Abstract: A machine for bending sheet metal provides at least one sheet metal resting tool, at least one sheet metal pressing tool, and at least one sheet metal bending tool, parallel to one another; for moving the tools along a first and a second axis perpendicular to one another at least two electric motors are provided for moving the sheet metal pressing tool along the second axis, at least two electric motors for moving the sheet metal bending tool along the first axis and at least two electric motors for moving the sheet metal bending tool along the second axis; a command and control unit connected to the electric motors commands and controls the driving of the electric motors to maintain the parallelism between the tools in the operating step. In this manner, using hydraulic drives is avoided.

Abstract: A method of bending a sheet of metal using a press brake includes pivoting die holders during the bending operation so bends can be made in opposite directions without having to turn over or flip over the sheet of metal. In the method a first die holder is driven downward toward a second die to thereby create a bend in the metal sheet when the first and second dies come together. The first die holder and the first die are then retracted away from a second die holder and the second die. The die holders are moved, preferably rotated, to a second position in which the first die holder is located over the second die holder. Then the second die holder is driven downward toward the first die to thereby create a second bend in the metal sheet when the first and second dies come together.

Abstract: The invention relates to a production plant (1), in particular for folding workpieces (2) to be produced from sheet metal, comprising a bending press (3), in particular a press brake, having a press beam (13, 16), at least one bending tool (4), such as a bending punch (5) and bending die (6), which is connected to the press beam (13, 16), and at least one angle-measuring device (46) for determining an angular position of at least one limb (35, 36) of the workpiece (2) formed by a bending operation relative to a reference plane (41, 42). The angle-measuring device (46) comprises at least one inclination sensor (39) having a reference surface (40) and the inclination sensor (39) is mounted by the angle-measuring device (46) so that it can be placed with the reference surface (40) lying in contact with a surface portion of at least one of the limbs (35, 36) of the workpiece (2).

Abstract: In a bending machine, there is provided at one back gauge abutting part (5) a plurality of contact confirmation sensors for confirming the contact thereof with a workpiece; and there is included control means driving a ram (1) on the conditions of ON of all the sensors automatically or manually specified among these contact confirmation sensors and ON of a foot pedal (6) when the workpiece is abutted.

Abstract: The invention relates to a continuous or instrumented indentation device for a material. The indentation device includes an indenter, a bearing means for the material to be indented, a means for moving the indenter and/or the bearing means for contacting the indenter with the material to be indented, and for pressing the indenter into the material, and a means for measuring the force and movement of the indenter when the indenter is pressed into the material. The bearing means includes a convex surface for receiving the material to be indented and is oriented towards the indenter so that the material is capable of bearing on the convex surface. The indenter may comprise a one-piece structure. The means for measuring the movement of the indenter when the indenter is pressed into the material includes at least three movement sensors angularly arranged at an equal distance about the indenter.

Abstract: A bending machine having: a punch and a die for bending a sheet-shaped work; pressurizing means which pressurizes the work in a space between the punch and the die by vertically moving a ram; inputting means (23) which inputs die information on the punch and the die, material information on the work and bending information; a database (25) which stores data on a pressure per unit length required for bending the work; calculating means (29) which calculates a pressure necessary for the pressurizing means based on various information inputted from the inputting means (23) and on the data on the pressure stored in the database (25); and controlling means (31) which controls the pressurizing means based on a result of calculation by the calculating means (29).

Abstract: A press-forming device has a punch (2), a die (7) which relatively moves with respect to the punch (2), a strain amount measuring means (8) which is provided inside a member to be controlled and measures a strain amount of the aforesaid member to be controlled which occurs in accordance with press-forming, when at least one of the punch (2) and the die (7) is made the aforesaid member to be controlled, and a strain amount control means (9) which is provided in the aforesaid member to be controlled and controls the strain amount of the aforesaid member to be controlled which occurs in accordance with press-forming. The strain amount control means (9) controls a drive amount of the aforesaid member to be controlled so that the strain amount measured by the strain amount measuring means (8) is in a predetermined range during forming. Thereby, reduction in a surface strain, improvement in shape fixability or the like of a press formed product can be achieved.

