JP5174079B2 - Control method of press machine - Google Patents

Description

  The present invention relates to a control method for a press apparatus that includes a plurality of press units and includes a work conveying device between adjacent press units.

  Conventionally, in a so-called tandem press line in which a plurality of presses are arranged in a line in the workpiece transfer direction and the workpiece is sequentially processed, a workpiece transfer method between adjacent presses is a robot method or a loader / unloader method. It has been known. Here, the robot system is such that an articulated handling robot is installed between adjacent presses, and the workpiece is unloaded from the press in the previous process by this handling robot, and the work is loaded into the press in the next process. It is a thing. On the other hand, in the loader / unloader system, a loader and an unloader having a link structure are respectively provided on the upstream side surface and the downstream side surface of the press body, and a shuttle carriage is provided between the upstream unloader and the downstream loader. The unloader and the loader are used to carry out and carry in the workpiece, respectively, and the workpiece is transferred to the next process by the shuttle carriage.

  However, in these conventional methods, it is necessary to convey the workpiece by following the intermittent movement of each of the upstream and downstream presses, and in order to prevent interference with a mold or the like during workpiece conveyance. Therefore, there is a problem that the handling speed of the workpiece cannot be increased, and there is a limit in improving the production speed. Furthermore, in the case of the robot system, there is a problem that it is difficult to teach the conveyance path and it takes a long time. In the case of the loader / unloader system, the shuttle carriage is placed between adjacent presses. Since installation is necessary, there is a problem that the apparatus becomes large and a large installation space is required.

  In order to solve these problems, the applicant of the present invention has a tandem press line workpiece transfer method and transfer device that can easily teach a workpiece transfer locus in a short time and can increase the workpiece transfer speed. Has already been proposed (Japanese Patent Application No. 2001-400849). The workpiece transfer device of the prior invention is provided with a lift beam that can move up and down in parallel with the workpiece transfer direction, and a carrier and a subcarrier that are movable along the longitudinal direction of the lift beam. And a crossbar having a work holding means.

  By the way, although different from the tandem press line as described above, in the servo transfer press, the press is continuously operated and the press angle is detected by an encoder (press angle detecting means), and the servo is controlled according to the detected angle. By controlling each axis of the feeder device to a predetermined position, the feeder device can be operated at high speed by following the press.

  However, since the invention of the prior application was proposed only for the hardware configuration of the workpiece transfer device for increasing the workpiece transfer speed in the tandem press line, the two presses operated independently and intermittently There is room for study on the control technology for efficiently transporting workpieces by following each press during intermediate transport.

  On the other hand, the control technology of the servo feeder device in the servo transfer press detects the press angle of a continuously operated press and controls the entry / retraction timing of the feeder device according to the press position. Is applied to the intermediate transfer of a tandem press that is operated intermittently, the feeder device will also stop when the tandem press as the tracking target stops. There is a problem that high speed cannot be realized. In addition, since the control technology of this servo transfer press is based on the premise that the feeder device follows the single press, the tandem is required to make the workpiece transfer device follow at least two presses. There is a problem that the control technology cannot be applied to the press line as it is.

  The present invention has been made to solve such problems, and can operate the workpiece transfer device even if the tracking target stops, and can also follow the workpiece transfer device for a plurality of tracking targets. Accordingly, it is an object of the present invention to provide a control method for a press apparatus that can remarkably improve the line speed.

In order to achieve the above object, a control method of a press device according to the present invention comprises:
A control method of a press apparatus comprising a plurality of press sections and a work transport device that is disposed between press sections adjacent to each other and transports a work from an upstream press section to a downstream press section,
A first press angle detecting means attached to the upstream press section for detecting the press angle of the upstream press section; and a press angle of the downstream press section attached to the downstream press section. Second press angle detecting means, and a signal generating means for generating a signal for controlling a work conveying device disposed between the upstream press section and the downstream press section,
In the preparatory section after the end of unloading of the work from the upstream press section and before the start of unloading of the work to the downstream press section, from the second press angle detection means of the downstream press section. The workpiece transfer device is controlled so as to gradually reduce the deviation based on the deviation between the signal and the signal from the signal generating means.

  In the present invention, after completion of unloading of the work from the upstream press section and before the start of loading of the work into the downstream press section, that is, a section synchronized with the downstream press section to be synchronized next. In the above, the workpiece transfer device is controlled based on a signal from a signal generating means for generating a signal for controlling the workpiece transfer device. In this way, the workpiece transfer device can be operated even if the upstream press unit that is the target of tracking when the workpiece is unloaded stops. Moreover, even if there are a plurality of press sections to be tracked, such as a tandem press line that requires the work transport apparatus to follow a plurality of press sections, the work transport apparatus can easily follow the plurality of press sections. be able to. Therefore, for example, when applied to workpiece transfer between a plurality of tandem presses that are independently operated intermittently, the line speed can be significantly improved. In addition, since the workpiece transfer device is controlled based on a signal from a signal generation unit separate from the press angle detection unit after the synchronous operation with the press unit is removed, vibration such as vibration during press molding of the workpiece is performed. There will be no adverse effects of disturbance.

