JP2002239631A - Bending method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bending method and a device thereof in which a work can be bent with high accuracy, damages on a back side of the work caused by a V-shaped grooved edge of a die are reduced, and the frequency of changing the die is reduced. SOLUTION: The predetermined preload is applied to the work W using a punch P and a die D by reciprocating either of an upper table 3 with the punch P fitted thereto or a lower table 5 with the die D fitted thereto. The work W is supported by forward and rear rollers 33F and 33R which are moved to and positioned at the predetermined position close to the die D in advance. The relative motion to the forward and rear rollers 33F and 33R is given to the work W under the preload, and the work W is bent in the cooperation of the punch P, the die D and the forward and rear rollers 33F and 33R. Since the forward and rear rollers 33F and 33R are moved to and positioned at the predetermined position so as to realize the optimum V-shaped width according to the material and the thickness of the work W, the work can be bent with excellent accuracy without changing the die.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bending method and a bending method.

[0002]

2. Description of the Related Art Conventionally, typical bending methods using, for example, a press brake as a bending apparatus include air bending, bottoming, and coining, which is a so-called bushing.

In the air bend processing, as shown in FIG. 11, a work W is placed on a die D provided with a V-groove, and the work W is pressed by a punch P at the center position of the V-groove to obtain a desired angle θ. The punch P or the die D is operated until it is obtained. At this time, the punch P does not bottom on the die D. Therefore, it is a total of three-point machining with one-point load with two-point support.

In the bottoming process, the punch P or the die D is further operated from the state of the air bending process shown in FIG. 11 as shown in FIG. . As a result, the workpiece W is plastically deformed, the springback is small, and the accuracy of the bending angle close to the mold accuracy can be obtained.

[0005]

By the way, in the conventional bending method, for example, air bend processing is performed on the work W
There was a problem that the V-groove edge of the die D caused scratches on the back surface of the die. In addition, air bend processing has a problem in that it is difficult to perform high-precision bending, so that trial bending is required many times, and that there is a large variation in bending angle.

The bottoming process has a problem that the punch P and the die D need to be replaced every time the bending angle is changed. In addition, the bottoming process can provide a high-precision bending angle, but has a problem that a high load is required because a load is applied to the entire V groove of the die D.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to perform bending with high precision.
Reduces scratches on the back of the work due to the V-groove edge of the die,
It is an object of the present invention to provide a bending method and a device capable of reducing mold replacement.

[0008]

According to a first aspect of the present invention, there is provided a bending method for supporting a workpiece by a support member which is previously moved and positioned at a predetermined position before and after a die. Then, at least one of the upper table on which the punch was mounted and the lower table on which the die was mounted was raised or lowered, the work was clamped by the punch and the die, a predetermined preload was applied, and this preload was applied. Punch, die, and bending of the work in cooperation with the front and rear support members and the front and rear support members by giving rise or fall relative movement to the front and rear support members and the upper table or the lower table. It is a feature.

Therefore, since the front and rear support members are moved and positioned at the predetermined front and rear positions so as to have an optimum V width depending on the material and the thickness of the work, it is not necessary to replace the die including the punch and the die. Since the workpiece is widely supported by the front and rear support members at the time of bending, a large moment is obtained, so that the bending is performed with a small load, and a highly accurate bending angle is obtained.

In addition, when a preload is applied to a work,
For example, the plastic deformation of bending is performed in a small V-groove just corresponding to the area of the bending radius of the die, and almost the same operation as in the bottoming process is obtained, and the work is given relative motion to the front and rear support members. High-precision bending is performed.

According to a second aspect of the present invention, in the bending method according to the first aspect, when the work is preloaded by the punch and the die, the second pressing force is smaller than the first pressing force of the upper table. It is characterized in that the lower table is opposed by pressure and the work is clamped.

Therefore, for example, when the upper table is lowered by the first pressing force, the work is reliably preloaded by the cooperation of the punch and the die by the lower table which is opposed by the second pressing force smaller than the first pressing force. Further, since the work is lowered in a state where the work is preloaded by lowering the upper table, the work is given relative motion to the front and rear support members, and the work is bent with high precision.