Abstract: The invention particularly relates to a so-called continuous or instrumented indentation device for a material, which includes: an indenter; a bearing means for the material to be indented; a means for moving the indenter and/or the bearing means for contacting said indenter with said material and for pressing the indenter into the material; a means for measuring the force and the movement of the indenter when the same is pressed into the material. The bearing means includes a convex surface for receiving said material and oriented towards the indenter so that said material is capable of bearing on said surface; said indenter is one-piece structure. The means for measuring the movement of the indenter when the same is pressed into the material includes at least three movement sensors angularly arranged at an equal distance about said indenter.

Abstract: The invention relates to an apparatus, in particular to a bending apparatus, including at least one movable apparatus part; an operating device for the operation of the apparatus, with at least one first signal for the actuation of the apparatus and one second signal for the stopping of the apparatus being able to be triggered via the operating device; a protection device for the monitoring of a protected zone of the apparatus; and a device for the selective adaptation of the protected zone before the actuation of the apparatus, with the device for the adaptation of the protected zone being able to be acted on by means of a third signal of the operating device. Alternatively, the device for the selective adaptation of the protected zone can include a voice input device.

Abstract: Labor required for knowing what extent of bending of a plate corresponds to what degree of angle of the bent portion is reduced. A bending angle detection apparatus (50) has a sensor ring L (64), a holder (62), bearings (70), the motor body of a servomotor (60), and a rotation angle sensor (102). The sensor ring L (64) produces a signal corresponding to whether the apparatus is contacted with a blade member plate or not. The holder (62) and the bearings (70) rotatably connect the sensor ring L (64) to a bending machine. The motor body of the servomotor (60) drives the sensor ring L (64) so that it is rotated. The rotation angle sensor (102) detects the rotation angle of the sensor ring L (64). In addition, the holder (62) and the bearings (70) connect the sensor ring L (64) to the bending machine so that the rotation axis of the blade member plate in the case where the bending machine bends the blade member plate coincides with that of the sensor ring L (64).

Abstract: A bending apparatus is provided with a ram start-up device so as to be movable in a lateral direction. A controller moves the ram start-up device to a point in front of positioning points of abutments corresponding to points of selected edges of a workpiece. The bending apparatus includes a foreign object detector that detects the entry of a foreign object into a region of movement of the ram start-up device. A controller prevents the ram start-up device from moving when the entry of the foreign object is detected.

Abstract: A method and apparatus for detecting a turned blank at a workstation in a progressive forging machine comprising simultaneously monitoring both the force on a tool in the workstation and the crank angle of the machine, determining a reference crank angle when the tool is subjected to a force at the workstation about to deliver a blow and a blank in the workstation is properly angularly aligned, operating the machine to forge blanks in a normal manner when a force on the tool at the workstation occurs substantially at the reference crank angle, and interrupting said normal manner when the force on the tool at the workstation occurs before said reference crankshaft angle to enable the blank being formed at the workstation to be separated from remaining blanks being forged in the machine.

Abstract: Methods and an apparatus for bending orthodontic wires are provided. An apparatus for bending an orthodontic wire can determine an optimal shape of a portion of an archwire to include a pair of nominal bends, apply an actual bend to the archwire at a location coinciding with the location of one of the pair of nominal bends, measure the actual bend applied, compare the actual bend to the nominal bend to determine an amount of deviation from that desired, determine corrective movements to substantially eliminate the deviation, iteratively reexecute such steps until the deviation is within a predefined tolerance, and recalculate a value of the other of the pair of nominal bends to compensate for any remaining deviation.

Abstract: Regarding predetermined positioning criteria (M1, M2), ((G1, G2), (N1, or N2), (K1, K2)), there is provided image processing means (40B) for obtaining by image processing, measured values (CD1, CD2) ((GD1, GD2), (ND1, or ND2), (KD1, KD2)) and reference values (CR1, CR2) ((GR1, GR2), (NR1, or NR2), (KR1, KR2)), and for moving a work (W) in a manner that the measured values (CD1, CD2) ((GD1, GD2), (ND1, or ND2), (KD1, KD2)) and the reference values (CR1, CR2) ((GR1, GR2), (NR1, or NR2), (KR1, KR2)) coincide with each other, thereby positioning the work (W) at a predetermined position.

