JP3871640B2 - Feeder emergency evacuation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an emergency retracting method for a feeder, and more particularly to an emergency retracting method for a feeder that includes a carrier that moves a workpiece in an advance / return direction between two presses and that drives the carrier with a plurality of linear motors. Is.
[0002]
[Prior art]
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.
[0003]
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.
[0004]
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.
[0005]
By the way, in the tandem press line as proposed in the invention of the prior application, the work conveying device (feeder) is operated in synchronism with the movement of the press slide, and the work holding means of the feeder and the die of the press are connected. The feeder is configured to move along a predetermined motion trajectory so as not to interfere. If an abnormality occurs in the servo drive system during the operation of the feeder, the servo drive system and the servo motor are separated by hard logic, the DC brake is applied to the servo motor, and the feeder is emergency stopped on the spot. The In addition, the press slide is also braked by detecting the abnormality of the feeder, and is stopped independently of the feeder.
[0006]
[Problems to be solved by the invention]
However, as mentioned above, there is no problem if the press slide and the feeder device can be stopped at the same time when a feeder failure occurs. However, the inertia of the press slide is actually larger than the feeder and its coasting distance is longer. In addition, the feeder stops first, and the press slide stops after a delay. At this time, depending on the emergency stop position of the feeder, there is a possibility that the press slide may interfere with the feeder, and this interference may damage or damage a very expensive press die or feeder. There is a point.
[0007]
The present invention has been made to solve such problems. In a feeder that moves a workpiece in the advance / return direction between two presses using a linear motor, an abnormality occurs in the drive system of the feeder. It is an object of the present invention to provide an emergency evacuation method for a feeder that can reliably prevent interference between a feeder and a press.
[0008]
[Means for solving the problems and actions / effects]
In order to achieve the above object, the feeder emergency evacuation method according to the present invention comprises:
Includes left and right carrier for moving the workpiece in advance-return direction between two press, a very saving method feeder right and left carriers are driven at the respective two or three linear motors,
When an abnormality occurs in another drive system, leaving at least one of the drive systems of the respective linear motors in the left and right carriers, the press and the feeder interfere with each other using the one drive system. The feeder is retracted from the interference area to the non-interference area.
[0009]
In the present invention, among the drive systems including two or three linear motors for respectively driving the left and right carriers for moving the workpiece in the advance / return direction, at least one drive system is left and another drive system is provided. When an abnormality occurs, the feeder is evacuated from the interference area where the press and the feeder interfere to the non-interference area by the remaining normal drive system. Therefore, even if the press slide is in the descending operation at the time of the failure of the drive system, it is possible to reliably avoid the press mold and the feeder from interfering with each other and prevent the press mold or the feeder from being damaged. be able to.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific embodiment of the feeder emergency evacuation method according to the present invention will be described with reference to the drawings.
[0011]
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.
[0012]
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. In the following description, “work transfer device” is referred to as “feeder”.
[0013]
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.
[0014]
Next, the detailed structure of the feeders 9 to 13 will be described. Since the basic configurations of these feeders 9 to 13 are substantially the same, the following description will focus on the configuration of the feeder 10 disposed between the presses 2 and 3 as a representative example.
[0015]
As shown in FIGS. 2 and 4, the feeder 10 includes a pair of lift beams 19 and 19 that are spaced apart from each other on both 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.
[0016]
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. Linear motors 24 (24A, 24B; 24C, 24D) are 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.
[0017]
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. (27A, 27B). 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.
[0018]
In the feeder 10 configured in this manner, the vacuum cup 30 is moved up and down 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. be able to. 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.
