JP2008173689A - Motor-driven press machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven press machine, which can shorten a time required for one pressing process by moving an upper die at high speed during a non-pressing period in which an object to be worked is not pressed. <P>SOLUTION: The motor-driven press machine comprises: a slider 5 which slides on struts 3; a connecting mechanism 30 equipped with a rotating part which vertically moves the slider 5 through a ball screw shaft 11 driven by an AC servomotor 9; a locking mechanism 16 for performing engagement and disengagement between a gear piece and a gear fixed to the ball screw shaft 11 in order to fix a crown 2 and the ball screw shaft 11; an AC servomotor 28 capable of rotating the rotating part of the connecting mechanism 30 in the normal and reverse directions, moving the slider 5 up and down through the normal/reverse rotation of the rotating part and, further, fixing the slider 5 to the rotating part of the connecting mechanism 30; a lower die mounted on a bed; a pulse scale 21 for detecting a position of the upper die installed to the under surface of the slider 5; and a control device 31 in which, based on a position signal detected by the pulse scale 21, the pressing of the object to be worked is controlled by rapidly lowering and raising the upper die 7 during the non-pressing period and lowering the upper die at a reducing speed under a locking action of the locking mechanism 16 during a pressing period. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric press machine, particularly an electric press machine that performs press processing using a motor as a drive source with an upper die attached to the lower end of a reciprocating slider and a lower die attached to a bed. Until the upper mold in the standby position is lowered and comes into contact with the workpiece placed on the lower mold or until just before contacting, and until the upper mold rises from the lower limit position and returns to the upper limit standby position. The present invention relates to an electric press machine that moves the upper die at high speeds to shorten one press step (cycle).

Conventionally, an electric press machine that performs press processing using a motor as a drive source matches the speed of the upper die for pressing the workpiece, and the upper die presses the workpiece even in a process where the workpiece is not pressed. When reciprocating, it was reciprocating at a constant speed. In addition, patent applications that attempt to solve this point have been filed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). However, there are still problems to be solved in actualization.
JP 2001-62597 A JP 2001-71194 A Patent No. 3051841

  The process of not pressing the workpiece as in the conventional method is also performed by pressing one step in accordance with the speed of the upper die when pressing the workpiece. In order to solve this problem, it has been found that it is necessary to lock the screw shaft in an electric press machine using a servo motor.

  The present invention aims to solve the above-mentioned drawbacks, and shortens the time required for one step of pressing by moving the upper die at high speed during the non-pressing period when the workpiece is not pressed. It aims at providing the electric press machine which can do.

Therefore, the electric press machine according to the present invention is provided in a frame formed by a bed, a crown, and a plurality of support columns, a slider in which an upper mold is attached to a lower end surface, and freely slides on the support columns, and a crown. A lock that fixes a coupling mechanism having a rotating portion that moves the slider up and down via a screw shaft that is driven forward / reversely by a first motor, and a screw shaft to which a crown and a locking gear are fixed. The mechanism and the slider are provided on the slider, and the rotating part of the coupling mechanism is rotated forward / reversely, and the slider is moved up and down through the forward / reverse rotation of the rotating part of the coupling mechanism. A contact position of a second motor capable of fixing the lower mold, a lower mold installed corresponding to the bed at a position corresponding to the upper mold, and a workpiece placed on the upper mold and the lower mold. Along with the upper limit of the upper mold Based on the position detector for detecting the position and the lower limit lowering position, and the position signal detected by the position detector, at least the first time until the time immediately before the upper mold contacts the workpiece placed on the lower mold. When the upper die is rapidly lowered through the rotation of the screw shaft by the motor, the crown and the screw shaft are fixed via the lock mechanism immediately after the first motor is stopped, and the upper die comes into contact with the workpiece. Alternatively, from the time immediately before contact to the time when the upper die descends to a predetermined lower limit lowering position, the lowering of the upper die is decelerated via the slider by the rotation of the coupling mechanism under the fixation between the crown and the screw shaft. Then, the upper mold reaches the lower limit lower position by controlling the upper mold to press the workpiece placed on the lower mold in the torque addition mode of the second motor with the crown and the screw shaft fixed. After that, under the fixed release of the slider and screw shaft With a control device for raising the upper die rapidly through the rider, the locking mechanism includes a gear piece having at least two teeth mutually meshing with gear locking, the gear piece and the lock the gear side A meshing attachment / detachment drive device having a mechanism for engaging and disengaging with a gear is provided.

