JPH064174B2 - Bending machine - Google Patents

Description

The present invention relates to a bending apparatus, and more particularly to a so-called draw bend type bending apparatus for holding a workpiece by a bending die and a clamping die. Bending apparatus.

[Prior Art] Conventionally, a draw bend type bending apparatus is known in a single bender, and for example, Japanese Patent Publication No. 53-4.
Apparatuses described in Japanese Patent No. 2549, Japanese Patent Publication No. 62-22693 and Japanese Utility Model Publication No. 62-86911 are known.
In the devices described in the above publications, the fixed head is moved to the bending head side as the bending head performs bending at a predetermined position. The device disclosed in Japanese Patent Publication No. 53-42549 has an integrated member between a fixed head and a bending head, and the bending head performs bending while attracting the fixed head. The devices described in the other two publications are The fixed head was equipped with an automatic feeding device and performed bending while approaching the bending head by itself.

As a bending device called a double-headed bender, for example, a device described in Japanese Patent Publication No. 52-20026 is known, but it is a so-called compression bend type, and a draw bend type bending device has been invented. There wasn't. This is because the draw bend type is known in which the fixed head is moved to the bending head side as described above, but it is impossible to move the fixed head in the double-head bender.

[Problems to be Solved by the Invention] According to the above-described conventional device, in the single bender, the bending head is acted on by the force to pull the work piece and the fixed head together. An external force in the axial direction of the work piece acts on the mold, and the work piece may slip and slip at the gripping portion. Therefore, it is necessary to secure a large so-called clamp width in order to surely hold the workpiece by the clamping die and the bending die. As a result, there is a problem that it is impossible to perform fine and complicated bending work.

Also, in the case of a double-headed vendor,
Since it is a compression bend type, the clamp width of the clamp for pressing the work piece to the bending die needs to be increased according to the maximum arc length. Therefore, similar to the problem in the single bender described above, it is fine and complicated. There was a problem that it could not be bent.

Configuration of the Invention The present invention has been made for the purpose of solving the above problems, and employs the following configurations.

[Means for Solving the Problems] That is, the gist of the present invention is to provide a fixed head for holding a rod-shaped or pipe-shaped workpiece and a bending die for the workpiece held by the fixed head. A bending head that bends along the bending mold while gripping with the clamping mold, and a moving base on which the bending head is mounted and the gap between the bending head and the fixed head can be adjusted, In a bending apparatus for bending a workpiece into a desired shape, when bending, the above-mentioned adjustment is performed so as to adjust the interval between the bending head and the fixed head in accordance with the bending processing speed of the bending head. The bending apparatus is provided with a moving table control means during bending for performing bending while moving the moving table.

[Operation] According to the bending apparatus of the present invention, by moving the moving table so as to approach the fixed head side in accordance with the processing speed of the bending head, and adjusting the interval between the bending head and the fixed head, Performs bend bend type bending. That is, since the clamping die and the bending die do not exert a force for axially shifting the workpiece unlike the conventional device, it is possible to reduce the clamp width. As a result, fine and complicated bending work is possible.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic front view of a double-headed draw bend axis bending apparatus (hereinafter simply referred to as a bending apparatus) 1 as an embodiment.

The bending device 1 includes a support frame 5 having a single linear rail 3, a fixed head 10 disposed substantially at the center of the support frame 5,
Bending heads 20L and 20R, bending heads 20L and 20R, which are arranged in a pair on the left and right as shown in FIG.
It is composed of movable bases 30L and 30R provided with R mounted thereon and movable along the rail 3, and movable motors 40L and 40R for moving the movable bases 30L and 30R in the left-right direction in the drawing. An air cylinder 50 for aligning the ends of the pipe P, which is a workpiece, is arranged at the left end of the support frame 3 in the figure. The fixed head 10 includes a chuck 60 and a rotary motor 8 which will be described in detail later.
0, a tightening motor 90 is provided.

