JP2008168353A - Collision deciding device and collision deciding system of die cushion mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely perform decision of collision in a short period of time, as regards a collision deciding device and a collision deciding system for deciding the collision between a slide and a die in a die cushion mechanism. <P>SOLUTION: This collision deciding device (110) which decides collision between the slide and the die cushion of the die cushion mechanism (20) generating force to the slide (24) of a press by taking a servomotor (18) as a drive source, and the device is provided with: a force detecting means (21) for detecting the force generated between the die cushion and the slide; and a comparing means (95) for comparing the detected value (Fd) of the force detected by the force detecting means and a prescribed threshold value (L1). The collision deciding device for deciding that the slide collides with the cushion is provided when the detected value of the force is larger than the threshold value. By comparing the differential values (Fd', Fd'') of the force detecting value, the detected value (Y1d) of a slide position or the command value (Y1c) of a slide position and other threshold values about them, collision decision can be performed. A collision deciding system in which a plurality of collision deciding procedures are implemented can be utilized. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a collision determination device and a collision determination system that determine whether a slide and a die cushion in a die cushion mechanism have collided with each other.

  In a press machine that performs press processing such as bending, drawing, and punching, a second die is attached to a movable side support member (generally referred to as a slide) that supports the first die used for press processing during the processing operation. It is known to equip a die cushion mechanism as an accessory device that applies a desired force (pressure) from the side of a supporting member (generally called a bolster) to be supported. A die cushion mechanism usually collides a movable element (generally referred to as a cushion pad) held at a predetermined pressure with a slide (or first mold) moving in a mold closing direction directly or indirectly, and then a mold. The cushion pad is configured to move with the slide while applying a force (pressure) to the slide until the mold is opened after closing (molding). During this time, for example, by pinching the peripheral region of the processed portion of the workpiece material between the cushion pad and the slide, generation of wrinkles of the workpiece material can be prevented.

  FIG. 15 is a functional block diagram of a conventional control device for a die cushion mechanism. The position control speed command value Vcx and the force control speed command value Vcf are generated based on the respective predetermined control methods in the position control unit 920 and the force control unit 940 of the control device 100. Next, the position control speed command value Vcx and the force control speed command value Vcf are supplied to the comparison calculation unit 950. The comparison calculation unit 950 compares the downward magnitude of the position control speed command value Vcx and the force control speed command value Vcf, that is, the speed magnitude in the direction in which the slide descends toward the cushion pad. . For example, when it is determined that the position control speed command value Vcx is larger, the position control unit 920 controls the die cushion, and when the force control speed command value Vcf is determined to be larger. The switching operation of the switching device 930 is performed so that the die cushion is controlled by the force control unit 940.

  By the way, the slide of the die cushion mechanism is initially waiting at its upper limit position. Since the position control speed command value Vcx is larger than the force control speed command value Vcf at the initial stage of the slide operation, the switch 930 causes the die cushion to be based on the force control speed command value Vcf from the position control unit 920. Descends. Such comparison processing in the comparison calculation unit 950 is repeatedly performed when the slide is lowered. When the force control speed command value Vcf becomes larger than the position control speed command value Vcx, it is determined that the slide has collided with the die cushion, and the switching operation from the position control unit 920 to the force control unit 940 is performed by the switch 930. Is done. As a result, the die cushion descends based on the force control speed command value Vcf of the force control unit 940, and an appropriate cushion pressure is generated.

  By the way, when the slide and the die cushion collide, the slide first comes into contact with the cushion pin, so that the slide and the cushion pad are integrally lowered. And if the force which acts on the damper of a cushion pad becomes large, a cushion pin will fall further and a bolster and a slide of a die cushion will collide via each model.

  For this reason, since it takes time to create the force control speed command value Vcf and the position control speed command value Vcx when the cushion pad is being lowered together with the slide, it is difficult to quickly determine the collision by comparing them. As a result, it may take a long time until the collision is determined after the actual collision occurs. Since such a collision determination delay leads to an increase in the amount of force overshoot, it is desired to perform the collision determination quickly.

  Furthermore, if the collision determination is wrong, the die cushion mechanism may be in a state where it cannot be pressed, so it is necessary to reliably determine the collision between the slide and the cushion pad.

  The present invention has been made in view of such circumstances, and provides a collision determination device and a collision determination system for a die cushion mechanism capable of reliably performing a collision determination between a slide and a cushion pad in a short time. With the goal.

  In order to achieve the above-described object, according to a first aspect of the present invention, there is provided a collision for determining a collision between the slide and the die cushion in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a driving source. A determination device, comprising: force detection means for detecting a force generated between the die cushion and the slide; and comparison means for comparing the force detection value detected by the force detection means with a predetermined threshold value. A collision determination device is provided that determines that the slide and the die cushion have collided when the force detection value exceeds the threshold value.

  According to a second aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source, A force detection means for detecting a force generated between a cushion and the slide; a force detection value detected by the force detection means; and a pre-operation force detection detected by the force detection means before the die cushion operates. Comparing means for comparing values is provided, and a collision determination device is provided that determines that the slide and the die cushion have collided when the force detection value exceeds the pre-operation force detection value.