During the non-pressing period when the work piece is not pressed, the upper die moves at a high speed, such as high-speed descent and high-speed, so the time required for one step (cycle) of the press processing can be shortened and the press mechanism is pressed by the lock mechanism. Accuracy and efficiency can be improved. In operating the lock mechanism, it is considered that the screw shaft is rarely turned undesirably (or kept in minute control) when the gear piece and the gear are coupled. .

1 and FIG. 2 respectively show a part of a schematic explanatory diagram of an embodiment of an electric press machine according to the present invention. The right end of the diagram of FIG. 1 is connected to the left end of the diagram of FIG. An overall view of the electric press machine according to the present invention is shown.

  In FIGS. 1 and 2, sliders 5 are provided inside a frame 4 formed by a bed 1, a crown 2, and a plurality of pillars 3. The pillars 3 engage with the pillars 3 at four corners of the slider 5. Sliding holes in which the slider 5 slides freely are provided in the axial direction.

  A plurality of mounting bases 6 such as two or four are provided on the upper surface of the crown 2, and each mounting base 6 is provided with a reduction gear 8 (the reduction gear 8 may be omitted). ) An AC servo motor (first motor) 9 incorporating an encoder is attached.

  Since the components and components related to each AC servo motor 9 mounted on the plurality of mounting bases 6 described below are exactly the same, only one of them will be described.

An output shaft 10 of an AC servomotor 9 that passes through a mounting base 6 attached to the upper surface of the crown 2 is connected to a tip end portion of a ball screw shaft 11 via a coupling 12. A bearing 15 fitted to the ball screw shaft 11 is attached to a hole 13 provided in the crown 2 via a bearing holder 14 so that the ball screw shaft 11 driven by the AC servo motor 9 can freely rotate to the crown 2. It is attached.

  The crown 2 is provided with a lock mechanism 16. The lock mechanism 16 will be described in detail later with reference to FIG. 3. When the lock mechanism 16 is activated, the ball screw shaft 11 is fixed to the crown 2, and the ball screw shaft 11 and the crown 2 are integrated. 11 cannot be rotated.

  A support 18 having a hollow interior 17 is fixed to the upper surface of the slider 5. The hollow 18 of the support 18 has a hole 19 provided in the slider 5 and a hole 23 sufficient to freely rotate the ball screw shaft 11 at the center. Two upper and lower thrust load bearings 24 and 25 are provided. There is provided a worm wheel 26 rotatably provided with the ball screw shaft 11 as a central axis, and an AC servo motor (second motor) 28 with a built-in encoder to which a worm 27 meshing with the worm wheel 26 is fixed. A ball screw mechanism 29 that is engaged with the ball screw shaft 11 and includes a ball and a nut member therein is fixed to the upper portion of the worm wheel 26 so as to project freely from the ceiling portion of the support 18. .

  When the AC servomotor 28 is stopped, the ball screw mechanism 29 fixed to the upper portion of the worm wheel 26 is engaged with the worm 27 and worm wheel 26 fixed to the output shaft of the AC servomotor 28. 5, the ball screw shaft 11 is driven by the forward / reverse rotation of the AC servo motor 9, and the ball screw mechanism 29, which is screwed to the ball screw shaft 11, the worm wheel 26, the two bearings 24, 25, the slider 5 is raised or lowered via the coupling mechanism 30 constituted by the support 18 and the like, and the slider 5 can be reciprocated by the rotation control of the AC servo motor 9.

  Further, when the lock mechanism 16 is operated and the ball screw shaft 11 is integrated with the crown 2 and the AC servo motor 28 is rotated forward and backward, the worm wheel 26 and the ball screw mechanism 29 are configured. The rotating part rotates through the ball screw shaft 11 in a stationary state, and raises or lowers the slider 5. That is, the slider 5 can be reciprocated by the rotation control of the AC servomotor 28.

  An upper mold 7 is attached to the lower end surface of the slider 5, and a lower mold 20 is provided on the bed 1 at a position corresponding to the upper mold 7. A pulse scale 21 for detecting the position of the slider 5 is attached along the four columns 3 between the bed 1 and the crown 2, and the workpiece 22 placed on the upper mold 7 and the lower mold 20, respectively. The upper limit standby position and the lower limit lowering position of the upper die 7 are detected.