Abstract: With a method according to the invention for free bending, a workpiece to be machined, such as a sheet metal plate, is brought into contact with a bending edge of a lower die. A bending punching tool is moved opposite to the lower die, such that the sheet metal plate is bent by the punching tool in terms of generating a predetermined target bending angle across the bending edge. In this case, the achieved bending angle is measured at least after a first bending process and the bending force to be applied and the measuring curve resulting therefrom are determined during the bending process as a function of the traverse path of the bending punching tool.

Abstract: A potentially dangerous machine is secured to protect against injuries and has first and second tool parts that define an opening gap between them. At least the first tool part is movable relative to the second tool part in a movement direction during an operating cycle for deforming a workpiece between them by reducing a size of the opening gap in the movement direction. The protected zone precedes the first tool part and extends over at least a portion of the opening gap in the direction of relative movement. The protected zone is monitored with an optoelectronic sensor, and a danger signal is generated in response to a breach of the protected zone. When the size of the opening gap in the movement direction becomes smaller than the protected zone, the size of the protected zone is correspondingly reduced until during subsequent closing movements of the first tool part substantially the entire opening gap is within the protected zone.

Abstract: Method of correcting a bending operation performed by a press brake, the bottom beam of which contains deformation compensation cylinders, in which a calibration nomogram is pre-recorded using very short calibration pieces, this nomogram establishing a correspondence between the forces measured at the side frames and the pressures applicable to the compensation cylinders in order to keep the bottom beam substantially straight. During a subsequent bending operation, pressure values resulting from this nomogram are applied to the compensation cylinders according to the forces measured at the side frames. A bottom dead center is recalculated by taking account of the deformation of the top beam, the deformation of the side frames, the actual length and thickness of the piece, and the spring effect.

Abstract: The invention concerns a machine for automatically shaping components via different types of bending provided in a common plane or different planes. The machine includes a first device for performing a sequential shaping with standard tools by individual bending, and a second device using a tool plate. Both devices are managed by a single digital control. The method for controlling such a machine is characterized in that digital control provides the possibility for producing a blank of a component by individual bending on the first device followed by transfer of the component on the second device for finishing the component. Digital control provides the possibility of shaping one part of the component on the first device and shaping the remaining parts on the second device. The digital control also provides the possibility of using each machine alone and the possibility of using both machines for producing the same component.

Abstract: The invention deals with a sheet-metal bending machine containing a lower machine part and an upper machine part mounted on it in a movable way where on either of the upper and lower machine part there is a pair of working tools designed as a bending arm and a holding arm where the principle is that the upper machine part (3), or at least the pair of the working tools connected to it, is, in relation to the lower machine part (2), or at least in relation to the pair of the working tools connected to it in the feeding direction (L) of the processed metal sheet (14), mounted in a mutually horizontally sliding bond.

Abstract: Regarding predetermined positioning criteria (M1, M2), ((G1, G2), (N1, or N2), (K1, K2)), there is provided image processing means (40B) for obtaining by image processing, measured values (CD1, CD2) ((GD1, GD2), (ND1, or ND2), (KD1, KD2)) and reference values (CR1, CR2) ((GR1, GR2), (NR1, or NR2), (KR1, KR2)), and for moving a work (W) in a manner that the measured values (CD1, CD2) ((GD1, GD2), (ND1, or ND2), (KD1, KD2)) and the reference values (CR1, CR2) ((GR1, GR2), (NR1, or NR2), (KR1, KR2)) coincide with each other, thereby positioning the work (W) at a predetermined position.

Abstract: A device for monitoring an area of coverage on a work tool may comprise a lighting unit, a camera, and an evaluation unit. The lighting unit may be adapted to emit light rays for illuminating the area of coverage. The camera may be adapted to detect two-dimensional images of the area of coverage, and the camera may comprise receiving elements arranged linearly. The evaluation unit may be coupled to the camera to evaluate the output signals of the receiving elements to determine a distance value for each receiving element based on the light rays emitted by the lighting device and reflected back from the area of coverage. The evaluation unit may have at least one switching output coupled to the work tool to activate the work tool such that the work tool is operational only if no object is located in the area of coverage.

