JP2005246464A - Control method for mechanical press and controller for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method for a mechanical press capable of avoiding the occurrence of crack, deformation, etc., in deep drawing. <P>SOLUTION: The controller of the mechanical press includes an angle detector for detecting the rotating angle of a crank shaft, a displacement detector for detecting the relative displacement of a second slide section with respect to a first slide section and a controller of a drive mechanism. The controller controls the drive mechanism in such a manner that the first slide section descends on the basis of the crank angle signal detected by the angle detector, and the second slide section descends from its ascending position to a descending position at a first relative speed upon passage of the first slide section through the first descending start position, that the second slide section ascends at a relative speed from the descending position to the ascending position right after the second slide section reaches the descending position and that the first slide section ascends right after the passage of the first slide section through a bottom dead point. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention basically relates to a control method and a control device for a mechanical press having a mechanism for converting a rotational movement of a crankshaft into a vertical movement of a slide.

  As one of the mechanical presses, it can be moved up and down between a frame, a crankshaft having a plurality of eccentric parts rotatably supported on the frame, and a top dead center and a bottom dead center arranged below the crankshaft. And a plurality of connections for converting the rotational movement of the eccentric part of the crankshaft into the up-and-down movement of the slide. The mechanical press has advantages in that it is superior in mechanical accuracy and productivity and can use a die having a large number of processes as compared with the hydraulic press.

  According to this, the upper die attached in advance to the slide is pressed against the plate material (work) placed on the lower die below the slide by the lowering of the slide, and stamping, punching, pressing, etc. Is done.

  By the way, such a mechanical press has a problem that due to its mechanism, it is inevitable that the slide decelerates with respect to the frame and thus the plate placed on the lower mold immediately before reaching the bottom dead center. For this reason, particularly in drawing, before the end of the lowering of the slide, that is, before completion of drawing, depending on the material, work hardening occurs in the upper part that has been subjected to drawing first, and cracks, deformation, etc. occur in this part. There is an inconvenience.

  It is considered that this problem can be solved by improving a part of the slide so as to move at a predetermined constant or variable descending speed.

  An example of a mechanical press improved so that a part of the slide is moved at a constant lowering speed is described in Patent Document 1 described later. In this mechanical press, the slide includes an inner slide and a blank holder around the inner slide, and the inner slider and the blank holder are driven by the crankshaft and the hydraulic jack, respectively.

  However, this improved mechanical press does not solve the above-mentioned problem in drawing because drawing in drawing is performed by the inner slider that receives the driving force of the crankshaft.

Japanese Patent Publication No.34-7847

  An object of the present invention is to provide a control method and a control device for a mechanical press that can avoid the occurrence of cracks, deformation, and the like in drawing.

  A control method and a control device for a mechanical press according to the present invention include a frame, a crankshaft rotatably supported by the frame and having a plurality of eccentric portions, and disposed below the crankshaft. A first slide part that is movable up and down between a top dead center and a bottom dead center, and has a first slide part provided with a through hole extending in the vertical direction, and the through hole of the first slide part A slide having a second slide part that can be raised and lowered between a raised position and a lowered position, and a plurality of connections for converting the rotational movement of the crankshaft into the vertical movement of the first slide part; A plurality of connections connected to the eccentric part of the crankshaft and the first slide part, and a drive mechanism for causing the second slide part to move up and down, and is attached to the first slide part It was applied to the mechanical press and a drive mechanism.

  The control method according to the present invention is a control method of the mechanical press, wherein the first slide portion is lowered, the position where the first slide portion that is being lowered starts to decelerate, and the bottom dead center. When the first slide part passes through a first descent start position of the second slide part set in advance, the second slide part is moved from the raised position to the lowered position. The first slide is moved from the lowered position to the raised position immediately after the second slide part has reached the lowered position by lowering the slide part at a first relative speed. And raising the first slide portion immediately after the first slide portion passes the bottom dead center.

  In the control method according to the present invention, the first slide portion is further raised, and is preset in the vicinity of the bottom dead center between the bottom dead center and the position at which the first slide portion starts to decelerate. When the first slide portion passes through the raised start position of the second slide portion, the second slide portion is moved from the raised position to the lowered position with respect to the first slide portion. The second slide portion is moved from the lowered position to the raised position immediately after the second slide portion reaches the lowered position, with respect to the first slide portion. It may include raising at a relative speed.