Further, as shown in FIG. 2, the bending head 20R has a bending shaft 2
A bending arm 23R that is rotated around the 1R by a hydraulic cylinder 22R as shown by an arrow A is provided. Bending axis 21R
Is provided with a bending die 24R having a groove matching the outer diameter of the pipe P and including a clamp piece 24Ra, and the bending arm 23R is provided with a clamping die 25R having a similar groove at a position facing the clamp piece 24Ra. Is provided. Tightening mold 2
5R is driven forward and backward with respect to the bending die 24R as shown by an arrow B in the drawing by a hydraulic cylinder 26R disposed above the drawing, and holds the pipe P in cooperation with the bending die 24R. Further, the pressure die 27R is arranged in parallel with the fastening die 25R, and the pressure die 27R is driven forward and backward by a hydraulic cylinder 28R as shown by an arrow C to push the pipe P gripped by the bending die 24R and the fastening die 25R downward in the figure. By doing so, the pipe P is prevented from floating during bending. These bending dies 24
The R, tightening die 25R, and pressure die 27R are provided so as to be replaceable according to the workpiece.

Further, the vertical frame 31R of the movable table 30R is provided with a payout member 33R that is driven by a hydraulic cylinder 32R in the direction of the arrow D to push up the pipe P that has been bent and lifted up from the bending head 20R. Also, the moving table 30R
Is driven by a moving motor 40R via a sprocket 41R and a chain 42R, and can be moved to any position along the rail 3. Although the right bending head 20R is described in FIG. 2 and the above description, the left bending head 20L has the same configuration.

Next, the structure of the chuck 60 arranged on the fixed head 10 will be described with reference to FIGS.

The chuck 60 is rotatably supported by the support frame 12 of the fixed head 10. The support frame 12 is made of thick steel plate,
A circular cutout 14 is provided at the substantially center, and the circular cutout 14 has an opening 16 on the right side in the drawing. Further, the support frame 12 is provided with six support rollers 18a to 18f arranged on the outer peripheral portion of the circular cutout 14 at concentric circles at equal intervals and fixed by hexagon bolts.

The chuck 60 serves as a rotating body and supports rollers 18a to 1a.
A rotating disk 6 whose outer peripheral portion is rotatably supported by 8f.
1 is provided. The rotating disk 61 has a cutout portion 62 of a predetermined width, which is provided so as to be replaced with a central portion from a predetermined position on the outer circumference. Further, a ring-shaped gear 63 formed with a slightly smaller radius is provided in the vicinity of the outer peripheral portion of the rotary disc 61 so as to project in the front direction in the drawing. Further, a cutout 62 is formed on the rotating disc 61.
Gripping members 64a and 64b capable of advancing and retreating into the cutout portion 62 are provided in the upper and lower portions in the drawing orthogonal to the above. Gripping member 64
The a and 64b are provided with replaceable holding pieces 65a and 65b at their tips, and are covered with protective frames 66a and 66b fixed to the rotating disc 61 by bolting from the front side in the drawing.

The gripping members 64a, 64b are provided at one end with an approach direction engagement step 67
a and 67b on the other end to the backward engaging step portions 68a and 68b
It is provided with concave portions 69a and 69b having. Recesses 69a, 6
Heads of rocking levers 70a, 70b that engage with the approach direction engagement step portions 67a, 67b or the retreat direction engagement step portions 68a, 68b to drive the gripping member forward and backward are inserted in 9b. The swing levers 70a, 70b are links 71a, 71b.
Is connected to the swinging member 72 via. Swing member 72
When the shaft is swung about the swing shaft 73 in the clockwise direction in FIG. 4, the links 71a and 71b, the swing levers 70a and 70b, and the gripping members 64a and 64b are moved or swung as shown by the alternate long and short dash line in the figure. However, the pipe P can be gripped.