Front view of a tandem press line according to an embodiment of the present invention Side view of FIG. Front view of workpiece transfer device used in tandem press line AA sectional view of FIG. Control system configuration diagram of this embodiment Diagram showing feeder motion

  Next, a specific embodiment of the control method of the press device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of a tandem press line according to an embodiment of the present invention, and FIG. 2 is a side view thereof. FIG. 3 is a front view of a work transfer device used for the tandem press line, and FIG. 4 is a cross-sectional view taken along line AA.

  The tandem press line 1 of the present embodiment includes a plurality of (four in the present embodiment) presses 2 arranged in series from the upstream side (left side in the figure) to the downstream side with a predetermined interval therebetween. 3, 4, 5, a material carry-in device 6 arranged on the upstream side of the most upstream press 2, a product carry-out device 7 arranged on the downstream side of the most downstream press 5, and the material carry-in device 6 The workpiece 8 is transferred between the workpiece transfer device 9 for transferring the upper workpiece 8 (see FIGS. 3 and 4) to the processing station of the first press 2 and the processing stations of the presses 2, 3, 4 and 5 adjacent to each other. Are provided with workpiece transfer devices 10, 11, 12 for transferring (unloading / loading) and a workpiece transfer device 13 for transferring the workpiece 8 from the processing station of the fourth press 5 onto the product unloading device 7. ing.

  Each of the presses 2, 3, 4, and 5 includes an upright 14 as a main body frame, an upper frame 15 that is disposed above the upright 14 and incorporates a driving force transmission mechanism, and is movable up and down on the upright 14. An upper mold mounted on the lower end of the slide 16, which includes a slide 16 supported and moved up and down via the driving force transmission mechanism, and a bolster 18 disposed on the bed 17 so as to face the slide 16. The workpiece 8 is processed by the lower mold attached to the upper end of the bolster 18.

  Next, the detailed structure of the workpiece transfer devices 9 to 13 will be described. Since the basic configuration of each of the workpiece transfer devices 9 to 13 is substantially the same, the following description will focus on the configuration of the workpiece transfer device 10 disposed between the presses 2 and 3 as a representative example. .

  As shown in FIGS. 2 and 4, the workpiece transfer device 10 includes a pair of lift beams 19 and 19 that are spaced apart from each other on the left and right sides in the workpiece transfer direction. A rod 20 extending upward along the upright 14 is attached to the upper portion of the lift beam 19. On the other hand, a lift shaft servo motor 22 is mounted on the upper portion of the upright 14 via a support member 21, and a pinion attached to the output shaft of the servo motor 22 meshes with a rack carved in the rod 20. The lift beam 19 is moved up and down by forward and reverse rotation of the servo motor 22. Here, the lift shaft servomotor 22 is controlled based on a feeder motion set in advance by a control signal from a controller 31 described later.

  Each of the left and right lift beams 19 is provided with a carrier (main carrier) 23 having a substantially U-shaped cross section so as to hold the lift beam 19 from below, and the carrier 23 extends along the longitudinal direction of the lift beam 19. It has been moved. As shown in FIG. 4, a pair of moving means for moving the carrier 23 along the lift beam 19 is provided between the outer side surfaces of the lift beam 19 and the inner side surface of the carrier 23 facing the lift beam 19. A linear motor 24 is arranged. Linear guides 25 are arranged between the upper outer surfaces of the lift beam 19 and the inner surface of the carrier 23 facing the upper beam, and between the lower surface of the lift beam 19 and the bottom surface of the carrier 23 facing the upper surface. The movement of the carrier 23 relative to the lift beam 19 is guided by these three-point supported linear guides 25. Here, the linear motor 24 has a magnet 24a disposed on both sides of the lift beam 19 along the transport direction (longitudinal direction), and a transport direction (longitudinal direction) on the inner surface of the carrier 23 facing the magnet 24a. The armature (carrier 23) having this coil 24b is moved linearly by the change of the magnetic field created on the stator (lift beam 19) having the magnet 24a. Has been.

