JPH0985347A - Method and device for exchanging die in bending equipment, and center die used for the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily remove a center die from a center die changing arm, and to improve the positioning accuracy in repeatedly fitting the center die to the center die changing arm. SOLUTION: When a holding piece 109 of a center die changing arm 37 is engaged with a second groove 107 of a center die C, the center die C is held by the center die changing arm 37. When the center die C is set to the fitting position, a hammer member 119 converts the rotational force of the die changing arm 37 into the pressing force to press the upper face of the center die C to allow the center die C to be accurately positioned to the center die changing arm 37. When the center die C is changed at the die changing position K, the hammer member 119 is lowered to make a small clearance and to avoid the interference with the center die C, and the center die C can be easily removed from the center die changing arm 37.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold exchanging method in a bending machine which is capable of exchanging a center mold forming a part of an upper mold in a press brake as a folding machine, and a method therefor. The present invention relates to a device and a center mold used for the device.

[0002]

2. Description of the Related Art Conventionally, a panel in which each end of four sides of a rectangular work is bent once or twice or more is used for a cabinet, a showcase, or the like. To manufacture such a panel, a work is bent by a bending device such as an ironing and bending machine.

Among the folding devices, as known from, for example, Japanese Patent Application Laid-Open No. 61-103626,
For example, dozens of thin-walled clamp dies, which are center dies, are attached to the center of the clamp dies that hold down the work, and the required number of thin-walled clamp dies are reversed according to the length of the work. Is being adjusted.

The above-mentioned thin clamp mold has a problem that it is weak in strength because it is literally thin and that machining is very complicated. In order to improve this problem, a thin clamp die is not used, but a large number of integrated center dies with a pitch of several mm are prepared, and one of the above center dies is selected according to the length of the work. There has been considered a die exchanging device of a bending apparatus in which a center die having a required length is selectively exchanged so that the length of the die can be easily adjusted.

[0005]

By the way, in the mold exchanging apparatus in the above-described bending apparatus, an attaching / detaching mechanism in which the center die is detachably attached to the tip of the center die exchanging arm is conventionally known. Since it uses a chuck claw, the mechanism is complicated and the operation at the time of attachment / detachment is very difficult, and the positioning accuracy of repetition is not very good.

An object of the present invention is to provide a bending apparatus capable of easily removing the center mold from the center mold exchanging arm and improving the positioning accuracy when the center mold is repeatedly attached to the center mold exchanging arm. It is an object of the present invention to provide a mold exchanging method, an apparatus therefor, and a center die used for the apparatus.

[0007]

In order to achieve the above object, the method of exchanging dies in the bending apparatus of the present invention according to claim 1 is such that the upper table which can be moved up and down can be swung approximately at the center of the lower table. An upper mold composed of a replaceable center mold provided on a provided center mold exchanging arm and a plurality of split molds slidably provided on the left and right parts of the center mold, and an upper mold A bending device that bends a work in cooperation with a lower mold placed opposite to the mold, and is stored in a mold magazine provided near the rear side of the upper table. A center member for exchanging the center die for exchanging the center die for exchanging the center die exchanging arm reciprocating between the die exchanging position of the center die for exchanging and the mounting position at the lower end of the upper table. The mold When bets are by the action of the clamp, it is characterized in that the allowed to transmit the load acting on the center mold when bending to the upper table.

According to a second aspect of the present invention, there is provided a die exchanging device in the bending apparatus according to the present invention. An upper mold composed of a possible center mold and a large number of split molds slidably provided on the left and right parts of the center mold, and a lower mold arranged so as to face the upper mold. It is a bending device that bends a work in cooperation with, and a mold magazine accommodating a plurality of replacement center molds is provided close to the rear side of the upper table, and is stored in this mold magazine. The center mold exchanging arm that reciprocates between the mold exchanging position of the replaced center mold and the mounting position at the lower end of the upper table is engageable with the groove formed in the center mold. A holding piece is provided and the die At the time of replacement, avoiding interference with the center mold, and transmitting the load acting on the center mold when setting the center mold at the mounting position to the upper table and clamping the center mold, the hammer member is replaced. It is characterized in that the arm is provided so as to be vertically movable.

A center mold used in the mold exchanging apparatus according to claim 2, wherein a first groove engageable and disengageable with a mold holder provided in the mold magazine, and the center mold exchanging arm. It is characterized in that a plurality of second grooves that can be engaged and disengaged are provided in a plurality of stages on the engaging portion provided on the.