According to a third aspect of the present invention, there is provided the bending method according to the first or second aspect, wherein the punch and the die are attached to at least one of the preloading and the bending. It is characterized in that micro-vibration is applied to cause vibration.

Therefore, when the punch and the die are vibrated at the time of preloading or bending, the plastic deformation of the work progresses little by little and the amount of springback is reduced, and the bending angle is made more precise.

According to a fourth aspect of the present invention, there is provided the bending method according to the first, second or third aspect.
The front and rear support members are at least two or more rotating bodies or long rotating bodies.

Accordingly, since the support member is a rotating body, the work is less likely to be scratched when the work is bent while moving on the rotating body during bending.

According to a fifth aspect of the present invention, in the bending method according to the fourth aspect, the rotating body is driven to rotate in synchronization with a movement speed of the workpiece by a bending speed. Things.

Therefore, since the rotating body is driven to rotate in synchronization with the moving speed of the work at the time of bending, abrasion of the work is minimized.

According to a sixth aspect of the present invention, there is provided a bending method wherein one of an upper table on which a punch is mounted and a lower table on which a die is mounted are reciprocated to clamp a work with the punch and the die. While applying a predetermined preload, the work is supported by a support member that is previously moved and positioned at a predetermined position before and after the die,
A punching step, a die, and a bending step of performing a main bending process of the work in cooperation with the front and rear support members by giving relative movement to the front and rear support members to the work with the preloaded applied thereto are performed in multiple stages. And various bending processes are performed in parallel with each other.

Accordingly, by combining the bending process including the preloading and the main bending in parallel in a multi-stage type, the distance between the front and rear support members is adjusted variously at each stage, and the workpiece is moved at each stage. Through the bending step, various bending shapes such as, for example, taper bending, round bending, and arc bending can be obtained.

According to a seventh aspect of the present invention, there is provided a bending apparatus wherein an upper table on which a punch is mounted and a lower table on which a die is mounted are provided so as to be vertically movable, and support members for supporting a work are provided before and after the die. It is characterized by being provided.

Therefore, since the work is widely supported by the front and rear support members at the time of bending, a large moment is obtained, so that the bending is performed with a small load, and a highly accurate bending angle is obtained.

Also, when the work is preloaded,
For example, the plastic deformation of bending is performed in a small V-groove just corresponding to the area of the bending radius of the die, and almost the same operation as in the bottoming process is obtained, and the work is given relative motion to the front and rear support members. High-precision bending is performed.

According to an eighth aspect of the present invention, in the bending apparatus according to the seventh aspect, the support member is fixedly provided.

Therefore, when the front and rear support members are fixed, the preloading and the main bending are continuously performed by lowering the upper table and the lower table.

According to a ninth aspect of the present invention, there is provided a bending apparatus according to the seventh aspect, wherein the support member is provided so as to be movable back and forth.

Therefore, the front and rear support members are moved and positioned at the front and rear predetermined positions so as to have an optimum V width depending on the material and the plate thickness of the work, so that it is not necessary to replace the die including the punch and the die.

According to a tenth aspect of the present invention, in the bending apparatus according to the seventh, eighth or ninth aspect,
First pressure driving means for driving one of the upper and lower tables at a first pressure is provided, and the other table is driven at a second pressure smaller than the first pressure. A second pressure driving means for driving the table in a direction opposite to the table is provided.

Therefore, the operation is similar to that of the second aspect. For example, when the upper table is lowered by the first pressing force,
The work is reliably preloaded by the cooperation of the punch and the die by the lower table which is opposed by the second pressing force smaller than the first pressing force. Further, since the work is lowered in a state where the work is preloaded by lowering the upper table, the work is given relative motion to the front and rear support members, and the work is bent with high precision.

According to an eleventh aspect of the present invention, in the bending apparatus according to any one of the seventh to tenth aspects, the die has a V-groove corresponding to a region of a bending R of the work. It is characterized in that a V-groove having a width is provided or a flat portion without a V-groove is provided.