  Furthermore, a base plate 23a having a required length is extended below the carrier 23 so as to extend along the workpiece conveyance direction, and the subcarrier 26 can be moved along the base plate 23a. The moving means of the subcarrier 26 includes a linear motor 27 including a magnet 27a disposed along the transport direction on the lower surface of the base plate 23a and a coil 27b disposed on the upper surface of the subcarrier 26 facing the magnet 27a. It is comprised by. In addition, linear guides 28 are disposed between the lower surfaces of both sides of the base plate 23a and the upper surfaces of the subcarriers 26 opposite thereto, so that the movement of the subcarrier 26 relative to the carrier 23 is guided by these linear guides 28. It is configured. A pair of subcarriers 26 and 26 facing each other are connected by a cross bar 29, and a plurality of vacuum cups 30 are attached to the lower surface of the cross bar 29, and the workpiece 8 is adsorbed by these vacuum cups 30. It is like that. Here, the linear motors 24 and 27 are controlled on the basis of a feeder motion set in advance by a control signal from a controller 31 described later, thereby moving the carrier 23 along the transport direction relative to the lift beam 19 and the carrier 23. The moving operation along the transport direction of the subcarrier 26 with respect to is controlled.

  In the workpiece transfer apparatus 10 configured in this way, the vacuum cup 30 is lifted and lowered via the carrier 23, the subcarrier 26 and the crossbar 29 by moving the lift beam 19 up and down by driving the lift shaft servomotor 22. Can be moved. Further, the carrier 23 is moved along the longitudinal direction of the lift beam 19 by driving the linear motor 24, and the subcarrier 26 is offset in the moving direction of the carrier 23 by driving the linear motor 27. 30 can be moved in the workpiece transfer direction. In this way, by controlling two orthogonal drive shaft positions in the vertical direction and / or the transport direction, the movement trajectory of the vacuum cup 30, in other words, the transport trajectory of the workpiece 8 can be controlled.

  The lift (down-down) operation and the transport (advance-return) operation of each workpiece transfer device are illustrated in FIGS. 5 and 6 in order to avoid interference between the workpiece 8 transferred by the workpiece transfer device and the mold. As shown, the lift shaft servomotor 22 and the linear motors 24 and 27 are controlled based on the stroke and timing set in advance in the controller 31, that is, on the feeder motion. In the present embodiment, the feeder motion is a two-dimensional motion in the feed axis direction (conveyance direction) and the lift axis direction (vertical direction), and each axis (feed axis and lift axis) as shown in FIG. It is determined based on the axial position command value with respect to the press angle set every time. According to the feeder motion of this embodiment, the work 8 is attracted from the lower mold of the processing station of the upstream press 2 at the suction point P and lifted in the lift (L) axial direction, and then the downstream press. 3 is transferred in the feed (F) axial direction up to the lower mold of the processing station 3, and is lowered in the lift axial direction so as to enter the lower mold. Next, the workpiece transfer device 10 is once lifted upward and moved in the return direction in order to return to the processing station of the upstream press 2, and then lifted and lowered again through the standby point R at a slightly lowered position. Returning to the suction point P, one cycle is completed.

  The upstream press 2 and the downstream press 3 are respectively provided with encoders (press angle detectors) 32 and 33, and the encoders 32 and 33 detect the press angles (crank angles) of the presses 2 and 3, This detected value is input to the controller 31. Specifically, the encoders 32 and 33 detect the number of pulse signals corresponding to the angular velocity of the crank angle, and the number of detected pulse signals is added to an up / down counter in the controller 31, thereby The number of pulse signals corresponding to the crank angle is counted by an up / down counter. The up / down counter is set so that the count value becomes the original value every time the crankshaft rotates once.

  The controller 31 receives a reference pulse signal having a predetermined period from an oscillator (signal generating means) 34, and the input pulse signal is added to an up / down counter in the controller 31, thereby counting the number of pulse signals. It has come to be. The oscillator 34 transmits an input signal to the controller 31 for controlling the lifting / lowering operation and the conveying operation of the workpiece conveying device 10, as in the encoders 32 and 33 arranged in the upstream and downstream presses 2 and 3. Therefore, it can be referred to as a virtual press angle detector (or virtual cam). The period of the reference pulse signal of the oscillator 34 can be changed as appropriate.

  The controller 31 executes a required calculation based on input information from the encoders 32 and 33 and the oscillator 34, and outputs a command value to each servo amplifier (servo driver) 35, 36, 37 and 38 based on the calculation result. Thus, the lift shaft servomotor 22 and the linear motors 24 and 27 of the workpiece transfer device 10 are controlled. The lift shaft servomotor 22 and the linear motors 24 and 27 are provided with speed sensors (not shown) for detecting the speeds of the motors, and speed signals detected by these speed sensors are input to the controller 31. Thus, speed feedback can be applied to each servo amplifier 35-38.

  Next, a control mode of the work transfer device 10 (same for the work transfer devices 9, 11, 12, and 13) in the present embodiment will be described.