  The position of the second slide portion relative to the frame when the second slide portion is lowered at the first relative speed and positioned at the lowered position is determined by the first slide portion being at the bottom dead center. And the same position as the second slide portion relative to the frame when the second slide portion is located at the raised position.

  The first relative speed is a lowering speed with respect to the frame when the first slide part passes the first lowering start position, and the first slide part is the first of the second slide part. The first descending speed of the second slide portion with respect to the frame is the same between the time when the second slide portion reaches the lowered position until the second slide portion reaches the lowered position. It can be set as the speed with respect to the slide part.

  The second relative speed may be a speed relative to the first slide part such that the second slide part reaches the ascending position when the first slide part reaches the bottom dead center. it can.

  The third and fourth relative speeds may be the same magnitude as the second and first relative speeds, respectively.

  In the control method, further, prior to lowering the first slide portion, the first lowering start position of the second slide portion is set to the rotation angle of the crankshaft corresponding to the operation delay of the drive mechanism. Can be determined in consideration of

  The first relative speed may be smaller than the second relative speed.

  The drive mechanism is composed of, for example, a hydraulic jack.

  The present invention is a control device for the mechanical press, wherein the angle detector for detecting the rotation angle of the crankshaft and the relative displacement of the second slide portion with respect to the first slide portion are detected. And a controller for the drive mechanism. The controller lowers the first slide part, and based on the crank angle signal detected by the angle detector, the position of the lowering first slide part to be decelerated and the bottom dead center When the first slide part passes through a first descent start position of the second slide part set in advance, the second slide part is moved from the raised position to the lowered position. The first slide portion is lowered from the lowered position to the raised position immediately after the second slide portion reaches the lowered position with respect to the slide portion at a first relative speed. In contrast, the drive mechanism is controlled to increase at a second relative speed.

  The controller further raises the first slide part, and based on the crank angle signal detected by the angle detector, the first slide part that is being raised becomes the bottom dead center and the first slide part. The second slide portion is moved to the raised position when the first slide portion passes through a second lowering start position of the second slide portion set in advance between the slide portion and the position at which the slide portion starts to decelerate. To the lowered position at a third relative speed with respect to the first slide part, and immediately after the second slide part reaches the lowered position, the second slide part is moved from the lowered position to the lowered position. The drive mechanism can be controlled to raise to the raised position at a fourth relative speed with respect to the first slide portion.

  According to the control method of the present invention, for the second slide portion in the through hole of the first slide portion, the second slide portion between the position where the descending first slide portion starts to decelerate and its bottom dead center. 1 descent start position is set, and when the first slide part passes through this position, the second slide part is lowered from the raised position to the lowered position at the first relative speed with respect to the first slide part. Since it did in this way, the speed equivalent to deceleration of the descent | fall speed of the 1st slide part with respect to a flame | frame is supplemented with the descent | fall speed of a 2nd slide part. That is, the lowering speed of the second slide part with respect to the frame is a speed obtained by adding the lowering speed of the first slide part and the lowering speed of the second slide part. Of the second slide part reaches the bottom dead center at substantially the same speed as the descending speed when the first descending start position of the second slide part is passed. As a result, it is avoided that the slide descending speed is decelerated immediately before reaching the bottom dead center, and the occurrence of cracks, deformation, etc. in the prior art can be prevented. Note that the first and second relative speeds may be constant or variable while moving at the relative speeds.

  The position of the second slide portion when the second slide portion is lowered and positioned at the lowered position at the first relative speed, the first slide portion is located at the bottom dead center, and When the second slide portion is positioned at the raised position, the second slide portion is lowered to the bottom dead center while maintaining the lowering speed of the second slide portion. It does not happen that the vehicle decelerates immediately before reaching the bottom dead center, and the conventional generation of cracks, deformations, etc. can be prevented.

  When the second relative speed is set to a speed at which the second slide part reaches the bottom dead center simultaneously with the time when the first slide part reaches the bottom dead center, The slide is substantially located at the bottom dead center from when the slide part is located at the bottom dead center until the first slide part is located at the bottom dead center. Thereby, in one press, since there is a stop step between the lowering and raising steps of the second slide portion, it contributes to the quality improvement of the press work.

  Furthermore, the timing at which the second slide portion descends is delayed due to a delay in the mechanism of the drive mechanism, and as a result, the second slide portion may decelerate immediately before reaching the bottom dead center. However, prior to lowering the first slide portion, a delay of the second slide portion (based on a mechanism delay of the drive mechanism) is calculated, and the first lowering is performed based on the calculated delay. By correcting the start position, it is possible to prevent the second slide portion from decelerating immediately before reaching the bottom dead center.