Therefore, when a V-groove having a V-groove width small enough to correspond to the bending radius area of the work is provided,
Bending plastic deformation is performed in the groove, and substantially the same operation as in bottoming is obtained. Further, V which is the receiving portion of the die
Since the distance of the groove width is small and approaches the area of the bend R, the scratch becomes less noticeable.

According to a twelfth aspect of the present invention, there is provided the bending apparatus according to any one of the seventh to eleventh aspects, wherein at least one of the upper and lower tables has a fine punch and a die. A vibration device for providing vibration is provided.

Therefore, the operation is similar to that of the third aspect, and when the punch and the die are vibrated during preloading or bending, the plastic deformation of the work progresses little by little and the amount of springback is reduced. And the bending angle becomes more precise.

According to a thirteenth aspect of the present invention, in the bending apparatus according to any one of the seventh to twelfth aspects, the front and rear support members each include at least two or more rotating bodies. Or a long rotating body.

Accordingly, the operation is similar to that of the fourth aspect, and since the support member is a rotating body, the work is less likely to be scratched when the work is bent while moving on the rotating body during bending.

According to a fourteenth aspect of the present invention, in the bending apparatus according to the thirteenth aspect, the rotating body is provided so as to be rotatable in synchronization with the movement speed of the workpiece by the bending speed. It is characterized by the following.

Therefore, the operation is the same as that of the fifth aspect, and the rotating body is driven to rotate in synchronization with the moving speed of the work at the time of bending, so that the abrasion of the work is minimized.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a bending method and apparatus according to the present invention will be described below with reference to the drawings, taking a hydraulic press brake as an example.

Referring to FIG. 1, the hydraulic press brake 1 is mounted and fixed to a lower surface of, for example, an upper table 3 as a movable table on which a punch P can move up and down, that is, a ram. The die D is driven by the operation of the upper table 3 and can be moved up and down.
It is mounted and fixed on the upper surface of.

In FIG. 1, which constitutes the main body frame, an upper table driving cylinder 9 is mounted on the upper side of the lower left and upper right side frames 7. The upper table 3 is connected to the lower end. The upper table driving cylinder 9 is electrically connected to the control device 13 as shown in FIG.

A lower table driving cylinder 15 is provided below the left and right side frames 7.
The lower table 5 is connected to the upper ends of the piston rods 17 of these lower table driving cylinders 15. The lower table driving cylinder 15 is connected to the control device 13 as shown in FIG.

A lower table guide plate 19 serving as a guide when the lower table 5 moves up and down is fixed to the lower part of the left and right side frames 7 on both front and rear side surfaces of the lower table 5.

At the substantially center of the lower table 5 and the front and rear lower table guide plates 19, two notches 21 are formed.
The two notches 21 are provided with, for example, two crowning cylinders (hydraulic cylinders) as crowning devices. By controlling the pressure of the piston of the crowning cylinder, the amount of deflection at the center of the lower table 5 is adjusted. Note that the crowning device is connected to the control device 13 as shown in FIG.

A roller left / right guide 25 extends substantially horizontally on the outer upper portion of the front and rear lower table guide plates 19, and extends in the left / right direction along the roller left / right guide 25. In the present embodiment, a total of four roller front-rear direction guides 27 that can be moved and adjusted are provided in front and rear, two each. Note that a roller left / right driving device 29 for driving the roller front / rear direction guide 27 in the left / right direction is connected to the control device 13 as shown in FIG.

A roller support arm 31 extending upward in a substantially vertical direction is provided on each roller front-rear direction guide 27 so as to be movable and adjustable in the front-rear direction along the roller front-rear direction guide 27. At the upper end of the arm 31, for example, rollers 33F and 33R (rotating bodies) as support members for supporting the workpiece W and the rollers 33F and 33R are provided.
For example, a roller rotation drive motor 35 is provided as roller rotation drive means for rotating the 33R in the forward and reverse directions. In addition, a roller longitudinal drive device 37 for driving the roller support arm 31 in the longitudinal direction and the roller rotation drive motor 35 are connected to the control device 13 as shown in FIG.

