JP2011218443A - Panel folding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a panel folding device high in accuracy and reliability by automatically adjusting and making up a deficiency of ram pressing force for every filling-up of a die according to a difference in workpiece bending diameter.SOLUTION: In the panel folding device that the power of a driving source 20 is doubled by booster mechanisms 7, 8, 9 and is converted to pressing force by up and down moving strokes of a ram 2 and the panel is bent into a desired form by a die including an upper die 3 held by the ram to move up and down integrally with it, the stroke of the ram which is reduced by the amount corresponding to an increment 10 in thickness is corrected to have a length enough to generate maximum pressing force by a stroke adjusting device 30 by replacing the upper die with a thickness-increased die.

Description

  The present invention is generally referred to as a forging machine, and relates to a panel bending apparatus such as a press brake or a panel bender for bending a metal panel such as a steel plate as a processing material.

  FIG. 9 schematically shows an example of sheet metal processing by the so-called “squeeze bending” in the manufacturing process when a metal panel is bent into a workpiece to manufacture a casing such as a product case or housing. FIG. 10 schematically shows a structure example of a panel bender that performs flange bending by squeeze bending. A ram 2 is provided on the frame 1 forming the entire skeleton of the bender main body so as to have a substantially full lateral width in the left-right direction, and both ends of the ram slide in the vertical direction and are supported on the frame side plate so as to be movable up and down. Further, the upper die 3 having substantially the same length along the lower end of the ram 2 is held by bolting or the like, and moves up and down integrally with the ram 2. A lower die 4 is fixedly provided on the upper surface of the base portion below the frame 1, and the lower die 4 is paired with the upper die 3 and has an equivalent length. The work 5 loaded and set in the machine body is sandwiched between a pair of dies by the upper die 3 and the lower die 4 and clamped by a pressing force indicated by an arrow P in FIG.

  Further, as shown in FIG. 9, on the back side of the frame 1, squeeze bending dies 6a and 6b are held by a holder so as to face the upper and lower positions. In the case of the illustrated example, the lower bending die 6a is moved upward, brought into contact with the ear end portion 5a of the workpiece 5 in the clamped state, raised, and bent to a required angle.

  A pressing force P for clamping the workpiece 5 by the upper die 3 is applied as the ram 2 moves downward. Until now, hydraulic pressure has been generally used for the power of ram vertical movement, but in recent years, in the forging industry including the present applicant, development of a servo drive system using an AC servo motor instead of a hydraulic drive system has been developed. It has become mainstream. In the case of the panel bender shown in FIG. 10, the rotation output of such an AC servo motor is transmitted to a booster device such as a toggle link mechanism, and the pressing force P doubled by the booster device is transmitted to the ram 2 and held by the ram 2. The workpiece 5 is clamped by the upper die 3 in cooperation with the lower die 4.

  In the toggle link mechanism, a pair of combinations each including two link members 7 and 8 are arranged on both sides of the frame 1 in the horizontal width direction. One end of each of the link members 7 and 8 and the long rod 9 are coupled together by a hinge pin 10 so as to be movable. The other end portion of the lower link member 7 is pivotally supported on the ram 2 by a hinge pin 12 and the other end portion of the upper link member 8 is pivotally supported on the upper frame 1 by a hinge pin 11. Yes. That is, the hinge pin 11 serves as a fulcrum for doubling the force as a toggle link mechanism, and the hinge pin 12 serves as a force point for pressing the ram 2 together with the upper mold 3 to apply the pressing force P to the workpiece 5.

  The rod 9 reciprocates in the horizontal direction indicated by the arrow F in FIG. 10, and the rod horizontal movement causes the link members 7, 8 to become a maximum obtuse angle before the top dead center where the obtuse angle α ° becomes a substantially straight shape. Change shape until The force for reciprocating the rod 9 is transmitted from a drive source mechanism that converts the rotational power of an AC servo motor (not shown) into reciprocation. Therefore, the maximum pressing force Pmax at the maximum obtuse angle near the top dead center is applied to the ram 2 as a pressing force, the upper die 3 integrally coupled to the ram 2 is pushed down, and the workpiece 5 is clamped in cooperation with the lower die 4. Position.