  The control method can be implemented by the control device according to the present invention.

  Referring to FIGS. 1 to 3, a mechanical press to which a control method and a control apparatus according to the present invention are applied is indicated by a reference numeral 10 as a whole.

  As shown in FIG. 1, a mechanical press 10 includes a frame 12, a crankshaft 14 that is horizontally supported rotatably on the frame, a slide 16 that can be moved up and down disposed below the crankshaft 14, and a crankshaft. A plurality of (two in the illustrated example) connections 18 that convert the 14 rotational movements into the up-and-down movement of the slide 16.

  The rotation angle of the crankshaft 14 is detected by a crank angle detector 94 such as a detector or encoder combining a resolver and a converter, and is output to the controller 100 (see FIG. 4) as a crank angle signal S1.

  The crankshaft 14 supported by the frame 12 via a plurality of bearings 20 has a plurality of eccentric portions 22. In the example of FIG. 1, there are two eccentric portions 22. Both eccentric portions 22 are spaced from each other in the longitudinal direction of the crankshaft 14 and are arranged with the same amount of eccentricity in the same direction. In the illustrated example, the amount of eccentricity is 20 mm (see FIG. 7).

  A flywheel 24 and a clutch 26 are disposed at the end of the crankshaft 14. The flywheel 24 is rotatably mounted around the end portion of the crankshaft 14 via a bearing 28, and the clutch 26 is attached to the end portion of the crankshaft 14 so as not to be relatively rotatable. The flywheel 24 is connected to a drive source 92 (see FIG. 4) such as a motor that gives rotational power to the flywheel 24 via, for example, a belt (not shown). The crankshaft 14 receives and transmits the rotational power from the flywheel 24 by the operation of the clutch 26.

  A plurality of connections 18 for converting the rotational movement of the crankshaft 14 into the up-and-down movement of the slide 16 are respectively connected to both eccentric portions 22 of the crankshaft 14 and one end portion (upper end portion) 30 rotatably connected thereto. And the other end portion (lower end portion) 32 pivotally attached to the first slide portion 34 described later. For this reason, when the crankshaft 14 rotates once, the first slide portion 34 moves up and down only once between the top dead center and the bottom dead center. In the illustrated example, the distance between the top dead center and the bottom dead center is 40 mm (see FIG. 7).

  In the illustrated example, the slide 16 is formed of a block body having a rectangular planar shape as a whole and having a relatively large thickness dimension (see FIG. 2). The slide 16 has a first slide part 34 and a second slide part 36.

  A hole 40 penetrating the first slide portion 34 in the vertical direction is provided in the central portion of the recess 35 formed in the substantially central portion of the first slide portion 34. The first slide portion 34 moves up and down with the rotational movement of the crankshaft 14 and receives a vertical guide action by a plurality of guide members 38 (see FIG. 2) attached to the frame 12.

  A second slide portion 36 is disposed in the through hole 40 of the first slide portion 34 so as to be movable up and down. The raising / lowering movement of the second slide portion 36 is attached to the first slide portion 34 between the raised position (position shown in FIGS. 1 and 7) and the lowered position (position shown in FIGS. 3 and 10). This is caused by the operation of the driving mechanism 42.

  A connecting plate 88 is attached to the lower portion of the second slide portion 36 by bolts 90 (see FIG. 3), and the lower surface of the connecting plate 88 substantially defines the lower surface of the second slide portion 36. When the second slide portion 36 is in its raised position when the upper mold is raised, the lower surface of the connecting plate 88 and the lower surface of the first slide portion 34 are on the same plane. In addition, a lower mold (not shown) is attached to the frame 12 via an absorbent material (not shown) such as rubber so that it can be pressed.

  As shown in FIG. 2, the through-hole 40 has a circular cross-sectional shape. Instead of a circle, any other shape such as a rectangle may be used. In addition, the through hole 40 may be provided and disposed at a location other than the recess 35 of the first slide portion 34.

  As shown in FIG. 3, the drive mechanism 42 including a hydraulic jack is attached to the first slide portion 34 via a flange joint 86. A piston rod 46 extending downward from the cylinder 44 of the hydraulic jack is received in and screwed into a hole 60 at the top of the second slide portion 36 slidably disposed in the through hole 40.

  The drive mechanism 42 can be, for example, a screw jack in addition to the illustrated hydraulic jack.