The roller rotation drive motor 35 may not be provided at the upper end of the roller support arm 31. For example, at the upper end of the roller support arm 31, rollers 33F, 3
3R is provided rotatably, and a roller rotation drive motor 35 is provided below the roller support arm 31. The rollers 33F and 33R are rotated by the roller rotation drive motor 35 via rotation transmission means such as a chain. You can also. The number of the rollers 33F and 33R as the rotating body is not limited to two before and after the die D as described above. For example, at least one long roller 33F, 33R as a rotating body may be provided before and after.

As described above, when the upper table 3 is lowered to perform bending, the work W is
Is pressurized by the load P1, the workpiece W is pushed up by the lower table 5 with the load P2 by the die D by the lower table 5 against the load P1, and is pre-loaded and clamped. Is configured to descend while being sandwiched by the punch P and the die D,
The work W is bent by cooperation of the punch P, the die D, the front roller 33F, and the rear roller 33R. At this time, P1> P2 and P2 ≠ 0.

Referring to FIG. 2, the die D according to the embodiment of the present invention is characterized in that the V-groove width is smaller than usual, and the die D may be a flat surface without the V-groove.

The vertices of the front roller 33F and the rear roller 33R disposed before and after the die D are disposed so as to be substantially the same height as the upper end surface of the die D raised to the top dead center. Distance V between front roller 33F and rear roller 33R
Is adjusted so as to have an optimal size according to the material and the plate thickness of the work W. Since this V dimension corresponds to the V groove width of the normal die D, it becomes a large factor for determining the bending angle of the work W.

Therefore, the front roller 33F and the rear roller 3
The 3R serves as a work support before bending, so that the work W is prevented from sagging, and the V dimension can be changed freely, thereby making it possible to cope with the size of the work W and the magnitude of the load. In other words, since a die D that matches the material and thickness of the work W as in the related art is not required, a punch P and a die changing device for the die D are not required. Since the workpiece W is widely supported by the front and rear support members at the time of bending, a large moment can be obtained, so that bending can be performed with a small load, and as a result, a highly accurate bending angle can be obtained.

The front roller 33F and the rear roller 33R
Is configured such that the rotation speed of the roller rotation drive motor 35 described above is synchronized with the bending speed in order to minimize damage to the work W generated during bending. In other words, when the work W is bent between the front roller 33F and the rear roller 33R, the work W is bent while moving on the front roller 33F and the rear roller 33R. Synchronization between the speed and the rotational speeds of the front and rear rollers 33F and 33R can minimize abrasion generated on the work W.

In order to explain the V-groove shape of the die D in detail, the concept of the bending angle will be described. For example, as shown in FIG. When the bending process is performed, the bending angle is Δ Δ corresponding to the distance of the punch tip R in the die D.
It is determined by the part of L. Incidentally, the region where the plastic deformation occurs in the work W is between AA ′ and BB ′ as shown in the enlarged view of FIG. In, plastic deformation occurs in the tensile direction. The portion (L−ΔL) is a region where no internal stress acts on the work W and the work W is only in contact with the punch P and the die D.

From the above, since it is ΔL that determines the bending angle, the V-groove width of the die D when the bending angle θ is 90 ° satisfies (ΔL + t) × √2. When the bending angle θ is 60 °, the V groove width of the die D is (ΔL + t) /
√3 and V of die D when bending angle θ is 120 °
The groove width is (ΔL + t) × √3.

Accordingly, the die D of the present embodiment has a small V-groove, and the V-groove width when the bending angle θ is 90 ° is (ΔL + t) × √2 as shown in FIG. Is set. As described above, the reason that the die D can be used without the V-groove is that the bending tip of the work W does not reach the V-groove of the die D in the normal air bending process, and the work W Considering that the bending angle is determined by the V groove width of the die D and the stroke amount of the tip of the punch, simply preloading with the plane of the die D and the punch P is effective.