  According to a third aspect of the present invention, there is provided a collision determination device that determines whether the slide and the die cushion collide in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source, Force detecting means for detecting a force generated between a cushion and the slide, and a comparing means for comparing a first-order differential value of the force detection value detected by the force detecting means with a predetermined threshold value, A collision determination device that determines that the slide and the die cushion have collided when the first-order differential value exceeds the threshold value is provided.

  According to a fourth aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. Force detecting means for detecting a force generated between a cushion and the slide, and a comparing means for comparing a second-order differential value of the force detection value detected by the force detecting means with a predetermined threshold, A collision determination device that determines that the slide and the die cushion have collided when a second-order differential value exceeds the threshold value is provided.

  According to a fifth aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. Force command means for commanding force generated between the cushion and the slide, force detection means for detecting force generated between the die cushion and the slide, and force detection detected by the force detection means Comparing means for comparing a value with a force command value commanded by the force command means, and determining that the slide and the die cushion collide when the force detection value exceeds the force command value A collision determination device is provided.

  That is, in the first invention, only the force detection value is detected and the collision is determined by comparison with a predetermined threshold value. In the second invention, only the force detection value is detected and the pre-operation force detection value is detected in advance. In the third aspect of the invention, only the force detection value is detected and subjected to first-order differentiation, and then the collision is determined by comparison with a predetermined threshold value. In the fourth aspect of the invention, Detects only the force detection value and second-order differentiates it to determine the collision by comparing with a predetermined threshold. In the fifth aspect of the invention, only the force detection value is detected and compared with the force command value. The collision is judged by. Therefore, in the first to fifth inventions, it is not necessary to use the force control speed command value and the position control speed command value when the collision is determined, and the collision can be determined in a short time.

  According to a sixth aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. A speed detecting means for detecting a speed of the cushion; and a comparing means for comparing a speed detection value detected by the speed detecting means with a predetermined threshold value, and the slide is detected when the speed detection value exceeds the threshold value. There is provided a collision determination device that determines that the die cushion has collided.

  According to a seventh aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. A speed detecting means for detecting the speed of the cushion; and a comparing means for comparing a first differential value of the speed detection value detected by the speed detecting means with a predetermined threshold value, wherein the first differential value is the threshold value. A collision determination device that determines that the slide and the die cushion have collided when exceeded is provided.

  According to an eighth aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. Acceleration detecting means for detecting the acceleration of the cushion, and comparison means for comparing the acceleration detection value detected by the acceleration detection means with a predetermined threshold, and the slide when the acceleration detection value exceeds the threshold There is provided a collision determination device that determines that the die cushion has collided.

  That is, in the sixth invention, only the speed detection value is detected and the collision is determined by comparison with a predetermined threshold value. In the seventh invention, only the speed detection value is detected and first-order differentiated. The collision is determined by comparison with a predetermined threshold. In the eighth aspect, only the acceleration detection value is detected, and the collision is determined by comparison with the predetermined threshold. Therefore, in the sixth to eighth inventions, it is not necessary to use the force control speed command value and the position control speed command value when determining the collision, and it is possible to determine the collision in a short time.

  According to a ninth aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. A slide position detection means for detecting the position of the slide position and a comparison means for comparing the slide position detection value detected by the slide position detection means with a predetermined threshold value, and when the slide position detection value falls below the threshold value A collision determination device for determining that the slide and the die cushion have collided is provided.

  According to a tenth aspect of the invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force with respect to a slide of a press machine using a servo motor as a drive source. When the slide position command value falls below the threshold value, the slide position command means for commanding the position of the slide position command means and a comparison means for comparing the slide position command value commanded by the slide position command means with a predetermined threshold value are provided. A collision determination device for determining that the slide and the die cushion have collided is provided.

  According to an eleventh aspect of the invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. A distance detecting means for detecting a distance between a cushion and the slide; and a comparing means for comparing the distance detected by the distance detecting means with a predetermined threshold value, when the distance falls below the threshold value. A collision determination device for determining that the slide and the die cushion have collided is provided.

  According to a twelfth aspect of the present invention, there is provided a collision determination device that determines whether the slide and the die cushion collide in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. Slide position detecting means for detecting the position of the die cushion, die cushion position detecting means for detecting the position of the die cushion, a slide position detection value detected by the slide position detecting means, and the die cushion position detecting means A collision judging device comprising: a comparing means for comparing the die cushion position detection value; and determining that the slide and the die cushion have collided when the slide position detection value falls below the die cushion position detection value. Provided.

  According to a thirteenth aspect of the present invention, there is provided a collision determination device for determining whether the slide and the die cushion collide in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. Slide position detecting means for detecting the position of the die cushion, die cushion position detecting means for detecting the position of the die cushion, a slide position detection value detected by the slide position detecting means, and the die cushion position detecting means A collision judging device comprising: a comparing means for comparing a die cushion position detection value; and determining that the slide and the die cushion collide when the slide position detection value and the die cushion position detection value coincide with each other. Is provided.