  Two guide rods 48 are disposed in a guide hole 50 provided in the first slide portion 34 and extending in the vertical direction so as to be movable up and down. The guide hole 50 is in the vicinity of the through hole 40 that receives the second slide portion 36 and extends in parallel therewith. The two guide rods 48 are connected to the second slide portion 36 via a connecting plate 88 and bolts 90 at the lower part thereof.

  In order to make the second slide part 36 and the guide rod 48 move up and down more smoothly, guide bearings 68 and 70 are respectively installed on the peripheral wall surfaces of the through hole 40 and the guide hole 50 in which they are received. . Accordingly, as the piston rod 46 is moved up and down, the second slide portion 36 and the guide rod 48 are moved up and down at the same time. At this time, the second slide portion 36 is guided by the guide rod 48, and thereby more linear. Make a proper up and down movement. The distance between the raised position and the lowered position of the second slide part 36 relative to the first slide part 34 can be arbitrarily set. In the illustrated example, it is about 1 mm (see FIG. 9).

  Therefore, by operating the hydraulic jack, the second slide portion 36 is lowered between the raised position and the lowered position at a preset speed with respect to the first slide portion 34. Can be raised.

  With reference to FIG. 4, the control apparatus 100 of a mechanical press is demonstrated. The control device 100 includes a controller 102, a motion setting device 104, a crank angle detector 94, and a second slide portion position detector 106 that measures the relative position of the second slide portion 36 with respect to the first slide portion 34. including. The controller 102 includes a second slide portion position command unit 108.

  The crank angle detector 94 detects the rotation angle of the crankshaft 14 and outputs the detected rotation angle to the second slide portion position command unit 108 as a crank angle signal S1.

  The second slide portion position detector 106 is attached to a hydraulic jack (drive mechanism) 42, always detects the displacement of the piston rod 46, and detects the second slide portion 36 relative to the detected first slide portion 34. Is output to the sensor amplifier 107 as a displacement signal S2.

  The sensor amplifier 107 converts the input displacement signal S2 into a prescribed voltage signal, and outputs it as a displacement voltage signal S2 'to the second slide portion position command unit 108 and the servo amplifier 110. A displacement measuring device such as a linear scale is used as the second slide portion position detector 106. The displacement voltage signal S <b> 2 ′ is also used as a position control signal for the second slide portion 36.

  The motion setter 104 receives the descending start timing, the descending end timing, the ascending start timing, the ascending end timing, the ascending position and the descending position of the second slide portion 36 by the operator. The setting signal S3 is output to the second slide portion position command unit 108.

  Lowering of the second slide portion 36 per disassembly angle (for example, 1 °) that can be detected by the crank angle detector 94 from the lowering timing and the lowering amount of the second slide portion 36 input to the motion setting device 104. Calculate the amount. Similarly, the rising amount of the second slide portion 36 per disassembly angle (for example, 1 °) that can be detected by the crank angle detector 94 is calculated from the rising timing and the rising amount of the second slide portion 36.

  The servo amplifier 110 generates a flow rate signal S5 indicating the flow rate of oil supplied to the inside of the cylinder 44 of the hydraulic jack 42 based on the position command signal S4 from the second slide portion position command unit 108 and the displacement voltage signal S2 ′. The servo valve 114 is supplied.

  The servo valve 114 is an electromagnetic valve that controls the flow rate of oil supplied from the hydraulic unit 112 to the lowering and raising valves of the cylinder 44 based on the flow rate signal S5.

  The two pressure sensors 116 and 117 respectively measure the hydraulic pressure of one and the other in the cylinder 44 to monitor the upper limit pressure, and output the pressure signals S6 and S7 to the second slide portion position detector 108. .

  The controller 102 controls the clutch 26 to be pressed against the flywheel 24 based on an ON switch signal from a switch (not shown) operated by an operator, and rotates the crankshaft 14. The first slide part 34 is moved up and down. The controller 102 outputs a signal for rotating the output shaft of the drive source 92 to the inverter 109 to drive the drive source 92 independently of the control for relatively pressing the clutch 26 against the flywheel 24. be able to.

  The mechanical press 10 and the control device 100 described above are controlled according to the flowcharts shown in FIGS.

