JPH0260408B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a bending machine for bending the edge of a workpiece, and the present invention provides a bending machine that bends the edge of a workpiece by changing the effective mold width of an upper mold according to a change in the bending width of the workpiece. More specifically, it is a bending machine that can change the length of the workpiece, and more specifically, the length of the upper die is determined by closely fitting the required number of split upper dies out of a number of split upper dies provided at the lower end of the ram according to the length of the workpiece. , relates to a bending width changing device for a bending machine that bends the edge of a workpiece by using the upper mold and the lower mold or in cooperation with a wing beam.

(Prior Art) For the doors, lids, etc. of metal cabinets in electrical equipment and furniture, panels in which the edges of plate materials are bent into a U-shape or an L-shape are often used. Generally, such panels are made by bending the short side edges of the workpiece, and then folding the long side edges into the same shape to match the inside of the short side bend. .

Therefore, conventional bending machines have a large number of specialized upper molds for bending molds depending on the length of the workpiece, and the upper molds are replaced manually each time the workpiece dimensions change, resulting in high costs. In addition, it did not improve work efficiency and was dangerous.

In order to improve these shortcomings, the upper mold is made into a split type, and molds with different lengths are combined, and the required number of split upper molds are installed manually depending on the length of the workpiece, or by using a sliding type or rotating type. There is a known method for entering and exiting the building by making a ceremony (for example, the
(Refer to Publication No. 16203 and Publication No. 1982-23051).

(Problems to be Solved by the Invention) By the way, among the above conventional examples, the slide type is equipped with a pair of left and right split horizontal slide mechanisms, and the width of the upper mold is adjusted while controlling these two slide mechanisms. Therefore, two sets of various devices are required for the split-type lateral slide, resulting in two problems: difficulty in control operation and enlargement of the folding machine. Furthermore, this one is 50mm
Since it uses a split mold with two widths, 55mm and 55mm, it is necessary to adjust the loading position onto the lower mold from left to right depending on the width of the workpiece, which causes troublesome loading work. have

In addition, the rotary type has a second intermediate split type rotary operation shaft and a screw shaft for sliding operation of the corner block inside the upper mold body attached to the lower end of the ram 4, and a wide first intermediate split type. Since each mold is equipped with a gear, a rack that meshes with the rack, and a hydraulic cylinder that moves the rack up and down, the equipment does not become complicated or large, and the In order to deviate the split mold rearward from under the ram by rotation, a rearward biased load is applied to the ram. Therefore, it becomes necessary to increase the strength of the ram support structure, resulting in an even larger device.

Therefore, the present invention successfully combines the advantages of the sliding type, which does not require consideration of unbalanced loads on the ram, and the advantage of the combination structure of the narrow-width split type and wide-width split type, which allows the workpiece loading position to be kept constant. At the same time, the device is miniaturized and the mold replacement work is simplified, and it is possible to bend both short and long sides using a series of molds without the troublesome work of changing molds as in conventional equipment. The purpose is to

(Means for Solving the Problems) The configuration of the present invention for achieving the above object will be explained below using FIGS. 1 to 9 corresponding to embodiments.

This invention provides a bending machine as described at the beginning, in which one block 7 is suspended from the lower surface of the ram 4, and a guide groove 6 is provided along the longitudinal direction of the ram so that a large number of first blocks 7 can be moved laterally. Intermediate split type 8
... are suspended and selectively and removably engaged with the holes 11 provided on the back surface of these first intermediate split molds 8... to forcibly move these first intermediate split molds 8 laterally. A forced slide mechanism 32 equipped with two hook pins 35 is provided on the back of the upper mold, and the other corner block 12 is arranged in parallel with the first intermediate divided mold 8...a large number of thinner second intermediate divided molds 13 in a group in a sealed state. A moving frame 16 is provided which holds the corner block 12 and is mounted on the back side of the ram and is forcibly moved laterally.
The intermediate split molds 8... are configured to be forcibly moved in and out from the rear rear to the front, and the second intermediate split molds 13...
A pusher 19 is provided on the back side of the split mold 13 for controlling the extrusion of the group of divided molds 13 from the rear of the back of the first intermediate divided mold 8 to a position slightly forward of the back surface position in the mold number selection movement process. The pusher 19 is provided with a pusher 19 that elastically absorbs the forward resistance of the divided molds 13 during the number selection movement stroke corresponding to each of the second intermediate divided molds 13.
A buffer structure 21 is provided to allow a forward pushing action, and a tailgating mechanism 28 is provided to collectively push out a selected group of second intermediate divided molds 13 further forward.