Further, as a rotary drive member for rotationally driving the rotary disc 61, a rotary motor 80, a rotary drive gear 82 provided on a motor shaft 81 of the rotary motor 80, and a rotary drive gear 82 are provided between the rotary drive gear 82 and the ring gear 63. , A first engaging gear 83 and a second engaging gear 84 that are two engaging members that engage with each other. First engagement gear 83 and ring gear 63
And the engagement position X of the second engagement gear 84 and the engagement position Y of the ring gear 63 are larger than the notch width of the notch portion 61. Compound gears 83, 8
4 and a rotary drive gear 82 are provided.

Further, the chuck 60 is provided with a driving member for the swinging member 72, which will be described below. As shown in FIGS. 5 to 7, four ring support rollers 74a to 74f are concentrically equidistantly attached to the back surface of the rotary disc 61 by bolting, and a boss into which the swing shaft 73 is fitted. 75 is also fixed by bolting. The swing shaft 73 is rotatably supported by bearings 76a and 76b provided at both ends of the boss 75. Further, the swing shaft 73 is integrally provided with a lever 77 bolted to the lower end side in FIG. 5, and the lever 77 is provided with an engaging projection 78 at the tip. The lever 77 is swung by a tightening ring 91 to be described below, and is operated as shown in FIG. 4 as described above to hold the gripping members 64a and 64b.
Perform a release operation.

As shown in FIG. 7, the tightening ring 91 is provided with a gear 92 on the outer periphery and is a partially cutout ring having an open portion 93 having the same width as the cutout width of the cutout portion 62.
It is rotatably supported from the inside of the ring by ~ 74f.
Further, two engaging projections 94a, 94b which are engaged with the engaging projection 78 by being sandwiched are arranged at predetermined positions of the tightening ring 91. Open portion 93, engaging projection 94a,
As shown in FIG. 7, the arrangement of 94b is such that the gripping members 64a and 64b are brought to the pipe open position via the lever 77 when the opening portion 93 coincides with the cutout portion 62.

The tightening ring 91 having the above structure is driven to rotate in the normal and reverse directions by the two tightening engagement gears 95 and 96 that engage with the gear 92 and the tightening drive gear 98 provided on the motor shaft 97 of the tightening motor 90. As shown in FIG. 4, gripping members 64a, 64b
The gripping / releasing operation of the pipe P is performed by. The tightening engagement gears 95 and 96 and the tightening drive gear 98 are arranged in parallel with the engagement gears 83 and 84 and the rotation drive gear 82 as shown in FIG.

In addition, the bending apparatus 1 further includes a control device 100 as a processing control means, and is configured to execute bending processing based on the bending processing command information input from the command device 110.

As shown in FIG. 8, the control device 100 has CPUs 101, R
The OM 102, the RAM 103, and the like are configured as a logical operation circuit, and the input port 1 is provided via the common bus 104.
05, connected to the input / output port 106 to perform input / output with the outside. In addition, the control device 100 has an input port 105.
Based on the bending command information input from the command device 110 via the hydraulic cylinders 22L, via the drive circuits 107a to 107h connected to the input / output port 106.
22R, 26L, 26R, 28L, 28R, 32L, 3
Servo valves 22La, 22Ra, 2 provided in 2R
6La, 26Ra, 28La, 28Ra, 32La, 3
The position sensor 22 outputs the drive signal to 2Ra.
Lb, 22Rb, 26Lb, 26Rb, 28Lb, 28
Detection signals from Rb, 32Lb, and 32Rb are input. Also, via the drive circuits 107i to 107l, servo motors 40La and 40R provided for the moving motors 40L and 40R, the rotary motor 80, and the tightening motor 90 are also provided.
a, 80a, 90a to drive signals, position sensors 40Lb, 40Rb, 80b, torque sensor 4
Detection signals from 0Lc, 40Rc, 90b are input.

Next, the function and effect of the bending apparatus 1 having the above configuration will be described.

