel drive (21, 21a) and a drive controller (22, 22a) in addition to the die drive (33, 49),
• the mandrel drive (21, 21a) is configured to move the first or second mandrel (27, 41) arranged in the interior of the hollow body (1) along the hollow body axis (3) through the die opening (11, 11a) with an axial mandrel movement counter to the axial die movement,
• the hollow body wall (2) can be subjected to tensile stress by means of the first or second mandrel (27, 41) driven by the mandrel drive in a direction of the axial mandrel movement due to the axial mandrel movement and can thereby be drawn through the die opening (11, 11a) relative to the respective first or second forming die (26, 40) in the direction of the axial mandrel movement, and
• the drive controller (22, 22a) of the first or second forming drive (34, 50) is configured to control the mandrel drive (21, 21a) and the respective first or second die drive (33, 49) in such a way that the axial mandrel movement and the axial die movement are superposed on one another.

A method for forming a tubular hollow body (1) having a hollow body wall (2) made of a plastically deformable material and a hollow body axis (3) extending in the longitudinal direction of the hollow body (1),

• arranging a forming die (9, 9a) on the outer side of the hollow body (1) and providing the forming die with a die opening (11, 11a) designed for receiving the hollow body (1),
• arranging a mandrel (10, 10a) in the interior of the hollow body (1) and providing the mandrel on a circumference with a shape-imparting mandrel profile (15, 15a) having mandrel profile projections (16, 16a) and mandrel profile intermediate spaces (17, 17a) formed between the mandrel profile projections (16, 16a), with the mandrel profile projections (16, 16a) and the mandrel profile intermediate spaces (17, 17a) extending along the hollow body axis (3) on the mandrel (10, 10a) arranged in an interior of the hollow body (1), and the mandrel profile intermediate spaces (17, 17a) opening towards an axially parallel inner side of the hollow body wall (2),
• moving the forming die (9, 9a) by means of a die drive (19, 19a) of a forming drive (20, 20a) with an axial die movement along the hollow body axis (3) relative to the hollow body (1) and thereby along the mandrel (10, 10a) arranged in the interior of the hollow body (1), wherein material of the hollow body wall (2) flows into the mandrel profile intermediate spaces (17, 17a) of the mandrel (10, 10a) due to the axial die movement and an associated exceeding of the flow limit of the material of the hollow body wall (2), forming an inner profile (18, 18a) of the hollow body wall (2),
• wherein
• the forming die (9, 9a) is moved by means of the die drive (19, 19a) with the axial die movement relative to the hollow body (1), which forming die is provided at the die opening (11, 11a) with a shape-imparting die profile (12, 12a) having die profile projections (13, 13a) and die profile intermediate spaces (14, 14a) formed between the die profile projections (13, 13a), wherein, when the forming die (9, 9a) is moved with the axial die movement,
• the die profile projections (13, 13a) and the die profile intermediate spaces (14, 14a) extend along the hollow body axis (3) and the die profile intermediate spaces (14, 14a) open towards an axially parallel outer side of the hollow body wall (2) and
• die profile projections (13, 13a) arranged on the axially parallel outer side of the hollow body wall (2) and mandrel profile intermediate spaces (17, 17a) arranged on the axially parallel inner side of the hollow body wall (2) as well as die profile intermediate spaces (14, 14a) arranged on the axially parallel outer side of the hollow body wall (2) and mandrel profile projections (16, 16a) arranged on the axially parallel inner side of the hollow body wall (2) in each case lie opposite to each other on the hollow body wall (2) in a radial direction of the hollow body axis (3), with the die profile projections (13, 13a) impinging material of the hollow body wall (2) in a direction of the mandrel profile intermediate spaces (17, 17a) opposite the die profile projections (13, 13a), forming the inner profile (18, 18a) of the hollow body wall (2),
• wherein the forming drive (20, 20a) has a mandrel drive (21, 21a) and a drive controller (22, 22a) in addition to the die drive (19, 19a),
• wherein the mandrel drive (21, 21a) moves the mandrel (10, 10a) arranged in the interior of the hollow body (1) along the hollow body axis (3) through the die opening (11, 11a) with an axial mandrel movement counter to the axial die movement,
• wherein the hollow body wall (2) is subjected to tensile stress by means of the mandrel (10, 10a) in a direction of the axial mandrel movement due to the axial mandrel movement and is thereby drawn through the die opening (11, 11a) relative to the forming die (9, 9a) in the direction of the axial mandrel movement, and
• wherein the drive controller (22, 22a) of the forming drive (20, 20a) controls the mandrel drive (21, 21a) and the die drive (19, 19a) in such a way that the axial mandrel movement and the axial die movement are superposed on one another.