(Function) When changing the bending width, the forced slide mechanism 32 is slid horizontally, and the first intermediate split mold 8, which is engaged with the hook pin 35, is guided by the guide groove 6 of the upper mold body 5 and moved upward. The required number of first intermediate divided molds 8 which are laterally slid along the longitudinal direction of the mold body 5 and brought into close contact with one corner block 7 side are the outermost one and the adjacent unnecessary one. A gap having a size equal to the sum of the other corner block 12 and the required number of second intermediate divided molds 13 is formed between them. Next, the moving frame 16 is laterally slid to carry the other corner block 12 and the second intermediate divided mold 13 to the rear of this gap, and then the pusher 19 moves all the second intermediate divided molds 13 to the front. pushed out. However, in this case, since the gap size is only as large as the number of molds required, the front ends of the divided molds 13 other than those required are the outermost first
It comes into contact with the back side of the intermediate divided molds 8 and is obstructed from further advancement, and only the required number of divided molds 13 are pushed forward a little, thereby selecting the number of molds. . At this time, the buffer structure 21 acts on the group of second intermediate divided molds 13 left behind, allowing the pusher 19 to move forward.

Next, the required number of second intermediate divided molds 13 that have been pushed forward a little are taken forward all at once by the tailgating mechanism 28 and are juxtaposed to the outermost intermediate divided mold 8, and the other The corner blocks 12 are also pushed forward and juxtaposed with the second intermediate split molds 13, thereby changing the length of the upper mold.

Therefore, the width can be changed using one corner block 7 side as a zero reference, and the first intermediate divided mold 8 can only be moved horizontally, and the other corner block 12 and the second intermediate divided mold can be moved back and forth. Since the length is changed only by

(Example) Next, the folding width changing device of the folding machine according to the present invention is used as a wing bender (folding machine).
An embodiment in which the present invention is applied will be described in detail based on the descriptions in FIGS. 1 to 7.

(Structure of the upper die) The bending machine according to the present invention is comprised of upper and lower dies 1 and 2 and a wing die 3, and the structure of the upper die 1 is characteristic.

The upper mold according to the present invention has two corner blocks 7,
12. The first large block sandwiched between both blocks
It consists of an intermediate divided mold 8... and a narrow second intermediate divided mold 13. In the example shown, two corner blocks with a width of 127.5 mm and a first intermediate divided mold 18 with a width of 50 mm are used.
The case is shown in which nine second intermediate split molds each having a width of 5 mm are used.

Therefore, in the upper mold 1, an upper mold main body 5 having a downward U-shaped cross section is attached to the lower part of the ram 4, and one corner block 7 is suspended from one end of the lower part of the upper mold main body 5.
A large number of first intermediate split molds 8 having a larger width are suspended toward the other end.

A dovetail shape 9 is integrally protruded from the inner bottom of the U-shaped guide groove 6 of the upper mold body 5, and each intermediate divided mold 8...
A dovetail groove 10 to be inserted into the dovetail shape 9 is formed in the upper part of the upper mold body 5, and each intermediate divided mold 8 is hung movably along the longitudinal direction of the upper mold body 5. In addition, an engagement hole 11 is formed on the back surface of each intermediate divided mold 8, into which a hook pin (described later) for moving the intermediate divided mold 8 along the longitudinal direction of the upper mold body 5 is fitted.

(Configuration of the other corner block and the second intermediate divided mold) On the other hand, the other corner block 12 and a large number of narrow second intermediate divided molds 13 are located below the back side of the upper die main body 5. , are provided so as to be movable along the longitudinal direction and the front-rear direction of the upper mold body 5. Specifically, a pair of dovetail molds 14 (the upper one is not shown) are integrally protruded from the back side of the upper mold 1 at a predetermined interval vertically along its longitudinal direction, and further on the back side thereof. Screw rods 15 arranged in parallel at appropriate intervals
A movable frame 16 supported by the movable frame 1 is arranged.
6, the other corner block 12 and the second intermediate split mold 13 are mounted closely side by side. Both ends of the screw rod 15 are held on the back of the upper mold 1 so that they can rotate freely, and one end is connected to a servo motor (not shown).
Connect to for forward/reverse rotation. As a result, the moving frame 16
is reciprocated along the longitudinal direction of the upper mold body 5.

