SHEET MATERIAL PROCESSING APPARATUS, PRESS DIE, AND DIE SETTING BODY

TECHNICAL FIELD

The present invention relates to a processing apparatus for processing a metallic sheet material, a press die, and a die setting body, and particularly, to a sheet material processing apparatus having a function of bending a sheet material and/or a function of pressing an end of the sheet material.

BACKGROUND ART

Laser-cutting or shearing a metallic sheet material, and thereafter, bending the sheet material frequently cause a warp S such as a boat warp on the sheet material W as illustrated in FIG. 12. It is known that the warp S occurs when the sheet metal W to be bent has a relatively small width and a relatively long ridge to be bent.

To suppress such a warp on a sheet material, the sheet material, which has been cut, is passed through a leveler and bent, or is first bent by press machine, reversed, and pressed to correct a warp. Using a leveler has a problem that a leveler capable of dealing with sheet materials of various sizes must be prepared between a cutting process and a bending process. Bending a sheet material by press machine and then correcting a warp have a problem that the warp correction is difficult.

Japanese Unexamined Patent Application Publication No. 2005-177790 (Patent Literature 1), for example, provides a die with a shape to give a sheet material a warp in a direction opposite to a U-bend to be applied to the sheet material and carries out a bending process in two steps by using retortion, thereby reducing a warp. Japanese Unexamined Patent Application Publication No. 2006-15404 (Patent Literature 2) bends a Z-shaped material or a hat channel material with a die, conducts retortion, and through these two steps, reduces a warp.

The Patent Literature 1, however, needs a special die, is unable to flexibly handle various sizes of sheet materials, and complicates the shape of a processed sheet material.

The Patent Literature 2 carries out a bending process in two steps to elongate a processing time and is unable to deal with special shapes.

The inventors of the present invention have studied a mechanism of a longitudinal warp in a bending process such as a V-bending process, clarified the occurrence and suppression of a warp in the bending process, and filed Japanese Patent Application No. 2011-5649 and Japanese Patent Application No. 2011-242372 that is a domestic priority claim application based on the Japanese Patent Application No. 2011-5649. These applications pressurize a cut edge of a sheet material to increase or decrease residual stress caused in the sheet material at the time of cutting the sheet material, thereby suppressing a warp.

SUMMARY OF INVENTION
Problems to be Solved by Invention

Bending a sheet material according to the proposals of the inventors of the present invention needs, in addition to a bending machine for bending the sheet material, a press machine for pressing a cut edge of the sheet material and necessitates pressing an end face of the sheet material by the press machine, and thereafter, moving the sheet material to the bending machine. This makes the handling of the sheet material troublesome and time and labor consuming.

To cope with this, pressing an end face of a sheet material and bending the same may be conducted by a single bending machine. This, however, requires a die for pressing the end face of the sheet material and a die for bending the sheet material must be replaced with each other according to a process to be carried out on the sheet material. This causes problems of increasing work steps and making the handling of the sheet material troublesome.

Using a bending machine to press an end face of a sheet material in a thickness direction for a predetermined width (for reducing a warp to be caused in a bending process) raises a problem that, depending on a pressing mode, the part of the sheet material to be pressed is incorrectly pressed.

Means to Solve Problems

The present invention is able to provide a sheet metal processing apparatus, a press die, and a die setting body (for supporting a die set on the processing machine), capable of easily handling a sheet material and improving workability.

Also, the present invention is able to provide a processing apparatus, a press die, and a die setting body, capable of correctly pressing a sheet material so as to minimize a warp that may occur when bending the sheet material.

A first technical aspect of the present invention provides a sheet material processing apparatus having a pressurizing part to pressurize a sheet material and a supporting part to support the sheet material pressurized by the pressurizing part. The processing apparatus includes an end face pressing upper press die that receives a pressurizing force from the pressurizing part, an end face pressing lower press die that is arranged on the supporting part and faces the end face pressing upper press die so that an end face of the sheet material is inserted between the end face pressing upper and lower press dies, an end face pressing part that, with the pressurizing force from the pressurizing part moving the end face pressing upper press die toward the end face pressing lower press die, presses the end face of the sheet material along a bend line of the sheet material to be bent, and an end face pressing width adjusting part that sets a pressing width of the end face of the sheet material so that, when the end face pressing part presses the end face, a contact face of the end face of the sheet material comes in front of, in a direction in which the sheet material is inserted between the end face pressing upper and lower press dies, a pressurizing center of the pressurizing force applied from the pressurizing part to the end face pressing upper press die.