According to the first and second aspects of the present invention, there is provided a method and apparatus for exchanging a die in a bending apparatus, wherein a center die and an upper die composed of split dies provided on the right and left sides of the center die are provided. The work is bent by causing the lower die and the upper table to move up and down in cooperation with each other.

The center mold exchanging arm holds the center mold by engaging an engaging portion provided on the center mold exchanging arm with a second groove formed in the center mold. It Then, when the center mold held by the center mold exchanging arm is set to the mounting position which is the lower end position of the upper table, the hammer member provided on the center mold exchanging arm causes the center mold to rotate to the center mold. Is converted into a force pressing the upper surface of the center mold, so that the center mold is accurately positioned on the center mold exchanging arm. Moreover, the positioning accuracy is improved because the positioning is performed in the same manner even if it is repeatedly performed. Further, when the center mold replacement arm is rotated to bring the center mold to the mold replacement position and replaces the center mold, the hammer member descends and a slight gap is created, resulting in interference with the center mold. Avoided. Also,
This hammer member transmits the force acting on the center mold to the upper table during bending.

In the center die of the present invention according to claim 3, since the first groove and the second groove have a plurality of steps,
The mold holder provided in the mold magazine is disengaged from the groove, and the engaging portion provided to the center mold exchanging arm is disengaged from the second groove.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIGS. 1 and 2, for example, a press brake 1 as a bending device is provided with left and right side frames 3 which are vertically installed, and a lower table is provided at a lower front portion of the side frames 3. 5 is fixed, and an upper table 7 that can move up and down is provided on the upper front side of the side frame 3.

A hydraulic cylinder 9 is provided on an upper portion of each side frame 3, and a lower end of a piston rod mounted on each hydraulic cylinder 9 is fixed to both sides of the upper table 7.

With the above structure, when the hydraulic cylinder 9 is operated, the upper table 7 is moved up and down with respect to the lower table 5 via the piston rod.

A lower die 1 is provided on the lower table 5.
1, and an upper die 13 is provided below the upper table 7. A back gauge 15 is provided behind the side frames 3 and is movable back and forth for abutting and positioning a work.

With the above structure, the back gauge 15 is preliminarily positioned at a desired position and one end of the work is abutted,
By operating the hydraulic cylinder 9 to move the upper table 7 up and down, the work is bent by the cooperation of the upper mold 13 and the lower mold 11. By bending the four sides of the work in the above-described manner, for example, a box-shaped bent product can be obtained.

As shown in FIG. 2, a mold supporting beam 17 is integrally provided on the lower portion of the upper table 7 by welding or the like. This mold supporting beam 1
A replaceable center mold C of the upper mold 13 is provided in the longitudinal direction of 7, that is, substantially in the center in the left-right direction in FIG. On the mold supporting beams 17 on the right and left sides of the replaceable center mold C, left split molds L1 to L17 are provided via a left centering mold L0, and right sides are provided via a right centering mold R0. Split mold R1 to R1
7 are provided. These split molds L0 to L17, R
The length of 0 to R17 is, for example, 100 mm. As the center mold C, a center mold C0 having a length of 100 mm as a reference, for example, a length of 5 mm is increased.
It is possible to replace it by including ~ C19.

The left and right reference molds L1 to L17,
A mold selection cylinder 19 is provided above R1 to R17. Further, the mold supporting beam 17 is provided with opening / closing cylinders 21L, 21R. By operating the opening / closing cylinders 21L, 21R to select and operate each mold selection cylinder 19, the left side is opened. , One of the right side reference dies L1 to L17 and R1 to R17 is selected, and the length of the divided dies is determined to be a desired length. The opening / closing cylinder 21L,
21R, the connection state of each mold selection cylinder 19 is already known, and thus a detailed description thereof will be omitted.

The replaceable center mold C is carried out by a mold changing unit 25 of a mold changing device 23 provided at a substantially central portion on the rear side of the upper table 7. Moreover, the center mold C0 for various exchanges of the center mold C
Twenty to C19 are stored in the storage portion of the mold magazine 27 attached to the upper table 7 above the mold replacement unit 25.

As shown in FIGS. 3, 4 and 5, the mold exchanging unit 25 in the mold exchanging device 23 has a first wedge member 29, on the rear side of the upper table 7, as shown in FIGS. The fixed frame 33 is attached with a plurality of bolts via the second wedge member 31.