  The mechanical press 10 stands by in the state shown in FIG. The crank angle at this time is 0 ° or the vicinity thereof (for example, ± 30 °, that is, a range of 330 ° to 30 °). In the example shown, this is 0 °. Further, the first and second slide portions 34 and 36 are located at the top dead center and the raised position, respectively, as indicated by a point Ps on the graph shown in FIG. 8 and a point Ps on the graph shown in FIG. ing.

  Here, the dotted line L1 on the graph shown in FIG. 8 indicates the position of the first slide part 34 with respect to the frame 12, and the solid line L2 indicates the position of the second slide part 36 with respect to the frame 12. The dotted line L1 coincides with the solid line L2 in the portion from the point Ps to the point P1 and the portion from the point P3 to the point Pe. The position of the second slide portion 36 relative to the first slide portion 34 is indicated by a solid line L2 in FIG.

  When the first and second slide portions 34 and 36 of the mechanical press 10 are in the positions shown in FIG. 7, the operator can place a press plate (workpiece) between the upper die and the lower die (not shown). ).

  Next, the operator activates the drive source 92, presses an operation switch (not shown) of the mechanical press 10, and presses the clutch 26 relative to the flywheel 24 (step ST001). Thereby, the 1st slide part 34 descends (step ST002). As a result, the upper die is lowered onto the lower die, and the plate material is pressed. The position of the first slide portion 34 with respect to the frame 12 (dotted line L1 in FIG. 8) gradually increases as the descending speed with respect to the frame 12 reaches a maximum in the vicinity of the crank angle of 90 °, and then reaches a crank angle of 137 ° (FIG. 8). In the range up to point P1), the speed slightly decreases, that is, decelerates. The slight deceleration that occurs in this range (crank angle 90 ° to 137 °) causes work hardening in the upper part of the plate material that has been previously drawn, and cracks, deformations, and the like occur in this part. There is no inconvenience.

  Further, the second slide portion 36 is not yet lowered by the drive mechanism 42 in the range of the crank angle from 0 ° to 137 ° (see the range from the point Ps to the point P1 in FIG. 9). Therefore, in this range, the position of the second slide portion 36 with respect to the frame 12 is substantially the same as that on the dotted line L1, as indicated by the solid line L2 in FIG.

  The second slide portion position command unit 108 monitors the crank angle signal S1, and the crank angle is set to a position where the first slide portion 34 starts to decelerate (a position where the crank angle is approximately 90 °), A crank angle (137 in the illustrated example) corresponding to a first lowering start position (also referred to as a height position with respect to the frame 12) of the second slide part 36 set in advance between the slide part 34 and its bottom dead center. It is determined whether or not the point P1) is reached in FIGS. 8 and 9 (step ST003). Step ST003 is executed until the crank angle is reached. Also during this time, the upper mold presses the plate material placed on the lower mold, and the plate material is continuously pressed.

  Next, when the crank angle (crank angle 137 °, point P1 in FIGS. 8 and 9) is reached, the second slide portion 36 is moved from its raised position to its lowered position with respect to the first slide portion 34. At a first relative speed (see FIG. 9) (step ST004). In the example shown in FIG. 9, the first relative speed of the second slide portion 36 is an average speed that descends by 1 mm at a crank angle of 23 ° with respect to the first slide portion 34. Therefore, the second slide portion 36 only needs to be lowered by 1 mm with respect to the first slide portion 34 while the crankshaft 14 rotates by 23 °. For example, the first relative speed of the second slide portion 36 is: It may be constant or change.

  The descending speed of the first slide part 34 after the first descending start position of the second slide part 36 is greatly reduced (range of crank angle 137 ° to 180 °, point P1 to point P3 in FIG. 8). Range). However, since the second slide portion 36 is lowered (see the solid line L2 in the range from the point P1 with a crank angle of 137 ° to the point P2 with a crank angle of 160 ° in FIG. 9), the slide 16 and thus the upper frame 12 (see the solid line L2 in the range from the point P1 at a crank angle of 137 ° to the point P2 at a crank angle of 160 ° in FIG. 8). Therefore, even if the first slide part 34 is greatly decelerated with respect to the frame 12, the second slide part 36 is lowered with respect to the first slide part 34. There is no inconvenience that work hardening occurs and cracks, deformations, and the like occur at this location.

  The first relative speed includes a lowering speed with respect to the frame 12 when the first slide part 34 passes the first lowering start position (point P1 in FIGS. 8 and 9), and the first sliding part 34. The first descending speed of the second slide part 36 with respect to the frame 12 is the same between the time when the second slide part 36 reaches the lowered position until the second slide part 36 reaches the lowered position. It can be set as the speed with respect to the slide part 34. The raising / lowering speed of the 2nd slide part 36 is hardly decelerated (refer FIG. 8).

