Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D41/00—Application of procedures in order to alter the diameter of tube ends
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D17/00—Forming single grooves in sheet metal or tubular or hollow articles
  • B21D17/02—Forming single grooves in sheet metal or tubular or hollow articles by pressing
  • B21D17/025—Forming single grooves in sheet metal or tubular or hollow articles by pressing by pressing tubes axially

Definitions

• the present invention relates to a device for shaping workpieces, in particular for plastically shaping pipe ends, with a shaping unit actuated by the pressure of a fluid and with a prestressing unit arranged on a common longitudinal axis and actuated by the pressure of a fluid, and with a conically shaped means by means of the prestressing unit tensionable clamping elements, wherein at least one separate pressure chamber is formed in the forming unit and in the pre-tensioning unit, which can be pressurized independently of the pressure chamber of the other unit.
• this method is not user-friendly, since some manual operations must be performed, which consist in placing the clamping jaws around the pipe, to insert the clamping jaws with a pipe in the apparatus' bias the jaws in the conical plate and the clamping jaws after the forming to be detached from the pipe again.
• Devices also belong to the prior art, in which a separate clamping cylinder is arranged at a 90 ° angle to the forming cylinder.
• the clamping elements are usually cuboid, two-part (not conical).
• Such a design is characterized by a high level of user comfort, since the jaws over the clamping cylinder can be moved automatically.
• the hydraulic clamping system has to be designed for very high clamping forces, since during the forming process the clamping force is not increased, for example via a cone system, so that 1.5 times the value of the forming force is selected as the usual design for the clamping force. Therefore, this construction leads to high weight, large installation space, high equipment costs and low cycle times when tensioning the pipe.
• a device for the plastic forming of pipe ends which represents a combination of the forming devices described above, that is, a system with a separate clamping cylinder arranged at a 90 ° angle to the forming cylinder and with conical clamping jaws.
• the pipe is prestressed with little force via the clamping cylinder.
• the preload is then increased when the forming process is initiated via the cylinder and the cone system.
• it is disadvantageous that during the forming process the full forming force acts back on the prestressing cylinder, and is even amplified many times over a very flat cone angle.
• the entire clamping system must therefore be designed for very high forces despite the low preload, which leads to high weight, large installation space and high costs.
• DE 195 11 447 A1 describes a device of the type mentioned at the outset for shaping the end region of a tube for use in screw connections.
• the forming and prestressing cylinders are arranged coaxially with one another.
• the preload piston is designed as an annular piston and sits on the piston rod of the forming piston.
• the tube is preloaded via the preload piston and the conical jaws.
• the clamping force is increased by the force introduced by the forming piston.
• the interlocking pistons and the surrounding housing parts must be exactly aligned to ensure the function and tightness of the machine. Therefore, the construction is very complex and expensive to manufacture.
• the rear, conical housing part must be completely removed to change the tool.
• connection point Since this connection point must transmit the full forming force, a quick-release fastener can hardly be implemented at this point. This leads to high ones Tool changing times.
• the tool change is complex and not user-friendly due to the poor accessibility.
• the forming area is completely covered by the closed housing construction and the preload ring piston. Optical monitoring of the forming process by the operator is therefore not possible.
• German patent DE 100 40 596 C1 or German patent application DE 100 40 595 A1 relating to the associated method
• the forming device corresponds in its basic structure to the device described in DE 195 11 447 A1
• the same disadvantages result, such as high manufacturing expenditure, complex tool changes and correspondingly long tool change times, as well as the impossibility of being able to carry out an optical monitoring of the forming process.
• a pressure relief valve designed as a pressure relief valve must be provided therein.
• the present invention has for its object to provide a device for deforming workpieces, in particular for the plastic reshaping of pipe ends of the type mentioned, which is characterized by reduced functionality in terms of equipment and manufacturing technology with high functionality, compact dimensions and low weight. Furthermore, the device according to the invention should also be more user-friendly in that it allows simple and quick tool change and optical monitoring of the forming process by the operator.
• this is achieved by a device of the type mentioned at the outset, in which the forming unit and the pretensioning unit are designed as structural units which are connected to one another but are completely sealed off from one another.
• both the forming unit and the biasing unit can be formed from commercially available pneumatic or in particular double or single-acting hydraulic cylinders.