Abstract: A method for processing sheet metal includes processing and forming a sample and a blank on a work while leaving a microjoint part in a blanking process. The method also includes detecting at least one of a plate thickness of the work in an optional position and a spring-back amount of the sample during bending. Information of at least one of the plate thickness and the spring-back amount is transmitted to a controller of a bending machine in a bending process after the blanking process. Bending is performed by calculating a ram control value in bending using data of at least one of the transmitted plate thickness and the spring-back amount.

Abstract: An apparatus for bending orthodontic wires has means for guiding and holding a wire. In order to prevent forces resulting from compressive or stretching strain during the bending process, one of these means does not apply any longitudinal forces onto the wire by design. In another implementation, the apparatus for bending orthodontic wires has a gimbal-mounted gripper for bending the wire. Furthermore, a method is disclosed for applying two bends at the same longitudinal wire location in two different directions.

Abstract: A press forming method is disclosed, wherein press forming can be effected at high speed while maintaining the horizontal state of a slide plate in press-forming work by a press machine. A press machine is used in which the slide plate is pressed by a plurality of servo-motor drive sources. In trial forming, the slide plate is sufficiently slowly moved to measure the delay of each drive source. According to the magnitude of the delay of each drive source or according to the difference between the trial forming speed and the production forming speed, the respective speeds of the drive sources are corrected, and trial forming is repeated on the basis of the corrected speed to derive conditions that enable press forming at high forming speed suitable for mass production while maintaining the horizontal state of the slide plate to the extent of ensuring sufficient product accuracy.

Abstract: Method and device for bending a portion of an element in a bending machine (12) comprising a bending assembly (14), a supporting plane (18) and an electronic processing unit (32), wherein the bending process is filmed and displayed on a screen (36). The portion (24) is bent with a first movement of the bending assembly (14) to make a first bend of a nominal value. By means of reference indicator elements an angle of deviation is determined and the portion is again bent with a new movement of the bending assembly (14), taking into account the angle of deviation. All movements of the bending assembly (14) are acquired by a position transducer (15) and recorded by the electronic processing unit (32) in order to have a global parameter for obtaining an angle which corresponds to the nominal value, and in order to use the global parameter in subsequent analogous or similar bends.

Abstract: An actual plate thickness and actual material constants are measured during punching before bending. The measured information is reflected on the bending, so that the bending is performed efficiently and accurately. Punching is carried out for each blank developed based on a nominal plate thickness and nominal material constants in blanking before the bending of a work W. Then, an actual plate thickness distribution and an actual material constant distribution of the work W are calculated based on various data containing a ram stroke and a pressure detected in the punching.

Abstract: A vertical position of a ram is directly detected by a ram position detector. A first speed arithmetic operating portion determines a first ram moving speed on the basis of a change of the detected position. A second speed arithmetic operating portion determines a second ram moving speed on the basis of a rotational number of a servo motor which is determined by a servo motor rotational number detector. A comparing portion compares the first ram speed with the second ram speed, and when a difference is equal to or more than a predetermined amount, a judging portion judges that an abnormality exists so as to immediately stop the servo motor and stop an operation.

Abstract: In bending a workpiece, a position of the workpiece relatively pressed down by a punch is directly detected by a plurality of position detectors provided in a V-groove of a die, and a bending speed calculation section obtains a bending speed from a change in this position. If bending speeds at position of the respective position detectors differ, a uniform speed arithmetic operation section calculates a bending speed to make the bending speeds at the positions of all of the position detectors, and a driving shaft instruction section controls driving shafts to bend the workpiece at the uniform bending speed.