A second technical aspect of the present invention provides a press die installed on and used by a processing apparatus that employs a punch, a die, and a pressurizing part to bend a sheet material. The press die includes an end face pressing upper press die that receives a pressurizing force from the pressurizing part that drives the punch toward the die, an end face pressing lower press die that is arranged to face the end face pressing upper press die so that an end face of the sheet material is inserted between the end face pressing upper and lower press dies, an end face pressing part that, with the pressurizing force from the pressurizing part moving the end face pressing upper press die toward the end face pressing lower press die, presses the end face of the sheet material along a bend line of the sheet material to be bent, and an end face pressing width adjusting part that sets a pressing width of the end face of the sheet material so that, when the end face pressing part presses the end face, a contact face of the end face of the sheet material comes in front of, in a direction in which the sheet material is inserted between the end face pressing upper and lower press dies, a pressurizing center of the pressurizing force applied from the pressurizing part to the end face pressing upper press die.

A third technical aspect of the present invention provides a die setting body installed on and used by a processing apparatus that employs a punch and a die to bend a sheet material. The die setting body includes a die setting part on which the die is set and an end face pressing part that presses an end face area of the sheet material along a bend line along which the sheet material is to be bent by the punch and the die set on the die setting part. The end face pressing part is positioned opposite to an apparatus base of the processing apparatus with a pressurizing center of the punch and die being interposed between the end face pressing part and the apparatus base.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view generally illustrating a bending apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a bending part of the bending apparatus.

FIG. 3 is a perspective view illustrating a backside of the bending part of the bending apparatus.

FIG. 4 is a perspective view illustrating a height adjusting mechanism of an end face pressing part.

FIG. 5 is a side view illustrating the height adjusting mechanism.

FIG. 6 is a perspective view illustrating the height adjusting mechanism with an end face pressing lower press die being omitted.

FIG. 7 is a front view illustrating an action of the height adjusting mechanism.

FIG. 8 is a side view illustrating a pressing width adjusting mechanism.

FIG. 9 is a plan view illustrating the pressing width adjusting mechanism.

FIG. 10 is a perspective view illustrating the pressing width adjusting mechanism.

FIG. 11 is a perspective view illustrating the pressing width adjusting mechanism.

FIG. 12 is a perspective view illustrating a sheet material causing a warp after a bending process.

FIG. 13 is a front view generally illustrating a bending apparatus according to a second embodiment of the present invention.

FIG. 14 is a side view seen from an arrow XIV of FIG. 13, generally illustrating the bending apparatus and corresponding to FIG. 2.

FIG. 15 is a perspective view illustrating a die setting body installed on the bending apparatus with a cover plate being removed.

FIG. 16 is a sectional view along XVI-XVI of FIG. 15.

FIG. 17 is a simplified view of FIG. 16.

FIG. 18 is a simplified sectional view along XVIII-XVIII of FIG. 15.

FIG. 19 is a view illustrating a state that a die holder (upper press die) is lowered from the state of FIG. 17 and a lower press die and the upper press die hold and press an end face of a sheet material.

FIG. 20 is a view illustrating a state that the lower press die is moved backward from the state of FIG. 17, the die holder (upper press die) is lowered, and the end face of the sheet material is not held or pressed.

FIG. 21 is a view illustrating a state that a stopper (stopper support) is moved to a rear end from the state of FIG. 18.

FIG. 22 is a view illustrating a state that a sheet material to be hemmed is set on the lower press die in the state of FIG. 21.

FIG. 23 is a view illustrating a state that the die holder (upper press die) is lowered from the state of FIG. 22 and the lower and upper press dies hold, press, and hem an end face of the sheet material.

FIG. 24 is a view illustrating a state that a die (the die holder) is lowered from the state of FIG. 17, a sheet material is set on the die, and a punch is lowered to hold and bend the sheet material against the die.

FIG. 25 is an enlarged view illustrating a part XXV of FIG. 24.

FIG. 26 is a perspective view illustrating a part for pressing a sheet material of a bending apparatus according to a third embodiment of the present invention with an end face pressing upper press die being lifted.

FIG. 27 is a view illustrating a state that the end face pressing upper press die is lowered from the state of FIG. 26, to press an end face of a sheet material (to reduce a warp to be caused when bending the sheet material).

FIG. 28 is a view illustrating a state that the end face pressing upper press die is lowered from the state of FIG. 26, to hem the sheet material.

FIG. 29 is a view seen from an arrow XXIX of FIG. 26.

FIG. 30 is a side view illustrating behaviors of the end face pressing upper and lower press dies during the pressing process of FIG. 27.

