Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
  • B23Q17/00—Arrangements for observing, indicating or measuring on machine tools
  • B23Q17/002—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring the holding action of work or tool holders
  • B23Q17/003—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring the holding action of work or tool holders by measuring a position
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2231/00—Details of chucks, toolholder shanks or tool shanks
  • B23B2231/26—Detection of clamping
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2260/00—Details of constructional elements
  • B23B2260/128—Sensors

Definitions

• the present invention relates to a tube processing machine chuck with a plurality of movable jaws for clamping a pipe to be machined and a method for monitoring such a tube processing machine chuck for correct clamping a tube with known tube geometry.
• the chuck states "open” and “unloaded” of the chuck are interrogated by means of on / off switches when the machine is at a standstill.
• the chuck state "cocked” can not be interrogated itself but results only indirectly from the fact that after a waiting period neither an open nor an empty state is measured. Also can with the
• On / Off switches are not detected when a tube is released from the chuck during machining. With four independently movable jaws a total of eight on / off switches are required, the setting is difficult and error-prone.
• the object of the present invention is to further develop a tube processing machine chuck of the type mentioned at the outset so that the chuck state "clamped" can also be queried directly.
• This chuck sensor system uses the jaw positions detected by the position sensors to determine whether a pipe is correctly clamped in the chuck and whether the pipe diameter of the clamped pipe is identical to the pipe diameter programmed in the CNC control.
• Chuck sensor can be detected in real time, whether a clamping error, such. a deformation of the tensioned tube due to excessive clamping pressure or a non-centric stretched pipe, is present.
• the jaw positions can be detected both at standstill and during operation with a rotating chuck. Further advantages of the chuck according to the invention are in particular:
• the position sensors detect the positions of their respective associated clamping jaws, preferably non-contact and can be designed, for example, as an inductive sensor or as a distance measuring sensor, in particular a laser distance measuring sensor.
• the chuck is rotatably mounted in a fixed chuck housing and the position sensor is mounted on the rotatably mounted chuck or on the fixed chuck housing.
• the position sensor is mounted on the rotatably mounted chuck and provided between the rotatably mounted chuck and the fixed chuck housing a particular non-contact data transmission connection, which transmits the data detected by the position sensor on the side of the fixed chuck housing and / or provides a non-contact energy transmission connection is that energizes the position sensor from the side of the fixed chuck housing.
• the data and / or power transmission connection may, for example, be via an inductive rotary transformer, a radio link, a sliding contact or any other manner known in the art.
• the position sensor is attached to the fixed chuck housing and cooperates with a Referenzfikiee the jaw together.
• all position sensors are connected to a monitoring unit, which monitors the chuck for correct clamping of a tube inserted into the chuck with known pipe geometry (pipe diameter or pipe outer cross section) on the basis of the detected jaw positions.
• a monitoring unit which monitors the chuck for correct clamping of a tube inserted into the chuck with known pipe geometry (pipe diameter or pipe outer cross section) on the basis of the detected jaw positions.
• the invention also relates to a method for monitoring the chuck described above for correct clamping of a tube with known tube geometry, wherein the clamping distance, in particular the clamping diameter of the clamping jaw exciting clamping jaws determined based on the detected by the position sensors jaw positions and compared with the known tube geometry of the tube becomes.
• This monitoring can take place both when the chuck is stationary and when the chuck is rotating, that is during the processing of the tube.
• FIG. 1 shows a mechanical system for the cutting processing of pipes in a perspective overall view
• Fig. 2 shows schematically a first embodiment of an inventive
• Fig. 3 shows schematically a second
• FIG. 1 a machine installation 1 for cutting workpieces, in the illustrated case of pipes 2, a processing device in the form of a laser cutting station 3, a feeding device 4 and a machine
• a laser cutting head 6 is provided, cut with the structures in the tube 2 or tube sections 7 are cut from the tubes.
• the respective tube 2 to be processed is mounted in a push-through chuck 8.
• the cut pipe sections 7 are transferred to the discharge station 5 to a support table 9.
• the pipe sections 7 can be removed from the machine system 1.
• the essential functions of the mechanical system 1 are CNC-controlled.
• Components of the feeding device 4 are a loading unit 10 and a workpiece holder designed as a turning and feeding station 11. By means of the rotary and feed station 1 1, the pipes to be processed 2 are moved relative to the laser cutting head 6 of the laser cutting station 3 in the manner required for processing.
• the tubes to be machined 2 are adjusted by means of the rotary and feed station 11 relative to the laser cutting head 6 in the tube longitudinal direction and rotated to create the separating cut around the tube longitudinal axis.
• the rotary and feed station 11 on a machine bed 12 of the pipe processing machine 1 in the direction of a double arrow 13 can be moved.
• a chuck 15 which in turn can be rotated in the direction of a double arrow 16 to the tube axis.
• the pipes to be processed 2 are mounted on pipe supports 17.
• the tube supports 17 are successively lowered into the machine bed 12 and can then be run over by the rotary and feed station 11.
• Fig. 2 shows in detail the rotatable chuck 15 for clamping the pipe to be machined 2.
• the chuck 15 is rotatably supported in the direction of the double arrow 16 in a fixed chuck housing 18 and has four each offset by 90 ° arranged clamping jaws 19, which are independent can be moved radially in the direction of a double arrow 20 in order to clamp together the tube 2 located therebetween.
• On the rotatable chuck 15 four position sensors 21 are fixed, which detect the respective position of the clamping jaws 19 along their travel path 20 without contact.