  The position of the second slide portion 36 relative to the frame 12 when the second slide portion 36 is lowered at the first relative speed and reaches the lowered position (crank angle 160 °, point P2 in FIGS. 8 and 9). ) Indicates the position of the second slide portion 36 relative to the frame 12 when the first slide portion 34 is located at the bottom dead center and the second slide portion 36 is at the raised position (points in FIGS. 8 and 9). Same as P3).

  Next, it is determined by the displacement voltage signal S2 'from the second slide portion position detector 106 whether or not the second slide portion 36 has reached its lowered position (step ST005). Step ST005 is repeated until the second slide part 36 reaches its lowered position. In the state of the mechanical press 10 when the crank angle is 160 ° (the state shown in FIG. 10), the second slide portion 36 is located at the lowered position (point P2 in FIGS. 8 and 9), and thereby The work of pressing (pressing) the plate placed on the lower mold against the upper mold is stopped. During this time, the first slide portion 34 continues to descend and has not reached its bottom dead center.

  Next, the second slide portion 36 is raised at the second relative speed (see the range from the point P2 having a crank angle of 160 ° to the point P3 having a crank angle of 180 ° in FIG. 9) (step ST006). In the illustrated example, the second slide portion 36 has an average speed that increases by 1 mm at a crank angle of 20 ° with respect to the first slide portion 34. Therefore, the second slide portion 36 only needs to rise 1 mm with respect to the first slide portion 34 while the crankshaft 14 rotates by 20 °. For example, the second relative speed of the second slide portion 36 is: It may be constant or change.

  The second relative speed is such that when the first slide part 34 reaches its bottom dead center (point P3 in FIG. 8), the second slide part 36 reaches the ascending position (point P3 in FIG. 9). The speed relative to the first slide portion 34, that is, the speed rising from the lowered position to the raised position in the crank angle range of 160 ° to 180 °. Since the second relative speed is a speed that is increased by 1 mm at a crank angle of 20 °, it is larger than the first relative speed. As a result, the position of the second slide portion 36 substantially maintains the position of the bottom dead center (the dotted line L2 in the range of the crank angle from 160 degrees to 180 degrees in FIG. 8).

  Next, it is determined whether or not the second slide portion 36 has reached its raised position (step ST007). Step ST007 is executed until the ascending position is reached. In the illustrated example, when the crank angle is 180 °, the second slide portion 36 reaches its raised position (see point P3 in FIGS. 8 and 9).

  Next, the rising of the second slide part 36 is stopped (step ST008). The crank angle at this time is 180 °, and in the state of the mechanical press 10 at this time, the first slide portion 34 is located at the bottom dead center (see the point P3 in FIG. 8), and the second slide portion. 36 is located at the raised position (see FIG. 1). The crankshaft 14 continues to rotate.

  Next, the first slide part 34 starts to rise (step ST009). At this time, it is determined whether or not the second slide portion 36 is lowered again (step ST010 in FIG. 6). When it is determined that the second slide part 36 is to be raised without being lowered, the first slide part 34 is raised to the top dead center together with the second slide part 36 that has stopped the lifting and lowering movement.

  When an off switch signal from a switch (not shown) is input to the controller 102, the controller 102 relatively disengages the clutch 26 and stops the first slide portion 34 at its top dead center. .

  As described above, when performing the drawing process, the mechanical press 10 lowers the second slide portion 36 under the operation of the drive mechanism 42, and thereby the plate material disposed on the lower die is moved. Apply pressure. As a result, the upper mold is lowered together with the second slide portion 36 at a predetermined speed, and drawing is performed.

  More specifically, after the first sliding portion 34 that is being lowered has started to decelerate, the first lowering start position that is set in advance before the first sliding portion 34 reaches its bottom dead center is the first descending start position. When the first slide portion 34 passes, the second slide portion 36 is lowered from its raised position to its lowered position with respect to the first slide portion 34 at a first relative speed. The lowering speed of the mold does not decelerate immediately before reaching the bottom dead center, and the occurrence of conventional cracks, deformations, etc. is avoided.

  The control method according to the present invention may further include a control for further lowering the second slide portion 36 in step ST010 of FIG. The control method will be described below with reference to FIGS.