MODE OF IMPLEMENTING INVENTION
First Embodiment

The present invention will be explained in detail according to the illustrated embodiments. FIG. 1 to 12 illustrate a sheet material bending apparatus (sheet material processing apparatus) 1 according to the first embodiment of the present invention, in which FIG. 1 is a side view generally illustrating the apparatus and FIGS. 2 and 3 are perspective front and backside views illustrating a bending part 2. FIGS. 4 to 7 illustrate an end face pressing part 3 and a height adjusting mechanism 41 of the end face pressing part 3, FIGS. 8 to 11 illustrate a pressing width adjusting mechanism 51 of the end face pressing part 3, and FIG. 12 illustrates press control of an end face of a sheet material.

The sheet material bending apparatus (for example, a press brake) 1 has a function of bending a metallic sheet material (sheet work) W, and in addition, a function of pressing an end face of the sheet material W to adjust residual stress caused by cutting the sheet material W. For this, as illustrated in FIG. 1, the bending apparatus 1 includes the bending part 2 for bending, for example, V-bending the sheet material W, the end face pressing part 3 for pressing one end face of the sheet material W before bending the sheet material, and an apparatus base 5 for integrally supporting them.

The apparatus base 5 includes an upper base 5a and a lower base 5b that are connected to each other so that they vertically face each other to form an elongated U-shape (or C-shape) when seen from a side. The bending part 2 is arranged on the upper base 5a and the end face pressing part 3 is arranged on the lower base 5b so that the end face pressing part 3 is under the bending part 2 and faces the same. In the bending apparatus 1, the end face pressing part 3 presses the one end face of the sheet material W cut by, for example, laser or shearing, thereby increasing or decreasing residual stress. After the one end face is pressed, the sheet material W is bent by the bending part 2. This results in reducing an occurrence of a warp of the sheet material W to be bent.

As illustrated in FIG. 1, the bending part 2 has a punch-side member 11 arranged on the upper base 5a, a die-side member 12 arranged under the punch-side member 11, and a bending driver (driver) 13 made of a hydraulic cylinder to drive the punch-side member 11. The hydraulic cylinder may be another actuator such as a servo motor. The bending driver 13, i.e., the hydraulic cylinder is vertically oriented and is attached to the upper base 5a of the apparatus base 5, so that extending and contracting actions thereof vertically move the punch-side member 11 toward and away from the die-side member 12. Instead of or in addition to vertically moving the punch-side member 11, the die-side member 12 may be configured to vertically move.

The punch-side member 11 is arranged under the bending driver 13 and has a punch 14 for pressing the sheet material W, a punch holder 15 to which the punch 14 is attached, and an upper table 16 to which the punch holder 15 is attached. The upper table 16 is connected to the bending driver 13 so that driving the bending driver 13 results in vertically moving the upper table 16, punch holder 15, and punch 14 to press the sheet material W.

The die-side member 12 faces the punch 14 and has a die 17 for receiving the sheet material W pressed by the punch 14, a die holder (first die holder) 18 for supporting a lower part of the die 17, and a lower table (second die holder) 21. The lower table 21 and die holder 18 sandwich and hold the die 17. Protruding from an upper part of the lower table 21 is a hold piece 21a that faces the die holder 18. The die 17 has a leg 17a that is held between the die holder 18 and the hold piece 21a. In this state, the die holder 18 is tightened with a screw to hold the die 17 between the die holder 18 and the lower table 21.

The lower table 21 is attached to a base frame 25 that is fixed to the lower base 5b of the apparatus base 5, so that the die-side member 12 as a whole is supported by the base frame 25. The base frame 25 has an L-shape in a side view and includes an upright side wall 25a. The lower table 21 is vertically movably attached to the side wall 25a of the base frame 25. As illustrated in FIG. 3, the side wall 25a of the base frame 25 has a plurality of vertically elongated long holes 26 at predetermined intervals. A back face of the lower table 21 is provided with a plurality of screws 27 that pass through the long holes 26, respectively. In this way, the lower table 21 is vertically movably attached to the base frame 25. With this configuration, the punch 14 is moved toward the die 17 to press the sheet material W against the die 17. Pressure of the punch 14 provides a downward moving force onto the lower table 21, and therefore, the lower table 21 moves in the same direction. Arranged inside the side wall 25a of the base frame 25 are return springs 28 corresponding to the screws 27. The return springs 28 are compressed by the downward movement of the lower table 21 and reaction force thereof returns the lower table 21 to an original height position.