  On the other hand, as shown in FIGS. 11 (a) and 11 (b), a part having different dimensions such as a flange bending diameter R of the ear end portion 5a, such as R1 and R2, in one workpiece 5 is bent by changing the process. There are many products. In that case, it is inconvenient if the mold corresponding to the processing of the bending diameters R1 and R2 is changed every time the processing tact becomes very long. Therefore, there is a case where a second upper die 10 separately prepared as shown in FIG. 12 is overlapped and joined to the upper die 3 used for the previous bending radius R1 to form a tie die that can be bent with the bending radius R2. is there. When returning to the bending process of the initial bending diameter R1, the second upper mold 10 is detached from the first upper mold 3 and returned to the original position, and is put on standby until the next bending process of the bending diameter R2.

  By the way, as shown in FIG. 12, when the second upper mold 10 is replenished, the stroke in which the ram 2 moves up and down by the increased mold thickness dimension A is shorter than the initially set length distance. . When the stroke of the ram 2 is shortened, the obtuse angle α ° formed by the link members 7 and 8 becomes smaller. For example, the maximum pressing force Pmax initially set before top dead center becomes weak and insufficient.

  Conventionally, various studies have been conducted in the forging industry to compensate for the shortage of the maximum pressing force Pmax (see, for example, Patent Document 1). According to the technique disclosed in Patent Document 1, the torsion spring having a semi-ring shape is elastically compressed by an amount corresponding to an increased thickness when the second upper die 10 is overlapped, and the clamping force of the workpiece is obtained by the spring elasticity. I want to get it.

  Japanese Patent Application No. 2000-612079

  However, in the case of the die clamping apparatus of the press machine disclosed in Patent Document 1, since the compression of the torsion spring is repeated numerous times over many years, it is experiential that the spring deteriorates over time due to metal fatigue or the like. I know. In addition, it is difficult to grasp the effective pressing force P quantitatively and qualitatively if spring force is used to assist the clamping force of the workpiece. There is a bug that affects

  Therefore, an object of the present invention is to automatically adjust the maximum pressing force when the ram stroke is shortened and the pressing force is insufficient when the mold is increased / decreased for each bending process of a part having a different workpiece bending diameter. By correcting, it is providing the panel bending apparatus with high precision and reliability.

  In order to achieve the above object, a typical panel bending apparatus according to the present invention doubles the power of a driving source with a booster mechanism to convert it into a pressing force due to the vertical movement stroke of the ram, and is held by the ram and integrated. When the panel is bent into a required shape by a mold including an upper mold that moves up and down, the stroke of the ram that is shortened by the thickness increase by changing the upper mold to one having an increased thickness, The stroke adjustment device corrects the length to generate the maximum pressing force.

  According to the panel bending apparatus of the first aspect of the present invention, the following effects can be obtained. When bending a panel of a workpiece, there are many products having a process in which a bending diameter is different for each part of one panel, for example. In that case, for example, a second upper die that is separately prepared may be overlapped with an upper die corresponding to the bending radius R1, and the bending of the bending radius R2 may be performed. By adding the second upper mold, the stroke of the ram is shortened by the mold thickness corresponding to the increased dimension. When the ram stroke is shortened, the maximum pressing force generated by the initially set stroke is insufficient and weakened. In order to compensate for this, the end of one link member connected to the ram by operating the stroke adjusting device, that is, the position of the link end serving as the force point of the doubled force is increased by the increased dimension of the upper mold. Displace and correct. By correcting the position of the force point of the link member, the toggle link mechanism can generate the maximum pressing force. As a result, highly reliable bending with high reliability is possible without insufficient force for pressing and clamping the panel.

  Hereinafter, a preferred embodiment of a panel bending apparatus according to the present invention will be described in detail with reference to the drawings. In addition, in order to clarify the essential points of the present embodiment in comparison with the structure of the conventional example shown in FIGS. 9 to 12, common members are denoted by the same reference numerals, and redundant description is omitted. Different reference numerals are given. The following description is a preferred embodiment, but the present invention is not limited to such an embodiment as long as the main idea is satisfied, and other embodiments are possible.