  After the AC servo motor 9 is stopped, the lock mechanism 16 is locked and the ball screw shaft 11 is fixed to the crown 2 when the upper die 7 presses the workpiece 22 placed on the lower die 20. With the reaction force, the ball screw shaft 11 is rotated by the action of moving the slider 5 upward. By the integration of the ball screw shaft 11 and the crown 2 described above, the ball screw shaft 11 is Since the rotation is prevented, the slider 5 does not move upward, but prevents the slider 5 from moving upward. That is, the upper die 7 can apply a predetermined press load to the workpiece 22.

  The control device 31 that controls each rotation of the AC servomotors 9 and 28 and controls the lock mechanism 16 that fixes or releases the ball screw shaft 11 to the crown 2 receives various set values in advance. In addition to the above, based on the position signal detected by the pulse scale 21 for detecting the position of the slider 5, that is, for detecting the position of the upper mold 7, the upper mold 7 at the upper limit standby position is Up to the time immediately before contact with the workpiece 22 placed on the lower mold 20, the rotation of the ball screw shaft 11 by the AC servomotor 9 and the rotation of the rotating part of the coupling mechanism 30 by the AC servomotor 28 are performed. The upper die 7 is rapidly lowered, and immediately after the AC servo motor 9 is stopped, the lock mechanism 16 is locked to fix the crown 2 and the ball screw shaft 11, and the upper die 7 is connected to the workpiece 22. From the time of touching or just before contact, until the upper mold 7 is lowered to a predetermined lower limit lowering position (imaginary line position (7) of the upper mold 7 in FIG. 2), the upper mold 7 is lowered. Under the fixation of the crown 2 and the ball screw shaft 11, the speed is reduced with respect to the rapid lowering speed via the slider 5 due to the rotation of the rotating portion of the coupling mechanism 30, and under the fixation of the crown 2 and the ball screw shaft 11. Then, in the torque addition mode of the AC servo motor 28, the upper die 7 presses the workpiece 22 placed on the lower die 20, and the workpiece 22 is controlled to be pressed into a predetermined shape. After 7 reaches the lower limit lower position, the lock mechanism 16 is unlocked, and the upper die 7 is moved via the slider 5 by the AC servo motors 9 and 28 under the fixed release of the crown 2 and the ball screw shaft 11. Raise rapidly to the original upper limit standby position It is adapted to carry out the control.

  FIG. 3 shows a block diagram of an embodiment of the locking mechanism used in FIG.

  The lock mechanism 16 shown in FIG. 3 includes a gear 39 fixed to the ball screw shaft 11 and a gear piece 41 attached to a plunger of a solenoid 40 fixed to the crown 2.

  When the coil of the solenoid 40 is energized, the gear piece 41 attached to the plunger of the solenoid 40 pops out and meshes with the gear 39. Since the solenoid 40 is attached to the crown 2, the ball screw shaft 11 is integrated with the crown 2 via the solenoid 40.

  The gear piece 41 attached to the plunger of the solenoid 40 is fixed to the ball screw shaft 11 by the elastic force of the spring provided therein when the solenoid 40 is turned off by the elastic force of the spring provided therein. The engagement with the gear 39 is released, and the integration of the ball screw shaft 11 and the crown 2 is released.

  The gear piece 41 may be driven by using a pneumatic cylinder instead of the solenoid 40, and the contact position between the workpiece 22 placed on the lower mold 20 and the upper mold 7 is detected, and the upper Although a pulse scale 21 is shown as a position detector for detecting the upper limit standby position and lower limit lowering position of the mold 7, other electronic devices can be used as long as they can detect the position and send the detection signal to the control device 31. Any type or mechanical position detector can be used.

Then, with the locking mechanism 16 locked and the crown 2 and the ball screw shaft 11 fixed, the worm wheel 26 is slightly rotated by the rotation of the AC servo motor 28, and the ball screw mechanism 29 is moved in the ball screw axis direction. By moving a minute distance, the meshing positional relationship between the ball screw shaft 11 and the ball screw mechanism 29 can be changed, and the balls constituting the ball screw mechanism 29 are engaged by line contact or point contact. It is possible to avoid local wear of the balls and ball grooves resulting from the above.