The bending part 2 bends the sheet material W into, for example, a V-shape and the bending of the sheet material W is conducted along a pressing center 7 (refer to FIG. 1) of the punch 14 and die 17.

The end face pressing part 3 has an end face pressing lower press die 31 arranged to face the lower table 21. The end face pressing lower press die 31 presses the end face of the sheet material W along a bend line of the sheet material W to be bent. The end face side of the sheet material W is placed on the end face pressing lower press die 31. In this state, the punch 14 is moved toward the die 17 to move the lower table 21 in the same direction. The movement of the lower table 21 holds the sheet material W between the lower table 21 and the end face pressing lower press die 31, thereby pressing the vicinity of the end face 19 of the sheet material W. To achieve this, a lower end of the lower table 21 corresponding to the end face pressing lower press die 31 is an end face pressing upper press die 32.

According to this configuration, the bending part 2 for bending the sheet material W and the end face pressing part 3 for pressing the end face of the sheet material W to suppress a warp of the sheet material W are arranged on the single apparatus base 5. Accordingly, the single apparatus is able to press the end face of the sheet material W and bend the sheet material W. This configuration easily handles the sheet material W, thereby improving workability. Pressing the end face 19 of the sheet material W to control residual stress of the sheet material W is carried out by using the drive force of the bending driver 13 of the bending part 2. This necessitates no separate driving source for pressing the end face 19 of the sheet material W, thereby simplifying the apparatus and saving energy.

As illustrated in FIG. 2, the end face pressing lower press die 31 has a plurality of fixed dies 33 and a plurality of movable dies 35. The fixed dies 33 are fixed in their height positions and are arranged on the base frame 25. The movable dies 35 are arranged adjacent to the fixed dies 33 and their height positions are changeable relative to the fixed dies 33. Changing the height positions of the movable dies 35 is carried out by a height adjusting mechanism 41.

As illustrated in FIGS. 4 to 6, the height adjusting mechanism 41 has a height adjust drive source 42 arranged behind the base frame 25 and a shim 43 arranged above the base frame 25. The height adjust drive source 42 may be a cylinder or a motor. According to this embodiment, it is a cylinder. The shim 42 is a flat plate and is arranged above the base frame 25 to face a lower face of the movable die 35. The lower face of the movable die 35 opposing the shim 43 is a stepped face including a higher plane 35a and a lower plane 35b.

The flat shim 43 is movable above the base frame 25 in a direction toward or away from the die-side member 12. To realize this movement, the height adjust drive source 42 has a piston 42a whose front end is provided with a connection bracket 44. To a front end of the connection bracket 44, the shim 43 is attached. The connection bracket 44 slides when driven by the height adjust drive source 42 in the above-mentioned direction toward or away from the die-side member 12.

When this movement causes the shim 43 to face the higher plane 35a, a large gap is created between the shim 43 and the higher plane 35a of the movable die 35, and therefore, the movable die 35 can be lowered by the large gap. In the lowered state, the movable die 35 is irrelevant to the pressing of the sheet material W. This state is illustrated in FIG. 7 in which the movable dies 35 are lower than the fixed dies 33. If, in this state, the punch 14 is lowered to lower the lower table 21, the end face pressing upper press die 32 of the lower table 21 and the fixed dies 33 press the end face of the sheet material W. The movable dies 35, however, conduct no pressing. When the shim 43 is moved to face the lower plane 35b to approach the lower plane 35b, a top face of each movable die 35 agrees with that of the fixed die 33 and stops thereat. In this lifted state of the movable dies 35, the movable dies 35 and fixed dies 33 together press the sheet material W.

By changing the height position of each movable die 35, the end face pressing lower press die 31 is able to partially press the end face of the sheet material W. It is possible, therefore, to press necessary parts of the sheet material W.

The bending apparatus 1 according to the present embodiment is able to adjust a pressing width of the end face of the sheet material W. This adjustment is carried out by the pressing width adjusting mechanism 51.

As illustrated in FIGS. 8 to 11, the pressing width adjusting mechanism 51 has end face stopper bars 53 arranged on the end face pressing lower press die 31 and a back gauge (not illustrated) to move the end face pressing lower press die 31.

The end face stopper bar 53 is arranged on the fixed die 33 of the end face pressing lower press die 31 and is inserted between the fixed die 33 and the lower table 21 of the die-side member 12. Inserted between the fixed die 33 and the lower table 21, the end face stopper bar 53 faces the end face 19 of the sheet material W set on the end face pressing lower press die 31 (refer to FIG. 1) and comes into contact with the end face 19 of the sheet material W. This results in stopping the sheet material W on the end face pressing lower press die 31. Accordingly, dimensions of a pressed face at the end face 19 of the sheet material W are adjustable.

