JPH06246354A - Method for bending damping steel sheet - Google Patents

Abstract

PURPOSE:To provide a method, for bending damping steel sheet, in which no special equipment is required and by which a gull shaped slippage between two layered steel sheet is surely prevented without adversely affecting the quality of a product. CONSTITUTION:In bending a work W which is made of a damping steel sheet, by placing both end edges of this work W on both shoulder parts of a second die 6, a preliminary bending is performed to the prescribed shallow bending angle while a bending moment is imparted over the entire area of the sheet surface of the work W including bending corners; and then, by means of a first die 5, a finish working is carried out to the fianl bending angle by the normal V-shaped bending.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bending a vibration-damping steel plate which comprises a resin sandwiched between two steel plates.

[0002]

2. Description of the Related Art Vibration-damping steel plates made by sandwiching a resin between two steel plates have excellent vibration-damping and sound-insulating effects and can be made lighter. Therefore, they are often used in various parts such as electric appliances, furniture, and automobiles. It is used. This vibration-damping steel plate is usually used after being V-bent by a bending machine such as a press brake having a punch and a die.

By the way, when such a vibration-damping steel plate is subjected to V-bending, the lengths of the bent portions of the steel plates on the front surface side and the back surface side of the resin layer are different, so that these steel plates are formed in the middle of the bending process. As shown in FIG. 9, there was a deviation, and as shown in FIG. 9, there was a shape defect in which the portions 52, 52 contacting both shoulders of the die 51 were bent to the opposite side in the bending direction, so-called seagull-like deformation.

Therefore, conventionally, the following method has been proposed as a method for preventing such a gull-like deformation. Japanese Unexamined Patent Publication (Kokai) No. 2-11225 discloses a processing method in which an elastic block having a V-shaped cross section is loaded on a forming V groove and bending is performed between the elastic block and the punch. In Japanese Patent Application Laid-Open No. 2-99222, the temperature of the intermediate resin layer of the vibration-damping steel plate is lowered by blowing a refrigerant gas near the V-bending line of the vibration-damping steel plate to cool the vibration-damping steel plate, and the shear bond strength thereof is increased. A processing method for doing so is disclosed. In Japanese Unexamined Patent Publication No. 3-128124, a process of applying a compressive stress in the plate thickness direction to a bent part of a vibration-damping steel plate in the initial stage of bending so that this part is yielded in advance and the bending process is performed. A method is disclosed.

[0005]

However, with the above method, although it is possible to obtain the effect of preventing seagull deformation to some extent, there is a problem that this seagull deformation cannot be completely eliminated. Further, in the above method, the cooling effect may not be sufficiently exerted depending on the type of resin sandwiched as the intermediate layer, or since the refrigerant gas is used, the production cost is high and the cooling time is required. There is a problem that a long processing time is required. Further, the above-mentioned method has a problem that the product quality may be adversely affected because the plate thickness is significantly reduced in the bent portion, and a special bending die is required at the time of working.

The present invention has been made in order to solve various problems of the conventional method, and does not require special equipment, and moreover, does not adversely affect the quality of the product and ensures the seam-like deformation. It is an object of the present invention to provide a method for bending a vibration-damping steel plate that can prevent the bending.

[0007]

DISCLOSURE OF THE INVENTION In view of the fact that seam-like deformation occurs in the vicinity of the boundary between a portion where a bending moment occurs inside the material during bending and a portion where it does not, the plate surface It has been found that it is possible to avoid the occurrence of seagull-like deformation by performing bending while applying a bending moment over the entire area of. That is, a method for bending a vibration-damping steel plate according to the present invention is a method for bending a vibration-damping steel plate that performs V-bending using a punch and a die, and includes (a) the vibration-damping steel plate including a bending corner portion. The pre-bending step of bending the damping steel plate to a predetermined shallow bending angle less than the final bending angle while applying a bending moment over the entire plate surface of V
A final bending step of bending to a final bending angle by bending is provided.

The pre-bending step is preferably carried out by placing both edges of the vibration-damping steel sheet on both shoulders of the die. This pre-bending step can be performed at each stage of the bending step. Is preferably performed by using a movable die whose groove width can be changed.

[0009]

In the present invention, the vibration-damping steel plate is bent to a predetermined shallow bending angle less than the final bending angle while applying a bending moment over the entire area of the plate surface in advance of the ordinary V-bending process. By doing so, since there is no distinction between a portion where a bending moment is generated inside the material during bending and a portion where it is not, the occurrence of seagull deformation is avoided.