A rotating shaft 35 extending in the left-right direction (direction orthogonal to the paper surface in FIGS. 4 and 5) is rotatably supported by the fixed frame 33. The rear end of the center mold exchanging arm 37 is attached to the rotating shaft 35, and the center mold exchanging arm 37 is attached.
A center mold C is detachably provided at the tip of the.
A pinion 39 is attached to the rotating shaft 35.

On the other hand, a rotating air cylinder 41 is attached to the fixed frame 33, and a tip end of a piston rod 43 mounted on the rotating air cylinder 41 has a rack 45 extending in the left-right direction in FIG. One end is attached. This rack 45 is the pinion 3
9 is meshed.

With the above structure, the rotating air cylinder 41 is provided.
Is operated to extend the piston rod 43 to the right in FIG. 5, the rack 45 is moved together with the piston rod 43, so that the pinion 39 is rotated. The rotation of the pinion 39 causes the center mold exchanging arm 37 to rotate 180 degrees clockwise in FIG. 5 via the rotation shaft 35. The position of the center mold C provided on the rotated center mold changing arm 37 (the position indicated by the chain double-dashed line in FIG. 5) becomes the mold changing position K.

As shown in FIG. 3, a center mold C rotated by a rotating shaft 35 is positioned as a mold exchange position K in the lower center of the mold supporting beam 17 and substantially in the center thereof. ing. Bearings 47 are hung on both sides of the center mold C and integrated with the mold supporting beam 17. Each of the bearings 47 has a left-hand screw 49 that is rotatable.
A ball screw 49 in which an L and a right screw 49R are integrated is supported. Nut members 51L and 51R are screwed into the left screw 49L and the right screw 49R, respectively, and the left and right punching dies L0 and R0 are integrated with the nut members 51L and 51R, respectively.

Servo motor 5 is attached to the fixed frame 33.
3 is provided, and the output shaft 5 of this servo motor 53
A drive pulley 57 is attached to the device 5. On the other hand, a driven pulley 59 is mounted on the ball screw 49, and the driven pulley 59 and the drive pulley 57 are connected to the belt 6 by the belt 6.
1 is wound.

With the above construction, when the servo motor 53 is driven, the drive pulley 57 is rotated via the output shaft 55, so that the ball screw 49 is rotated via the belt 61 and the driven pulley 59. Due to the rotation of the ball screw 49, the left and right punching dies L0 and R0 are moved toward and away from the center die C via the nut members 51L and 51R.

On the upper rear side of the upper table 7, as shown in FIGS. 6, 7 and 8, the horizontal direction (the direction orthogonal to the paper surface in FIG. 6, the horizontal direction in FIG. 7). A plurality of guide rails 63 extending to are laid, and a movable base 67 is provided on each of the guide rails 63 via a plurality of linear guide blocks 65.

The tip of one piston rod 71 mounted on the double-headed air cylinder 69 is fixed to the upper table 7 by a mounting bracket 73, and the piston rod 75 of the other piston rod 75 mounted on the double-headed air cylinder 69 is fixed. The tip is fixed to the movable base 67.

Drum bases 77L and 77R are integrated on the left and right sides of the movable base 67. The upper drive sprocket 7 is located above and below the drum bases 77L and 77R.
9L, 79R and lower drive sprockets 81L, 81R are connected by a shaft 83 and are rotatably supported. Chains 85L and 85R are respectively wound around the upper drive sprockets 79L and 79R and the lower drive sprockets 81L and 81R. With these structures, a pair of drums 86L and 86R are formed.

Each of the chains 85L and 85R is provided with a die holder 87 as a die accommodating portion at an appropriate interval, for example, 1 each.
Each of the die holders 87 holds 0 pieces, and replaceable center dies C0 to C19 are detachably provided.

The upper table 7 is provided with a rotation drive motor 89, and a drive sprocket 93 is attached to an output shaft 91 of the rotation drive motor 89.
On the other hand, a drive sprocket 95 is mounted on the shaft 83 on which the drive sprocket 81R is mounted. A chain 97 is wound around the driven sprocket 95 and the drive sprocket 93.

As shown in FIG. 7, stopper members 99L and 99R are provided on both left and right sides of the movable base 67, and the stopper members 99L and 99R are also provided.
Stopper pins 101L and 101R corresponding to the above are provided on the upper table 7.