As illustrated in FIG. 11, the present embodiment provides the fixed die 33 with a bar accommodation groove 56 into which the end face stopper bar 53 is received. The bar accommodation groove 56 contains a coil-shaped support spring 57 that supports the end face stopper bar 53. In such a support structure, the lower table 21 descends to come into contact with the end face stopper bar 53 and the end face stopper bar 53 compresses the support coil spring 57 and enters into the bar accommodation groove 56. When the lower table 21 ascends, the torque of the compressed support spring 57 pushes the end face stopper bar 53 out of the bar accommodation groove 56 so that the end face stopper bar 53 appears from the top face of the fixed die 33. In this way, the end face stopper bar 53 is able to appear and disappear from the fixed die 33.

The back gauge serves as a mover to move the fixed dies 33 in a direction orthogonal to the direction in which the punch 14 is pressed to the die 17. The back gauge is, for example, a cylinder to which connection blocks 59 are connected. Each connection block 59 is attached to the fixed die 33. In this configuration, a pressing operation of the back gauge advances each fixed die 33 in the direction orthogonal to the direction in which the punch 14 presses the die 17. As illustrated in FIGS. 9 to 11, a back face of the fixed die 33 is in contact with a return spring 60 that is compressed when the fixed die 33 advances. When the back gauge stops, the advanced fixed die 33 returns to an original position due to reaction of the bent return spring 60.

The pressing width adjusting mechanism 51 of the above-mentioned configuration moves the fixed dies 33 in the direction orthogonal to the pressing direction of the punch 14 toward the die 17, thereby adjusting a contact position of the end face stopper bars 53 with respect to the end face of the sheet material W. Accordingly, a pressing dimension (width in an insertion direction) of the end face 19 of the sheet material W to be pressed by the lower table 21 (the end face pressing upper press die 32) and the end face pressing lower press die 31 is adjustable according to residual stress of the sheet material W.

Namely, it is possible to easily control the residual stress of the sheet material W.

To adjust the pressing width of the end face of the sheet material W with the pressing width adjusting mechanism 51, the end face 19 of the sheet material W is inserted between the lower table 21 and the end face pressing lower press die 31 toward the die-side member 12. Thereafter, the bending driver 13 is driven to move (lower) the punch 14 toward the die 17 to lower the lower table 21 under the die 17 so that the end face side (an edge area adjacent to the end face 19) of the sheet material W is pressed between the end face pressing upper press die 32 of the lower table 21 and the end face pressing lower press die 31.

As illustrated in FIG. 1, the part of the sheet material W to be pressed (the part held between and pressed by the end face pressing upper press die 32 and the fixed dies 33 and movable dies 35) is positioned on the insertion side of the sheet material W from the pressing center 7 of the punch 14 and die 17. The pressing width adjusting mechanism 51 may move the fixed dies 33 to move the end face stopper bars 53 relative to the pressing center, so that the pressed width of the sheet material W is properly adjusted. The pressed part of the sheet material W may be positioned so that part thereof is beyond the pressing center 7 in the insertion direction of the sheet material W.

The embodiment mentioned above is capable of precisely setting the position of the end face 19 of the sheet material W, i.e. the position of an area around the end face of the sheet material W to be pressed, with the use of the pressing width adjusting mechanism 51. Accordingly, the embodiment is capable of properly dealing with the problem of residual stress of the sheet material.

As explained above, the sheet material bending apparatus 1 according to the present embodiment has the bending part 2 for bending the sheet material W and the end face pressing part 3 for pressing an end face of the sheet material W to suppress a warp, the parts 2 and 3 being arranged on the single apparatus base 5. Accordingly, the single apparatus can carry out an end-face pressing process and a bending process on the sheet material W, to make the handling of the sheet material easier and improve workability.

The pressing width adjusting mechanism 51 having the end face stopper bars 53 to be brought into contact with an end face of the sheet material W is able to adjust a pressing width of the end face 19 of the sheet material W. Namely, press dimensions around the end face of the sheet material W are adjustable according to residual stress of the sheet material W to easily control the residual stress of the sheet material W.

Pressing the end face of the sheet material W by the end face pressing part 3 to control the residual stress of the sheet material W is achieved by using the driving force of the bending driver 13 of the bending part 2 for bending the sheet material W. This eliminates a need of an additional drive source for pressing the end face of the sheet material W, simplifies the structure of the apparatus, and saves energy.