The front end of the other corner block 12 is moved from the same level as the front end of the first intermediate divided mold 8 to slightly rearward of the rear end of the first intermediate divided mold 8 by means of a fluid pressure cylinder 17 arranged on the back side thereof. It is structured so that it can be moved in and out at will.

In the figure, 121 is a guide rod integrally connected to the rear end of the other corner block 12, and a dovetail type 123 is fitted into a pair of front and rear guide bodies 122, 122 fixed to the lower surface of the moving frame 16. .

In addition, the second intermediate split mold 13... is long in the front and back (first
(approximately 2.5 times that of the intermediate split type), and
A mold number selection mechanism 18 for the second intermediate divided molds 13 is provided on the back side, and the number of molds can be increased or decreased as appropriate depending on the width of the workpiece.

(Configuration of the mold number selection mechanism) Specifically, the configuration of the mold number selection mechanism 18 includes a pusher 19 having a width equal to the entire width of the group of second intermediate divided molds 13, and a fluid for moving the pusher back and forth. It consists of a pressure cylinder 20 and a buffer structure 21 provided within the pusher 19 corresponding to each second intermediate split mold 13 . This buffer structure 21... is the fourth
As shown in the figure, holes 22 are made in the front surface of the pushing tool 19 in correspondence with the second intermediate split molds 13, springs 23 are loaded inside the holes 22, and the springs 23 are used to constantly push the tip. It is formed of pins 24 that protrude forward from the front surface of the tool 19, and the pins 24 are loaded so as to be retractable against the elastic force of the springs 23.

(Structure of Tailgating Mechanism) 25... is an engagement piece raised integrally on the upper side of the second intermediate split mold 13 at the same position near the rear end, and each of the engaging pieces 25... A hook pin 29 of a tailgating mechanism 28 is provided with a through hole 26 which penetrates through the hole 26, and moves a selected required number of second intermediate divided molds 13 to the front end position of the first intermediate divided mold 8. It has a structure that allows it to be inserted. In the figure, reference numerals 27a and 27a designate side plates of the container 27, which also serve as guide plates, which are provided to sandwich the second intermediate split molds 13 from the left and right sides, and 27b is a bottom plate.

The tailgating mechanism 28 is arranged on the movable frame 16 on the other corner block 12 side beside the second intermediate divided mold 13 group, and includes a fluid pressure cylinder 30 whose axis is along the longitudinal direction of the upper mold body 5 and its axis. The piston rod is formed from the hook pin 29.
functions as The tailgating mechanism 28 is configured to be able to move back and forth along a dovetail-shaped guide 218 in the same way as the other corner block 12 by means of a fluid pressure cylinder 31 arranged on the moving frame 16 with its axis aligned in the front-rear direction. It's summery.

(Configuration of forced slide mechanism) Reference numeral 32 denotes a forced slide mechanism of the first intermediate split type 8 provided beside the other corner block 12, which consists of a fluid pressure cylinder 33 whose axis is along the front and back direction and its piston rod 34. A hook pin 35 that integrally projects forward from the front end, and a frame body 3 that holds the hydraulic cylinder 33 and the hook pin 35.
6, and a guide rod 37 and a threaded rod 38 which support the upper and lower parts of the frame 36 and whose axes are aligned along the longitudinal direction of the upper mold body 5 and which are arranged in parallel vertically at an appropriate interval; It consists of a servo motor (not shown) that rotates the rod 38, and the piston rod 3
4, the hook pin 35 is inserted into and removed from the engagement hole 11 formed on the back surface of the first intermediate split mold 8. The body 36 is moved along the longitudinal direction of the upper mold main body 5, and the required number of first intermediate divided molds 8 are slid along the longitudinal direction of the upper mold main body 5.

In the figure, reference numeral 39 denotes a pusher 4 that is supported by the dome shape 9 of the U-shaped groove 6 of the upper die main body 5 and reciprocates along the groove 6.
0 and a fluid pressure cylinder (not shown) that moves this pusher 40.