[0019]
The raising / lowering (lift-down) operation and conveyance (advance-return) operation of each feeder are set in advance in the controller 31 (see FIG. 6) in order to avoid interference between the workpiece 8 conveyed by the feeder and the mold. The lift shaft servomotor 22 and the linear motors 24 and 27 are controlled based on the stroke and timing, that is, the feeder motion. In this embodiment, the feeder motion is a two-dimensional motion in the feed axis direction (conveying direction) and the lift axis direction (vertical direction), and the press angle set for each axis (feed axis and lift axis) Is determined based on the axial position command value for. As shown in FIG. 5, according to the feeder motion of this embodiment, the workpiece 8 is attracted from the lower mold of the processing station of the upstream press 2 at the suction point P and lift (L) axial direction. Is lifted to the lower die of the processing station of the press 3 on the downstream side, conveyed in the feed (F) axial direction, and lowered into the lift axial direction to enter the lower die, and the workpiece is released at the release point Q. Adsorption is released. Next, the feeder 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 is lifted and lowered again through the standby point R at a slightly lowered position. Returning to the point P, one cycle is completed.
[0020]
Next, the servo control system of the feeder 10 according to the present embodiment will be described focusing on the operation of loading and retracting the workpiece 8 to the downstream press 3. The workpiece unloading operation from the upstream press 2 is performed in the same manner.
[0021]
As shown in FIG. 6, the press angle (crank angle) of the press 3 is detected by an encoder (press angle detector) 32 attached to the press 3, and this detected value is input to the controller 31. In the controller 31, when the press angle detected by the encoder 32 is within a predetermined press angle range related to the unloading / carrying-in of the workpiece, the linear motors 24A to 24A are connected via the servo drivers 33a, 33b,. Control signals are output to 24D, 27A, 27B and the lift shaft servomotor 22. The linear motors 24 and 27 and the lift shaft servomotor 22 are provided with a speed sensor for detecting the speed of these motors and a position sensor (both not shown) for detecting the current positions of these motors. The speed signal detected by the sensor and the position signal detected by the position sensor are input to the controller 31 to apply speed feedback and position feedback to the servo drivers 33a, 33b,.
[0022]
Thus, the feeder 10 moves up and down the lift beam 19 and moves the carrier 23 and the subcarrier 26 in the feed direction so as to synchronize (follow up) the movement of the press 3 when the work 8 is carried into the press 3. Thus, after the vacuum cup 30 is moved into the lower mold of the processing station and the work 8 is loaded, an operation of retracting from the lower mold is executed.
[0023]
Because of this configuration, when the servo drivers 33a, 33b,..., The controller 31 and the like are operating normally, the carrier 23 of the feeder 10 has left and right as shown in FIG. Each pair of linear motors 24A, 24B; 24C, 24D is moved along the transport direction.
[0024]
In this normal state, for example, when an abnormality occurs in one linear motor 24A (or 24B) or the servo driver 33a (or 33b) of the left pair of linear motors 24A and 24B in FIG. A stop command is issued to the press 3 by a control signal from. At this time, even if the feeder 10 is in an interference area (dangerous area) where it interferes with the slide 16 of the press 3, the other normal linear motor 24B (or 24A) or its servo driver 33b (or 33a) One end side can be driven, and the interference area can be retracted to the non-interference area. Here, since the driving force on the side where the abnormality has occurred is halved, a slight twisting force acts on the crossbar 29, but there is no hindrance to movement so as to retreat from the interference region. In addition, after retreating from this interference area, the feeder 10 is stopped following the stop operation of the press 3.
[0025]
As described above, according to the present embodiment, a pair of drive systems for the linear motor that drives the carrier 23 are provided on the left and right, respectively, so that an abnormality occurs in one of the drive systems. During the emergency stop, the feeder 10 can be reliably retracted from the interference area to the non-interference area and stopped at a predetermined position by the linear motors 24A, 24B,. Therefore, even if the press slide is moving down during an emergency stop, it is possible to reliably avoid interference between the press mold and the feeder, and to prevent damage to the press mold or the feeder. it can.
[0026]
In this embodiment, as shown in FIG. 4, the arrangement structure of the linear motor 24 and the linear guide 25 in the carrier 23 and the lift beam 19 includes a pair of linear motors 24 with respect to either the left or right carrier 23. has been described ones provided structure, as this arrangement, it is possible to adopt other various structures.