Second Embodiment

A processing apparatus (sheet material bending apparatus) 101 according to the second embodiment is configured similar to the bending apparatus 1 according to the first embodiment. It has a function of bending a metallic sheet material (sheet work) W and a function of pressing an end face of the sheet material W to adjust residual stress caused by cutting. It operates like the bending apparatus 1 of the first embodiment and provides like effects.

As illustrated in FIGS. 13, 14, 19, 24, and the like, the bending apparatus (for example, a press brake) 101 has a bending part 103 for bending, for example, V-bending the sheet material W, an end face pressing part 105 for pressing one end face of the sheet material W before bending the sheet material W, and a C-shaped apparatus base 107 for supporting them together.

As illustrated in FIG. 14, the apparatus base 107 includes an upper base 107a and a lower base 107b that are connected to each other so that they vertically face each other to form a C-shape when seen from a side. The bending part (bending press part) 103 is arranged on the upper base 107a and the pressing part (end face pressing part) 105 is arranged on the lower base 107b so that the end face pressing part 105 is under the bending part 103 and faces the same.

In the bending apparatus 101, the end face pressing part 105 presses an end face of the sheet material W cut by, for example, laser or shearing, thereby increasing or decreasing residual stress. After the end face or both end faces are pressed, the sheet material W is bent by the bending part 103. This results in suppressing an occurrence of a warp and bending the sheet material W with a minimized boat warp.

The bending part 103 has a punch-side member 109 arranged on the upper base 107a, a die-side member 111 arranged on the lower base 107b under the punch-side member 109, and a bending driver (driver) 113 made of a hydraulic cylinder 163 or a servo motor to drive the punch-side member 109. The hydraulic cylinder 163 of the bending driver 113 is vertically oriented and is attached to the upper base 107a of the apparatus base 107, so that extending and contracting actions thereof vertically move the punch-side member 109 toward and away from the die-side member 111.

Changing pressure of hydraulic oil supplied to the hydraulic cylinder 163 results in adjusting thrust of the punch-side member 109. Instead of or in addition to vertically moving the punch-side member 109, the die-side member 111 may be configured to vertically move.

The punch-side member 109 is arranged under the bending driver 113 and has a punch 115 for pressing the sheet material W, a punch holder 117 to which the punch 115 is integrally attached, and an upper table 119 to which the punch holder 117 is integrally attached. The upper table 119 is connected to the bending driver 113 so that driving the bending driver 113 results in vertically moving the upper table 119, punch holder 117, and punch 115 to press the sheet material W.

The die-side member 111 faces the punch 115, and as illustrated in FIGS. 16, 17, 24, and the like, has a die 121 for receiving the sheet material W pressed by the punch 115, a die holder (die hold body) 125 for supporting a lower part of the die 121, and an upper press die (an end face pressing upper press die; a die holder support member) 127.

The die holder 125 is integrally provided with the die 121 and upper press die 127. The die-side member 111 is attached to a base frame 123 that is fixed to the lower base 107b (a lower table 159) of the apparatus base 107. Namely, the die-side member 111 (the die holder 125, die 121, and upper press die 127) is supported by the base frame 123 and is vertically movable relative to the base frame 123.

The die-side member 111 is upwardly pushed by a push member such as a cylinder (for example, a pneumatic cylinder) 129. When compressed air is fed into a lower cylinder chamber of the pneumatic cylinder 129, the die-side member 111 ascends as illustrated in FIG. 17. If pressure of the compressed air fed into the pneumatic cylinder 129 is constant, the die-side member 111 is always pushed upward under the constant pushing force without regard to the position thereof.

When the compressed air into the lower cylinder chamber of the pneumatic cylinder 129 is stopped, i.e. when the lower cylinder chamber and an upper cylinder chamber of the pneumatic cylinder 129 are opened to the atmosphere, the die-side member 111 descends due to its own weight.

The die-side member 111 may forcibly be lowered by feeding compressed air into the upper cylinder chamber of the pneumatic cylinder 129 and opening the lower cylinder chamber to the atmosphere.

Instead of the cylinder, a resilient body such as a compression coil spring may be employed to upwardly bias the die-side member 111 like the bending apparatus 1 of the first embodiment. It is possible that the bending apparatus 1 of the first embodiment employs a cylinder to upwardly bias the die-side member 12.

Instead of the cylinder or the resilient body such as the compression coil spring, an actuator such as a servo motor may be employed to vertically move and optionally position the die holder 125 and end face biasing upper press die 127.