  FIG. 1 is a diagram showing a panel bending apparatus of this embodiment applied to an AC servo drive system panel bender as viewed from the back. However, the drive method is not limited to the AC servo drive method. Therefore, here, the power drive source 20 is provided with an encoder for use in the AC servomotor 21 to detect its output rotation, speed and direction. In addition to control for feeding back a detection signal of information detected by the encoder to a servo amplifier (control unit), an electronic control method based on detection of various signals can be employed. The rotation output of the AC servo motor 21 is transmitted to the ball screw 22 through an appropriate mechanism such as a speed reducer, and the rotation of the ball screw 22 is horizontally applied to the rod 9 constituting one member of a toggle link mechanism described below. Is converted to reciprocating motion.

    2 (a) and 2 (b), the ram 2 which is a long pressing plate member is provided at a substantially horizontal width in the horizontal direction of the frame 1 forming the skeleton of the apparatus main body. . The ram 2 is supported by left and right side frames so that it can slide up and down in both longitudinal directions and move up and down. Further, the upper die 3 is held at the lower end of the ram 2 by bolting or the like over almost the entire length in the longitudinal direction, and moves up and down as shown in the drawing together with the ram 2. On the upper surface of the base portion of the frame 1, a lower mold 4 having a substantially equivalent length that is paired with the upper mold 3 is held in a fixed state. The workpiece 5 that has been carried in is sandwiched between dies by the upper die 3 and the lower die 4 and clamped by a pressing force indicated by an arrow P in FIG.

  On the other hand, on the back side of the frame 1, a squeeze bending die 6 is held by a holder (not shown) and is on standby, and moves up and down when the operation signal is turned on. As shown in FIGS. 3 (a) and 3 (b), the squeeze bending die 6 scoops up the ear end 5a of the work 5 clamped by its upward movement from below to bend the flange to a required angle. It is a mold for. After the bending process, as shown in FIGS. 4A and 4B, the upper mold 3 moves up with the ram 2 and retreats to a height position that does not interfere with the removal of the work 5, and the bending mold 6 Is also configured to move downward and retract.

  Next, the configuration of the toggle link mechanism and the stroke adjusting device 30 interlocked with the mechanism will be described.

  First, in the toggle link mechanism, a pair of two link members 7 and 8 are arranged on the left and right sides of the device, and one end of the link members 7 and 8 is connected to the rod 9 by a hinge pin 10 in three bodies. It is pivotally supported so that it can be rotated along with the horizontal movement. The other end portion of the lower link member 7 shown in the figure is connected to the ram 2 so as to be pivotable by a hinge pin 12. The other end of the upper link member 8 is pivotally supported by a hinge pin 11 and connected to the upper portion of the frame 1. The hinge pin 11 is a fixed pin that does not move relative to the frame 1 and serves as a fulcrum for doubling the force as a toggle link mechanism.

  The rod 9 reciprocates in the horizontal direction indicated by the arrow F in FIG. 1, and the reciprocating motion of the rod 9 causes the link members 7 and 8 to change from a rectangular shape with an obtuse angle α ° to a substantially straight shape to a maximum obtuse angle before top dead center. The shape changes until it becomes or vice versa. The link members 7 and 8 generate the maximum pressing force Pmax at the maximum obtuse angle before top dead center. In that case, the maximum pressing force Pmax is applied to the ram 2 via an eccentric shaft 34 (described later) connecting the ends of the lower link member 8 with the upper hinge pin 11 as a fulcrum. The maximum pressing force Pmax applied to the ram 2 is transmitted as a pressing force by the upper die 3, and the workpiece 5 is clamped in cooperation with the lower die 4. In this state, the flange 5 is prepared for bending the workpiece 5 by the squeeze bending die 6 (see FIG. 3).

  Here, the stroke adjusting device 30 will be described with reference to FIGS.

