JP3504329B2 - Bending equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to a fold processing equipment performs an L-shaped bending the workpiece.

[0002]

2. Description of the Related Art Conventionally, as a bending apparatus for bending a work, for example, a press brake or an ironing bending machine is known. In press brakes, it is known to embed a sensor for detecting a distance to a work in a die to detect a bending angle, as is known from, for example, Japanese Patent Laid-Open No. 63-49327.

Further, in an ironing and bending machine, as known from, for example, Japanese Patent Laid-Open No. 61-63317, a bend beam is rotated to be provided on a bend beam when a work is bent. It is known to detect the bending angle by detecting the distance to the workpiece with the provided sensor.

[0004]

By the way, of the above-mentioned conventional techniques, the former bending angle sensor is practically difficult to embed in the V groove of the die,
Limited to ultra-small sensors. Further, in the case of a fully-automated system, a follow-up device is required because the work is rebounded, which is not suitable for the fully-automated system.

Since the latter bending angle sensor uses the rotation angle of the bend beam as a reference, it has a problem that the bending angle of the work is estimated in combination with an encoder and the bending angle sensor is easily affected by bending of the mechanical system.

When an L-shaped bending process is performed on a work, since a bending angle for accurately detecting the bending angle of the bent work is not provided, an accurate bending angle can be determined based on this bending angle. There is a problem in that it is not possible to obtain a bent product that the user has.

An object of the present invention is to obtain a desired bending angle while detecting a springback amount of a work during a bending process in order to cope with automation of the bending process in an L-shaped bending process. It is an object of the present invention to provide a bending apparatus with high accuracy and improved tact time, and a bending method using the apparatus.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art. The invention according to claim 1 is an L-shaped work held by a lower presser die and an upper presser die. A ram that is equipped with a bending die that performs the bending process of
Of providing the bottom when both provided a pair of upper and lower bent portions to the bending tool, a bending portion of the lower side provided freely increase the bending tool to a position where the upper of the work, the lower
After bending the work downward by the bending part of
The upper bent portion contacts the work and the work is
It is structured so that it can be driven in freely .

According to a second aspect of the invention, in the bending apparatus according to the first aspect, the bending die is the ram.
On the other hand, it is provided so as to be movable in the direction of approaching and separating from the work.

The invention according to claim 3 is the invention according to claim 1 or 2.
In bending apparatus according, the spring-back detecting device for detecting the spring back of the workpiece, the vertical
A structure provided for the bending mold between the pair of bending portions.
It is a success .

The invention according to claim 4 is the invention according to claim 1, 2 or
In the bending apparatus according to 3, the presser lower mold side
Or / and bending angle when the work is bent to the upper mold side
The bending angle detecting device for detecting the degree is provided .

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

Embodiments of the present invention will be described in detail below with reference to the drawings. Referring to FIG. 1, the bending apparatus 1 is provided with a base 3, and on the base 3, a mold holder 7 in which a pressing lower mold 5 is integrated is provided upright on the base 3. A pressing die 9 for holding the work W is provided on the pressing lower die 5. Further, a preferable non-contact type laser sensor 11 as a bending angle detecting device for detecting the bending angle of the bent work W is provided above the die holder 7.

Above the die holder 7, there is provided a vertically movable ram 13 which moves vertically by, for example, a crank movement or a hydraulic cylinder. A fluid cylinder 17 such as a hydraulic cylinder or a pneumatic cylinder is attached to a lower portion of the ram 13 via a support block 15. A bending metal is attached to a tip (left end) of a piston rod 19 attached to the fluid cylinder 17. A mold 21 is provided.

A pair of bending portions 23U and 23D are provided above and below the front portion (left portion) of the bending die 21. A laser sensor 25 is attached to the support block 15 as a feedback sensor for detecting the position of the bending die 21 and feeding it back. Further, for example, a pressure sensor 26 as a springback detection device for detecting springback is built in the bending die 21. A mechanical sensor 29 for detecting the vertical displacement of the bending die 21 and the pressing die 5 is attached to the left side of the ram 13 via a bracket 27.