The bending part 103 bends the sheet material W into, for example, a V-shape and the bending of the sheet material W is conducted along a pressing center 131 (refer to FIG. 24 and the like) of the punch 115 and die 121.

The end face pressing part 105 has an end face pressing lower press die (a lower press die) 135 arranged to face the upper press die 127. The lower press die 135 presses the end face of the sheet material W along a bend line of the sheet material W to be bent.

The end face side of the sheet material W is placed on the end face pressing lower press die 135. In this state, the punch 115 is moved (downward) toward the die 121 to move the die holder 125 and upper press die 127 in the same direction. Due to this movement, the sheet material W is held between the upper press die 127 and the lower press die 135 and the end face of the sheet material W is pressed (refer to FIG. 19).

The lower press die 135 is divided into a plurality of press dies 137 (137A, 137B, 137C) and 139 (139A, 139B, 139C, 139D, 139E, 139F) (refer to FIG. 15 and the like) to press the end face of the sheet material W against the die-side member 111 (the upper press die 127), in corporation with the end face pressing upper press die 127 of the die-side member 111.

Among the divided press dies 137 and 139, the press dies 137A, 137B, and 137C, for example, are able to selectively press (pressurize) the sheet material W against the die-side member 111.

The selective pressing is carried out to secure pressing force of the end face pressing part 105 applied to the sheet material W even when pressing force (pressurizing force) of the bending driver 113 is insufficient.

In more detail, pressing the end face of the sheet material W by the end face pressing part 105 (in a thickness direction of the sheet material W) is carried out by using pressing force of the bending apparatus 101 (the hydraulic cylinder 163 of the bending driver 113). It is assumed that the end face pressing lower press die 135 is divided into three press dies (a first press die 137A, a second press die 137B, and a third press die 137C) (refer to FIGS. 13 and 15).

The length of the first press die (divided die) 137A (the length including the press dies 139A and 139B), the length of the second press die 137B (the length including the press dies 139C and 139D), and the length of the third press die 137C (the length including the press dies 139E and 139F) are equal to one another and are each about 500 mm. The first to third press dies 137A, 137B, and 137C are connected to each other in the length direction to make the length (in the left-right direction) of the end face pressing lower press die 135 to 1500 mm. The lengths of the press dies (divided dies) 139A to 139F are equal to one another and are each about 50 mm, which is sufficiently shorter than the length of the press die 137.

The length of an end face of the sheet material W along a bend line is slightly shorter than 1500 mm. A 500-millimeter end part of the end face having the length slightly shorter than 1500 mm of the sheet material W is pressed by the press die 137A and press dies 139A and 139B (the press dies 139C to 139F can be included in some case). Similarly, a 500-millimeter central part of the end face is pressed by the second press die 137B and the 500-millimeter remaining part thereof is pressed by the third press die 137C.

The bending apparatus 101 (bending driver 113) is supposed to have a maximum pressing force of 50 t (50000 kgf; about 500 kN). It is supposed that a pressing force of 60 t, which is greater than the maximum pressing force of 50 t, is required if simultaneously pressing the end face of the sheet material W (made of, for example, SPCC) having the length slightly shorter than 1500 mm along the bend line with the use of the first to third press dies 137A to 137C and the press dies 139A to 139F to contain a boat warp caused when bending the sheet material within an allowable range.

In this case, the first press die 137A is first selected and the 500-millimeter end part of the sheet material W is pressed only by the first press die 137A (including the press dies 139A to 139F) under a pressing force of about 20 t. Thereafter, the second press die 137B is selected and the 500-millimeter central part of the sheet material W is pressed only by the second press die 137B (including the press dies 139A to 139F) under a pressing force of about 20 t. Thereafter, the third press die 137C is selected and the 500-mm remaining part of the sheet material W is pressed only by the third press die 137C (including the press dies 139A to 139F) under a pressing force of about 20 t.

The selection mentioned above is realized by separately moving the press dies 137 and 139 in a direction (an orthogonal direction; a front-rear direction) intersecting with the driving (moving) direction (the direction to press the sheet material W; a vertical direction) in which the punch-side member 109 (punch 115) is moved toward the die-side member 111 (die 121).

If, for example, the press die 137 is moved backward, the press die 137 comes obliquely under the punch-side member 109 (punch 115) as illustrated in FIG. 20. If the upper press die 127 descends in this state, the sheet material W is not held between or not pressed by the upper press die 127 and press die 137.