Next, FIG. 8 shows another embodiment of the tailgating mechanism 28, in which the tailgating mechanism 28 is loaded into the other corner block 12. A cylinder chamber 311 is formed by penetrating the round hole 310 along the longitudinal direction of the upper mold body 5 in the upper part of the corner block 12, and a piston rod 312 is inserted into the cylinder chamber 311 with its tip facing toward one corner block 7. After loading, the other opening of the round hole 310 is closed 313. When such a configuration is adopted, the second piston rod 312 is inserted to function as the hook pin 29.
The through holes 26 of the intermediate split molds 13 only need to be provided at the same position near the front end of the second intermediate split mold 13, and there is no need to provide the engaging pieces 25. The fluid pressure cylinder 31 and guide 281 that move in the front-back direction are also unnecessary.

Furthermore, FIG. 9 shows another embodiment of the forced slide mechanism 32, which is mounted integrally on the moving frame 16.
is fixed to the lower surface of the movable frame 16 with its axis directed in the front-rear direction, and a hook pin 3 is attached to the front side of the movable frame 16.
The guide frame 351 of No. 5 is fixed, so that it can be moved left and right together with the movable frame 16.
Reference numeral 352 is a connection tool for connecting the hook pin 35 to the piston rod 34. When such a configuration is adopted, the guide rod 37, the screw rod 38, the servo motor for rotating the screw rod 38, and the frame 36 are no longer necessary, and the control operation of the forced slide mechanism 32 is simplified. , accuracy can also be improved.

It goes without saying that the configurations shown in the embodiments above can be applied not only to wing benders, but also to press brakes and even foot benders.

Next, the operation of the above embodiment is shown in FIGS. 5, 6, and 7.
This will be explained based on Figures A to E.

FIG. 5 shows a case where both corner blocks 7, 12 and all intermediate divided molds 8, 13 between them are used to form an upper mold of maximum length (for example, 1200 mm).

If the length of the workpiece needs to be changed from this state, the actual length of the upper mold is changed by the following operation. For example, if you want to bend the short side of 575mm, you will need to reduce the length of the upper mold by 625mm in total, including 12 first intermediate split molds and 5 second intermediate split molds.The procedure is as follows. becomes.

First, from the state shown in FIG.
The hydraulic cylinder 31 that moves the hydraulic cylinder 17 and the tailgating mechanism 28 back and forth is actuated to move the other corner block 12 and the second intermediate divided mold 13 to a position slightly behind the back of the first intermediate divided mold 8. Retire to the standby position (Figure 7a). Next, move frame 1
6 is caused to slide sideways toward one corner block 7 by operating the servo motor and rotating the screw rod 15, and the forced slide mechanism 32
By operating the servo motor and rotating the screw rod 38, the 12th piece of the first intermediate split mold 8 (from the corner block 7 side) (7th item) horizontally until it reaches the back side (Figure 7b).

Next, the hook pin 35 of the forced slide mechanism 32
Activate the fluid pressure cylinder 33 to insert the twelfth piece into the engagement hole 11 of the first intermediate split mold 8 (Fig. 7B), and then rotate the servo motor in the opposite direction. Slide the frame 36 laterally in the original direction. As a result, the twelve first intermediate divided molds 8 are pushed away from one corner block 7, and a gap is formed between the sixth and seventh molds. When this distance reaches the sum of the other corner block 12 and four second intermediate split molds 13, the operation of the servo motor is stopped.

Next, move the moving frame 16 with the servo motor,
It is moved in the opposite direction to the side away from the one corner block 7, from the sixth first intermediate divided mold 8 to the other corner block 12 and the second intermediate divided molds 13 . . . 4 connected thereto. At the point when the pieces protrude to the right in the figure, that is, when they branch out to the rear of the above-mentioned interval, the servo motor stops and the moving frame 16
stops (Figure 7c).

Next, the fluid pressure cylinder 20 of the model number selection mechanism 18
operates to push the pusher 19 forward. The amount of extrusion is set such that the front ends of the second intermediate divided molds 13 are approximately 3 mm in front and rear of the rear surface of the first intermediate divided molds 8, respectively, and are approximately 6 mm in total.

Due to the extrusion action of the pusher 19, all of the second intermediate divided molds 13... are pushed forward, but for the five pieces on one corner block 7 side, a sixth first intermediate divided mold 8 exists in front of them. Therefore, the front ends of the five second intermediate divided molds 13 come into contact with the back surface of the sixth first intermediate divided mold 8. However, since the pusher 19 is pushed further forward, the four pieces that should be selected are pushed further forward, but the five pieces that are unnecessary are affected by the buffer structure 21 provided on the pusher 19, that is, via the pin 24. The spring 23 elastically contracts to allow the pusher 19 to move forward, thereby completing the selection of the second intermediate split mold 13 (FIG. 7D).