This mechanical sensor 29 is an A / D converter 31.
Is connected to the NC device 33 via. A servo controller 37 is connected to the NC device 33 via a D / A converter 35. A linear servo valve 39 is connected to the servo controller 37, and the linear servo valve 39 is connected to a pump 41.

The laser sensors 11 and 25 and the pressure sensor 26 are connected to the A / D converter 31, and the laser sensor 25 is connected to a servo controller 37. The fluid pressure cylinder 17 is connected to a linear servo valve 39 via a passage 43.

With the above structure, the operation of bending the work W into an L-shape will be described with reference to the operation explanatory view shown in FIG. 2. First, as shown in FIG. Whether the bending die 21 is positioned above the work W.
Allowed to lower the Luo ram 13. When the ram 13 is lowered,
As shown in FIG. 2B, the bending portion 23D of the bending die 21 contacts the work W, and the work W is bent downward. At this time, as shown in FIG.
In a state in which the work W is largely projected from the lower die 5 etc.
It can be positioned .

Next, when the ram 13 descends by a predetermined distance, as shown in FIG. 2 (C), the work W is bent so that the work W has an angle slightly larger than the final bending angle (α ₀ ). And the first bending angle (α
₁ ) is detected by the laser sensor 11. After detecting the first bending angle (α ₁ ), the fluid cylinder 17 is operated to move the bending die 21 in the direction away from the work W, that is, in the right direction in FIG. 2 (C), and as shown in FIG. 2 (D). Completely disengage to provide unpressurized condition as shown. The second bending angle (α ₂ ) at that time is detected by the laser sensor 11.

First and second detected by the laser sensor 11
The bending angles (α ₁ , α ₂ ) are taken into the NC device 33, and the NC device 33 calculates the springback (α ₁ -α ₂ ). Based on the calculated spring back (α ₁ -α ₂ ), the fluid cylinder 17 is activated again to move the bending die 21 in the direction of the work W, that is, in FIG.
In (E), the bent portion 23D of the bending die 21 is brought into contact with the work W by making it approach to the left. At this time, FIG. 2 (E)
As shown in FIG. 3, the ram 13 is further lowered so that the bending portion 23U of the bending die 21 comes into contact with the work W and the work W
The bending die 21 lowers the ram 13 to a predetermined stroke end (overbend). Then, as shown in FIG. 2 (F), the fluid cylinder 17 is operated to move the bending die 21 to the right so as to be completely separated from the work W, and then the ram 13 is moved to the top dead center position. By raising the work W, the bending work for achieving the desired bending angle (α ₀ ) is completed.

Alternatively, after the first bending angle (α1) is detected, the fluid cylinder 17 is operated to move away from the work W, that is, when the bending die 21 is moved to the right in FIG. 2C , Spring back is detected by the pressure sensor 26. Highly accurate bending is performed by similarly performing auxiliary bending on the basis of the detected springback.

When the work W is bent at a desired bending angle α ₀ = 90 °, first, as shown in FIG. The fluid cylinder 17 is controlled to a position of about 86 °, the bending die 21 is moved in the direction of the work W, and a stroke is performed to perform the first bending process (α ₁ = 86 °). ． After the first bending, the bending die 21 is completely separated from the work W, and the bending angle α ₂ at that time is detected by the laser sensor 11. That is, α ₂ = 93 ° is detected by the laser sensor 11. Therefore, by incorporating α ₁ = 86 and α ₂ = 93 into the NC device 33, the springback amount (= 93 °
-86 ° = 7 °) is calculated. ． By this calculated springback amount of 7 °, 83 ° (= 9
By overbending to around 0 ° -7 °),
It is possible to perform bending work with a bending angle of 90 °. In order to prevent the overshoot more reliably, it is desirable to perform the correction bending a plurality of times.

As described above, by providing the laser sensor 11 on the die holder 7, the bending angle when the work W is bent can be reliably detected on the spot, and the springback amount is calculated. You can ask.
Therefore, it is possible to perform a highly accurate bending process in consideration of the springback amount.