In order to perform the bending process with the bending device 1, first, the pipe P is chucked from the first front direction, that is, from the right side in FIG.
After being inserted into the notch 62 of 0 and positioned between the holding members 64a and 64b, the tightening motor 90 is driven and tightened via the tightening drive gear 98 and the tightening engagement gears 95 and 96. Rotate the ring 91 in the gripping direction. Then, the engaging protrusion 94
The lever 77 is rotated in the gripping direction via a and 94b,
As shown in FIG. 4, the holding members 64a and 64b are provided with the cutouts 62.
The pipe P is moved inward and the pipe P is securely gripped between the gripping pieces 65a and 65b. Then, the moving motor 40R is driven to move each bending head 20R to a predetermined bending position, and the bending die 24
The hydraulic cylinder 26R is driven to grip the pipe by the R and the clamp 25R. At the same time, the hydraulic cylinder 28
The pressure die 27R is pressed against the pipe P by driving R. The same operation is performed on the left side bending head 20L, and the pipe P is gripped by the fixed head 10 and the bending heads 20L and 20R to be in a bendable state. Here, the tightening motor 90 is still energized so that a slight torque is applied in the gripping direction so that the gripping force by the gripping members 64a and 64b is not weakened.

Subsequently, bending is performed. In the following description, only the right bending head 20R will be described, but the left bending head 20L is similarly bent.

In the bending head 20R, the bending arm 23R is rotated to a desired angle by the hydraulic cylinder 22R. Pipe P
Is a clamp piece 24Ra of the bending die 24R and a clamping die 25R.
While being gripped, the part on the fixed head 10 side from the gripping position is wound around the concave groove of the bending die 24R and bent to a desired angle. During this time, the pressure die 27R prevents the above-mentioned wound portion of the pipe P from floating upward in FIG. Here, since the bending apparatus 1 employs the draw bend method as described above, the interval between the bending head 20R and the fixed head 10 is adjusted in the approaching direction as shown by the dashed line in FIG. There is a need.

Therefore, in the bending process, the control device 100 can execute the following processes. Even when the bending direction is changed, the control device 100 also controls the pipe gripping force to prevent the bending direction from being inaccurate due to the displacement of the pipe. The bending control by the draw bend method and the chuck rotation control when changing the bending direction will be described below with reference to FIGS. 9 and 10. For the sake of simplicity, processing and operations common to the left and right bending heads 20L and 20R will be described only for the right bending head 20R.

First, from the command device 110, bending processing command information such as a bending position, a bending direction, a bending angle, a material, a diameter, and a wall thickness of the pipe is input. Then, the bending control shown in FIG. 9 is executed.

At step 200, various variables and flags are initialized.
Next, at step 210, the bending heads 20L and 20R are moved to respective predetermined bending positions. Position sensor 40
When it is confirmed by the detection signals from Lb and 40Rb that the object has been moved to the predetermined position, the routine proceeds to step 220. In step 220, the hydraulic cylinders 26R and 28R are driven, and the pipe P is gripped by the bending head 20R. In the following step 230, the hydraulic cylinder 22R is driven and the bending arm 23R is rotated clockwise in FIG. at the same time,
The drive motor 40R is driven and the movable table 30R is moved to the left in FIG. At this time, the position sensors 28Rb and 40Rd are arranged so that the rotational speed dθ / dt of the bending arm 23R and the moving speed dx / dt of the moving table 30R satisfy the following equation.
Is controlled based on the detection signal.

dx / dt = R · dθ / dt + α (1) Here, R ... Radius to the bottom of the concave groove of the bending die 24R α ... Minute speed. In the formula (1), the moving table 30R is moved by a very small speed α.
The pipe P is bent while a slight compressive force is applied to the pipe P by making the moving speed thereof slightly higher than the rotating speed of the bending arm 23R. In this way, by slightly applying a compressive force, the bending resistance force applied to the bending arm 23R can be reduced, and the bending error can be eliminated due to the pipe P extending along with the bending. In addition, dθ / dt,
The value of α changes depending on the material, diameter, wall thickness, etc. of the pipe.