When the selection of the second intermediate split molds 13 is completed, the fluid pressure cylinder 30 of the tailgating mechanism 28 is operated to cause the hook pin 29 to protrude and
It is inserted into the through hole 26 of.... In this case, the four second intermediate divided molds 13 that have been selected and protrude slightly forward are the through holes 26 of the group and the first intermediate divided molds 8...
Since the former is maintained in a relative position with the through-holes 26 of the group of five second intermediate split molds 13 that are in contact with the back surface of the group, the former is maintained in a relative position with the former slightly protruding forward, so the hook pin 29 is attached to the fourth of the former. After being inserted into the through-holes 26, the front end comes into contact with the side surface of the fifth second intermediate split mold 13, and further protrusion is inhibited, and the protrusion operation is automatically stopped.

Next, the fluid pressure cylinder 31 that moves this tailgating mechanism 28 back and forth and the fluid pressure cylinder 17 that moves the other corner block 12 back and forth are operated together,
The four selected intermediate divided molds 13 and the other corner block 12 are pushed forward until their front ends match the front ends of the first intermediate divided molds 8, and then the die clamper 39 is operated to push out the other corner block 12. The corner blocks 12 of the two are pressed toward one corner block 7 side to form each corner block and each of the first and second intermediate divided molds 13 into a series of molds arranged closely side by side.
By doing this, the length of the upper mold is reduced (FIG. 7-E, FIG. 6).

In order to return the state shown in FIG. 6 to the state shown in FIG. It is retired to a standby position slightly behind the back of the split mold 8.

At this time, the tailgating mechanism 28 moves the four second intermediate split molds 13 at the rear end to the remaining five second intermediate molds 13...
Retract it to the same position as intermediate split mold 13...
When the through holes 26 are aligned on the same straight line, the hydraulic cylinder 30 is actuated to further extend the hook pin 29, and the five second intermediate split molds 13
They are inserted into the through holes 26 of..., and then all nine sheets are retreated to the standby position behind the upper mold body 5.

The forced slide machine 32 is then removed from the
Move the 12 first intermediate split molds 8 to the rightmost rear and insert the hook pin 3 into the engagement hole 11 of the split mold 8.
5 are inserted and engaged, and then the forcible slide mechanism 32 is moved toward the pair of corner blocks 7, and the 12 divided molds are brought together in series with the selected 6 divided molds. Then, the hook pins 35 are pulled out, the forced slide mechanism 32 is moved to the right, and the moving frame 16 is also moved to the right to remove the other corner block 12 and the second intermediate split mold 13.
After moving the group to the right, they are pushed out to the rightmost side of the first intermediate split mold 8... and the die clamper 39 is operated to bring both corner blocks, first and second intermediate split molds into close contact. They are installed side by side and put back together.

Needless to say, the above-mentioned length of the upper die can be easily changed by push button or NC control depending on the length of the side of the workpiece.

In the modified example shown in FIG. 8, the back and forth movement of the selected second intermediate split mold 13...
By operating a hydraulic cylinder 17 that moves the upper mold body back and forth, it can move back and forth integrally with the other corner block 12, and in the modification shown in FIG. The reciprocating motion along the longitudinal direction) is controlled by the movement of the moving frame 16.

(Effect) In this invention, the first intermediate divided mold 8..., the second intermediate divided mold 13... and the other corner block 12
By making the structural device for moving each of the parts external to the upper die body, etc., rather than internally, the overall structure of the device can be simplified and downsized, and it is also easier to perform repairs and inspections. It has the advantage of being easy to use. Also the first
It is possible to horizontally slide the intermediate split type 8 with a single forced slide mechanism.In addition, even if it is an exterior type, there is a forced slide mechanism on the back side of the ram, the other corner block 12, and the 2 intermediate split type 1
3...And because of these actuating devices, unbalanced loads on the ram are less likely to occur, so there is an advantage that further miniaturization can be achieved.

Further, the width is set by moving the first intermediate split mold 8 laterally along the guide groove 6 and pushing only the other corner block 12 and the second intermediate split mold 13 forward. After being set, the front edges of each intermediate split mold and both corner blocks are neatly aligned in a straight line, and unlike the conventional rotary type, due to the difference in rotation angle due to manufacturing errors of individual parts. The front edge of the split mold becomes irregular in a zigzag pattern, which causes an uneven pattern at the bending corner of the workpiece. This eliminates the drawback of forming a clean corner.