With the above structure, when the rotation drive motor 89 is driven, the drive sprocket 93 is rotated via the output shaft 91. The rotation of the drive sprocket 93 causes the lower shaft 83 to rotate via the chain 97 and the driven sprocket 95.
The R and 81L are rotated and the chains 85R and 85L are rotated.

By rotating the chains 85R and 85L,
The center molds C0 to C19 provided on the chains 85R and 85L via the mold holder 87 are rotated.

By operating the double-headed air cylinder 69 to expand and contract the piston rods 71 and 75, the movable base 67 moves in the left-right direction in FIG.
Stopper members 99L, 99 provided on the movable base 67
When R contacts the stopper pins 101L and 101R, the center mold C held by the chains 85L and 85R is positioned at the mold replacement position K.

Therefore, the operation of exchanging the center mold C with the center mold exchanging arm 37 rotated to the mold exchanging position K (the state shown in FIG. 6) will be described. First,
The center mold exchanging arm 37 holding the center mold C at the mold exchanging position K is rotated and positioned. Then, the rotation drive motor 89 is driven to drive the chains 85L and 85R to rotate, and the empty die holder 87 not holding the center die C is brought to the lower end and stopped. It is operated to move the empty mold holder 87 to the mold replacement position K. Next, the center mold C held by the mold exchanging arm 37 is removed and held by the empty mold holder 87.

Then, the movable base 67 is returned to its original position, and the center mold C to be held by the center mold exchanging arm 37 is selected. The selected center mold C is the chain 85L or 85R. Run to rotate to the bottom so that it stops. Next, the selected center mold C is moved to the mold exchange position K. The center mold C is held by the center mold exchanging arm 37, so that the center mold C can be automatically exchanged.

Then, the position where the center mold exchanging arm 37 is rotated is fixed as the mold exchanging position K, and the exchanging center mold C stored in the mold magazine 27 is moved to the left and right. The center die C can be automatically exchanged from the die magazine 27 to the center die exchange 37 or from the center die exchange arm 37 to the die magazine 27 by positioning at the die exchange position K. Moreover, it is possible to improve the positioning accuracy of the center mold C whose mold replacement position K is always constant.

Referring to FIGS. 4 and 9, a grip 103 is attached to the base of the center mold C with a plurality of bolts, and a first groove for engagement is provided on the lower and upper parts of the grip 103. 105 and a second groove 107 are formed. Also,
A holding piece 109 is provided on the mold exchanging arm 37 with a pin 111.
Is provided so as to be swingable with respect to a fulcrum, and the holding piece 109
Rear part (upper part in FIG. 4) and the mold changing arm 37
A spring 113 is attached between and. A vertical groove 103T is formed in the grip portion 103.

With the above-described structure, the holding piece 109 swings about the pin 111 as a fulcrum by the urging force of the spring 113, and the projection 109T at the tip of the holding piece 109 engages with the vertical groove 103T, so that the center metal is always operated. The mold C is held by the center mold exchanging arm 37.

As shown in FIG. 9, the center mold exchanging arm 37 is rotated by 180 degrees, for example, to move the mold exchanging position K.
When the holding piece 1 is positioned, the piston rod 117 of the air cylinder 115 provided on the fixed frame 33 extends to the left side in FIG.
09 resists the biasing force of the spring 113 and rotates clockwise around the pin 111 as a fulcrum in FIG. 9, so that the projecting portion 109T of the holding piece 109 is disengaged from the vertical groove 103T.

As shown in FIGS. 4 and 9, a hammer member 119 is mounted in the center mold exchanging arm 37, and a hammer member 119 is mounted below the hammer member 119 as shown in FIG. A center mold C is provided. The hammer member 119 is biased upward by the spring 121 in FIG. This hammer member 119
A moving block 123 is provided on the upper part of. An engaging portion 37K that engages with the second groove 107 is provided at the tip of the mold arm 37.

With the above structure, the center mold exchanging arm 3
7 is rotated by 180 degrees, for example, and the mold replacement position K shown in FIG.
Then, the hammer member 119 is slightly moved downward by the urging force of the spring 121, and the upper surface (lower surface in FIG. 9) of the grip 103 of the center mold C and the hammer member 1 are moved.
Since a slight gap is formed between the upper surface of 19 and the center die C, it is possible to avoid interference with the center die C when the die is exchanged, and the die can be smoothly exchanged.