[0027]
FIG. 7 shows a modification of the carrier structure of the present embodiment shown in FIG. In FIG. 7, portions corresponding to the present embodiment are denoted by the same reference numerals as those in FIG. 4 or corresponding symbols with dashes (′). In the example shown in FIG. 7A, the linear motor 24 is disposed on both outer surfaces and the lower surface of the lift beam 19, and the linear guide 25 is disposed on both outer surfaces of the lift beam 19. Further, in the example shown in FIG. 7B, the linear motor 24 on the lower surface of the lift beam 19 is omitted in the configuration shown in FIG. Further, in the example shown in FIG. 7C, a linear guide 25 is also arranged on the lower surface of the lift beam 19 in addition to the configuration of FIG. In the example shown in FIG. 7D, a pair of linear motors 24 is disposed on one outer surface of the lift beam 19 and a linear guide 25 is disposed on the other outer surface and the lower surface of the lift beam 19. Has been. Further, in the example shown in FIG. 7E, the carrier 23 has an L-shaped cross section, a pair of linear motors 24 are disposed on one outer surface of the lift beam 19, and the linear guide 25 is provided on the lift beam 19. The outer surface and the lower surface are arranged. Further, in the example shown in FIG. 7F, the carrier 23 has an L-shaped cross section, a pair of linear motors 24 are disposed on one outer surface and a lower surface of the lift beam 19, and the linear guide 25 is lifted. The beam 19 is disposed on the outer and lower surfaces thereof.
[0028]
In any of these configurations, the carriers 23 and 23 ′ are driven by the pair of linear motors 24, so that the same operational effects as in the present embodiment can be achieved.
[0029]
FIG. 8 is a cross-sectional view showing a carrier structure according to another embodiment.
[0030]
In the present embodiment, a bracket 41 having a substantially T-shaped cross section is attached to the lower surface of the central portion of the lift beam 40, and a carrier 42 is disposed so as to hold the bracket 41 from below. A magnet 43a is disposed along the longitudinal direction, and a coil 43b is disposed along the longitudinal direction on the inner surface of the carrier 42 facing the magnet 43a. The linear motors 43A and 43B are configured by the magnet 43a and the coil 43b. . Guide frames 44 and 45 are attached to the lower surfaces of both sides of the lift beam 40, and a pair of linear guides 46 are provided between the bottom surfaces of the guide frames 44 and 45 and the lower upper surface of the carrier 42 facing the guide frames 44 and 45. ing. Even with such a configuration, the same effects as those of the above-described embodiment can be obtained.
[0031]
In each of the above-described embodiments, the example applied to the tandem press line has been described. However, the technical idea of the present invention is not limited to this tandem press line as long as it is a feeder that transports workpieces between two presses. It can also be applied to other various systems. Moreover, it is applicable also to the feeder between each press part adjacent to the press of a press provided with a some press part.
[Brief description of the drawings]
FIG. 1 is a front view of a tandem press line according to an embodiment of the present invention.
FIG. 2 is a side view of FIG. 1;
FIG. 3 is a front view of a work transfer device used in a tandem press line.
4 is a cross-sectional view taken along the line AA in FIG. 3. FIG.
FIG. 5 is an explanatory diagram of feeder motion according to the present embodiment.
FIG. 6 is a block diagram of a servo control system.
FIGS. 7A to 7F are cross-sectional views showing modifications of the carrier structure of the present embodiment.
FIG. 8 is a cross-sectional view showing a carrier structure according to another embodiment.
[Explanation of symbols]
1 Tandem press line 2, 3, 4, 5 Press 8 Work 9, 10, 11, 12, 13 Work transfer device (feeder)
16 Slide 18 Bolster 19, 40 Lift beam 22 Lift axis servo motor 23, 42 Carriers 24A-D, 27A, 27B, 43A, 43B Linear motor 26 Subcarrier 29 Crossbar 31 Controller 32 Encoder (Press angle detection means)

Claims (1)

Includes left and right carrier for moving the workpiece in advance-return direction between two press, a very saving method feeder right and left carriers are driven at the respective two or three linear motors,
When an abnormality occurs in another drive system, leaving at least one of the drive systems of the respective linear motors in the left and right carriers, the press and the feeder interfere with each other using the one drive system. An emergency retracting method for a feeder, wherein the feeder is retracted from an interference area to a non-interference area.

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