  According to a fourteenth aspect of the invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates a force against a slide of a press machine using a servo motor as a drive source. A slide position command means for commanding the position of the die cushion, a command position command means for commanding the position of the die cushion, a slide position command value commanded by the slide position command means, and a command commanded by the die cushion position command means A collision judging device comprising: a comparing means for comparing a die cushion position command value; and determining that the slide and the die cushion have collided when the slide position command value falls below the die cushion position command value. Provided.

  According to a fifteenth aspect of the invention, there is provided a collision determination device for determining whether the slide and the die cushion collide with each other in a die cushion mechanism that generates force against a slide of a press machine using a servo motor as a drive source. A slide position command means for commanding the position of the die cushion, a command position command means for commanding the position of the die cushion, a slide position command value commanded by the slide position command means, and a command commanded by the die cushion position command means A comparison unit that compares a die cushion position command value with a comparison unit, and determines that the slide and the die cushion have collided when the slide position command value and the die cushion position command value match. Is provided.

  That is, in the ninth invention, only the slide position detection value is detected and the collision is determined by comparison with a predetermined threshold value. In the tenth invention, only the slide position command value is used and compared with the predetermined threshold value. In the eleventh aspect of the invention, only the distance between the slide and the die cushion is detected and the collision is determined by comparison with a predetermined threshold. In the twelfth and thirteenth aspects, the slide position is determined. Only the detection value and the die cushion position detection value are detected and the collision is determined by comparing them. Furthermore, in the fourteenth and fifteenth inventions, only the slide position command value and the die cushion position command value are used for comparison. The collision is judged by. Therefore, in the ninth to fifteenth inventions, it is not necessary to use the force control speed command value and the position control speed command value when determining the collision, and it is possible to determine the collision in a short time.

  According to a sixteenth aspect of the present invention, the apparatus includes at least one collision determination device among the first to fifteenth collision determination devices, and at least one other collision determination device among the first to fifteenth, A collision determination system that determines that the slide and the die cushion have collided when at least one collision determination device and the at least one other collision determination device determine a collision is provided.

  That is, in the sixteenth aspect, since two different collision determination devices are used, collision determination can be performed reliably without causing erroneous determination.

  According to the seventeenth invention, one of the first to fifteenth collision determination devices, one of the first to fifteenth collision determination devices, and the position of the slide And a switching unit that switches between a position control unit that controls the slide and a force control unit that controls the slide according to a force acting on the slide, and the one collision determination device determines a collision and the switching unit. After the switching operation for switching from the position control unit to the force control unit, if the other collision determination device does not determine a collision, it is determined that the slide and the die cushion do not collide. Thus, a collision determination system is provided in which the switching means switches from the force control unit to the position control unit.

  That is, in the seventeenth invention, when one collision determination device determines a collision, the switching operation is switched from position control to force control, so that the switching operation can be performed more quickly than in the sixteenth invention. Further, when another collision determination device does not determine a collision after switching, it is possible to prevent erroneous determination by returning from force control to pressure control.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following drawings, the same members are denoted by the same reference numerals. In order to facilitate understanding, the scales of these drawings are appropriately changed.
FIG. 1A and FIG. 1B are schematic views showing a basic configuration of a die cushion mechanism 20 of a press machine provided with a control device 10 according to the present invention, and show an open state and a closed state of the press machine, respectively. ing. As shown in these drawings, two support portions 12 extend in the vertical direction from the base 11, and flat plate bolsters 15 are disposed at the tips of the support portions 12 via dampers 13, respectively. As shown in these drawings, a die cushion mechanism 20 is provided below the bolster 15.

  The die cushion mechanism 20 according to the present invention includes an elastic element 30 that expands and contracts in a direction perpendicular to the lower surface of the bolster 15, a cushion pad 16 that is incorporated in a press machine and moves according to the operation of the slide 24, and a cushion And a servo motor 18 for raising and lowering the pad 16. In the present invention, the elastic element 30 is not necessarily required. However, in the following description, it is assumed that the elastic element 30 is present. As illustrated, the bottom surface of the elastic element 30 is held by the cushion pad 16. Here, the elastic element 30 can employ an elastic body such as rubber, a spring, an oil chamber, or the like. The plurality of cushion pins 31 extending from the top surface of the elastic element 30 protrude from the bolster 15 through the hole of the bolster 15. The workpiece material 35 is supported at the tip of the cushion pin 31.

  The slide 24 supports a first die 26 used for press working. Then, the slide 24 moves toward or away from the second die 27 supported by the bolster 15 at a speed V required for pressing. The slide 24 may be moved by a servo motor different from the servo motor 18.

  The cushion pad 16 is disposed in association with the second mold 27 and is connected to the output shaft of the servo motor 18 via the ball screw device 17. The slide 24 (or the first mold 26) directly or indirectly collides with the cushion pad 16 waiting at a predetermined position while moving in the mold closing direction. Normally, the cushion pad 16 is configured to move together with the slide 24 while applying a required force (pressure) F to the slide 24 until the mold is opened after the mold is closed (molded). In the present specification, the cushion pad 16 and members related thereto are appropriately referred to as a die cushion.