A method for forming a tubular hollow body (1) having a hollow body wall (2) made of a plastically deformable material and a hollow body axis (3) extending in the longitudinal direction of the hollow body (1),

• the method comprising a first method stage and a second method stage with the second method stage following the first method stage in the method,
• a preform (32) of a finished formed hollow body being produced in the first method stage from the hollow body (1) in an initial state,
• the preform (32) being designed as a tubular hollow body (1) having a preform wall (38) made of a plastically deformable material and having a preform axis (37) coinciding with the hollow body axis (3), and
• in the second method stage, a subsequent form of the preform (32), which is the finished formed hollow body, is produced, which has a subsequent form wall,
• wherein
• in the first method stage the following steps are performed:
• arranging a first forming die (26) of a first forming device (7) on an outer side of the hollow body (1) in such a way that the first forming die (26) receives the hollow body (1) at a first die opening (28),
• arranging a first mandrel (27) of the first forming device (7) in an interior of the hollow body (1) and providing the first mandrel on a circumference with a first shape-imparting mandrel profile (29) having first mandrel profile projections (30) and first mandrel profile intermediate spaces (31) formed between the first mandrel profile projections (30), with the first mandrel profile projections (30) and the first mandrel profile intermediate spaces (31) extending along the hollow body axis (3) on the first mandrel (27) arranged in the interior of the hollow body (1), and the first mandrel profile intermediate spaces (31) opening towards an axially parallel inner side of the hollow body wall (2), and
• moving the first forming die (26) by means of a first die drive (33) of a first forming drive (34) of the first forming device (7) with an axial die movement along the hollow body axis (3) relative to the hollow body (1) and thereby along the first mandrel (27) arranged in the interior of the hollow body (1), wherein material of the hollow body wall (2) flows into the first mandrel profile intermediate spaces (31) of the first mandrel (27) due to the axial die movement of the first forming die (26) and an associated exceeding of the flow limit of the material of the hollow body wall (2), forming an inner profile (39) of the preform wall (38), and
• in the second method stage, the following method steps are performed:
• arranging a second forming die (40) of a second forming device (8) on an outer side of the preform (32) in such a way that the second forming die (40) receives the preform (32) at a second die opening (42),
• arranging a second mandrel (41) of the second forming device (8) in an interior of the preform (32) and providing the second mandrel on a circumference with a second shape-imparting mandrel profile (46) having second mandrel profile projections (47) and second mandrel profile intermediate spaces (48) formed between the second mandrel profile projections (47), with the second mandrel profile projections (47) and the second mandrel profile intermediate spaces (48) extending along the preform axis (37) on the second mandrel (41) arranged in the interior of the preform (32), and the second mandrel profile intermediate spaces (48) opening towards an axially parallel inner side of the preform wall (38) and receiving the inner profile of the preform wall (38), and
• moving the second forming die (40) by means of a second die drive (49) of a second forming drive (50) of the second forming device (8) with an axial die movement along the preform axis (37) relative to the preform (32) and thereby along the second mandrel (41) arranged in the interior of the preform (32), wherein material of the preform (32) flows into the second mandrel profile intermediate spaces (48) of the second mandrel (41) due to the axial die movement of the second forming die (40) and an associated exceeding of the flow limit of the material of the preform wall (38), forming an inner profile (53) of a subsequent form wall,
• wherein the second forming die (40) is moved by means of the second die drive (49) with the axial die movement relative to the preform (32), which second forming die is provided at the second die opening (42) with a shape-imparting die profile (43) having die profile projections (44) and die profile intermediate spaces (45) formed between the die profile projections (44), wherein, when the second forming die (40) is moved with the axial die movement,
• wherein the die profile projections (44) and the die profile intermediate spaces (45) of the second forming die (40) extend along the preform axis (37) and the die profile intermediate spaces (45) open towards an axially parallel outer side of the preform wall (38) and
• wherein die profile projections (44) arranged on the axially parallel outer side of the preform wall (38) and second mandrel profile intermediate spaces (48) arranged on the axially parallel inner side of the preform wall (38) as well as die profile intermediate spaces (45) arranged on the axially parallel outer side of the preform wall (38) and second mandrel profile projections (47) arranged on the axially parallel inner side of the preform wall (38) in each case lie opposite to each other on the preform wall (38) in a radial direction of the preform axis (37), with the die profile projections (44) impinging material of the preform wall (38) in a direction of the second mandrel profile intermediate spaces (48) opposite the die profile projections (44), forming the inner profile (53) of the subsequent form wall,
• wherein at least one of the first or second forming drives (34, 50) has a mandrel drive (21, 21a) and a drive controller (22, 22a) in addition to the die drive (33, 49),
• wherein the mandrel drive (21, 21a) moves the first or second mandrel (27, 41) arranged in the interior of the hollow body (1) along the hollow body axis (3) through the die opening (11, 11a) with an axial mandrel movement counter to the axial die movement,
• wherein the hollow body wall (2) is subjected to tensile stress by means of the first or second mandrel (27, 41) driven by the mandrel drive in a direction of the axial mandrel movement due to the axial mandrel movement and is thereby drawn through the die opening (11, 11a) relative to the respective first or second forming die (26, 40) in the direction of the axial mandrel movement, and
• wherein the drive controller (22, 22a) of the first or second forming drive (34, 50) controls the mandrel drive (21, 21a) and the respective first or second die drive (33, 49) in such a way that the axial mandrel movement and the axial die movement are superposed on one another in the first or second forming stage.