Abstract: A bending apparatus reciprocates at least one of an upper table to which a punch is mounted and a lower table to which a corresponding plurality of adjacent divided dies are mounted. At least one bending angle detector is provided between the dies to detect a bending angle of the workpiece. A main body inserts the bending angle detector into a gap between the dies and withdraws the bending angle detector from the gap between the dies. A lift is biased upward by a first elastic body and is configured to be pressed downward by the workpiece at approximately a center of a groove portion of the dies. The lift includes a first engagement member. A rotor support is biased upward by two second elastic bodies having smaller biasing forces than the first elastic body. The rotor support includes second engagement members. Two rotors are provided on opposite sides of the groove portion at an upper portion of the rotor support. The two rotors include workpiece contacts that contact the workpiece.

Abstract: A ram descends due to its own weight and pressure of a rod-side cylinder chamber of a hydraulic cylinder which vertically moves the ram is detected by an oil pressure detector. A determination section detects a position at which a punch attached to the ram contacts an upper surface of a workpiece, based upon a change in the detected pressure. When the upper surface of the workpiece is detected, a plate thickness calculation section calculates a plate thickness of the workpiece based on an upper surface position of a die, that is known in advance and stored in a memory.

Abstract: A computer readable recording medium which stores control data to control the action of a sheet metal bending system which is provided with a press brake and a sheet metal support device, where the press brake is provided with a punch and die which bends the sheet metal along the bending line by approaching to and parting from each other, and a back gauge to determine the position of the sheet metal against the punch and die, the sheet metal support apparatus is provided with a support arm which supports the sheet metal and may be rotated freely centered on the rotation axis which is parallel to the bending axis, the control data is a control data to control the bending process which includes a plurality of bending processes to produce sheet metal parts (parts) with a plurality of bending lines by the press brake and sheet metal support device by controlling the approach and parting motion of the punch and die and at least the rotational motion of the support arm, and the control data is related to the sheet

Abstract: A system manufactures a product by bending a sheet material includes a three-dimensional stereoscopic diagram creator that creates a three-dimensional stereoscopic diagram, including a desired bending angle and a desired flange width, based on graphic information of a product. A displayer displays a bending angle value in the vicinity of a bending angle, and/or a dimension value in the vicinity of a flange, in the created three-dimensional stereoscopic diagram. A test piece displayer displays a test piece of a material proposed for use in the product and displays the bending angle value(s) in the vicinity of the bending angle(s), and/or the dimension value(s) in the vicinity of the flange(s), of the test piece. A measuring device measures the bending angle value(s) and the dimension value(s) for the test piece bent by the bending machine.

Abstract: A plate thickness detector for a bending machine causes a punch to make a relative stroke and bend a workpiece mounted on an upper surface of a die cooperatively by the punch and the die. A displacement gauge is provided in the die, is always urged upward from a V-groove of the die, and measures a distance from the upper surface of the die to a lower surface of the workpiece. A ram position detector detects a relative stroke quantity of the punch to the die. The punch is caused to bend the workpiece from a position away from the die by a reference inter-blade distance.

Abstract: A bending method is provided for bending two sides of a workpiece to form flanges. The bending method includes measuring a bent flange to obtain a flange dimension. The bending method also includes setting a back gauge value for processing another flange, based on a measured dimension of the workpiece. The other flange is bent using the set back gauge value.

Abstract: Method and device for bending a portion of an element in a bending machine (12) comprising a bending assembly (14), a supporting plane (18) and an electronic processing unit (32), wherein the bending process is filmed and displayed on a screen (36). The portion (24) is bent with a first movement of the bending assembly (14) to make a first bend of a nominal value. By means of reference indicator elements an angle of deviation is determined and the portion is again bent with a new movement of the bending assembly (14), taking into account the angle of deviation. All movements of the bending assembly (14) are acquired by a position transducer (15) and recorded by the electronic processing unit (32) in order to have a global parameter for obtaining an angle which corresponds to the nominal value, and in order to use the global parameter in subsequent analogous or similar bends.

Abstract: A method for bending a work of a plate shape by moving a die with the work being butted against a butting member, and an apparatus for executing the method are provided. The bending apparatus is provided with an input unit for inputting data on bending conditions including respective target values of a bending angle and a bending dimension, as well as respective measured values of a bending angle and a bending dimension of the work obtained in trial bending. A control device installed in the apparatus executes an initial computation for computing an operation amount of the die when the data on bending conditions are inputted. Further, the control device executes computation for a correction value for an operation amount of the die and computation for an estimated value of a bending dimension when the respective measured values of the bending angle and the bending dimension obtained in trial bending are inputted.