Referring to FIG. 6, as the control device 13, the CPU 39 serving as a central processing unit sends bending work conditions such as a work width, a work bending length, a material of the work W, a plate thickness, a bending angle, and a flange size. An input device 41 for inputting data such as a machining program and the like, a display device 43, and a memory 45 for storing the input data are electrically connected.

The CPU 39 includes the input device 4
1, the D value (stroke amount) from the time of preloading based on the bending processing condition input, the L value as the position of the front and rear rollers 33F and 33R in the front-rear direction and the left-right direction, and the punch in preloading. An arithmetic unit 47 for calculating a sandwiching load of the workpiece W by the P and the die D; a roller movement command unit 49 for giving a command to move the front and rear rollers 33F, 33R based on the L value calculated by the arithmetic unit 47; The preload command unit 51 for driving the upper table 3 to apply a predetermined preload to the work W with the punch P and the die D, and performs bending based on the D value calculated by the arithmetic unit 47 described above. The main bending command part 53 for giving a command to the upper table driving cylinder 9 and the lower table driving cylinder 15 is connected.

The above-mentioned D value means that the work W is clamped by the punch P and the die D when the upper table 3 is lowered, and is raised and lowered to obtain a predetermined angle θ in a state where a predetermined preload is applied. Means the stroke amount in which the upper table 3 and the lower table 5 descend synchronously.

The operation at the time of bending with the above configuration will be described with reference to the flowchart of FIG. 7 and the operation explanatory diagram of FIG. 8. The bending conditions include, for example, the work width, the work bending length, and the material of the work W. The data such as sheet thickness, bending angle, and flange dimension are input by the input device 41 of the control device 13 and stored in the memory 45 (step S1).

The D value and the L value are calculated by the arithmetic unit 47 of the control device 13 based on the input data (step S2).

Based on the L value calculated by the arithmetic unit 47, a command is issued from the roller movement command unit 49,
The rear rollers 33F and 33R move to predetermined positions. For example, the V dimension in the front-rear direction of the front and rear rollers 33F, 33R is determined based on the material and the plate thickness, and the four roller support arms 31 before and after the die D are moved in the front-rear direction by the roller front-rear drive unit 37. Is set. Also,
The moving amount of the front and rear rollers 33F and 33R in the left-right direction is determined based on the work length, and the four roller front-rear direction guides 27 before and after the die D are driven by the roller left-right driving device 2.
9 to be moved and set in the left-right direction along the roller left-right direction guide 25 (step S3).

The work W is a die D and front and rear rollers 33.
F, 33R, the upper table 3 is lowered, and based on the preload calculation performed by the arithmetic unit 47 of the control device 13, the work W as shown in FIG.
Is sandwiched between the punch P and the die D at a predetermined preload. That is, the work W is pressurized by the load P1 by the punch P, and is pushed up and sandwiched by the die D by the load P2 by the lower table 5 against the load P1. At this time, as described above, P1> P2 and P2 ≠ 0.

By this preloading, for example, plastic deformation of bending is performed in a V-groove small enough to correspond to the region of the bending R of the die, and almost the same operation as bottoming is obtained. Sometimes high-precision bending is performed. Further, since the V-groove width of the die D is small, the V-groove edge is located at a position close to the region of the bend R, so that the scratch due to the V-groove edge becomes inconspicuous. (Step S4).

Based on the D value calculated by the arithmetic unit 47 of the control device 13, the work W is set in the preload state in step S 4 based on the relative movement of the punch P and the die D based on the command from the main bending command unit 53. Punch P and die D
8B, the punch P and the die D synchronize with each other and drop by a predetermined stroke amount, that is, the D value, so that the workpiece W is bent at the bending angle θ.
(Step S5).

Referring to FIG. 8C, the work W
Is lowered by the punch P and the die D based on the relative movement in the step S5 when the punch P and the die D are vibrated by being given a small vibration. Since the process proceeds in small increments and the amount of springback decreases, the bending process becomes more precise.

In the case of the punch P, for example, in the case of the punch P, a hydraulic cylinder is embedded in the lower portion of the upper table 3 and the piston of the hydraulic cylinder is vertically Is repeated to generate minute vibration. Since the punch P is coupled to the tip of the piston, the minute vibration of the piston is transmitted to the punch P and vibrated. The same applies to the vibration device 55 for the die D. The vibration device 55 is connected to the control device 13 as shown in FIG.