An arrangement for forming a tubular hollow body (1) having a hollow body wall (2) made of a plastically deformable material and a hollow body axis (3) extending in the longitudinal direction of the hollow body (1), comprising:

• a first forming device (7) and a second forming device (8), the second forming device (8) being arranged downstream of the first forming device (7) in a forming process,
• wherein the first forming device (7) is designed to produce a preform (32) of a finished formed hollow body from the hollow body (1) in an initial state,
• wherein the preform (32) is designed as a tubular hollow body having a preform wall (38) made of a plastically deformable material and having a preform axis (37) coinciding with the hollow body axis (3), and
• wherein the second forming device (8) is designed to produce a subsequent form from the preform (32), which has a subsequent form wall, wherein the subsequent form is the fully formed hollow body,
• wherein
• the first forming device (7) comprises:
• a first forming die (26) designed to be arranged on an outer side of the hollow body (1) and provided with a first die opening (28) designed for receiving the hollow body (1),
• a mandrel (27) designed to be arranged in an interior of the hollow body (1) and provided on a circumference with a shape-imparting mandrel profile (29) having mandrel profile projections (30) and mandrel profile intermediate spaces (31) formed between the mandrel profile projections (30), with the mandrel profile projections (30) and the mandrel profile intermediate spaces (31) extending along the hollow body axis (3) on the mandrel (27) arranged in the interior of the hollow body (1), and the mandrel profile intermediate spaces (31) opening towards an axially parallel inner side of the hollow body wall (2), and
• a first forming drive (34) with a first die drive (33), by means of which the first forming die (26) is movable with an axial die movement along the hollow body axis (3) relative to the hollow body (1) and thereby along the mandrel (27) arranged in the interior of the hollow body (1), wherein material of the hollow body wall (2) flows into the mandrel profile intermediate spaces (31) of the mandrel (27) due to an axial die movement of the first forming die (26) and an associated exceeding of a flow limit of the material of the hollow body wall (2), forming an inner profile (39) of the preform wall (38), and
• wherein the second forming device comprises:
• a second forming die (40) designed to be arranged on an outer side of the preform (32) and having a second die opening (42) designed for receiving the preform (32),
• the mandrel (27), and
• a second forming drive (50) with a second die drive (49), by means of which the second forming die (40) is movable with an axial die movement along the preform axis (37) relative to the preform (32) and thereby along the mandrel (27) arranged in the interior of the preform (32), wherein material of the preform (32) flows into the second mandrel profile intermediate spaces (31) of the mandrel (27) due to the axial die movement of the second forming die (40) and an associated exceeding of a flow limit of the material of the preform wall (38), forming an inner profile (53) of the subsequent form wall,
• wherein the second forming die (40) is provided at the second die opening (42) with a shape-imparting die profile (43) having die profile projections (44) and die profile intermediate spaces (45) formed between the die profile projections (44), and wherein, when the second forming die (40) is moved with the axial die movement,
• the die profile projections (44) and the die profile intermediate spaces (45) of the second forming die (40) extend along the preform axis (37) and the die profile intermediate spaces (45) open towards an axially parallel outer side of the preform wall (38) and
• die profile projections (44) arranged on the axially parallel outer side of the preform wall (38) and second mandrel profile intermediate spaces (48) arranged on the axially parallel inner side of the preform wall (38) as well as die profile intermediate spaces (45) arranged on the axially parallel outer side of the preform wall (38) and mandrel profile projections (30) arranged on the axially parallel inner side of the preform wall (38) in each case lie opposite to each other on the preform wall (38) in a radial direction of the preform axis (37), with the die profile projections (44) impinging material of the preform wall (38) in a direction of the mandrel profile intermediate spaces (31) opposite the die profile projections (44), forming the inner profile (53) of the subsequent form wall,
• and wherein:
• at least one of the first or second forming drives (34, 50) has a mandrel drive (21, 21a) and a drive controller (22, 22a) in addition to the die drive (33, 49),
• the mandrel drive (21, 21a) is configured to move the mandrel (27) arranged in the interior of the hollow body (1) along the hollow body axis (3) through the die opening (11, 11a) with an axial mandrel movement counter to the axial die movement,
• the hollow body wall (2) can be subjected to tensile stress by means of the mandrel (41) driven by the mandrel drive in a direction of the axial mandrel movement due to the axial mandrel movement and can thereby be drawn through the die opening (11, 11a) relative to the respective first or second forming die (26, 40) in the direction of the axial mandrel movement, and
• the drive controller (22, 22a) of the first or second forming drive (34, 50) is configured to control the mandrel drive (21, 21a) and the respective first or second die drive (33, 49) in such a way that the axial mandrel movement and the axial die movement are superposed on one another.