• the entire pretensioning unit advantageously has to be designed only for small forces (low pressure), so the entire device according to the invention can be manufactured with comparatively compact dimensions and low weight.
• the device according to the invention permits a structural design which does not require dismantling of (pressure-bearing) housing parts for the purpose of tool change and which moreover offers very good access to the tool room.
• Forming tools such as clamping elements or upsetting heads can be quickly and detachably fixed, for example, by inserting them into guide grooves accessible from above and holding them there by their own weight.
• the device according to the invention can be manufactured in a closed or open design, the latter enabling the operator to visually monitor the forming process.
• Fig. 1 shows a longitudinal section through a device according to the invention for deforming workpieces, in particular for plastically deforming pipe ends
• Fig. 2 shows a compression head for the invention shown in Fig. 1
• Fig. 3 shows an example of a formed with the device according to the invention
• Fig. 4 is a clamping element for the invention shown in Fig. 1
• a device for shaping workpieces, in particular for plastically shaping pipe ends, has a shaping unit U actuated by the pressure p2 of a fluid and a shaping unit U arranged on a common longitudinal axis XX and actuated by the pressure p1 of a fluid Preload unit V on.
• the forming unit U is formed from a double-acting cylinder 1, in particular, and from a piston 2 which is axially movable therein.
• the pretensioning unit V is formed from a cylinder 3, in particular a single-acting cylinder, and a piston 4 which is axially movable therein.
• both pressure chambers D1, D2 - that of the forming unit U and that of the prestressing unit V have a full-area, preferably a circular, shape in the cross section running transverse to the longitudinal axis XX. (“Full-area” is understood here to mean that the area is not circular or frame-like or is interrupted by “holes”.)
• the forming unit U and the pretensioning unit V are mutually closed off by at least one wall running transversely to the longitudinal axis X-X (in particular by the walls designated as the rear wall 1a of the cylinder 1 of the forming unit U and the rear wall 3a of the cylinder 3 of the pretensioning unit V).
• the forming unit U and the pretensioning unit V are therefore designed on the one hand as interconnected units, but on the other hand as completely closed units.
• the device according to the invention essentially consists of three main assemblies, which are moved relative to one another parallel to the longitudinal axis X-X during the forming process.
• components which also belong to a main assembly
• hatching in FIG. 1 as well as 5a to 5d.
• the first, in the present example stationary, main assembly consists of the cylinders 1, 3 of the forming unit U and the preload unit V and a yoke plate 5 arranged transversely to the longitudinal axis X-X, all of which are rigidly connected to one another.
• Tie rods 6a are arranged parallel to the longitudinal axis X-X and are used to form the rigid connection and to transmit force between the cylinder 1 of the forming unit U and the yoke plate 5.
• the piston 4 of the pretensioning unit V is via its piston rod 4a and an adapter part 7, such as that shown, transverse to the longitudinal axis XX arranged adapter plate, with a driver plate 8 also arranged transversely to the longitudinal axis XX for the piston 2 of the forming unit U and with a receiving plate 9 arranged transversely to the longitudinal axis XX for clamping elements (described in detail below) clamping elements.
• the driving plate 8 there is a bore (not designated in more detail) arranged coaxially to the cylinder 1 of the forming unit U, in which the piston 2 of the forming unit U, in particular with its piston rod 2a, is guided.
• step-shaped recess 9a which is open at the top as a fastening means for inserting the clamping elements.
• Tie rods 6b are again arranged parallel to the longitudinal axis XX and serve to form the rigid connection and to transmit power between the piston 4 of the prestressing unit V and the two plates 8, 9.
• the third main assembly consists only of the piston 2 of the forming unit U.
• a tool set is required for the forming, which consists of a compression head 10 (FIG. 2) and at least one clamping element 11 (FIG. 4).
• a tube end 12 was selected as an example, which has the bead contour 12a shown in FIG. 3.
• any axially compressible tube contour can be produced with the device according to the invention.
• the upsetting head 10 contains on one side a depression 10a, counter-contour of the pipe contour 12a to be formed, and on the opposite side a connection possibility 10b to the piston 2 of the forming unit - in the present case a T-groove.
• the shaping unit U in particular a free end of the piston rod 2a of the piston 2, likewise has fastening means 2b for releasably fastening the upsetting head 10.
• the clamping element 11 is formed by clamping jaws 11a, which consist of several, preferably four, segments arranged in a ring. These are usually guided over cylindrical pins 11b and held in an open position via compression springs 11c in the unloaded state. They interact with the conical surface of the opening 5a in the yoke plate 5 and also have a conical shape for this purpose. formed outer surfaces 11d. With their usually slightly roughened or toothed inner side 11e, the clamping jaws 11a press on the tube 12 during clamping.
• the tools (upsetting head 10, clamping jaws 11a) can be inserted into the corresponding receptacles 2b, 9a from above, with good access to the tool space. Dismantling of device components for tool change is not necessary.