  Such an operation is performed by the control device 10 of the press machine according to the present invention. The specific operation of the press machine will be described with reference to FIGS. 1 (a) and 1 (b). During the operation of the press machine, the slide 24 descends and the first die 26 presses the plurality of cushion pins 31 through the workpiece material 35. Thereby, the elastic element 30 is compressed in the vertical direction, and the cushion pad 16 is pushed downward. In response to the lowering operation of the cushion pad 16, the servo motor 18 rotates so as to lower the bolster 15 similarly. When the force (pressure) acting on the elastic element 30 is increased, the cushion pin 31 is further lowered, and the workpiece 35 is gripped between the first die 26 of the slide 24 and the second die 27 of the bolster 15 and pressed. Processed. At this time, the bolster 15 is slightly lowered by the slide 24. Next, when the slide 24 reaches its bottom dead center, the slide 24 starts to rise, the other members return to their initial positions, and the press work is finished.

  As described above, the control device 10 controls the servo motor 18 to generate a relative pressure (ie, force F) between the cushion pad 16 and the slide 24. As can be seen from FIGS. 1A and 1B, the force detection unit 21 that detects this pressure (that is, the force F) is connected to the control device 10. Similarly, a speed detector 22 that detects the rotational speed of the servo motor 18 as the speed of the die cushion is also connected to the control device 10. As shown in FIGS. 1A and 1B, the position detection unit 25 is disposed adjacent to the support unit 12, and the position detection unit 25 is also connected to the control device 10. The position detector 25 can detect the vertical position of the die cushion mechanism 20, particularly the vertical position of the cushion pad 16, and can also detect the vertical position of the slide 24. That is, the position detection unit 25 can serve as a die cushion position detection unit and a slide position detection unit. Further, the position detection unit 25 can also detect the distance between the slide 24 and the die cushion. The force detector 21 can employ a known force sensor, the speed detector 22 can employ a known encoder, and the position detector 25 can employ a known linear scale. In an embodiment not shown, a dedicated position detector (not shown) for detecting the vertical position of the die cushion mechanism and a dedicated position detector (not shown) for detecting the vertical position of the slide 24 are separately provided. You may make it provide. Although not shown in the drawings, the control device 10 of the present invention also includes a position control unit 920 and a switch 930 similar to those of the prior art (see FIG. 15).

  FIG. 2 is a functional block diagram showing the control device for the die cushion mechanism according to the first embodiment of the present invention. As shown in FIG. 2, the control device 10 according to the first embodiment includes a force command unit 51 that is included in the force control unit 940 and commands the force Fc generated in the die cushion mechanism 20, and the die cushion mechanism. 20 includes a force detection unit 21 that detects a force Fd generated at 20, and a first differentiation circuit 23 a and a second differentiation circuit 23 b connected to the force detection unit 21. Further, the control device 10 includes the force command value Fc commanded by the force command unit 51 of the force control unit 940, the force detection value Fd detected by the force detection unit 21, and the force detection value first-order differentiated by the first differentiation circuit 23a. Fd first-order differential force detection value Fd ′ The second-order differential force detection value Fd ″ of the force detection value Fd subjected to second-order differentiation by the first differentiation circuit 23a and the second differentiation circuit 23b is set to the respective threshold value or the pre-operation force described later. A comparison operation unit 95 for comparing with the detected value Fd0 is provided.

  As described above, the die cushion initially operates under the control of the position control unit 920. When the collision between the slide 24 and the die cushion is determined, the collision determination signal is supplied to the switch 930, whereby the die cushion is transferred from the control of the position control unit 920 to the force control unit 940. It becomes possible to switch to the control.

  Hereinafter, the collision determination between the slide 24 and the die cushion by the control device 10 of the die cushion mechanism 20 according to the first embodiment of the present invention will be described with reference to FIGS. It is assumed that the collision determination programs (methods) 110 to 230 and the programs 240 and 250 in the flowchart shown in the drawing are stored in advance in a storage unit (not shown) of the control device 10. These collision determination programs 110 to 230 are repeatedly executed during the operation of the die cushion mechanism 20.

  In the collision determination program 110 shown in FIG. 3A, after the force detection value Fd is fetched from the force detection unit 21 (step 111), the comparison calculation unit 95 compares the force detection value Fd with the threshold L1 (step 111). Step 113). It is assumed that the threshold value L1 and other threshold values to be described later are obtained in advance by experiments or the like and stored in the storage unit of the control device 10. Next, when the force detection value Fd is larger than the threshold value L1, it is determined that the slide 24 and the die cushion have collided (step 114). When the force detection value Fd is not larger than the threshold value L1, there is no collision. (Step 115).

  In the collision determination program 120 shown in FIG. 3B, first, the preload value Fd0 is fetched from the force detector 21 (step 121). The preload value Fd0 is a pressure detection value of the force detection unit 21 when the slide 24 and the die cushion do not collide, specifically, before the cushion pin 31 contacts the slide 24. Then, after taking in the force detection value Fd from the force detection unit 21 (step 122), the comparison calculation unit 95 compares the force detection value Fd with the preload value Fd0 (step 123). Next, if the force detection value Fd is greater than the preload value Fd0, it is determined that the slide 24 and the die cushion have collided (step 124), and if the force detection value Fd is not greater than the preload value Fd0, they collide. It is determined that it is not present (step 125).