  The operation of the electric press machine according to the present invention configured as described above will be described with reference to a cycle diagram of one embodiment of FIG.

  The vertical axis in FIG. 4 represents the operations of the upper mold 7, the AC servo motor 9, the lock mechanism 16, and the AC servo motor 28 in order from the top, the horizontal axis represents time, and the top solid line represents the upper mold 7. The trajectory is shown. In the figure corresponding to the AC servo motor 9 and the AC servo motor 28, the height from the reference line of the part indicated as “forward rotation” and the reference line of the part indicated as “reverse rotation” are shown. The height is the same.

  T0 on the time axis represents the cycle start point when the AC servo motor 9, the lock mechanism 16, and the AC servo motor 28 are in the off state and the upper die 7 is in the upper limit standby position.

  During time T1 to T2, the AC servomotors 9 and 28 are energized in the forward direction, the slider 5 starts to descend, and the lowering period (high-speed approach period) of the upper die 7 by both the AC servomotors 9 and 28 is reached. Represents.

  The time axis T2 represents the time when the upper die 7 comes into contact with the surface of the flat workpiece 22 placed on the lower die 20, and the rotation of the AC servo motor 9 is stopped. In operation, the integration of the ball screw shaft 11 and the crown 2 and the energization of the AC servo motor 28 in the forward rotation are continued, and at least at this time, the slider by the AC servo motor 28 alone is in the torque addition mode. Represents the point in time when the descent of 5 starts.

  That is, the time T1 to T2 is a non-pressing period from the upper limit standby position of the upper die 7 to contact with the workpiece 22 placed on the lower die 20, and the rapid ball screw shafts of the AC servomotors 9 and 28. The upper mold 7 is rapidly lowered by the rotation of 11 and the rapid rotation of the rotating part of the coupling mechanism 30.

  Times T <b> 2 to T <b> 3 are a pressing period (pressurizing stroke period) in which the upper die 7 is pressed through the slider 5 in the torque addition mode of the AC servomotor 9 and the workpiece 22 is placed on the lower die 20. Represents.

  The time axis T3 represents the time point when the upper die 7 reaches the predetermined lower limit lowering position, and immediately after that, the lock mechanism 16 is released and the ball screw shaft 11 and the crown 2 are integrated and the AC servomotor is released. It represents that energization of reverse rotation of 9 and 28 is performed.

  During times T3 to T4, the slider 5 is raised by the reverse rotation of both the AC servo motors 9 and 28 under the integrated release of the ball screw shaft 11 and the crown 2, and the upper die 7 is moved to the lower limit lowering position. Represents an ascending period (high speed return period) during which the vehicle rapidly rises to return to the upper limit standby position.

  At T4 on the time axis, the reverse rotation of the AC servomotor 9 stops, the slider 5 returns to the original position at the start of lowering, and represents the time when the upper mold 7 reaches the upper limit standby position. The AC servomotor 28 stops rotating before reaching the time axis T4, and the original positional relationship between the ball screw mechanism 29 and the ball screw shaft 11, that is, the cycle in which the upper die 7 is at the upper limit standby position. It has returned to the starting position and finished.

  T5 on the time axis represents the completion point of one cycle. In this way, in the non-pressing period between time T1 and T2 and time T3 to T4, the time required for one step (cycle) of press working is shortened by rapidly lowering and raising the upper die 7. Yes.

  In the above description, the AC servomotor 9 starts to rotate forward at T1 on the time axis, but may be started just before T2 on the time axis.

  FIG. 5 is an explanatory view of another embodiment of the upper die moving mechanism portion of the electric press machine according to the present invention.

  In FIG. 5, the same components as those in FIG. 1 are denoted by the same reference numerals, and basically have the same configuration as that in FIG. It is a point.

  That is, the ball screw mechanism 32 with a differential mechanism is separated into a ball screw mechanism 33 and a ball bearing position adjusting means 34, and the ball bearing position adjusting means 34 is provided between the slider 5 and the base board 35. The internal structure of the nut member 36 of the ball screw mechanism 33 is also different.

  In the internal structure of the nut member 36 of the ball screw mechanism 33, as shown in FIG. 5, the ball disposed in the ball groove of the ball screw shaft 11 is moved upward from the lower ball groove by the rotation of the ball screw shaft 11. This circulation of the ball avoids localized intensive wear of the ball.