Abstract: An angle detecting head provided with an emitter and a pair of receivers is rocked, and a bent surface of a workpiece bent by a punch and a die of a bending machine is irradiated with a measurement light from the emitter, a reflected light is received by the pair of receivers, and a bending angle of the workpiece is obtained from a peak value of the light received by the respective receivers. The angle detecting head is movable parallel to the die, is movable in a direction close to and away from the workpiece, and is movable in a direction in which the die is raised/lowered. The angle detecting head is positioned in an optimum angle measurement position of the workpiece and the bending angle is measured.

Abstract: A stretch bending device that can conduct accurate bending without using heavy material. A tension application mechanism 62 comprises first and second drive sources for movably supporting both ends of a guide member 12 with respect to a pair of arm members 28, 30 and moving the guide member 12 along the arm members 28, 30. Between the arm members 28, 30, a work piece 6 is arranged. There are tension sensor 98 for detecting tension applied to the work piece 6 and position sensors for detecting positions of the guide member 12. Torque of the first drive source is controlled based on the tension detected by the tension sensor 98, and the second drive force is controlled based on the positions detected by the position sensors.

Abstract: The subject invention provides a sheet bending brake assembly for securing a work piece. The sheet bending brake assembly includes a clamping member having a lower leg extending therefrom and a pivoting arm pivotally supported by and extending from the clamping member. The pivoting arm defines a clamping area with the lower leg. A base supports the clamping members and provides support to the assembly while moving the pivoting arm between the open position and the clamped position. A guide mechanism reacts between the clamping member and the pivoting arm for moving the pivoting arm between the open position and the clamped position. The guide mechanism has a guide slot with a detent positioned within the guide slot between the first and the second ends for positioning the pivoting arm in an intermediate position to allow for precisely aligning the work piece.

Abstract: A three-dimensional stereoscopic diagram creator creates a three-dimensional stereoscopic diagram including a desired bending angle based on graphic information of a product. A major dimension displayer displays a major dimension, tolerance and the like with respect to the three-dimensional stereoscopic diagram. On the other hand, a test piece displayer displays a test piece of the same material proposed for use as the material used for producing the product. The test piece displayer carries out trial bending on the test piece. A bending angle after a bending load is removed is measured by a bending angle measuring device. A spring back amount setter calculates a spring back amount from a difference in bending angle between before and after the load is removed. A stroke calculator calculates a stroke value relative to the desired bending angle considering the obtained spring back amount. Actual bending is performed on a product piece using the calculated stroke value.

Abstract: A pressing tool apparatus with a clamping pincer and a sensory mechanism that permits a measurement of a displacement which the piston covers with the closure procedure of the clamping pincer. With the first closure of the clamping pincer, without a pressing, there results a nominal displacement value which is realized by a displacement sensor and a ring magnet. Electronics in the housing store a measured nominal value and compares it to subsequent closure procedures with a pressing, accounting for programmable tolerance values. Pressings within a permitted range or outside the range are suitably displayed.

Abstract: A numerical control device for a bending machine includes a keyboard, a memory and a processor. The memory stores one or more groups of data, each containing bending conditions, a bend angle and at least one penetration depth. The memory further stores program instructions for searching whether data input with the keyboard is stored in the memory, in a same group of data, and that sends a signal to the bending machine so that the bending machine peforms bending according to the penetration depth included in the group of data. The processor that executes said program instructions.

Abstract: A system and method for adjusting the orientation of trim tabs on a helicopter rotor blade includes a gage, a bender and a calibrator plate. The gage is secured to the calibrator plate which holds the gage in an orientation that simulates a rotor blade with trim tabs at zero degrees so that the gage can be zeroed. The gage is then removed and positioned on a rotor blade. Because the gage is supported on the blade by rollers, it is free to roll along the length of the blade and may thereby be positioned and repositioned quickly. Once in position, the bender is applied to the trim tabs adjacent to the gage and tightened using thumb screws. The handle of the bender allows the trim tabs to be adjusted while verifying that the amount of adjustment indicated by the gage dial indicator matches the preselected angle.