As another vibrating device 55, actuators for directly applying micro vibration to the punch P and the die D are provided on the upper table 3 and the lower table 5,
The actuator itself may reciprocate. This actuator is applicable to any form as long as it gives a minute vibration, such as an ultrasonic vibration device.

Further, as another bending method according to another embodiment of the present invention, the upper table 3 and the lower table 5 of the press brake 1 are provided with a bending mechanism as shown in FIG. Can be configured to perform various bending processes in parallel with each other. as a result,
For example, various bending shapes such as taper bending, R bending, and arc bending can be easily obtained.

Referring to FIGS. 9 and 10, in the case of arc bending, the work W is moved from right to left in the direction in which the workpiece W is bent into an arc shape, and is shown in FIG. 2 of the above-described embodiment. Punch P, die D and front and rear rollers 3
In the present embodiment, three bending mechanisms 57, 59, 61 are arranged in the press brake 1 in a multistage manner in parallel with each other in the work moving direction. Have been. For example, FIG. 9 and FIG.
0, the front and rear rollers 33F, 33F are bent by the bending mechanism 57 at the right end so as to be bent at a bending angle halfway in the first stage.
The V dimension of 33R is widely adjusted, and the workpiece W is shown in FIG.
In the above, the bending mechanism 57 gradually performs the arc bending while being gradually moved in the arc-shaped work moving direction.

Next, in the central bending mechanism 59, the V dimension of the front and rear rollers 33F and 33R is adjusted to be narrower than that of the first stage so that the bending is performed at a bending angle halfway in the second stage. The workpiece W bent at the first stage is gradually bent by the second-stage bending mechanism 59 while being gradually moved in the arc-shaped workpiece moving direction.

Further, in the bending mechanism 61 at the left end, the V dimension of the front and rear rollers 33F, 33R is adjusted to be smaller than that of the second stage so that the bending is performed at the final predetermined bending angle in the third stage. The workpiece W bent in the second stage is gradually bent by the third-stage bending mechanism 61 while being gradually moved in the arc-shaped workpiece moving direction.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. The press brake according to the present embodiment is directed to a descending hydraulic press brake, but may be a mechanical press brake such as a crank instead of an upward press brake or a hydraulic press brake. In the case of a mechanical press brake, the table on the opposite side for preloading can be configured to apply a load by a biasing means such as a spring.

In the above-described embodiment, the support member including the front and rear rollers 33F and 33R is provided before and after the die D. However, a support member including a non-rotating sliding member may be used.

In the above-described embodiment, the front and rear rollers 33 are held while the workpiece W is sandwiched and preloaded.
The height of F, 33R is fixed, and the punch P and the die D are simultaneously lowered. The upper table on which the punch P is mounted is provided to be movable up and down, and the lower table on which the die D is mounted is fixed. Alternatively, the support member may be provided so as to be vertically movable. In other words, the workpiece is preloaded by lowering the punch P to sandwich the workpiece W with the die D, and then the front and rear support members are raised in this state, whereby bending is performed.

When the lower table on which the die D is mounted is vertically movable and the punch P is fixed and the support member is vertically movable, the die D is raised and placed on the support member. After the workpiece is sandwiched by the punch P and preloaded, the front and rear support members are raised in this state, whereby the bending is performed.

[0075]

As will be understood from the above description of the embodiments of the present invention, according to the first aspect of the present invention, the front and rear support members have an optimum V width depending on the material and plate thickness of the work. Can be moved to a predetermined position before and after
Appropriate bending can be performed on various workpieces without changing the mold. Since the workpiece can be widely supported by the front and rear support members, a large moment can be obtained at the time of bending, the bending can be performed with a small load, and the bending angle can be performed with high precision.

When preloading a work,
For example, since the plastic deformation of the bending is performed in the small V-groove only corresponding to the region of the bending R of the die, almost the same effect as the bottoming is obtained, and the work is given relative motion to the front and rear support members. , High-precision bending can be performed.