  First, when the work 8 is unloaded from the upstream press 2, the press 2 in a predetermined press angle range a to b (see FIG. 6) in which the slide 16 of the press 2 enters the ascending process past the bottom dead center. 2, a control signal is output from the controller 31 to each of the servo amplifiers 35 to 38 based on the signal from the encoder 32 attached to 2, so that the work conveying device 10 is synchronized (follows) with the movement of the press 2. By moving the vacuum cup 30 into the lower mold of the processing station and holding the workpiece 8 by moving the carrier 23 and the subcarrier 26 in the feed direction, the workpiece 8 is held from within the lower mold. Is carried out (synchronized section with upstream press).

  Next, after this synchronization section is completed, in other words, after the predetermined press angle range a to b is reached, the section b until the start point c of the synchronization section with the next downstream press 3 is reached. In .about.c (self-running section), based on the signal from the oscillator 34, a control signal is output from the controller 31 to each of the servo amplifiers 35 to 38. More specifically, the self-running section is a preparatory section before entering the synchronous drive with the downstream press 3, and a signal from the encoder 33 attached to the downstream press 3, and the oscillator 34 The servo amplifiers 35 to 38 are controlled so as to gradually reduce the deviation based on the deviation from the signal. Thus, even if the upstream and downstream presses 2 and 3 are operated at independent speeds, the operating speed of the work transfer device 10 is gradually adjusted to the operating speed of the next press 3 in the preparation section. Therefore, the movement of the work transfer device can be controlled more smoothly, and the line speed can be improved. Moreover, even if each of the upstream and downstream presses 2 and 3 is operated with a phase difference, it can be dealt with by adjusting the movement of the work transfer device in the preparation section.

  Thereafter, in the press angle range c to d after the end of the self-running section, the controller 31 controls the servo amplifiers 35 to 38 based on a signal from the encoder 33 attached to the downstream press 3. A signal is output, and the workpiece transfer device 10 is moved up and down by the lift beam 19 and moved by the carrier 23 and the subcarrier 26 in the feed direction so as to synchronize (follow) the movement of the press 3. Carries the workpiece 8 into the lower mold of the processing station (synchronized section with the downstream press).

  Note that the return process after the work 8 is carried into the lower die of the downstream press 3 is also substantially the same as the transfer of the work 8 in the feed direction described above, after the synchronization section with the downstream press 3. Then, the control of entering the synchronous section with the upstream press 2 through the self-running section (including the standby point R) is executed.

  As described above, according to the present embodiment, at the time of loading / unloading a workpiece with respect to the presses 2 and 3 (synchronized section), the encoders 32 and 33 attached to the presses 2 and 3 to be loaded and unloaded are provided. On the other hand, in the self-propelled section after the workpiece carrying-in / carrying-out operation is completed, the workpiece carrying device 10 is controlled to synchronize with the movement of the slide 16 in the presses 2 and 3 as the object based on the press angle signal. Since the workpiece transfer device 10 is controlled based on the signal from the oscillator (virtual press angle detector) 34, the upstream press 2 and the downstream press 3 are intermittently operated independently. Even when the workpieces are being carried in / out, even if the presses 2 and 3 that are the tracking targets are stopped, the workpiece conveyance device 10 can be operated without any trouble. Therefore, there is an excellent effect that the line speed of the tandem press line 1 can be remarkably improved. In addition, there is an advantage that it is not adversely affected by disturbance such as vibration during the press molding of the workpiece 8.

  In this embodiment, the example applied to the tandem press line has been described. However, the technical idea of the present invention is a tandem press line as long as it is a workpiece transfer device that intermediately transfers a workpiece between two presses. The present invention is not limited to this and can be applied to other various systems. Also, the workpiece transfer device can be applied to, for example, a conventional robot system or a loader / unloader system.

1 Tandem press line 2, 3, 4, 5 Press 8 Work 9, 10, 11, 12, 13 Work transfer device 16 Slide 18 Bolster 19 Lift beam 22 Lift shaft servo motor 23 Carrier 24, 27 Linear motor 26 Sub carrier 29 Cross Bar 31 Controller 32, 33 Encoder (Press angle detection means)
34 Oscillator (Signal generation means)

Claims (1)

A control method of a press apparatus comprising a plurality of press sections and a work transport device that is disposed between press sections adjacent to each other and transports a work from an upstream press section to a downstream press section,
A first press angle detecting means attached to the upstream press section for detecting the press angle of the upstream press section; and a press angle of the downstream press section attached to the downstream press section. Second press angle detecting means, and a signal generating means for generating a signal for controlling a work conveying device disposed between the upstream press section and the downstream press section,
In the preparatory section after the end of unloading of the work from the upstream press section and before the start of unloading of the work to the downstream press section, from the second press angle detection means of the downstream press section. A control method for a pressing device, wherein the workpiece conveying device is controlled so as to gradually reduce the deviation based on a deviation between the signal from the signal and the signal from the signal generating means.

Images