In the following step 240, it is determined whether or not the output torque of the moving motor 40R detected by the torque sensor 40Rc during the moving is equal to or less than a predetermined value. That is, when the torque exceeds a predetermined value, the compressive force applied to the pipe P during bending is too large, and the pipe P is prevented from buckling. When a negative determination is made in step 240, the process proceeds to step 250, the energization current to the moving motor 40R is limited, the buckling is prevented, and the process proceeds to step 260 as in the case of the positive determination in step 240.

In step 260, it is judged whether or not one bending process is completed. If it is not completed yet, the processes from step 230 onward are repeated, and if the bending process is completed, in step 270 the hydraulic cylinder 22R, Moving motor 40
R is stopped. In the following step 280, the hydraulic cylinders 26R and 28R are driven, and the clamping die 25R and the pressure die 27 are driven.
While the gripping force on the pipe P by R is released,
The hydraulic cylinder 32R is driven, the pipe P is pushed upward by the payout member 33R, and the process ends.

When the second bending process is required at another position after the first bending process is completed as described above, the process shown in the flowchart of FIG. 9 is executed again. Here, when the second bending apparatus performs bending in a direction different from the first bending direction, the tenth operation is performed prior to the bending operation.
The chuck rotation control process shown in the figure is executed.

Here, the information regarding the bending direction is input by the command device 110 as described above, and the processing is started. First, in step 300, various variables and flags are initialized. Next, in step 310, the servo motor 80a is driven, and the rotary motor 80 is rotationally driven based on the information regarding the bending direction. Subsequently, at step 320, it is judged if the output torque of the tightening motor 90 detected by the torque sensor 90b is equal to or more than a predetermined value. If an affirmative decision is made, the operation proceeds to step 340, and if a negative decision is made, the operation proceeds to step 330. In step 330, control is performed to increase the current supplied to the servomotor 90a and make the output torque of the tightening motor 90 equal to or greater than a predetermined value, and the process proceeds to step 340. In step 340, the position sensor 80
The rotational position of the rotary motor 80 detected by b, that is,
It is determined whether the rotational position of the chuck 60 has reached the position corresponding to the bending direction information. If it has not been rotated to the desired position, the process returns to step 310 and the above control is continued. On the other hand, when rotating to the desired rotation position, the routine proceeds to step 350, where the energization of the rotary motor 80 is stopped, and the energizing current to the tightening motor 90 is a predetermined value, that is, the pipe P is gripped. The value is returned to the value required for setting, and the process ends.

Here, the first and second engaging gears 83 and 84 are provided with the cutout portion 62.
By engaging with the ring-shaped gear 63 at an interval larger than the notch width of the second engagement gear 84, for example, even when the first engagement gear 83 is located in the notch 62, the second engagement gear 84 has the ring-shape. The gear 63 is securely engaged with the chuck 60, and the chuck 60 can be further rotated in a desired direction. Tightening engagement gears 95, 9
6 and the tightening ring 91 are also the same, and the tightening force can be continuously transmitted to the gripping members 64a and 64b regardless of the position of the opening portion 93.

As described above, according to the present embodiment, it becomes possible to perform the draw bend type bending process even in the double head bender. That is, since the bending heads 20L and 20R can be bent while being moved to the fixed head 10 side according to the bending amount and bending speed, the clamp width, that is, the width of the clamping die 25R and the clamp piece 24Ra can be reduced. It became possible to do. As a result, fine and complicated bending can be performed. In addition, the movement motors 40L, 4
Torque sensors 40Lc and 40Rc are provided on the 0R, and the load applied to the bending arm 23R is reduced in order to move the moving bases 30L and 30R while slightly applying a compressive force in the axial direction of the pipe P while detecting the output torque. In addition, bending can be performed so that the pipe P does not buckle.
Further, by inputting the material, diameter, wall thickness, etc. of the pipe P from the command device 110 and changing the bending speed dθ / dt and the minute speed α in accordance therewith, various pipe materials can be efficiently processed at the optimum processing speed. Can be bent.