A pair of bending portions 23 above and below the bending die 21.
By providing U and 23D, it is possible to perform the first bending and the auxiliary bending in one stroke, so that the tact time can be shortened. Also, the bending die 21
By providing the fluid cylinder 17 that moves and positions the horizontal direction, it is possible to perform a bending work without a clearance while serving as a shock absorber.

By detecting the springback with the pressure sensor 26 as the springback detection device, the springback can be calculated in a shorter time. It is preferable that a plurality of pressure sensors 26 are provided above and below for detection.

In the present embodiment, the example in which the laser sensor 11 as the bending angle detecting device is provided on the presser lower mold 5 side has been described, but it may be provided on the presser upper mold 9 side or the bending mold 21 side. can do.

FIG. 4 and FIG. 5 show another embodiment of the present invention. In FIGS. 4 and 5, the bending apparatus 43 is provided with an elevating frame 47 which is vertically movable above the fixed frame 45.

More specifically, the fixed frame 45 is roughly box-shaped, and one of the fixed frames 45 is
The upper part of the vertical front plate 49 that constitutes the part,
The presser foot mold 51 is appropriately fixed. The pressing lower die 51 supports the work W to be bent, and as shown in FIG. 4, is provided by extending in the left-right direction.

As can be seen from FIG. 5, the elevating frame 47 is constructed by arranging a plurality of arm plates 53 extending in the front-rear direction (left-right direction in FIG. 5) as appropriate in the left-right direction. The front end of each arm plate 53 is integrally fixed to a plate pressing plate 55 extending in the left-right direction, and the lower rear end of each arm plate 53 is integrated with a connecting plate 57 extending in the left-right direction. Fixed.

In order to support the lifting frame 47 so that it can move up and down with respect to the fixed frame 45, the connecting plate 57 is used.
Swing brackets 59 are provided at appropriate positions (in the present embodiment, both left and right end portions and a central portion). The swinging bracket 59 is attached to a roughly clevis-like bearing bracket 61 which is erected on the upper portion of the fixed frame 45, and the pivot 6 is attached.
It is swingably supported via 3.

An upper pressing die 65 is provided on the elevating frame 47 for holding and fixing the work W to be bent on the lower pressing die 51. More specifically, as shown in FIG. 4, the presser upper mold 65 includes a plurality of selectable molds 67 made of thin plates, a plurality of block molds 69 located on both sides of the selectable mold 67, and the like. The length of the work W can be appropriately adjusted according to the width of the work W.

With the above construction, the work W is clamped and fixed between the presser lower mold 51 and the presser upper mold 65 by swinging the elevating frame 47 up and down about the pivot 63. Will be released.

In order to move the elevating frame 47 up and down, the elevating frame 47 is provided with an elevating operation device 71. More specifically, as shown in FIG. 5, supporting plates 73 are attached to the facing surfaces of the arm plates 53 in the lifting frame 47, and between the supporting plates 73, an example of the lifting operation device 71 is provided. Fluid pressure cylinders 75 are respectively arranged. A trunnion 77 is provided on each side of each fluid pressure cylinder 75, and the trunnion 77 is supported by a bearing 79 attached to each support plate 73. That is, each fluid pressure cylinder 75 is swingably supported by the elevating frame 47.

The piston rod 81 projecting downward from the fluid pressure cylinder 75 is screwed and connected to the upper end of the column 83. The lower end of the column 83 is pivotally supported by a bearing 85 attached to the frame of the fixed frame 45 via a pin 87. A step 89 is provided at the upper end of the pillar 83.
A seat plate 91 fitted to the column 83 is supported on the step 89.

A plurality of adjusting bolts 93 are provided penetrating the fluid pressure cylinder 75 through the seat plate 91. The adjusting bolts 93 are elastically fitted between the seat plate 91 and the fluid pressure cylinder 75. An adjusting nut 97 for adjusting the stored force of the bullet 95 such as a mounted disc spring or urethane rubber and the amount of elevation of the elevating frame 47 by the bullet 95 is screwed. The ammunition 95 is used for the lifting frame 47.
It is stored enough to push up etc.