• FIG. 5b shows the insertion position for the workpiece. From the end position shown in Fig. 5a, the entire second main assembly moves under the effect of the fluid pressure p1 in the pressure chamber D2 parallel to the longitudinal axis X-X by an amount X relative to the first (stationary) main assembly (to the right in the drawing).
• the piston 2 of the forming unit U which is in unpressurized circulation, is also carried along via the driver plate 8.
• the clamping jaws 11a are still slightly open in the insertion position, so that the tube 12 can be guided cleanly when it is inserted until it comes to an end on a (not designated) contact surface in the recess 10a on the upsetting head 10.
• the tube 12 is then tensioned (FIG. 5c).
• the entire second pretensioning unit assembly is again moved parallel to the longitudinal axis X-X, this time by the amount Y (to the right).
• the clamping jaws 11a are closed without a gap against the force of their springs 11c and the tube 12 is held in place.
• the pretensioning unit V can also be operated in the low pressure range.
• the known forming process (FIG. 5d), in which the bulge 12a is formed on the tube 12 in an known manner by axially moving the piston 2 by the pressure p2 of the fluid on the piston 2 Forming unit U initiated and requires high forces.
• the forming unit U is therefore preferably designed for the high pressure area.
• first and second main assemblies each represent self-contained separate systems with regard to the forces occurring in them, which are only indirectly coupled by force via the clamping jaws 11a held in the receiving plate 9 and pressed into the yoke plate 5, but the pretensioning unit V or the second main assembly is not additionally loaded by the high forming forces and can therefore be dimensioned in its entirety for low forces, advantageously by means of a low-pressure design.
• the conical design of the tensioning elements leads to the fact that the prestressing force introduced via the prestressing unit V is further increased during the tube forming, there is no reaction of the forming force on the prestressing unit V, as is the case with the device known from DE 100 40 595 A1 occurs.
• the tool change position (FIG. 5a) is again approached to remove the pipe, this being able to take place under the action of a fluidic counterpressure p3 in the pressure space D1 of the forming unit U.
• a fluidic counterpressure p3 in the pressure space D1 of the forming unit U.
• this purpose it would also be possible for this purpose to provide only a single-acting cylinder with spring return or a switchable driver mechanism instead of a double-acting cylinder in the forming unit U and a double-acting cylinder for this purpose in the pretensioning unit V.
• the invention is not limited to the exemplary embodiment shown, but also encompasses all embodiments having the same effect in the sense of the invention.
• a kinematic reversal is also possible in the sense that the prestressing second main assembly is stationary and stationary and serves as a machine frame or is attached to a machine frame.
• the first main assembly with the yoke plate 5 is moved axially, which has the advantage that the tube 12 is no longer moved after reaching the axial tube stop position. (In the variant described above, the tube 12 is also moved by the amount Y during tensioning.)
• the device according to the invention can also be designed with a pretensioning unit V rotated through 180 °.
• the rear wall 3a of the cylinder 3 of the pretensioning unit V then lies against the adapter plate or can itself be designed as an adapter part 7, and the piston 4 is coupled to the rear wall 1a of the cylinder 1 of the forming unit U.
• a housing with connecting plates could also be constructed or, as in the known ring piston systems, a rotationally symmetrical, tubular housing could be implemented.
• the invention is not limited to the combination of features defined in claim 1, but can also be defined by any other combination of features of all the individual features disclosed overall. This means that in principle each individual feature of claim 1 can be omitted or replaced by at least one feature disclosed elsewhere in the application. In this respect, claim 1 is only to be understood as a first attempt at formulation for an invention.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Jigs For Machine Tools (AREA)
• Mounting, Exchange, And Manufacturing Of Dies (AREA)
• Forging (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Actuator (AREA)
• Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)

Applications Claiming Priority (3)

Publications (2)

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Cited By (1)

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• 2002
  • 2002-04-12 DE DE20205807U patent/DE20205807U1/de not_active Expired - Lifetime
• 2003
  • 2003-03-17 WO PCT/EP2003/002731 patent/WO2003086679A1/fr active IP Right Grant
  • 2003-03-17 DK DK03712027T patent/DK1494827T3/da active
  • 2003-03-17 US US10/511,195 patent/US7237420B2/en not_active Expired - Fee Related
  • 2003-03-17 DE DE50305355T patent/DE50305355D1/de not_active Expired - Lifetime
  • 2003-03-17 AU AU2003218771A patent/AU2003218771A1/en not_active Abandoned
  • 2003-03-17 EP EP03712027A patent/EP1494827B1/fr not_active Expired - Lifetime
  • 2003-03-17 AT AT03712027T patent/ATE342141T1/de active
  • 2003-03-17 ES ES03712027T patent/ES2272956T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

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