Further, since the chuck 60 can rotate in the forward and reverse directions without being limited in the rotation range, it is possible to improve the work efficiency of the bending process. Further, the fixed head 10 and the bending head 20
For both L and 20R, pipe P from the front of Fig. 1
Since it can be attached and detached, automation of work is possible. Furthermore, the provision of the payout member 33R and the air cylinder 50 enables almost complete automation.

Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modes can be adopted without departing from the scope of the invention.

For example, the movable bases 30L and 30R have chains 42L and 42R.
Instead of R, it may be driven by a screw gear or the like. Further, as the input device 110, a material selection button or an adjusting volume may be provided so as to be able to input at least one of the above-mentioned machining command information, and the dedicated bending device is provided with an input device. It doesn't matter. Further, instead of the control processing by the control device 100, for example, the moving motors 40L and 40R may be hydraulically driven to control the opening amount of the servo valve fixedly, and the hydraulic cylinder 22R may be set to the opening amount of the servo valve 22Ra. It may be synchronized.

The moving speed dx / dt may be set to dx / dt = R · dθ / dt (2) so that no axial compressive force is applied to the pipe P. Further, the control by the torque sensors 40Lc and 40Rc may not be performed.

The bending direction of the bending arm 23R may also be such that the bending arm 23R is rotated from the lower side to the upper side, and in this case, there is also an advantage that the upper space can be effectively used. Similarly, the notch 62 of the chuck 60 may be horizontally rotated, and the pipe may be detachable from above.

Further, instead of the engagement gears 83, 84 and the tightening engagement gears 95, 96 of the chuck 60, a rubber roller or the like is used to engage with the outer peripheral portion of the rotating body by frictional force to drive the rotating body to rotate. Good. Further, the forward / backward drive of the gripping member may be tightened and loosened by a bolt or the like. By adopting the bending die 24R and the fastening die 25R having a heart-shaped concave groove, it is possible to prevent the pipe from being crushed when the ultrafine copper pipe or the like is bent.

EFFECTS OF THE INVENTION As described above, according to the present invention, even a double-headed bender can be bent by a draw bend method, and the clamp width can be reduced for both the double-headed bender and the single bender, resulting in a finer and more complicated bending. Processing became possible.

[Brief description of drawings]

FIG. 1 is a schematic front view of a bending apparatus having a chuck of an embodiment, FIG. 2 is a front view of a bending head thereof, FIG. 3 is a left side view of the chuck, and FIG. 5 is a sectional view taken along line AA in FIG. 3, FIG. 6 is a sectional view taken along line BB in FIG. 5, and FIG. 7 is a right side view of the chuck.
FIG. 8 is a block diagram showing a configuration of a control device of the bending apparatus, FIG. 9 is a flowchart of bending processing control, and FIG.
The figure is a flowchart of chuck rotation control. 1 ... Bending apparatus 10 ... Fixed head 20L, 20R ... Bending head 24R ... Bending die 25R ... Tightening die 30L, 30R ... Moving stand

Claims (1)

[Claims] 1. A fixed head for holding a rod-shaped or pipe-shaped workpiece, and a workpiece which is held by the fixed head is held by a bending die and a fastening die along the bending die. In a bending apparatus for bending a bending head and a moving table on which the bending head is placed and the gap between the bending head and the fixed head can be adjusted, the bending apparatus for bending the workpiece into a desired shape. During bending, the bending table is moved while the movable table is moved so as to adjust the distance between the bending head and the fixed head according to the bending speed of the bending head. A bending apparatus having a table control means.