With the above-mentioned structure, the elevating frame 47 is vertically swung by appropriately operating the fluid pressure cylinder 75. Therefore, the lifting frame 47
By lowering, the work W placed and positioned on the lower presser die 51 is held and fixed to the lower presser die 51 by the upper presser die 65. Further, by raising the elevating frame 47, the holding and fixing of the work W is released. At this time, when the supply of the working fluid to the fluid pressure cylinder 75 is stopped and the fluid pressure cylinder 75 is put into a rest state, the elevating frame 47 causes the lift frame 47 to move.
A slight amount is pushed up by the action of 5, and the holding and fixing of the work W is released.

In order to bend the rear end edge of the work W clamped and fixed by the lower presser die 51 and the upper presser die 65 upward or downward in an L-shape, a bending portion 99D is formed.
And the bent portion 99U is provided so as to be vertically separated.
More specifically, the upper and lower bent portions 99U and 99D are provided to extend in the left-right direction to have substantially the same length as the presser foot mold 51, and the upper and lower bent portions 99U and 99D are provided to the presser foot mold 5 respectively.
1, a bending die 1 arranged at a rear position of the presser foot die 65
01 are provided to face each other vertically.

The bending die 101 is stretched in the left-right direction, and the bending die frame 103 is swingable in the vertical direction near the left and right end portions and the central portion of the bending die 101.
Is supported at the front end of the. More specifically, the bending die frame 103 is composed of a pair of right and left swing plates,
The rear end of the bendable frame 103 is rotatably supported by an eccentric portion 105E of an eccentric shaft 105 that is rotatably supported by the bearing bracket 61 at a position substantially the same as the pivot shaft 63. .

In order to bring the minute gap between the eccentric portion 105E of the eccentric shaft 105 and the pivotal support portion of the bending die frame 103 to one side, an ammunition for urging the bending die frame 103 in one direction is provided. .

As can be understood from the above structure, the bendable frame 103 is vertically swingable about the eccentric portion 105E of the eccentric shaft 105 and is always pulled backward by the action of the ammunition. It is a thing. Therefore,
Eccentric portion 105E of eccentric shaft 105 and bending frame 103
The small gap with the pivotal part of the is always pushed to the rear side. Therefore, even if an external force is applied to the bending die frame 103 in the backward direction, the bending die frame 103 does not move at all.

Referring again to FIG. 5, the bending die frame 103 is swung in the vertical direction to form the upper and lower bending portions 99.
In order to bend the rear end edge of the work W by U and 99D, the bending drive device 10 is attached to the bending die frame 103.
7 is provided. More specifically, the bending drive device 107 is composed of a fluid pressure cylinder 109 in this embodiment. The fluid pressure cylinder 109 is swingably supported by the bending frame 103 via a trunnion 111. The lower end portion of the piston rod 112 protruding downward from the fluid pressure cylinder 109 is pivotally supported by a bracket mounted on the fixed frame 45 via a pin.

As shown in FIGS. 4 and 5, a bending angle detecting device is provided at the rear of the presser lower mold 51 side and / or the presser upper mold 65 side at appropriate intervals in the left-right direction. Laser sensor 113 is provided.

With the above-described structure, the work W is held between the presser foot lower die 51 and the presser foot upper die 65 as shown in FIG. 6 (A).
As shown in FIG. 5, the bending die frame 103 is moved down to bring the bending portion 99D into contact with the work W to start bending. When the bending die frame 103 is further lowered, the work W is bent by the bending portion 99D as shown in FIG. 6B. Laser sensor 1 in this state
The bending angle (α ₁ ) of the work W bent at 13 is detected.

Next, the eccentric shaft 105 is moved in the direction away from the work W, and as shown in FIG. 6C, the laser sensor 113 is used with the bent portion 99D completely separated from the work W. Detect the bending angle (α ₂ ). The springback amount (= α ₁ −α ₂ ) is calculated based on the detected bending angles α ₁ and α ₂ . Based on this calculated springback amount, FIG.
As shown in (D), by lowering the bending die frame 103 and moving the eccentric shaft 105 in the direction of the work W, the work W is bent at a desired L-shaped bending angle. Obtainable.