• the position sensors 21 may, as shown in FIG. 2 only by way of example, be designed as inductive scanning heads, which cooperate with respective magnetic measuring tapes 22, which are attached to the clamping jaws 19.
• the detected by the position sensors 21 position data of the tape measures 22 and thus the jaws 19 are wirelessly transmitted from the rotatable chuck 15 to a stationary monitoring unit 23, which may be integrated into the machine control.
• the transmission can for example be centrally via an inductive rotary transformer, which is attached to a fixed chuck housing 18 inductive primary part 24 which surrounds the chuck 15 annularly and is connected to the evaluation unit 23, and an inductive secondary part 25 which is fixedly mounted on the rotatable chuck 15 and is connected to the monitoring unit 23 has.
• the co-rotating with the chuck 15 secondary part 25 is designed as a small block and separated by an air gap 26 from the primary part 24.
• the power supply of the position sensors 21 can also be made inductively via the primary and secondary parts 24, 25.
• An alternative is the power supply via a battery on the rotatable chuck 15.
• the energy for the position sensors 21 may also be generated from the rotational movement of the chuck 15 or transmitted to the rotatable chuck 15 by means of light or a strong alternating electromagnetic field (radio wave).
• the positions of the clamping jaws 19 can be determined at each rotational position of the chuck 15 and thereby detected by the monitoring unit 23 in real time, whether at standstill or during processing, ie during rotation of the chuck 15, when clamping a pipe 2 with the programmed in the CNC control, ie known pipe geometry (eg pipe diameter), a clamping error is present.
• the monitoring unit 23 can calculate the clamping diameter of the tube 2 clamping jaws 19 and compare this with the tube diameter of the tensioned tube 2. If the calculated clamping diameter corresponds to the programmed pipe diameter, the pipe 2 is correctly tensioned.
• the calculated clamping diameter is not identical to the programmed pipe diameter, there is a clamping error. If the calculated clamping diameter is smaller than the programmed pipe diameter, for example, there is a deformation of the clamped pipe 2. if the calculated clamping diameter, however, greater than the programmed pipe diameter, the tube 2 is not on all jaws 9, for example, because the pipe 2 is not centered clamped due to a jaw jaw 19, a jammed cutting or incorrect Konturzugver ein.
• the presented inductive transmission technology can also be used for the signal and / or energy transmission from or to further, additional or alternative components of the chuck 15. These components shown below can be used in any combination. It is possible to apply pressure sensors to the jaws 19, which can measure the pressure of the jaws 19 and thus ensure that the workpiece is held only as tight as necessary to "lose” the tube 2 due to low pressure and deformations or scratches The pressure can be regulated by a control attached to the sensor or by means of a modified monitoring unit 23.
• a temperature sensor can monitor the temperature, in particular of the chuck 15 but also of the tube 2, whereby it is possible to identify problems in the cutting process.
• a poor cut quality or too high laser power can lead to increased temperatures of chuck 15 and / or tube 2, for example due to scattered radiation.
• This increase in temperature can be made accessible to the operator by means of the data transmission to the monitoring unit 23 and thus indicate a possible problem and / or be used to control the laser power or other laser parameters in order to avoid damage to chuck 15 or workpiece 2 and optimum machining parameters guarantee.
• the chuck 15 shown in FIG. 3 differs from the chuck of FIG. 2 in that in each case two mutually opposite clamping jaws 19 are reciprocally coupled with respect to each other and thus centrosymmetrically, as well as by a modified chuck sensor.
• the chuck sensor comprises two laser distance measuring sensors 31, which are arranged offset on the fixed chuck housing 8 by 90 ° to each other and the distance to reference surfaces 32 of the clamping jaw 19, for example, to the radially outwardly facing back Stirnflä- Chen the jaw 19, capture.
• the reference surfaces 32 are convex.
• the position data of the clamping jaws 19 detected by the distance measuring sensors 31 are transmitted to the monitoring unit 23 which can determine therefrom in real time as described above, whether at certain standstill rotational positions of the chuck 15 or during processing, ie during rotation of the chuck 15 Clamping a pipe 2 with the programmed in the CNC control, ie known workpiece geometry / pipe diameter a clamping error is present.
• the positions of the clamping jaws 19 can be detected at any pipe diameter with sufficiently high accuracy.
• the positions of the clamping jaws 19 can be detected during operation. Since the clamping jaws 19 span centrally, the clamping state of both clamping planes can be detected in a grid of approximately 90 ° ⁇ 10 °, that is, of the total angular range of 360 °, approximately 80 ° can be detected. Since the processing of rectangular and square tubes takes place predominantly on the flat surfaces, the monitoring, seen in the processing, is still significantly higher.
• the chuck sensor means distance measuring sensors 31 requires no major design changes, it is also suitable for a retrofit solution. - For the transmission of the sensor signal, no rotary feedthrough from the rotating chuck 17 to the fixed chuck housing 18 is required.
• the two chuck sensor systems described above each allow the chuck 15 to be scanned for the clamping states "released”, “cocked” and “unloaded”, both at standstill and during the current machining operation, and a plausibility check of the tube geometry of the chuck stretched pipe.
• the two chuck sensor systems described above can also be used in the push-through chuck 8 in order to detect and monitor its jaw positions.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Gripping On Spindles (AREA)

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Cited By (4)

Families Citing this family (15)

Citations (4)

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• 2010
  • 2010-04-09 DE DE201010003807 patent/DE102010003807B4/de not_active Expired - Fee Related
• 2011
  • 2011-03-29 WO PCT/EP2011/054778 patent/WO2011124499A1/de active Application Filing
  • 2011-03-29 CN CN201190000426.7U patent/CN203185069U/zh not_active Expired - Lifetime

Patent Citations (4)

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