  The stroke adjusting device 30 has a length extending over two sets of link members 7 and 8 disposed on both sides of a rack gear 31 that is long in the longitudinal direction of the ram 2, that is, in the left-right direction. Horizontal movement is possible. The rack gear 31 is connected to the piston of the cylinder device 35 and reciprocates in the horizontal direction. The rack gear 31 meshes with the rack gear 31 and the pinion gear 33 can rotate on the gear shaft 32 in the clockwise direction or the counterclockwise direction. .

  Further, an eccentric shaft 34 whose shaft center is offset by an eccentric amount A is coupled to the gear shaft 32 of the pinion gear 33 so as to be integrally rotatable. On the axis of the eccentric shaft 34, the other end of the link member 7 is integrally coupled. As will be described below, the amount of eccentricity A is set to be equivalent to the “mold thickness dimension A” of the second upper mold 10 that is replenished by overlapping the first upper mold 3 from below.

  In the present embodiment, the pinion gear 33 is set so as to rotate, for example, by an angle of 180 ° and a half in the clockwise direction or the counterclockwise direction by the reciprocation of the rack gear 31. The eccentric shaft 34 half-rotates integrally with the half-rotation of the pinion gear 33, and further, the position of the link member 7 fluctuates in the vertical direction of the figure by an eccentric amount (A / 2) corresponding to the 180 ° angle phase. It is supposed to be. The eccentric shaft 34 coupled with the end of the link member 7 serves as a support shaft that transmits the pressing force P to the ram 2, and serves as a power point (action point) that transmits the force doubled by the toggle link mechanism to the ram 2 as a pressing force. That is, the end portion of the link member 7, that is, the position of the power point is displaced by the eccentric amount A of the rotational phase in which the eccentric shaft 34 rotates by 180 ° half. Therefore, the gist of the present embodiment is that the end of the link member 7 is displaced, and the obtuse angle α ° with the upper link member 8 is toggled so as to be at or above the top dead center at which the maximum pressing force Pmax is generated. The shape of the link mechanism is changed by the stroke adjusting device 30.

  From the above configuration, the panel bending apparatus of the present embodiment can operate as follows to obtain the required action and effect.

  As shown in FIGS. 2A and 2B, the workpiece 5 is clamped and held with the maximum pressing force Pmax at an obtuse angle before the top dead center where the link members 7 and 8 are aligned in a straight line. Subsequently, as shown in FIGS. 3A and 3B, the squeeze bending die 6 moves upward, and the ear end portion 5a of the work 5 is squeezed from below to bend the flange to a required angle. As shown in FIGS. 4A and 4B, when the flange bending process is completed, the ram 2 rises and the upper die 3 is retracted to a height position where the processed work 5 can be removed together with the ram 2.

  In order to correspond to the flange bending process of the part where the bending diameter R changes from R1 to R2 in one workpiece 5, the apparatus operates as follows.

  As shown in FIGS. 7A, 7B, and 8, the second upper mold 10 that is held by the mold replenishment swing mechanism 40 and is waiting is set on the first upper mold 3 that is initially used. To do. When an operation signal is sent from the control device, the mold replenishment swing mechanism 40 swings and moves the second upper mold 10 held so as to overlap the first upper mold 3 from below. Since there are various structures such as concave-convex fitting and bolt connection after the second upper mold 10 is attached to the first upper mold 3 from below, a detailed description is omitted here. Further, the mold replenishment swing mechanism 40 is not particularly limited to the structure shown in FIG. In short, any mechanism that can supply the second upper mold 10 to the position where the second upper mold 10 is superposed on the first upper mold 3 by automation without relying on the manpower exchanging work may be used.

  When the second upper mold 10 is replenished, the stroke of the ram 2 is shortened by the mold thickness dimension A of the second upper mold 10, and the obtuse angle α ° formed by the link members 7 and 8 is shown in FIG. ) Becomes smaller as indicated by the phantom line in the figure. As a result, the maximum pressing force Pmax applied to the ram 2 becomes weak and insufficient. The shortage of the pressing force Pmax is corrected by adjusting the stroke adjustment device 30 as follows.