When the center mold exchanging arm 37 is rotated, for example, 180 degrees from the mold exchanging position K and set to the mold mounting position shown in FIG. 4, the load applied by the hammer member 119 to the center mold C is increased. Is transferred to the moving block 123, the clamping force is converted into a pressing force by the hammer member 119 so that the clamping force is applied between the lower surface of the hammer member 119 and the upper surface of the grip portion 103. Works. Further, a ball plunger 120 is provided on the outer periphery of the engaging portion 37, and the plunger 120 is previously pressed before clamping to serve as a reference. Then, the center mold C is replaced by the center mold exchanging arm 37.
Can be accurately positioned. Moreover, the positioning is performed in the same manner even if it is repeated, so that the positioning accuracy can be improved.

The vertical groove 103T provided in the grip portion 103 of the center mold C allows the holding piece 109 to be easily engaged and disengaged, and the first groove 105 is provided in the mold magazine 27, the details of which will be described later. The lock piece can be easily engaged and disengaged.

When the rotating air cylinder 41 is operated, the center mold exchanging arm (also referred to as the center mold supporting member) 37 is rotated counterclockwise in FIG. 4, and the center mold C is moved to the position shown in FIG. In, the position is moved from the position of the solid line to the position of the chain double-dashed line.

Referring to FIGS. 4 and 10, the moving block 123 provided on the upper portion of the hammer member 119.
However, when the center mold C is rotated forward, it is moved to the position indicated by the dotted line in FIG. The movement of the movement block 123 is performed by the movement mechanism shown in FIG.

That is, in FIG. 10, movable base plates 133A and 133B are attached to the mold support arm 17 with a plurality of bolts, and guides extending in the left-right direction in FIG. 10 are provided inside the movable base plates 133A and 133B. The rail 135 is integrated. The moving block 123 is slidably provided on each of the guide rails 135.

A bracket 137 is attached to the left side of the moving block 123 in FIG. 10 with a plurality of bolts. Moreover, this bracket 137 has a long hole 13
9 is formed.

On the other hand, the rear side of the upper table 7 (see FIG.
A rotary actuator 141 is provided on the left side of FIG. A rotary shaft 143 of the rotary actuator 141 is rotatably supported by a base portion 145A of a rotary arm 145, and a tip portion 14 of the rotary arm 145 is supported.
5B is provided with a pin 147. This pin 147
Is accommodated in the long hole 139 of the bracket 137.

When the rotary actuator 141 is driven by the above-mentioned structure, the rotary shaft 143 moves to the position shown in FIG.
When it is rotated clockwise in
5 is also rotated in the same direction. As a result, the rotating arm 145
The pin 147 provided at the tip portion 145B of the
After moving within 39, the moving block 123 is guided by the guide rail 135 and moved leftward in FIG.

When the moving block 123 is returned to its original position, the rotary shaft 143 is rotated in the reverse direction, whereby the rotary arm 145 is rotated counterclockwise in FIG. 10, and the tip portion of the rotary arm 145 is rotated. 145B is the moving block 123
By pushing the left side wall of the moving block 123, the moving block 123 is guided by the guide rail 135 and returned to its original position.

Split mold L1 constituting the upper mold 13
The shapes of L17 to R17 (R1 to R17) are as shown in FIG. That is, in FIG. 11, an outer protruding portion 149 protruding outward is provided at a lower portion of the split molds L1 to L17 (R1 to R17), and a left punching mold L0.
An inwardly projecting portion 151 that can freely come into contact with the side surface of the (right side punching die R0) is provided.

With the above construction, when the bent product G is taken out from the mold as shown in FIG. 12, the rotary actuator 141 is first driven to avoid the moving block 123 shown by the dotted line in FIG. It is moved to the position so that it does not interfere with the hammer member 119.

Next, the rotating air cylinder 41 is operated to rotate the center mold exchanging arm 37 counterclockwise in FIG. 4 to move the center mold C from the position indicated by the solid line to the position 2 in FIG.
By turning the position indicated by the dotted line, that is, by slightly rotating it in the forward direction, the left and right left and right middle punching dies L0, R0
The contact with is released.

Then, the left and right punching dies L0, R0
When the split molds L1 to L17 and R1 to R17 are moved to the center side as shown by the arrows in FIG. 12, the left and right outward protruding portions 149 of the split molds L1 to L17 and R1 to R17 are bent products. Since it is pulled out from the G groove G _V ,
The bent product G can be easily taken out of the mold.