[0010]

EXAMPLES Next, specific examples of the method for bending a vibration damping steel sheet according to the present invention will be described with reference to the drawings.

1 to 4 show the main structure of a press brake applied to a method for bending a vibration damping steel plate according to an embodiment of the present invention. In the press brake of this embodiment, the sliding member 2 is provided on the upper surface of the fixed table 1, and the upper surface of the sliding member 2 is driven in the front-rear direction (left-right direction in FIG. 1) by driving the die base driving cylinder 3. A slidable die base 4 is supported. The upper surface of the die base 4 is provided with a first die 5 for finish bending on the front part and a second die 6 for pre-bending on the rear part.
Is provided. The first die 5 is a so-called V die having a V groove 5a formed on the upper surface, and is bolted to the die base 4. The second die 6 is arranged adjacent to the first die 5 and includes a fixed die 7 fixed to the die base 4 by bolts and a movable die 8 arranged opposite to the fixed die 7 so as to be slidable in the front-rear direction. It consists of
The fixed die 7 and the movable die 8 have a shape in which the upper portions of the surfaces facing each other are obliquely cut out, and a V groove is formed on the upper surface when the die 7 and 8 come into contact with each other by these cutout portions 7a and 8a. It has become so.

The movable die 8 is reciprocated by a linear head 9 fixed to the rear end surface of the die base 4. That is, when the motor 10 of the linear head 9 is rotated in the forward and reverse directions, the rotational movement is reduced by the gears and converted into the linear movement of the rack 11, and the movable die fixed to the end of the rack 11. 8 is moved in the direction of arrow A in FIG. The movable die 8 is held on the die base 4 by a die clamper 12 embedded in the die base 4. As shown in FIG. 4, the die clamper 12 has a cylindrical casing 13, a piston 14 slidably provided in the casing 13 in the up-down direction, and the casing 13 fixed to the piston 14. The clamp bar 15 is provided so as to project upward from the above, and the disc spring 16 is provided in the upper chamber of the casing 13 defined above the piston 14 and constantly presses the piston 14 downward. . The casing 13 is provided with a hydraulic passage 17 which communicates with a lower chamber defined below the piston 14 and supplies a hydraulic pressure for moving the piston 14 upward against the pressing force of the disc spring 16. Further, on the upper portion of the clamp bar 15, there is provided a flange portion 15a for pressing the movable die 8 toward the die base 4 side by engaging with a predetermined portion of the movable die 8. As shown in FIG. 2, the die clampers 12 having such a configuration are installed at three locations in the longitudinal direction of the die base 4, and the hydraulic passages 17 of the respective die clampers 12 are connected to the hydraulic pipes 18 for movable die unclamping. .

With such a configuration, when the hydraulic pressure is not supplied to the hydraulic passage 17 of the die clamper 12, the piston 14 is pressed downward by the disc spring 16 so that the flange of the clamp bar 15 is pressed. The movable die 8 is pressed against the die base 4 by the portion 15a, and the movable die 8 is held. In this state, when hydraulic pressure is supplied from the movable dian clamp hydraulic pipe 18 to the lower chamber of the casing 13 via the hydraulic passage 17, the piston 14 is moved upward against the pressing force of the disc spring 16 and the clamp bar 15 is pressed. The pressing of the movable die 8 by the collar portion 15a is released. In this released state, the motor 1 of the linear head 9
0 is driven to move the movable die 8 as shown by a chain double-dashed line in FIG. 1, and the die clamper 12 is actuated again at the moving position to fix the movable die 8 to the die base 4. In FIG. 2, reference numeral 19 is a stopper that restricts the rearward movement of the die base 4 by a predetermined amount or more.

Next, the bending process of the damping steel plate in this embodiment using the press brake constructed as described above will be described with reference to FIGS. Note that FIG. 6 (a)
(D) shows the set state of the work at the time of pre-bending, and these are the process No. of FIG. It corresponds to each bending process of 1, 3, 5, and 7, respectively.