  When the movement of the second upper mold 10 held by the mold replenishment swing mechanism 40 is detected, the control device sends an operation signal to the stroke adjusting device 30 almost in synchronism with the operation. In the stroke adjusting device 30, the piston of the cylinder device 35 is operated to move the rack gear 31 horizontally, for example, in the right direction in the figure. As the rack gear 31 moves, the pinion gear 33 rotates, for example, 180 ° counterclockwise.

  As shown in FIG. 5C, the coaxial eccentric shaft 32 is integrally rotated by half by 180 ° half rotation of the pinion gear 33. By the half rotation of the eccentric shaft 32, the link member 7 is displaced by a distance corresponding to the angle phase, that is, the mold thickness dimension A of the second upper mold 10 to lower the position (eccentric lower side). As a result, the link members 7 and 8 can change to the shape of the maximum obtuse angle α ° before the top dead center shown in FIGS. 2 and 3 that generates the maximum pressing force Pmax. That is, the ram 2 can be pushed down with the maximum pressing force Pmax due to the obtuse angle before top dead center obtained when only the first upper die 3 is mounted.

  As shown in FIG. 5 (b), with respect to the workpiece 5 clamped with the maximum pressing force Pmax, the squeeze bending die 6 moves up the squeal end 5a and raises the squeeze to target the stern end 5a. The flange is bent at a bending diameter R2.

  When the flange bending process with the bending diameter R2 of the workpiece 5 is completed, as shown in FIG. 6B, the squeeze bending die 6 is moved down and retracted to a position where it does not interfere with the processed workpiece. When the second upper mold 10 is not required in the next bending step, the first upper mold 3 is moved up together with the ram 2 to be retracted to a position where it does not interfere with the workpiece to be processed. Almost in synchronization with this retracting operation, the mold replenishment swing mechanism 40 is operated to disengage the second upper mold 10 from the first upper mold 3 and return to the original position (see FIG. 8).

In accordance with such a series of operations, as shown in FIG. 6C, the stroke adjusting device 30 operates to horizontally move the rack gear 31 in the left direction of the figure, for example. The pinion gear 33 is rotated 180 ° by half in the clockwise direction, and the eccentric shaft 34 is also integrated with the pinion gear 33 in the clockwise direction.
Rotate 80 ° halfway. As a result, the link member 7 fluctuates by the eccentric amount A to raise the position (upper eccentric side).

  As described above, each time the bending process is changed from R1 to R2 for the same workpiece 5, or every time the processing of the bending diameter R2 is finished and the processing of the bending diameter R1 is resumed, 2 The upper mold 10 is replenished or removed. When the mold is replenished, the stroke adjusting device 30 is operated each time to compensate for the insufficient pressing force so that the maximum pressing force Pmax of the ram 2 applied by the link members 7 and 8 of the toggle link mechanism is not insufficient. . That is, the eccentric amount A by the eccentric shaft 34 of the stroke adjusting device 30 is set so that the link members 7 and 8 have a shape with a maximum obtuse angle α ° before the top dead center at which the maximum pressing force Pmax is generated every time the mold is compensated. Only the fluctuation position of the link member 7 is adjusted.

  In the present embodiment, the case of the mold thickness dimension A for the second upper mold 10 to be replenished has been described, but it is of course not limited to such a mold thickness dimension A. Even when various second upper molds 10 having other thickness dimensions are replenished, this is possible. In that case, the pressing assist device 30 uses the eccentric shaft 34 designed to have an eccentric amount corresponding to the change in the mold thickness dimension of the second upper mold 10. Therefore, various eccentric shafts 34 corresponding to the various second upper molds 10 can be prepared, and the structure can be detachably and integrally coupled to the gear shaft 32 of the pinion gear 33. From such an application example, it will be understood that the number of the second upper mold 10 is not limited to one, but is increased to the third, fourth,.

  In the present embodiment, the case where the bending diameter of one workpiece 5 is changed from R1 to R2 has been described. This is just one example of processing, and lot production is completed for the same large number of workpieces 5 in which the flange bending process with the bending diameter R1 is completed in the first step and then the process is shifted to the flange bending process with the bending diameter R2. Of course, this is applicable.