  Since the ball bearing position adjusting means 34 is provided between the slider 5 and the base board 35, the differential member 38 moves in the left-right direction of the drawing by turning the screw portion 37. Accordingly, the nut member 36 of the ball screw mechanism 33 is moved by a small distance in the vertical direction via the base board 35 to which the support 18 is attached. As a result, the position of the ball groove in the nut member 36 of the ball screw mechanism 33 that contacts the ball disposed in the ball groove of the ball screw shaft 11 changes at the time of press working load, that is, the ball screw at the time of press working load. The position at which the ball groove of the nut member 36 of the mechanism 33 contacts the ball changes, and the durability of the nut member 36 of the ball screw mechanism 33 is ensured as compared to that of FIG. 1 where the ball contacts the same position every time.

It is a partial figure of one Example schematic explanatory drawing of the electric press processing machine which concerns on this invention. FIG. 2 is a partial view of an embodiment of the electric press machine according to the present invention, schematically illustrating the electric press machine according to the present invention in which the right end of FIG. 1 is connected to the left end of FIG. 2. Is shown. It is a block diagram of an embodiment of the locking mechanism used in FIG. It is a cycle diagram of one Example in the automatic driving | operation of the electric press processing machine which concerns on this invention. It is another Example explanatory drawing of the upper mold | type moving mechanism part of the electric press processing machine which concerns on this invention.

Explanation of symbols

1 Bed 2 Crown 3 Post 4 Frame 5 Slider 6 Mounting Base 7 Upper Mold 8 Reducer 9 AC Servo Motor (First Motor)
DESCRIPTION OF SYMBOLS 10 Output shaft 11 Ball screw shaft 12 Coupling 13 Hole 14 Bearing holder 15 Bearing 16 Lock mechanism 17 Hollow 18 Support body 19 Hole 20 Lower mold | type 21 Pulse scale 22 Workpiece 23 Hole 24, 25 Bearing 26 Warm wheel 27 Warm 28 AC Servo motor (second motor)
DESCRIPTION OF SYMBOLS 29 Ball screw mechanism 30 Connection mechanism 31 Control apparatus 32 Ball screw mechanism with a differential mechanism 33 Ball screw mechanism 34 Ball bearing position adjustment means 35 Base board 36 Nut member 37 Screw part 38 Differential member 39 Gear 40 Solenoid 41 Gear piece

Claims (1)

A frame formed by a bed, a crown, and a plurality of columns;
A slider on which the upper mold is attached to the lower end surface and freely slides on the support;
A coupling mechanism having a rotating portion that moves the slider up and down via a screw shaft that is driven forward / reversely by a first motor provided on the crown;
A locking mechanism for fixing the crown and a screw shaft to which a locking gear is fixed ;
It is provided on the slider, and the rotating part of the coupling mechanism is rotated forward and backward, and the slider is moved up and down through the forward and backward rotations of the rotating part of the coupling mechanism, and the slider and the rotating part of the coupling mechanism are fixed. A possible second motor;
A lower mold installed corresponding to the bed in a position corresponding to the upper mold,
A position detector that detects the contact position between the upper mold and the workpiece placed on the lower mold, and detects the upper limit standby position and lower limit lowering position of the upper mold,
Based on the position signal detected by the position detector, at least until the upper mold comes into contact with the workpiece placed on the lower mold, the upper mold is moved through at least the rotation of the screw shaft by the first motor. Immediately after the first motor stops, the crown and the screw shaft are fixed via the lock mechanism, and the upper die is determined in advance from the time when the upper die comes into contact with the workpiece or just before the contact. Until the lower limit lowering position is reached, the lowering of the upper die is decelerated via the slider by the rotation of the coupling mechanism under the fixation of the crown and the screw shaft, and the second lowering is performed under the fixation of the crown and the screw shaft. When the upper mold reaches the lower limit lower position, the slider and screw shaft are fixed and released after the upper mold reaches the lower limit position. Control device that rapidly raises upper die through slider Provided with a,
The locking mechanism includes a gear piece having at least two teeth that mesh with the locking gear and a mechanism that allows the gear piece to engage and disengage the gear piece and the locking gear on the gear piece side. An electric press machine comprising a detachable drive device .

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