  Further, in the collision determination program 130 shown in FIG. 4A, after the force detection value Fd is fetched from the force detection unit 21 (step 131), the first differentiation circuit 23a performs first-order differentiation of the force detection value Fd. . The first-order differential force detection value Fd ′ thus obtained is supplied to the comparison operation unit 95, and the comparison operation unit 95 compares the first-order differential force detection value Fd ′ with the threshold value L2 (step 133). Next, when the first-order differential force detection value Fd ′ is greater than the threshold value L2, it is determined that the slide 24 and the die cushion have collided (step 134), and the first-order differential force detection value Fd ′ is greater than the threshold value L2. If not, it is determined that there is no collision (step 135).

  Similarly, in the collision determination program 140 shown in FIG. 4B, after the force detection value Fd is fetched from the force detection unit 21 (step 141), force detection is performed by the first differentiation circuit 23a and the second differentiation circuit 23b. The value Fd is second-order differentiated. The second-order differential force detection value Fd ″ obtained in this way is supplied to the comparison operation unit 95, and the comparison operation unit 95 compares the second-order differential force detection value Fd ″ with the threshold value L3 (step 143). Next, when the second-order differential force detection value Fd ″ is larger than the threshold value L3, it is determined that the slide 24 and the die cushion have collided (step 144), and the second-order differential force detection value Fd ″ is larger than the threshold value L3. If not, it is determined that there is no collision (step 145).

  In the collision determination program 150 shown in FIG. 5, first, the force command value Fc is fetched from the force command unit 51 (step 151). Then, after taking in the force detection value Fd from the force detection unit 21 (step 152), the comparison calculation unit 95 compares the force detection value Fd with the force command value Fc (step 153). Next, when the force detection value Fd is larger than the force command value Fc, it is determined that the slide 24 and the die cushion have collided (step 154), and when the force detection value Fd is not larger than the force command value Fc. It is determined that there is no collision (step 155).

  When the collision is determined in the methods 110 to 150 of the first embodiment, the switch 930 switches the die cushion from the control of the position control unit 920 to the control of the force control unit 940, and as a result, an appropriate cushion is selected. Pressure is generated.

  Thus, in the first embodiment of the present invention, the position control speed command value Vcx and the force control speed command value Vcf are not compared as in the prior art. As described above, when the cushion pad is lowered, the collision determination based on the comparison between the force control speed command value Vcf and the position control speed command value Vcx may be difficult, and the collision determination may be delayed. Since the control speed command value Vcf and the position control speed command value Vcx are not used, the collision can be determined in a short time. As a result, in the first embodiment, an increase in the amount of force overshoot based on the collision determination delay is also prevented.

  FIG. 6 is a functional block diagram showing a control device for a die cushion mechanism based on the second embodiment of the present invention. As shown in FIG. 6, the control device 10 according to the second embodiment includes a speed detection unit 22 that detects the speed of the die cushion, a third differentiation circuit 23 c connected to the speed detection unit 22, and a die cushion. And an acceleration detector 29 (not shown in FIG. 1) for detecting the acceleration of the motor. Further, the control device 10 includes a die cushion speed detection value Vd detected by the speed detection unit 22, a first-order differential speed detection value Vd ′ obtained by first-order differentiation by the third differentiation circuit 23c, and an acceleration detection unit. A comparison calculation unit 95 is provided for comparing the detected acceleration value Ad of the cushion cushion 29 with each threshold value.

  In the collision determination program 160 of the second embodiment shown in FIG. 7A, after the die cushion speed detection value Vd is fetched from the die cushion speed detection unit 22 (step 161), the comparison calculation unit 95 The die cushion speed detection value Vd is compared with the threshold value L3 (step 163). Next, if the die cushion speed detection value Vd is greater than the threshold value L3, it is determined that the slide 24 and the die cushion have collided (step 164), and the die cushion speed detection value Vd is not greater than the threshold value L3. Is determined not to collide (step 165).

  In the collision determination program 170 of the second embodiment shown in FIG. 7B, after the die cushion speed detection value Vd is fetched from the die cushion speed detection unit 22 (step 171), the third differentiation is performed. The speed detection value Vd is first-order differentiated by the circuit 23c. The first-order differential speed detection value Vd 'obtained in this way is supplied to the comparison operation unit 95, and the comparison operation unit 95 compares the first-order differential speed detection value Vd' with the threshold value L4 (step 173). Next, when the first-order differential speed detection value Vd ′ is larger than the threshold value L4, it is determined that the slide 24 and the die cushion have collided (step 174), and the first-order differential speed detection value Vd ′ is larger than the threshold value L4. If not, it is determined that there is no collision (step 175).

  Further, in the collision determination program 180 of the second embodiment shown in FIG. 8, after the acceleration detection value Ad of the die cushion is taken from the acceleration detection unit 29 of the die cushion (step 181), the comparison calculation unit 95 The acceleration detection value Ad of the cushion is compared with the threshold value L5 (step 183). Next, when the acceleration detection value Ad of the die cushion is larger than the threshold value L5, it is determined that the slide 24 collides with the die cushion (step 184), and the acceleration detection value Ad of the die cushion is not larger than the threshold value L5. Is determined not to collide (step 185).