According to the second aspect of the present invention, when the upper table is lowered by the first pressing force, the lower table which is opposed by the second pressing force smaller than the first pressing force ensures the cooperation of the punch and the die. Work can be preloaded. Further, by lowering the upper table, the workpiece can be lowered while the workpiece is preloaded and a relative motion with respect to the front and rear support members can be given to the workpiece, so that bending can be performed with high precision.

According to the third aspect of the present invention, by vibrating the punch and the die during preloading or bending, the plastic deformation of the work progresses in small increments and the amount of springback can be reduced. Can be made more accurate.

According to the fourth aspect of the present invention, since the support member is a rotating body, the work is less likely to be scratched when the work is bent while moving on the rotating body during bending.

According to the fifth aspect of the present invention, since the rotating body is driven to rotate in synchronization with the moving speed of the workpiece during bending,
Scratches on the work can be minimized.

According to the sixth aspect of the present invention, since the bending step including the preloading and the main bending is combined in parallel in a multi-stage form, the distance between the front and rear support members can be variously adjusted at each stage. The workpiece can be bent step by step through each bending step, and various bending shapes such as taper bending, R bending, and arc bending can be obtained.

According to the seventh aspect of the present invention, since the work can be widely supported by the front and rear support members, a large moment can be obtained at the time of bending, the bending can be performed with a small load, and the bending angle can be performed with high precision. In addition, when preloading the work, for example, the plastic deformation of the bending is performed in a small V-groove only corresponding to the region of the bending R of the die, so that substantially the same effect as the bottoming is obtained. Since the relative movement with respect to the support member is given, highly accurate bending can be performed.

According to the eighth aspect of the present invention, when the front and rear support members are fixed, the preloading and the main bending can be easily performed continuously by lowering the upper table and the lower table. .

According to the ninth aspect of the present invention, the front and rear support members can be moved and positioned at the front and rear predetermined positions so as to have an optimum V width depending on the material and plate thickness of the work. It is possible to perform appropriate bending on the work.

According to the tenth aspect of the present invention, in the same manner as the effect of the second aspect, when the upper table is lowered by the first pressing force, the lower table is opposed by the second pressing force smaller than the first pressing force. The work can be reliably preloaded by cooperation between the punch and the die. Further, by lowering the upper table, the workpiece can be lowered while the workpiece is preloaded and a relative motion with respect to the front and rear support members can be given to the workpiece, so that bending can be performed with high precision.

According to the eleventh aspect of the present invention, when a V-groove having a small V-groove width corresponding to the region of the bending R of the work is provided, the V-groove is subjected to bending plastic deformation and bottoming. Approximately the same operation can be obtained. Furthermore, the distance of the V-groove width, which is the receiving portion of the die, is small and approaches the region of the bend R, so that the scratch becomes less noticeable.

According to the twelfth aspect of the invention, the effect is the same as that of the third aspect, and by vibrating the punch and the die during preloading or bending, the plastic deformation of the work progresses in small steps. Therefore, the amount of springback can be reduced, so that the bending angle can be made more precise.

According to the thirteenth aspect of the present invention, the effect is the same as that of the fourth aspect, and since the support member is a rotating body, when the work is bent while moving on the rotating body at the time of the bending process, the support member has Scratches can be reduced.

According to the fourteenth aspect of the present invention, the effect is the same as that of the fifth aspect, and the rotating body is driven to rotate in synchronization with the moving speed of the work at the time of bending, thereby minimizing abrasion of the work. it can.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is a perspective view of a press brake.

FIG. 2 is a schematic explanatory view schematically showing a bending apparatus according to an embodiment of the present invention.

FIG. 3 is a bottoming diagram illustrating the concept of bending according to the embodiment of the present invention.

FIG. 4 is an enlarged view of FIG. 3;

FIG. 5 is a side view of a die used in the embodiment of the present invention.

FIG. 6 is a block diagram of a control device.

FIG. 7 is a flowchart of the embodiment of the present invention.