In addition, as shown in the embodiment, the forced slide mechanism 3
2 on the moving frame 16, the overall structure can be simplified and lightened, and the ease of operation can be further improved.Furthermore, by incorporating the tailgating mechanism 28 in the other corner block 12, it can be made even more compact. above,
Since all of these are set in a movable frame, the manufacturing process and assembly process at the delivery destination are greatly simplified, and it can also be handled in an organized manner for wheel transportation, etc. It also has the advantage of being advantageous in terms of cost.

[Brief explanation of the drawing]

Fig. 1 is an enlarged perspective view of the main part, with the moving frame and various devices above it omitted; Fig. 2 is an enlarged perspective view of the main part, which also shows the moving frame and various devices above it; Figure 3 is a side view of the forced slide mechanism, Figure 4 is a partially cutaway enlarged sectional view of the buffer structure, and Figure 5 is a side view of the forced slide mechanism.
Fig. 6 is a front view of the upper mold, Fig. 7 A to E are explanatory diagrams of the operation, Fig. 8 is a sectional view showing a modification of the tailgating mechanism, and Fig. 9 is a modification of the forced slide mechanism. FIG. 1; Upper die, 2; Lower die, 4; Ram, 5; Upper die body, 6; Guide groove, 7; One corner block, 8;
First intermediate divided mold, 11; Engagement hole of first intermediate divided mold, 12; Other corner block, 13; Second intermediate divided mold, 16; Moving frame, 18; Model number selection mechanism, 1
9; Pusher, 20; Fluid pressure cylinder, 21;
Buffer structure, 23; Spring, 24; Pin, 2
8; Tailgating mechanism, 29; Hook pin, 30; Fluid pressure cylinder, 31; Fluid pressure cylinder, 32; Forced slide mechanism, 33; Fluid pressure cylinder, 34; Piston rod, 35; Hook pin.

Claims (1)

[Claims] 1. The length of the upper mold is determined by closely fitting a required number of divided upper molds among a large number of divided upper molds provided at the lower end of the ram according to the length of the workpiece, and In a bending machine that bends the edge of a workpiece by hand or in cooperation with a wing beam, one corner block 7 is suspended from the lower surface of the ram 4, and a guide groove 6 is provided on the lower surface along the longitudinal direction of the ram. A large number of first intermediate divided molds 8 are suspended so as to be movable in the lateral direction, and these first intermediate divided molds 8 are selectively and removably engaged with holes 11 provided on the back surfaces of these first intermediate divided molds 8. A forced slide mechanism 32 equipped with one hook pin 35 for forcibly moving the first intermediate divided mold 8 horizontally is provided on the back of the upper mold, and the other corner block 12 and the first intermediate divided mold 8 are connected to a large number of The two intermediate divided molds 13... are held side by side in close contact, and a moving frame 16 is installed on the back of the ram and forcibly moved laterally, and the other corner block 12 is divided into the first intermediate divided type. The mold 8... is configured so that it can be forcibly moved in and out from the back rear to the front, and the second
These split molds 1 are on the back side of the intermediate split mold 13...
3. A pusher 19 is provided to manage the extrusion of the group in the mold number selection movement process from the rear of the back surface of the first intermediate divided mold 8 to a position slightly in front of the rear surface existing position. A buffer structure 21 is provided corresponding to the intermediate divided molds 13 to elastically absorb the forward resistance of the divided molds 13 during the number selection movement process and allow the pusher 19 to push forward. A folding width changing device for a folding machine, characterized in that a tailgating mechanism 28 is provided for collectively pushing out the group of second intermediate divided molds 13 further forward. 2. The tailgating mechanism 28 is internally installed in the through hole 26 formed through the front end of the second intermediate split mold 13 and the upper part of the other corner block 12 with its axis along the longitudinal direction of the upper mold body 5, and has a piston rod. A bending width changing device for a bending machine according to claim 1, which comprises a hydraulic cylinder 312 that can move outwardly and retractably. 3. The forced slide mechanism 32 includes a fluid pressure cylinder 33 fixedly connected to the moving frame 16 and a hook pin 35 that is moved in and out by the hydraulic cylinder 33. Device. 4. The folding width changing device for a folding machine according to claim 1, wherein the moving frame 16 is provided with a tailgating mechanism 28 and a forced slide mechanism 32.