In the case of FIG. 6C, when the bent piece of the work W is short as shown in FIG. 6E, the corner portion of the bending die 101 is bent. Since it is longer than the length, it is not necessary to allow the bending die frame 103 to escape in the left-right direction, and the next bending process can be performed.

For example, as shown in FIG. 7, two upper and lower laser sensors 113A and 11A are provided on the side of the presser foot mold 51.
3B may be provided. The bending angle in this case can be obtained as shown in FIG. That is, the bending angle α is as shown in FIG.
In the case of an acute angle as shown in FIG.
13A, a ₁ the distance between 113B and bent piece, a _2, and a distance between the laser sensor 113A and 113B is L, since the _{tanβ = (a 1 -a 2)} / L, β = tan -1 It becomes {(a ₁ −a ₂ ) / L}.

Since α = 90-β, α = 90-ta
The bending angle θ can be obtained from n ⁻¹ {(a ₁ −a ₂ ) / L}.

Further, when the bending angle θ is an obtuse angle as shown in FIG. 8B, tan β = (a ₂ −a ₁ ) / L, so β = tan ⁻¹ {( a ₂ −a ₁ ) / L}.

Since α = 90 + β, α = 90 + ta
The bending angle θ can be obtained from n ⁻¹ {(a ₂ −a ₁ ) / L}.

A plurality of laser sensors are provided above and below when the pressure sensor 26 detects the spring back.
Springback can be detected by operating in the same manner as the bending angle is detected by 3A and 113B.

FIG. 9 shows another embodiment of the present invention. In FIG. 9, the bending apparatus 115 is configured in such a manner that an upper frame 117U is vertically movable above a box-shaped lower frame 117L.

More specifically, the upper and lower frames 117U,
Plural upper and lower hinge brackets 119U and 119D are arranged on the rear side of 117L (right side in FIG. 9),
The upper and lower hinge brackets 119U and 119D are the pivot 1
It is pivotally connected via 21.

In order to swing the upper frame 117U up and down about the pivot 121, the upper frame 117
A vertically moving motor M1 is mounted on the upper portion of U, and a crankshaft 129 rotated by an output gear 123, an intermediate gear 125 and a driven gear 127 of the motor M1 is attached to an upper portion of an upper frame 117U. 131
It is rotatably supported by. The upper ends of a plurality of C-shaped connecting members 135 are connected to the distal ends of the plurality of crank arms 133 fixed to the crank shaft 129 via pins 137, and the lower ends of the connecting members 137 are It is pivotally attached to the lower frame 117L via a pin 139.

With the above structure, when the motor M1 is driven to rotate the crankshaft 129 in the clockwise direction in FIG. 9, the upper frame 117U swings upward about the pivot 121 and the lower frame 117L and the upper frame 117L. The front side of the frame 117U is wide open vertically.

When the motor M1 is re-driven in the reverse direction,
The upper frame 117U descends and closes the front side.

In order to sandwich and fix the work W to be bent from above and below, a presser-up die 141U extending in a direction perpendicular to the paper surface in FIG. 9 is attached to the lower front portion of the upper frame 117U. A lower presser die 141L facing the upper presser die 141U is attached to the front upper portion of the lower frame 117L.

Therefore, by driving the motor M1 and swinging the upper frame 117U up and down as described above, the upper presser die and the lower presser die 141U, 141L are pressed.
This allows the work W to be held from above and below,
Moreover, the holding of the work W can be released.

The upper presser die and the lower presser die 141U, 1
The lower frame 117L and the upper frame 117U are provided with a lower bending mechanism 143L for bending the end side of the work W clamped and fixed by 41L upward and an upper bending mechanism 143U for bending downward. ing.

The upper bending mechanism 143U is provided with an upper bending portion holder 147U detachably supporting an upper bending portion 145U for bending the end portion side of the work W downward so as to be vertically movable.