  If it is determined in step ST010 that the second slide portion 36 is further lowered, the second slide portion 36 is positioned at the second descent start position (point P3 in FIGS. 11 and 12) in step ST011. Judgment is made. The second lowering start position refers to a frame 12 that is set in advance between the bottom dead center of the first slide part 34 that is being raised and the position at which the first slide part 34 starts to decelerate. The height position. At this time, since the first slide portion 34 exceeds the crank angle of 180 °, the first slide portion 34 has started to rise (see the range from the point P3 to the point Pe in FIG. 11).

  When the first slide portion 34 passes the second lowering start position (point P3 in FIGS. 11 and 12), the drive mechanism 42 lowers the second slide portion 36 at the third relative speed ( ST012). The third relative speed in the illustrated example can be set to be the same as the second relative speed. That is, the average speed is such that it is located at the ascending position (point P4 in FIGS. 11 and 12) when the crank angle is 200 °. Therefore, the second slide portion 36 only needs to be lowered by 1 mm with respect to the first slide portion 34 while the crankshaft 14 rotates by 20 °. For example, the third relative speed of the second slide portion 36 is: It may be constant or change.

  At this time, the first slide portion 34 is raised with respect to the frame 12, but the second slide portion 36 is lowered with respect to the first slide portion 34, and the second slide portion 36 has a frame. The position with respect to 12 hardly changes (see the range from point P3 to point P4 in FIG. 11).

  Next, it is determined whether the second slide portion 36 has reached its lowered position (step ST013). In step ST013, the second slide part 36 is lowered until the second slide part 36 reaches the lowered position (see the range from point P3 to point P4 in FIG. 12). At this time, the mechanical press 10 is again in the state shown in FIG.

  Next, when the second slide part 36 reaches its lowered position, the second slide part 36 is raised at the fourth relative speed (step ST014). The fourth relative speed in the illustrated example raises the second slide portion 36 at the first relative speed when the crank angle is 200 °. That is, when the crank angle is 223 °, the average speed is such that it is located at the ascending position (point P5 in FIGS. 11 and 12). Therefore, the second slide portion 36 only needs to rise 1 mm with respect to the first slide portion 34 while the crankshaft 14 rotates 23 °. For example, the fourth speed of the second slide portion 36 is constant. Or may change.

  Next, it is determined whether or not the second slide portion 36 has reached its raised position (step ST015). Step ST014 raises the 2nd slide part 36 until the 2nd slide part 36 arrives at a raise position (refer the range of the point P4 to the point P5 of FIG. 12).

  Next, when the 2nd slide part 36 arrives at a raise position, the raise of the 2nd slide part 36 is stopped (step ST016). In the example shown in the drawing, the second slide portion 36 stops rising when the crank angle is 223 ° (see point P5 in FIGS. 11 and 12).

  Next, the first slide portion 34 rises to its top dead center with the second slide portion 36 positioned at the raised position (see the range from point P5 to point Pe in FIGS. 11 and 12). When the crank angle reaches 360 °, the pressing operation is completed.

  The present invention is not limited to the above embodiments.

It is a schematic longitudinal cross-sectional view of the mechanical press controlled by the control apparatus which concerns on this invention. In the state shown in the drawing, the first slide portion is located at the bottom dead center. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. It is an expanded partial sectional view of the slide of the mechanical press shown in FIG. It is a block diagram of the control apparatus which concerns on this invention. It is a flowchart figure of the control apparatus shown in FIG. It is a flowchart figure following FIG. It is a schematic longitudinal cross-sectional view for demonstrating operation | movement of the mechanical press shown in FIG. In the state shown in the figure, the first slide portion is located at its top dead center. It is a graph which shows the raising / lowering motion of the 1st and 2nd slide part of the mechanical press shown in FIG. It is a graph which shows the raising / lowering motion of the 2nd slide part of the mechanical press shown in FIG. It is a schematic longitudinal cross-sectional view for demonstrating another operation | movement of the mechanical press shown in FIG. It is a graph which shows the raising / lowering motion of another 1st and 2nd slide part of the mechanical press shown in FIG. It is a graph which shows the raising / lowering motion of another 2nd slide part of the mechanical press shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Mechanical press 12 Frame 14 Crankshaft 16 Slide 18 Connection 22 Crankshaft eccentric part 34,36 1st slide part and 2nd slide part 40 Through-hole 42 Drive mechanism (hydraulic jack or screw jack)
48 Guide rod 50 Guide hole 68, 70 Guide bearing

Claims (12)