As shown in FIGS. 5, 6, 9 and 13, a pair of drums 86L and 86R are provided with die holders 87 (10 pieces in this embodiment), which are storage parts. The tip portion 87A of each die holder 87 has a first groove 105 formed in the grip portion 103 of the center die C.
It is possible to engage and disengage.

A lock piece 153 is swingably provided by a pin 155 on the right side of each mold holder 87 in FIGS. 9 and 13. A lock pin 157 is provided at the tip of the lock piece 153. Moreover, FIG. 9 and FIG.
3, the spring 159 is interposed between the mold holder 87 and the upper portion of the lock piece 153. On the other hand, the vertical groove 103T is formed in the grip 103 of the center mold C.

With the above-described structure, the lock piece 153 is always rotated clockwise in FIG. 13 with the urging force of the spring 159 about the pin 155 as a fulcrum, so that the lock pin 157 is moved to the vertical groove 103T of the center mold C. Locked in. Therefore, the center mold C is the mold holder 8
It will always be held at 7.

As shown in FIGS. 13 and 14, the fixed frame 33 is provided with an air cylinder 163, and an arm member 167 is attached to the tip of a piston rod 165 attached to the air cylinder 163. It is installed. As shown in FIG.
4, a lock release piece 169 extending in the vertical direction is attached with a plurality of bolts. The fixed frame 3
3, the lower end of the swing arm 171 is pivotally supported by a pin 173, and the upper end of the swing arm 173 is provided on the arm member 167 by a pin 175.

With the above construction, when the air cylinder 163 is operated, the piston rod 165 extends in FIG. 13, and the swing arm 171 connected to the arm member 167 rotates counterclockwise in FIG. 13 with the pin 173 as a fulcrum. It is rotated. As a result, the lock release piece 169
By pressing the upper end of the lock piece 153, the lock piece 153 is rotated counterclockwise in FIG. 13 against the biasing force of the spring 159 about the pin 155 as a fulcrum. Vertical groove 1 of mold C
After being unlocked from 03T, the center mold C is free from the mold holder 87.

Therefore, when delivering the center die C between the die exchange position K and the die holder 87, when delivering the center die C from the center die exchange arm 37 to the die holder 87, The lock piece 153 provided on the die holder 87 and the vertical groove 103T provided on the center die C are locked in the engaged state.

Further, when the center mold C is transferred from the mold holder 87 to the center mold exchanging arm 37, the lock piece 153 can be easily retracted from the lock position when the mold magazine 27 is moved left and right. Can be delivered. The length of the lock release piece 169 is only the maximum length of the center mold C in order to move the center mold C housed in the mold holder 87 of the pair of drums 86L and 86R by moving the center mold C left and right. Although necessary, in order to move the center mold C stored in the mold holder 87 of the drum 86L or 86R on only one side to the left and right and replace it,
The length of the lock release piece 169 may be at least ½ of the maximum length of the center mold C.

At the mold exchange position K, the mold holder 87
Side lock piece 153 is a vertical groove 103T on the center mold C side.
When the mold magazine 27 is moved left and right while being disengaged from the center mold C and engaged with the engaging portion 37 of the mold exchanging arm 37 in the second groove 107 on the center mold C side, The tip of the die holder 87 is removed from the groove 105, and the center die C is held by the center die exchange arm 37.

In order to hold the center mold C in the empty mold holder 87 at the mold changing position K, the mold holder 87 is used.
Is engaged with the first groove 107 of the center mold C, and the lock pin 157 of the lock piece 153 is engaged with the vertical groove 103T of the center mold C. Furthermore, the second of center die C
The center mold C is held by the mold holder 87 by removing the tip of the mold holder 87 from the groove 107.

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

[0069]

As can be understood from the above description of the embodiments, the invention according to claims 1 and 2 provides that the holding piece provided on the center mold exchanging arm serves as a center mold. The center mold is held by the center mold exchanging arm by being engaged with the formed second groove. When the center mold held by the center mold exchanging arm is set to the mounting position which is the lower end of the upper table, the hammer member provided on the center mold exchanging arm applies the rotational force of the mold exchanging arm to the center mold. The center mold can be accurately positioned on the center mold exchanging arm by converting the upper surface of the center mold into a pressing force. Moreover, the positioning accuracy can be improved because the positioning is performed in the same manner even if it is repeated. When the center mold exchanging arm is rotated to bring the center mold to the mold exchanging position for exchanging, the hammer member descends and a slight gap is created to avoid interference with the center mold. The center die can be easily removed from the center die exchange arm. Further, this hammer member also has a role of transmitting the force acting on the center mold to the upper table during bending.