More specifically, the upper bending portion holder 14 is
7U is the presser upper die, presser lower die 141U, 141L
And the upper bending portion holder 147U.
A plurality of holder brackets 149U which are inclined and extended rearward and upward are provided on the upper side of the. In addition, the upper bending portion holder 1 is provided at a plurality of positions on the rear surface of the upper bending portion holder 147U.
A plurality of upper guide links 1 for guiding the vertical swing of 47U
The tip end of 51U is pivotally connected via a hinge pin, and the base side of each upper guide link 151U is pivotally attached to a plurality of upper support brackets 153U mounted on the lower surface of the upper frame 117U via a pivot. is there.

An upper shaft 155U is rotatably supported on the upper frame 117U to move the upper bent portion holder 147U up and down, and upper bell cranks 157U are attached to a plurality of positions of the upper shaft 155U. . One end of the bell crank 157U is pivotally connected to the upper end of the holder bracket 149U via a pin. The other end of the bell crank 157U is the intermediate link 1
59U is pivotally connected to one end of the intermediate link 159U via a pin, and the other end of the intermediate link 159U is pivotally connected to a crank arm 161U via a pin.

The crank arm 161U is mounted on a rotary shaft 163U which is rotatably supported by a plurality of brackets mounted on the upper frame 117U.
The intermediate gear 167 is attached to the driven gear 165U attached to the 63U.
U is meshed. And in the intermediate gear 167U,
The output gear 169U of the motor M2 mounted on the upper frame 117U is meshed.

With the above structure, when the motor M2 is driven to rotate the rotary shaft 163U in the clockwise direction in FIG. 9, the bell crank 157U is passed through the intermediate link 159U.
Is rotated counterclockwise, the upper bending portion holder 147U is moved downward.

When the upper bending portion holder 147U moves downward, the upper bending portion holder 147U moves downward toward the workpiece W while drawing a large arc under the restriction of the upper guide link 151U. In this case, the upper guide link 151U is extremely long as compared with the plate thickness of the work W, and the locus of the tip end portion thereof is a part of an extremely large arc, so it can be considered that the upper guide link 151U moves substantially linearly.

The rotation of the bell crank 157U progresses, and the holder bracket 149U and the bell crank 157U are rotated.
When the pin 171U connecting the and reaches the position of the position 171A, the pin 171U is located at a position immediately before contacting the tip end work W of the upper bending portion 145U.

When the rotation of the bell crank 157U further progresses and the pin 171U reaches the position 171B, the tip end of the upper bending portion 145U is pressed down by the pressing lower die 141L.
The work W is bent downward by 90 ° or more at the position where it is rotated downward, and the overbend is performed.

As will be understood from the above description, in the initial state, the upper bending portion 145U is located at the upper position, which is largely separated from the bending position of the work W. Then, in the vicinity of the position where the upper bending portion 145U bends the end portion side of the work W downward, the upper guide link 15
1U is in a substantially horizontal state and swings up and down slightly, and the upper bending portion holder 147U supporting the upper bending portion 145U swings back and forth around the hinge pin at the tip of the upper guide link 151U. As a result, the tip of the upper bending portion 145U rotates downward while drawing a trajectory.

That is, according to this embodiment, since the upper bending mechanism 143U is constituted by the link mechanism, the upper bending portion 145U can be largely retracted upward from the bending position. Therefore, the rising dimension of the rising portion when the end portion side of the work W is bent upward can be increased.

When the end portion side of the work W is bent downward, the upper bending portion 145U approaches a substantially straight line (to be exact, a large arc shape) at a position immediately before contacting the work W from the upward retracted position. Then, after bending the end portion side of the work W, the tip portion of the upper bending portion 145U draws a sharp curve by swinging around the pin to hold down the lower die 141L.
The work W can be bent accurately because it is pivoted downward to perform the overbend.

The lower bending mechanism 143L for bending the end portion side of the work W upward is composed of the lower frame 1
The work W can be bent by driving the motor M3 attached to 17L. The lower bending mechanism 143L is slightly different in that the length of the lower guide link 151L is shorter than that of the upper guide link 151U, and other configurations are the same as the upper bending mechanism 14L.
It is vertically symmetrical with 3L.

Therefore, a component L having the same function is denoted by a symbol L instead of a symbol U, and a detailed description of the configuration and operation of the lower bending mechanism 143U is omitted.