It is possible to move up and down between a frame, a crankshaft rotatably supported on the frame and having a plurality of eccentric parts, and a top dead center and a bottom dead center disposed below the crankshaft. The first slide part is a first slide part provided with a through-hole extending in the vertical direction, and can be moved up and down between an ascending position and a descending position arranged in the through-hole of the first slide part. A slide having a second slide part, and a plurality of connections for converting the rotational movement of the crankshaft into the lifting / lowering movement of the first slide part, the eccentric part of the crankshaft and the first slide part; A control method of a mechanical press comprising: a plurality of connections coupled to each other; and a drive mechanism that causes the second slide portion to move up and down and is attached to the first slide portion. I,
Lowering the first slide part,
The first slide portion has passed a first descent start position of the second slide portion that is set in advance between the position where the first slide portion that is descending starts to decelerate and the bottom dead center. Sometimes lowering the second slide part from the raised position to the lowered position at a first relative speed with respect to the first slide part;
Immediately after the second slide portion reaches the lowered position, the second slide portion is raised from the lowered position to the raised position at a second relative speed with respect to the first slide portion. , Control method of mechanical press. Furthermore, raising the first slide part,
A second descent start position of the second slide portion preset in the vicinity of the bottom dead center between the bottom dead center and the position at which the first slide portion starts to decelerate is set to the first slide. Lowering the second slide part from the raised position to the lowered position at a third relative speed with respect to the first slide part when the part passes through;
Immediately after the second slide portion reaches the lowered position, the second slide portion is raised from the lowered position to the raised position at a fourth relative speed with respect to the first slide portion. The control method according to claim 1.   The position of the second slide portion relative to the frame when the second slide portion is lowered at the first relative speed and positioned at the lowered position is determined by the first slide portion being at the bottom dead center. 3. The control method according to claim 1, wherein the position of the second slide portion is the same as the position of the second slide portion with respect to the frame when the second slide portion is located at the raised position.   The first relative speed is a descending speed with respect to the frame when the first slide portion passes the first descending start position, and the first slide portion is the first slide portion of the second slide portion. The second lower slide portion has an average lowering speed that is the same as the average lowering speed of the second slide portion with respect to the frame from when the first slide start position is passed to when the second slide portion reaches the lower position. The control method according to claim 1, wherein the control method is a speed for one slide portion.   The second relative speed is a speed with respect to the first slide part such that the second slide part reaches the raised position when the first slide part reaches the bottom dead center. Item 5. The control method according to any one of Items 1 to 4.   The control method according to any one of claims 1 to 5, wherein the third relative speed is the same magnitude as the second relative speed.   The control method according to any one of claims 1 to 6, wherein the fourth relative speed is the same magnitude as the first relative speed.   Further, prior to lowering the first slide portion, the first lowering start position of the second slide portion is determined in consideration of the rotation angle of the crankshaft corresponding to the operation delay of the drive mechanism. The control method according to any one of claims 1 to 7.   The control method according to claim 1, wherein the first relative speed has a magnitude smaller than the second relative speed.   The control method according to any one of claims 1 to 9, wherein the drive mechanism includes a hydraulic jack. A control device for a mechanical press according to claim 1,
An angle detector for detecting the rotation angle of the crankshaft;
A displacement detector for detecting a relative displacement of the second slide portion with respect to the first slide portion;
A controller of the drive mechanism,
The controller lowers the first slide part, and based on the crank angle signal detected by the angle detector, the position of the lowering first slide part to be decelerated and the bottom dead center When the first slide part passes through a first descent start position of the second slide part set in advance, the second slide part is moved from the raised position to the lowered position. The first slide portion is lowered from the lowered position to the raised position immediately after the second slide portion reaches the lowered position with respect to the slide portion at a first relative speed. A control device for a mechanical press that controls the drive mechanism so as to be raised at a second relative speed.   The controller further raises the first slide part, and based on the crank angle signal detected by the angle detector, the first slide part that is being raised becomes the bottom dead center and the first slide part. The second slide portion is moved to the raised position when the first slide portion passes through a second lowering start position of the second slide portion set in advance between the slide portion and the position at which the slide portion starts to decelerate. To the lowered position at a third relative speed with respect to the first slide portion, and immediately after the second slide portion reaches the lowered position, the second slide portion is moved from the lowered position to the lowered position. The control device according to claim 11, wherein the drive mechanism is controlled to be raised to a raised position at a fourth relative speed with respect to the first slide portion.

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