  Similarly to the case of the first embodiment, when a collision is determined in the methods 160 to 180 of the second embodiment, the switch 930 causes the die cushion to change from the control of the position control unit 920 to the force control unit 940. As a result, an appropriate cushion pressure is generated.

  As described above, the second embodiment of the present invention does not compare the position control speed command value Vcx and the force control speed command value Vcf as in the prior art. That is, in the second embodiment, since the force control speed command value Vcf and the position control speed command value Vcx are not used, the collision can be determined in a short time, and the force overshoot amount based on the delay of the collision determination Is also prevented from increasing.

  FIG. 9 is a functional block diagram showing a control device for a die cushion mechanism according to the third embodiment of the present invention. As shown in FIG. 9, the control device 10 according to the third embodiment includes a slide position detection unit 25 that detects the position of the slide 24, a slide position command unit 61 that commands the position of the slide 24, and a die cushion. A die cushion position detecting unit 25 for detecting the position of the die cushion, a die cushion position commanding unit 62 for commanding the position of the die cushion, and a distance detecting unit 25 for detecting the distance between the slide 24 and the die cushion. Is done. Note that, as described above, the position detection unit 25 also serves as a die cushion position detection unit, a slide position detection unit, and a distance detection unit.

  Further, the control device 10 detects the slide position detection value Y1d detected by the slide position detection unit 25, the slide position command value Y1c commanded by the slide position command unit 61, and the die cushion position detection value detected by the die cushion position detection unit 25. Y2d, a die cushion position command value Y2c commanded by the die cushion position command unit 62, a distance detection value Dd between the slide and the die cushion detected by the distance detection unit 25, and a comparison calculation unit 95 that compares the respective threshold values. I have.

  In the collision determination program 190 of the third embodiment shown in FIG. 10A, after the slide position detection value Y1d is taken from the slide position detection unit 25 (step 191), the comparison calculation unit 95 performs the slide position detection value. Y1d is compared with threshold value L6 (step 193). Next, when the slide position detection value Y1d is smaller than the threshold value L6, it is determined that the slide 24 and the die cushion have collided (step 194), and when the slide position detection value Y1d is not smaller than the threshold value L6, they collide. It is determined that it is not present (step 195).

  In the collision determination program 200 of the third embodiment shown in FIG. 10B, after the slide position command value Y1c is fetched from the slide position command unit 61 (step 201), the slide position command value Y1c is read by the comparison calculation unit 95. The command value Y1c is compared with the threshold value L7 (step 203). Next, when the slide position command value Y1c is smaller than the threshold value L7, it is determined that the slide 24 and the die cushion have collided (step 204). When the slide position command value Y1c is not smaller than the threshold value L7, the collision occurs. It is determined that it is not present (step 205).

  Furthermore, in the collision determination program 210 of the third embodiment shown in FIG. 11A, the slide position detection value Y1d is first taken from the slide position detection unit 25 (step 211). Then, after fetching the die cushion position detection value Y2d from the die cushion position detection unit 25 (step 212), the comparison calculation unit 95 compares the slide position detection value Y1d with the die cushion position detection value Y2d (step 213). Next, when the slide position detection value Y1d is equal to or less than the die cushion position detection value Y2d, it is determined that the slide 24 collides with the die cushion (step 214), and the slide position detection value Y1d is equal to or less than the die cushion position detection value Y2d. If not, it is determined that there is no collision (step 215).

  In step 213 of the collision determination program 210 shown in FIG. 11A, the collision determination is made when the slide position detection value Y1d matches the die cushion position detection value Y2d (Y1d = Y2d). Good. However, since the force acting between the slide 24 and the die cushion is relatively large, the distance between the detection position of the slide 24 and the detection position of the die cushion contracts at the time of a collision, and instantly “the slide position detection value Y1d”. <Die cushion position detection value Y2d ”. In such a case, since it may be impossible to determine if the collision is determined by “Y1d = Y2d”, the collision is determined by “Y1d ≦ Y2d” as shown in step 213 of FIG. 11A. Is preferred.

  Further, in the collision determination program 220 of the third embodiment shown in FIG. 11B, first, the slide position command value Y1c is taken from the slide position command unit 61 (step 221). Then, after fetching the die cushion position command value Y2c from the die cushion position command unit 62 (step 222), the comparison calculation unit 95 compares the slide position command value Y1c with the die cushion position command value Y2c (step 223). Next, when the slide position command value Y1c is equal to or less than the die cushion position command value Y2c, it is determined that the slide 24 collides with the die cushion (step 224), and the slide position command value Y1c is equal to or less than the die cushion position command value Y2c. If not, it is determined that there is no collision (step 225).

  Similarly, in step 223 of the collision determination program 220 shown in FIG. 11B, when the slide position command value Y1c matches the die cushion position command value Y2c (Y1c = Y2c), the collision determination may be performed. Good. However, since the command values Y1c and Y2c created from the slide position command unit 61 and the die cushion position command unit 62 of the control device 10 are changed by an equal multiple of the respective resolutions, the collision is caused by “Y1c = Y2c”. If judged, it may be impossible to judge. For this reason, it is preferable to make a collision determination by “Y1c ≦ Y2c” as shown in step 223 of FIG.