FIG. 8A is an explanatory diagram of a state at the time of preloading, and FIG.
Is a state explanatory diagram at the time of main bending, and (C) is a state explanatory diagram when micro-vibration is applied to the mold during bending.

FIG. 9 is a plan view showing a state in which bending mechanisms are arranged in parallel in a multi-stage form for performing arc bending.

FIG. 10 is a schematic front view of FIG. 9;

FIG. 11 is an explanatory view of a state of a conventional air bending process.

FIG. 12 is a diagram illustrating a state of a conventional bottoming process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Press brake (bending apparatus) 3 Upper table 5 Lower table 9 Upper table drive cylinder 13 Control device 15 Lower table drive cylinder 25 Roller left-right guide 27 Roller front-rear guide 31 Roller support arm 33 Roller (support member, rotating body) 35 roller rotation drive motor (roller rotation drive means) 47 arithmetic unit 49 roller movement command unit 51 preload command unit 53 main bending command unit 55 vibrating device 57, 59, 61 bending mechanism

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E063 AA01 BA07 CA01 FA01 FA09 GA01 GA06 JA01 JA06 JA07 LA02 LA08 LA11 LA17 4E090 AA01 AB01 BA01 BB06 CA02 EA01 EC01 HA02

Claims (14)

[Claims] A work is supported by a support member which is previously moved and positioned at a predetermined position before and after a die, and at least one of an upper table on which a punch is mounted and a lower table on which the die is mounted are mounted. Raise or lower, clamp the work with the punch and die, apply a predetermined preload, and raise or lower the support member before and after and the upper table or the lower table with the preload applied. A bending method, wherein the workpiece is bent by cooperation with a punch, a die, and front and rear support members by giving a relative motion. 2. The method according to claim 1, wherein when the work is preloaded by the punch and the die, the work is clamped by opposing the lower table with a second pressure smaller than the first pressure of the upper table. The bending method described. 3. The punch and die are vibrated by applying a slight vibration to at least one of the preloading and the bending.
Or the bending method according to 2. 4. The bending method according to claim 1, wherein the front and rear support members are at least two or more rotating bodies or a long rotating body, respectively. 5. The bending method according to claim 4, wherein the rotating body is driven to rotate in synchronization with a moving speed of the workpiece based on a bending speed. 6. A workpiece is supported by a support member which is previously moved and positioned at a predetermined position before and after a die, and at least one of an upper table on which a punch is mounted and a lower table on which the die is mounted. Raise or lower, clamp the work with the punch and die, apply a predetermined preload, and raise or lower the support member before and after and the upper table or the lower table with the preload applied. The bending step of bending the work in cooperation with the punch, the die, and the front and rear support members by giving a relative motion is performed by performing various bending processes in parallel in multiple stages. Bending method. 7. A bending process wherein an upper table on which a punch is mounted and a lower table on which a die is mounted are provided so as to be vertically movable, and support members for supporting a work are provided before and after the die. apparatus. 8. The bending apparatus according to claim 7, wherein the support member is fixedly provided. 9. The bending apparatus according to claim 7, wherein the support member is provided so as to be movable in a forward and backward direction. 10. A first pressure driving means for driving one of the upper and lower tables at a first pressing force, and a second pressing force smaller than the first pressing force for the other table. 10. The bending apparatus according to claim 7, further comprising a second pressure driving means for driving the table in a direction opposite to the one side table. 11. The die according to claim 7, wherein a V-groove having a V-groove width corresponding to a bending radius of the workpiece is provided on the die, or a flat portion without the V-groove is provided. The bending apparatus according to any one of the above. 12. The apparatus according to claim 7, wherein at least one of the upper table and the lower table is provided with a vibrating device for applying a fine vibration to a punch and a die. Bending equipment. 13. The bending according to any one of claims 7 to 12, wherein the front and rear support members are each composed of at least two or more rotating bodies or a long rotating body. Processing equipment. 14. The bending apparatus according to claim 13, wherein the rotating body is provided so as to be rotatable in synchronization with a moving speed of the workpiece by a bending speed.