As described above, when the work W is bent on the end side and the plate thickness of the work W is changed, the work clamp upper and lower molds 1 holding and fixing the work W are held.
It is desirable to adjust the clearance between 41U and 141L and the upper and lower bent portions 145U and 145D according to the plate thickness.

Therefore, in the present embodiment, the above-mentioned clearance can be adjusted.

That is, the upper guide link 151U
Support bracket 153U supporting the base side of the
Can be moved in the front-rear direction by being guided by a guide member 173U provided in the upper frame 117U in the front-rear direction (left-right direction in FIG. 9). The tip end of the adjustment link 175U is pivotally connected to each upper support bracket 153U via a pivot 177U, and the base side of each adjustment link 175U is rotatably attached to a bracket 117B provided on the upper frame 117U. Supported adjustment shaft 179U
Is fitted to the eccentric portion 179E.

Therefore, the adjustment shaft 179U is rotated by rotating the output gear 183 of the motor M4 meshing with the gear 181 (see FIG. 10) attached to the adjustment shaft 179U, and the eccentric portion 179E causes eccentric rotation to cause the eccentric rotation. The upper support bracket 153U is moved in the left-right direction in FIG.

Therefore, the upper bending portion holder 147U is moved in the left-right direction in FIG. 9 via the upper supporting brackets 153U and the upper guide link 151U, and the upper bending portion 145 supported by the upper bending portion holder 147U.
The clearance between U and the pressing upper mold and the pressing lower mold 141U, 141L can be adjusted according to the plate thickness of the work W. The back-and-forth movement of the upper bending portion holder 147U for adjusting the clearance corresponds to the plate thickness of the work W and is therefore small, and cannot be used for the above-described overbend.

As described above, when the end portion side of the work W is bent up and down, the upper and lower bent portions 145U and 145L receive a component force in the horizontal direction due to the drag force of the work W during the bending process. Due to this horizontal component force, the upper and lower bent portions 145
The upper and lower plates 14 are the central portions in the longitudinal direction of U and 145L.
It tends to bend away from 1U and 141L. In the above curve, the width of the work W is smaller than the length of the upper and lower bent portions 145U and 145L, and the upper and lower bent portions 145
This is remarkable when the horizontal component force acts only near the central portion of U, 145L.

Therefore, in the present embodiment, the upper and lower bent portions 145U and 145L are pre-curved in the opposite direction of the curving, so that the curving which tends to occur when the work W is bent can be corrected in advance. is there.

That is, as shown in FIG. 10, an eccentric portion 177E is provided on the pivot 177U that pivotally connects the adjustment link 175U and the upper support bracket 153U. However, the eccentric amount of the eccentric portion 177E differs depending on each position, the eccentric amount of the eccentric portion 177E1 at the central portion in the longitudinal direction of the adjustment shaft 179U is zero, and the eccentric portion 177E2 on the inner side in the longitudinal direction is closer to the end. Eccentric part 177
The eccentricity amount of E3 is set larger.

Since the eccentric directions of the eccentric portions 177E2 to 177E3 are the same (for example, upward or downward),
When the pivot 177U is appropriately rotated by the motor M5 provided as appropriate, each upper support bracket 153U is moved to the position shown in FIG.
In FIG. 10, it slightly moves in the left-right direction with respect to the adjustment link 175U. In this case, each eccentric portion 177E1
Since the eccentricity of 177E3 is different, each support bracket 1
The amount of movement of 53U is different, and as a result, the central portion of the upper bending portion holder 147U in the longitudinal direction can be curved so as to project in the direction of the upper presser die and the lower presser die 141U, 141L.

Therefore, it is possible to correct the bending of the upper bending portion holder 147U due to the horizontal component force received when the work W is bent, and the work W can be bent with higher accuracy.

Referring again to FIG. 9, a laser sensor 185 as a bending angle detecting device for detecting a bending angle when the work W is bent is provided on the upper presser die and the lower presser die 141U, 141L side. Has been.