According to the third aspect of the present invention, the holding piece provided in the die magazine can be easily engaged with and disengaged from the first groove provided in the center die, and the center die is provided with the holding piece. It is possible to easily engage and disengage the holding piece provided with the center mold exchanging arm in the second groove.

[Brief description of drawings]

FIG. 1 is a left side view of a press brake as a bending device according to an embodiment of the present invention.

FIG. 2 is a rear view of FIG.

FIG. 3 is an enlarged view of a portion indicated by an arrow III in FIG.

FIG. 4 is an enlarged cross-sectional view of the IV arrow part in FIG.

FIG. 5 is an enlarged cross-sectional view of the V arrow view part in FIG.

FIG. 6 is an enlarged cross-sectional view of a VI arrow portion in FIG.

FIG. 7 is a front view of a movable base portion of the mold magazine.

FIG. 8 is a front view of a rotary drive portion that rotates a pair of drums in the mold magazine.

FIG. 9 is an enlarged side view of a portion where a center mold exchanging arm is rotated to a mold exchanging position.

FIG. 10 is an enlarged plan view of a moving block portion in FIG.

FIG. 11 is an enlarged front view of the split mold.

FIG. 12 is an operation explanatory view of taking out a bent product from the mold.

FIG. 13 is another enlarged view of the portion where the center mold exchanging arm is rotated to the mold exchanging position.

FIG. 14 is a view on arrow XIV in FIG. 13.

[Explanation of symbols]

 1 Press Brake (Bending Machine) 7 Upper Table 11 Lower Die 13 Upper Die 23 Die Changer 25 Die Exchange Unit 27 Die Magazine 33 Fixed Frame 37 Center Die Exchange Arm (Die Support Member) ) 37K Engagement part 67 Movable base (base) 77 Drum base 86L, 86R Drum 87 Mold holder (mold storage part) 103 Grip part 103T Vertical groove 105 First groove 107 Second groove 119 Hammer member 123 Moving block 141 Rotary actuator 149 Outer protrusion 151 Inner protrusion 153 Lock piece 157 Lock pin 169 Lock release piece C, C0 to C20 Center mold L0, R0 Medium die L1 to L17, R1 to R17 Split mold G Bending product

Claims (3)

[Claims] 1. A replaceable center mold provided on a center mold exchanging arm that is pivotally provided substantially at the center of the lower end of a vertically movable upper table, and is slidable on the left and right parts of the center mold. A bending device for bending a work by cooperation of an upper mold composed of a large number of divided molds provided on the lower mold and a lower mold arranged so as to face the upper mold. The reciprocating motion between the mold replacement position of the replacement center mold housed in the mold magazine provided near the rear side of the upper table and the mounting position at the lower end of the upper table. A hammer member provided on the center mold exchanging arm so that it can move up and down.When the center mold is set on the upper table, it acts as a clamp, and the load acting on the center mold during bending is applied to the upper table. Communicate to A method for exchanging a mold in a bending apparatus, which is characterized by tightening. 2. A replaceable center mold provided on a center mold exchanging arm rotatably provided substantially at the center of the lower end of a vertically movable upper table and slidable on the left and right parts of this center mold. A bending device for bending a work by cooperation of an upper mold composed of a large number of divided molds provided on the lower mold and a lower mold arranged so as to face the upper mold. A mold magazine accommodating a plurality of replacement center molds is provided near the rear side of the upper table,
The center mold is formed on the center mold exchanging arm that reciprocates between the mold exchanging position of the replacement center mold housed in the mold magazine and the mounting position at the lower end of the upper table. A retaining piece that can be engaged with the groove is provided, and interference with the center mold is avoided during mold replacement, and the load acting on the center mold when the center mold is set at the mounting position is applied to the upper table. A mold exchanging device in a bending device, wherein a hammer member for transmitting and clamping a center die is provided on the exchanging arm so as to be vertically movable. 3. A center mold used in the mold exchanging device according to claim 2, wherein a first groove detachably engaged with a mold holder provided in the mold magazine, and the center mold. A center mold comprising: a plurality of second grooves that are engageable and disengageable with an engaging portion provided on an exchange arm.