  In addition, other embodiments, application examples, modified examples, and combinations thereof are possible without departing from the spirit and scope of the present invention.

The figure which shows the apparatus main body at the time of applying to an AC servo drive panel bender as a panel bending apparatus of suitable embodiment which concerns on this invention from the back. (A), (b) is the rear view and side view which show a workpiece clamp state before the 2nd upper mold replenishment of this embodiment. (A), (b) is the rear view and side view which show the example of a workpiece bending process before the 2nd upper mold replenishment of this embodiment. (A), (b) is the rear view and side view which show the mold release after completion | finish of a workpiece bending process before the 2nd upper mold replenishment of this embodiment. FIGS. 5A to 5C are a rear view, a side view, and a pressing assist device for a main part showing a work clamp state in which the second upper mold is replenished and prepared for squeak bending in the present embodiment. FIGS. 4A to 4C are a rear view, a side view, and a pressing assist device for a main part showing a mode of bending work by supplementing the second upper mold in the present embodiment. (A), (b) is the rear view and side view which show the aspect which replenishes the 2nd upper mold | type in this embodiment. The side view which shows the type | mold replenishment swing mechanism in this embodiment. The conventional side view which shows an example of a shigoki bending process. The rear view of the apparatus which shows an example of the panel vendor using a toggle link mechanism roughly. FIGS. 4A and 4B are workpiece cross-sectional views showing two states when a workpiece is subjected to flange bending with a bending diameter R1 and a bending diameter R2. The side view by the partial cross section which shows an example of the aspect corresponding to the flange bending process by the bending diameter R2 by replenishing the 2nd upper mold | type.

DESCRIPTION OF SYMBOLS 1 ... Apparatus body frame 2 ... Ram 3 ... 1st upper mold | type 4 ... Lower mold | type 5 ... Work 6 ... Shigoki bending type | mold 7, 8, ... Link member (toggle link mechanism) )
9 ... Rod (Toggle link mechanism)
DESCRIPTION OF SYMBOLS 10 ... 2nd upper mold | type 20 ... Drive source mechanism 21 ... AC servo motor 22 ... Ball screw 30 ... Stroke adjustment device 31 ... Rack gear 32 ... Pinion gear shaft 33- .... Pinion gear 34 ... Eccentric shaft 40 ... Mold replenishment swing mechanism A ... Eccentricity

Claims (6)

The power of the drive source is doubled by a booster mechanism and converted to a pressing force by the ram's vertical movement stroke, and the panel is bent into the required shape by a mold that includes the upper mold that is held by the ram and moves up and down integrally. In the panel bending apparatus to
A panel in which the stroke of the ram, which is shortened by the thickness increase by changing the upper die to one having an increased thickness, is corrected to a length that generates the maximum pressing force by a stroke adjusting device. Bending device.   2. The toggle link according to claim 1, wherein the boost mechanism is a toggle link formed by connecting a plurality of link members, and one end of the link member is connected to the ram with a force point multiplied by a pressing force. The panel bending apparatus as described.   The panel bending apparatus according to claim 2, wherein the stroke adjusting device changes the toggle link to a maximum pressing shape by displacing a position of a force point that is an end portion of the link member.   The panel according to any one of claims 1 to 3, wherein when the upper mold is changed to one having an increased thickness, the upper mold having an increased thickness is composed of a single piece or a plurality of pieces. Bending device.   Each time the number of the upper molds is increased or decreased corresponding to the bending process of the parts having different bending diameters in the panel, the toggle link is changed by the stroke adjusting device to the maximum pressing shape. The panel bending apparatus according to any one of claims 1 to 4, wherein:   The stroke adjusting device has an eccentric shaft that connects the end portion, which is the power point of the link member, and the ram, and the eccentric amount of the eccentric shaft is set equal to the increased dimension of the upper die having increased thickness. The panel according to any one of claims 1 to 5, wherein the position of a force point that is an end portion of the link member is displaced by the amount of eccentricity by rotating the eccentric shaft with rotational power. Bending device.

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