  Furthermore, in the collision determination program 230 of the third embodiment shown in FIG. 12, after the distance Dd is captured from the distance detection unit 25 that detects the distance Dd between the slide and the die cushion (step 231), the comparison is performed. The calculation unit 95 compares the distance Dd between the slide and the die cushion with the threshold value L8 (step 233). Next, when the distance Dd between the slide and the die cushion is smaller than the threshold value L8, it is determined that the slide 24 and the die cushion have collided (step 234), and the distance Dd between the slide and the die cushion is the threshold value. If it is not smaller than L8, it is determined that there is no collision (step 235).

  Similar to the above-described embodiment, when the collision is determined in the methods 190 to 230 of the third embodiment, the switch 930 causes the die cushion to be controlled from the control of the position control unit 920 to the force control unit 940. As a result, an appropriate cushion pressure is generated.

  Thus, even in the third embodiment of the present invention, the position control speed command value Vcx and the force control speed command value Vcf are not compared as in the prior art. That is, in the third embodiment, since the force control speed command value Vcf and the position control speed command value Vcx are not used, the collision can be determined in a short time, and the force overshoot amount based on the delay of the collision determination Is also prevented from increasing.

  By the way, since the collision determination programs (methods) 110 to 230 in the first to third embodiments are shorter than the determination methods of the prior art, some of the collision determination programs (methods) 110 to 230 are performed. It may be. FIG. 13 is a program flowchart showing the operation of the collision determination system according to the present invention. In the program 240 shown in FIG. 13, first, any one of the collision determination programs (methods) 110 to 230 is executed (step 241). When it is determined that there is a collision determination, another method of the collision determination programs (methods) 110 to 230 is executed (step 242). If it is determined that there is a collision determination by another method, the process proceeds to step 244 to perform a collision determination in the collision determination system of the program 240. On the other hand, if it is determined in step 241 that there is a collision determination, but no collision determination is made in step 242, there is a high possibility of erroneous determination, so the collision determination system of the program 240 does not make a collision determination (step 245).

  As described above, in the collision determination system shown in FIG. 13, when at least two of the above-described collision determination programs (methods) 110 to 230 are executed and a collision is determined by both the collision determination programs, the collision is determined. A collision determination is made in the determination system. For this reason, in the case of the collision determination system shown in FIG. 13, the reliability of the collision determination result is higher than when the above-described collision determination programs (methods) 110 to 230 are executed alone, and the press is performed based on the erroneous determination. It becomes possible to avoid the state where processing becomes impossible as much as possible.

  FIG. 14 is another flowchart showing the operation of the collision determination system according to the present invention. Also in the program 250 shown in FIG. 14, first, any one of the collision determination programs (methods) 110 to 230 in the first to third embodiments is executed (step 251). Thus, when it is determined that there is a collision determination, the switch 930 switches from the position control unit 920 to the force control unit 940 (step 254). For this reason, the switching operation by the switch 930 is performed more quickly than in the case of the collision determination system shown in FIG.

  Next, simultaneously with the switching operation by the switching device 930, a timer is started and the elapsed time T from the switching operation is recorded (step 255). It is assumed that a timer (not shown) is incorporated in the control device 10.

  After starting the timer, another method of the collision determination programs (methods) 110 to 230 is executed in step 256. If it is determined that there is a collision determination in another method, the collision determination is performed in the collision determination system shown in FIG. 14 (step 260). In this case, since it can be determined in step 254 that the switching operation by the switch 930 has already been appropriate, the process is terminated without performing an additional operation of the switch 930.

  On the other hand, if no collision is determined in step 256, the elapsed time T is referred to (step 257), and it is determined whether or not the elapsed time T is smaller than a predetermined value T0 (step 258). The elapsed time T is the time from the end of the collision determination method in step 251 to the end of the collision determination method in step 256. When the elapsed time T is smaller than the predetermined time T0, it can be determined that the determination in step 256 is performed within the predetermined time T0 from step 251. Therefore, it is determined that the collision determination in step 256 is appropriate and the collision determination in step 251 is an erroneous determination, and the collision determination is performed in the collision determination system shown in FIG. 14 (step 259). In this case, since the switching operation of the switching unit 930 in step 254 is unnecessary, switching is performed so that the force control unit 940 returns to the position control unit 920 in step 261. Such a configuration can prevent erroneous determination.

  If the elapsed time T is not smaller than the predetermined value T0 in step 258, the collision determination method in step 256 has not been performed within the predetermined time, so the collision determination result in step 256 is not adopted, and step 260 is performed. Proceed and finish the process. If no collision is determined in step 251, the process proceeds to step 253, and the process is terminated without performing the switching operation of the switch 930.

  In the collision determination system described with reference to FIGS. 13 and 14, two of the collision determination programs (methods) 110 to 230 are executed. However, these collision determination systems may employ a larger number of collision determination programs 110 to 230, thereby further improving the reliability of the collision determination result.