With the above structure, the work W is pressed down and the lower die 1 is pressed.
The lower bending portion holder 147D is lowered while being held between 41L and the presser upper die 141U.
The work W is bent at 5 L. In this state, the laser sensor 185 detects the bending angle α ₁ . Then, the adjustment shaft 179 is moved to the right side in FIG.
45L is completely separated from the work W. The bending angle α ₂ of the work W bent in the separated state is detected by the laser sensor 185.

The springback amount (= α ₁ −α ₂ ) is obtained based on the detected bending angles α ₁ and α ₂ , and the upper bending portion holder 147 is obtained based on this springback amount.
U can be lowered and the adjustment shaft 179 can be moved in the direction of the workpiece W to perform bending work at the upper bending portion 145U so that a desired bending angle (α ₀ ) can be obtained.

When performing the auxiliary bending process in the upper bending portion 145U based on the springback amount at each position in the longitudinal direction of the work W, the eccentric portions 177E1 to 177E3 of the adjusting shaft 179U.
By adjusting and adjusting the adjustment shaft 179U in the direction of the work W, the bending angle of the work W in the longitudinal direction can be bent with high accuracy.

The present invention is not limited to the above-described embodiments, but can be implemented in other modes by making appropriate changes.

[0097]

As can be understood from the above description of the embodiments, according to the present invention, in the bending process of the L-shape, the work is made to significantly protrude from the lower die.
It can be arranged .

[0098] Further, by providing the bending angle detecting device into presser lower mold side or / and the pressing upper die side or / and bending tool side, the bending angle at the time of bending the workpiece in situ It can be reliably detected and the springback can be calculated and obtained. Therefore, it is possible to perform a highly accurate bending process in consideration of the springback amount.

[0099]

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a bending apparatus of the present invention.

FIG. 2 is an explanatory view explaining the operation of the bending method of the present invention.

FIG. 3 is an operation explanatory view for obtaining a bending angle of 90 ° on a work.

FIG. 4 is a front view showing another bending apparatus of the present invention.

5 is a right side view of FIG. 4. FIG.

FIG. 6 is an operation explanatory view of bending a work by the bending apparatus shown in FIG.

FIG. 7 is an explanatory diagram in which a plurality of laser sensors are provided above and below a presser foot mold 51.

8 is an explanatory diagram for detecting a bending angle with the laser sensor shown in FIG.

FIG. 9 is a right side view showing another bending apparatus of the present invention.

10 is a cross-sectional plan view of FIG.

[Explanation of symbols]

1 Bending machine 5 Presser foot mold 7 Mold holder 9 Presser die 11 Laser sensor (bending angle detector) 13 Ram 17 fluid cylinder 19 piston rod 21 Bending die 23U, 23D bending part 26 Pressure sensor (springback detection device) 33 NC device

Continuation of the front page (56) Reference JP-A-3-180215 (JP, A) JP-A-61-232018 (JP, A) Actual development 5-70721 (JP, U) (58) Fields investigated (Int .Cl. ⁷ , DB name) B21D 5/04

Claims (4)

(57) [Claims] 1. A bending die (21) for performing an L-shaped bending process on a work (W) held by a lower presser die (5) and an upper presser die (9) is movable up and down. Prepared for Ram
A pair of upper and lower bent portion provided at the bottom when both the bending tool (21) of (13) to (23U, 23D) provided, the position where the lower bent portion (23D) is above said workpiece (W) The bending die (21) is provided so as to be able to move up ,
The work (W) is formed by the lower bent portion (23D).
After bending down, the upper bent part (23U)
Touch the work (W) and follow the work (W) by a predetermined amount.
A bending device characterized by being configured so that it can be inserted freely . 2. The bending apparatus according to claim 1, wherein the bending die (21) is attached to the ram (13).
The bending apparatus is provided so as to be movable toward and away from the work (W). 3. The bending apparatus according to claim 1, wherein a springback detection device (26) for detecting springback of the work (W) is provided in a pair of upper and lower front parts.
The bending die between the bending portions (23U, 23D)
A bending apparatus provided in (21) . 4. The bending apparatus according to claim 1, 2 or 3, wherein the work (W) is bent toward the presser lower die (5) side and / or the upper die (9) side. And a bending angle detecting device for detecting the bending angle of the bending angle.