Abstract: A support medium is capable of being read by a numerical control system of a bending machine. The support medium stores program instructions for searching, in a memory region storing at least one group of data, each containing bending conditions, a bend angle and at least one penetration depth, whether input data including a desired bend angle and bending conditions are stored in the memory region, in a same group of data. The support medium sends a signal to the bending machine so that the bending machine executes a bending according to the penetration depth included in the same group of data.

Abstract: A method of adjusting the stroke of a press brake having a movable beam (1) supporting a punch (2), a fixed beam (3) supporting a die (4), means of displacing (5, 5′) the movable beam with respect to the fixed beam, said displacement means resting on side frames (6, 6′) immovably attached to the fixed beam, linear encoders (9, 9′) for measuring the displacement of the movable beam with respect to the side frames, at least one sensor (8, 8′) measuring a physical parameter (p) varying with the force exerted by said punch on a metal sheet placed on said die, and an electronic device for controlling (7) the bending movement controlling the speed of said displacement movement between top dead center and bottom dead center (BDC), provided with a calculation means for correcting the value of said bottom dead center depending on the measurement of said displacement and said physical parameter.

Abstract: The present invention provides a bending machine that enables an angle measuring instrument to be compactly built into a mold for accurate processing. The present invention also provides an operation method besed on learning control which achieves accurate bending with this bending machine taking spring back into consideration. A bending machine carries out bending using lineraly extending an upper die 4 and a lower die 2, the upper die 4 having a built-in angle measuring instrument 9. The angle measuring instrument 9 is composed of a corner contacting member 12 with links and an inductive linear position detector 13 for measuring displacement of the corner contacting member 12. In operation for learning, the position of and a load on the upper die 4 and a bend angle are measured during a bending process and a bend angle after spring back is subsequently measured.

Abstract: A sheet metal bending machine is provided with a bending unit moved by hydraulic cylinders with sliding pistons. The cylinders are controlled by a closed loop control system comprising temperature measuring means for measuring the cylinder temperature, position detecting means for detecting the piston position and a control unit for varying the rate of hydraulic fluid fed to the cylinders according to the measured cylinder temperature and the detected piston position.

Abstract: A bending machine comprises a bending unit moved by hydraulic actuators controlled by a variable displacement hydraulic pump provided with an electronic closed-loop flow rate, pressure and power control system including an electrically controlled proportional valve. The valve includes a valve spool for the control of the swivel angle of the pump and a proportional solenoid for moving the valve spool to a position corresponding to a desired swivel angle of the pump. The control system includes an inductive position transducer, a pump swivel angle transducer, a pump pressure transducer and a programmed electronic control unit which receives position, swivel angle and pressure signals from said transducers and predefined pressure, power and flow rate commands and supplies a control signal to said proportional solenoid.

Abstract: The numeral control device for a bending machine comprises means for inputting, as input data, a desired bend angle and bending conditions or criteria, means for storing groups of data, each containing bending conditions, a bend angle and a penetration depth, and means for searching whether the input data is stored in the memory means, in the same group of data. Moreover, means are provided for transmitting a signal representative of a penetration depth included in the group of data stored in the memory means, or for transmitting a signal for controlling the bending machine according to this penetration depth.

Abstract: A pressing tool (13) includes a fluid pump (4), a cylinder element (5) arranged connecting with this and a piston which can be slid forward in the cylinder element (5) by pressure fluid of the fluid pump (4) and reset by a return spring (20a). A piston rod (6) is passed out to the cylinder element (5) as an activation part. The pressing tool (13) is moreover outfitted with a position measuring device (12, 12a; 112, 212, 212a) which measures without contact which makes the piston position continuously detectable over a positioning range free of disturbance and with a presence sensor (52). The presence sensor (52) verifies the presence of a jointing clamp (51) and issues an indicator signal in the event that a jointing clamp (51) is missing or improperly fastened and shuts the pressing tool (13) off following a delay period to the extent that no orderly inserted jointing clamp (51) is yet available.