When a product having four bending corners b, c, d and e as shown in FIG. 7 is bent from a plate-like work w, first, the V width k of the movable die 8 is the width of the work w. The position of the movable die 8 is set so that it becomes slightly shorter, that is, both edges of the work w rest on both shoulders of the second die 6, and in that state, the punch 20 is lowered to bend the bending corner portion. Pre-bending of b is performed (step 1). In this preliminary bending step, positioning of the work w until the punch 20 contacts the work w is performed by a positioning means (not shown) such as a backstop device. In addition, the movable die 8
Is controlled by the linear head 9 and the die clamper 12 so that both edges of the work w are always held on the shoulders of the second die 6. Thus, in this preliminary bending step, bending work is performed while applying a bending moment over the entire area of the surface of the work w including the bending line. After that, when the pre-bending is performed until the predetermined bending angle is reached, the punch 20 is once lifted and the die base 4 is slid by the driving of the die base driving cylinder 3, so that the first die 5 is positioned below the punch 20. And let
The work w is placed on the upper surface of the first die 5 and finish bending is performed up to the final bending angle (90 °) of the bending corner portion b (step 2).

When the bending of the corner portion b is completed in this way, the corner portion c is again formed by the second die 6 in the same manner as described above.
Pre-bending (step 3), then again the first die 5
Then, the corner portion c is subjected to finish bending (step 4).

Next, the front and rear positions of the work w are set in the opposite direction, the preliminary bending of the corner e (step 5) and the finish bending (step 6) are sequentially performed in the same manner as described above, and the corner d is further added.
The bending process is completed by sequentially performing the preliminary bending (step 7) and the final bending (step 8).

The control of the bending work as described above is performed by the NC control device attached to the press brake. As shown in FIG. 8, the control system in the NC control device is sandwiched between the work w to be bent, the plate thickness, the size, the bending angle, and the plate thickness ratio of the two steel plates or the middle thereof. A work information input section 21 for inputting work information such as material properties such as resin properties, a list of conditions for favorable bending such as a preliminary bending angle, conditions for use die specifications and use machine specifications, etc. Condition database unit 22 for storing
And are provided. Then, the work information input unit 21
From the condition database unit 22 selected according to the input data from the condition data and the bending angle of the work w and the die 5,
The V width of 6 is determined, and the depth value (pushing amount) of the punch 20, BS value (pack stop related data), die V width, die used, etc. in the machine control data calculation unit 24 according to the conditions thus determined. Is calculated, and each actuator 26 such as the linear head 9 and the die clamper 12 is controlled by an output signal from the machine control data output section 25 based on the calculated data.

According to this embodiment, it is possible to process a work having a complicated shape including bending of a plurality of corners without causing the work w to deform like a seagull.

[0020]

As described above, according to the present invention, the bending moment is applied to the whole area of the plate surface, the preliminary bending is performed up to a predetermined shallow bending angle less than the final bending angle, and then the normal V bending process is performed. Since it is configured to do so, it does not require special equipment such as a cooling device and a back pressure applying device, it can use conventional dies and reliably prevent seagull deformation without adversely affecting product quality. can do.

[Brief description of drawings]

FIG. 1 is a side view showing a main structure of a press brake applied to a method for bending a vibration damping steel sheet according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a view on arrow B of FIG.

FIG. 4 is a sectional view of a die clamp in a press brake according to an embodiment of the present invention.

FIG. 5 is an explanatory view of a bending process according to an embodiment of the present invention.

FIG. 6 is an explanatory view of a bending process in the embodiment of the present invention.

FIG. 7 is a diagram showing a product processed by a bending process according to an embodiment of the present invention.

FIG. 8 is a block diagram of a control system for controlling bending in one embodiment of the present invention.

FIG. 9 is a diagram illustrating a conventional bending process.

[Explanation of symbols]

 4 Die Base 5 First Die 6 Second Die 7 Fixed Die 8 Movable Die 20 Punch w Work

Claims (3)

[Claims] 1. A method for bending a vibration-damping steel sheet, which is V-bent using a punch and a die, comprising: (a) a bending moment over the entire plate surface of the vibration-damping steel sheet including a bending corner portion. The pre-bending step of bending the damping steel plate to a predetermined shallow bending angle less than the final bending angle while applying
A bending method for a vibration-damping steel sheet, comprising a finishing bending step of bending to a final bending angle by bending. 2. The method for bending a vibration-damping steel plate according to claim 1, wherein the preliminary bending step is performed by placing both edges of the vibration-damping steel plate on both shoulders of the die. 3. The pre-bending step is performed using a movable die in which the groove width of the die can be changed.
The method for bending a vibration-damping steel sheet according to.