(A) It is a schematic diagram which shows the basic composition of the die cushion mechanism of the press machine provided with the control apparatus based on this invention, and has shown the open state of the press machine. (B) It is a schematic diagram which shows the basic composition of the die cushion mechanism of the press machine provided with the control apparatus based on this invention, and has shown the closed state of the press machine. It is a functional block diagram which shows the control apparatus of the die cushion mechanism based on 1st embodiment of this invention. (A) It is a flowchart which shows the collision determination operation | movement of the control apparatus in 1st embodiment of this invention. (B) It is another flowchart which shows the collision determination operation | movement of the control apparatus in 1st embodiment of this invention. (A) It is another flowchart which shows the collision determination operation | movement of the control apparatus in 1st embodiment of this invention. (B) It is another flowchart which shows the collision determination operation | movement of the control apparatus in 1st embodiment of this invention. It is another flowchart which shows the collision determination operation | movement of the control apparatus in 1st embodiment of this invention. It is a functional block diagram which shows the control apparatus of the die cushion mechanism based on 2nd embodiment of this invention. (A) It is a flowchart which shows the collision determination operation | movement of the control apparatus in 2nd embodiment of this invention. (B) It is another flowchart which shows the collision determination operation | movement of the control apparatus in 2nd embodiment of this invention. It is another flowchart which shows the collision determination operation | movement of the control apparatus in 1st embodiment of this invention. It is a functional block diagram which shows the control apparatus of the die cushion mechanism based on 3rd embodiment of this invention. (A) It is a flowchart which shows the collision determination operation | movement of the control apparatus in 3rd embodiment of this invention. (B) It is another flowchart which shows the collision determination operation | movement of the control apparatus in 3rd embodiment of this invention. (A) It is another flowchart which shows the collision determination operation | movement of the control apparatus in 3rd embodiment of this invention. (B) It is another flowchart which shows the collision determination operation | movement of the control apparatus in 3rd embodiment of this invention. It is another flowchart which shows the collision determination operation | movement of the control apparatus in 3rd embodiment of this invention. It is a flowchart which shows operation | movement of the collision determination system based on this invention. It is another flowchart which shows operation | movement of the collision determination system based on this invention. It is a functional block diagram which shows the control apparatus of the die cushion mechanism in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Control apparatus 15 Bolster 16 Cushion pad 18 Servo motor 20 Die cushion mechanism 21 Force detection part 22 Speed detection part 23a-23c Differentiation circuit 24 Slide 25 Slide position detection part, Die cushion position detection part, Distance detection part 29 Acceleration detection part 30 Elastic element 31 Cushion pin 35 Work material 51 Force command unit 61 Slide position command unit 62 Die cushion position command unit 95 Comparison operation unit 110 to 230 Collision determination program (method)
240, 250 program 920 position control unit 930 switch 940 force control unit Ad acceleration detection value Dd distance detection value Fc force command value Fd force detection value Fd 'first-order differential force detection value Fd''second-order differential force detection value Fd0 before operation Force detection value (preload value)
L1 to L8 Threshold value T Elapsed time T0 Predetermined time Vd Speed detection value Vd 'First-order differential speed detection value Y1c Slide position command value Y1d Slide position detection value Y2c Die cushion position command value Y2d Die cushion position detection value

Claims (3)

A collision determination device that determines whether the slide and the die cushion collide in a die cushion mechanism that generates force against a slide of a press machine using a servo motor as a drive source,
Force command means for commanding a force generated between the die cushion and the slide;
Force detecting means for detecting a force generated between the die cushion and the slide;
First comparison means for comparing the force detection value detected by the force detection means with the force command value commanded by the force command means;
Slide position detecting means for detecting the position of the slide;
A second comparison means for comparing the slide position detection value detected by the slide position detection means with a predetermined first threshold;
A collision determination device that determines that the slide and the die cushion have collided when the force detection value exceeds the force command value and the slide position detection value falls below the first threshold. A collision determination device that determines whether the slide and the die cushion collide in a die cushion mechanism that generates force against a slide of a press machine using a servo motor as a drive source,
Force command means for commanding a force generated between the die cushion and the slide;
Force detecting means for detecting a force generated between the die cushion and the slide;
First comparison means for comparing the force detection value detected by the force detection means with the force command value commanded by the force command means;
Slide position command means for commanding the position of the slide;
A second comparison means for comparing the slide position command value commanded by the slide position command means with a predetermined first threshold;
A collision determination device that determines that the slide and the die cushion have collided when the force detection value exceeds the force command value and the slide position command value falls below the first threshold. A collision determination device that determines whether the slide and the die cushion collide in a die cushion mechanism that generates force against a slide of a press machine using a servo motor as a drive source,
Force command means for commanding a force generated between the die cushion and the slide;
Force detecting means for detecting a force generated between the die cushion and the slide;
First comparison means for comparing the force detection value detected by the force detection means with the force command value commanded by the force command means;
Slide position detecting means for detecting the position of the slide;
Second comparison means for comparing the slide position detection value detected by the slide position detection means with a predetermined first threshold;
Slide position command means for commanding the position of the slide;
A third comparison means for comparing the slide position command value commanded by the slide position command means with a predetermined second threshold;
The slide and the die when the force detection value exceeds the force command value and the slide position detection value falls below the first threshold value or the slide position command value falls below the second threshold value. A collision determination device that determines that the cushion has collided.

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