If the press die 137 is moved forward, the press die 137 comes just under the punch-side member 109 (punch 115) as illustrated in FIG. 19. If the upper press die 127 is lowered in this state, the sheet material W is held between and pressed by the upper press die 127 and press die 137.

The press die 137A illustrated in FIG. 15 is divided into a plurality of (for example, three) press dies. These press dies are connected together with a connection member 141 (141A) and are moved in the front-rear direction by an actuator such as a pneumatic cylinder (not illustrated). Similarly, press dies 137B are connected together with a connection member 141 (141B) and are moved in the front-rear direction. Also, press dies 137C are connected together with a connection member 141 (141C) and are moved in the front-rear direction.

Among the press dies 137 and 139, the press dies (stopper supports) 139 (139A to 139F illustrated in FIG. 15) are moved and positioned in the front-rear direction by a back gauge 143 of the bending apparatus 101 (refer to FIGS. 13 and 14).

The press die 139 has a stopper (contact bar) 145 to which the sheet material W is pushed (brought into contact) (refer to FIG. 18 and the like). An end face of the sheet material W is pressed to position the sheet material W and determine a pressing width (a dimension L1 in FIG. 19) of the sheet material W to be pressed by the end face pressing part 105.

The bending apparatus 101 has, for example, two back gauges 143 that are separately moved and positioned.

There are arranged at least two (six in FIG. 15) stopper supports (press dies) 139. Among the plurality of stopper supports 139, two are in integrated with the two back gauges 143, respectively.

The stopper supports 139 to be engaged with the back gauges 143 are properly selected according to the length of an edge of the sheet material W in a length direction of the bend line along which the punch 115 and die 121 bend the sheet material W.

The two stopper supports 139 engaged with the two back gauges 143 are separately moved and positioned with the respective back gauges 143 in the front-rear direction.

As is already understood, the stopper supports 139, stoppers 145, back gauges 143, and the like form the pressing width adjusting mechanism of the bending apparatus 101.

The bending apparatus 1 according to the first embodiment similarly uses back gauges to position the press dies (stopper supports; contact bar supports).

The stopper 145 appears and disappears from a face (sheet material pressing face) 149 of the stopper support 139 that presses the sheet material W. The stopper 145 is pushed by a resilient body such as a compression coil spring 151 so that the stopper 145 protrudes upward from the sheet material press face 149. When the sheet material W is positioned, the stopper 145 protrudes upward from the sheet material press face 149. When the sheet material W is pressed by the end face pressing upper press die 127 and end face pressing lower press die 135, the stopper 145 is pushed by the end face pressing upper press die 127 and is moved into the stopper support 139 (the press die of the end face pressing lower press die 135).

The bending apparatus 101 (also the bending apparatus 1 of the first embodiment) has a hemming part 153 to hem the sheet material W (refer to FIGS. 22 and 23).

The hemming part 153 is included by (serves also as) the end face pressing part 105.

The die-side member 111 having the die holder 125 and upper press die 127, the base frame 123, the lower press die 135, and the like form a die setting body (die setter) 155.

As is already understood, the die setting body 155 is installed on and used by the bending apparatus 101 (also the bending apparatus 1 of the first embodiment) that employs the punch 115 and die 121 to carry out a bending process and the like on the sheet material W.

The die setting body 155 has a die setting part 157, the end face pressing part 105, and the hemming part 153. On the die setting part 157, the die 121 is arranged. It may be configured to set the punch 115 instead of the die 121.

As mentioned above, the end face pressing part 105 presses the end face of the sheet material W along a bend line before the sheet material W is bent by the punch 115 and the die 121 set on the die setting part 157.

The end face pressing part 105 is divided into the plurality of press dies 137 and 139 in the extending direction of the bend line along which the sheet material W is bent. When pressing the end face of the sheet material W along the bend line, the divide press dies 137 are selectively used.

As mentioned above, the press die 139 having the stopper 145 is moved and positioned by the back gauge 143 of the bending apparatus 101.

In FIG. 15, three die setting bodies 155A, 155B, and 155C are connected to one another in a longitudinal direction. The die setting body 155 illustrated in FIG. 15 is installed on the bending apparatus 101.

The bending apparatus 101, die setting body 155, and the like will be explained in more detail.

For the sake of explanation, a horizontal direction (left-right direction) is set as an X-axis direction, another horizontal direction (front-rear direction) orthogonal to the X-axis direction as a Y-axis direction, and a direction (top-bottom direction) orthogonal to the X- and Y-axis directions as a Z-axis direction.

As illustrated in FIGS. 13 and 14, the lower table 159 is integrally arranged at a front lower part of the apparatus base (frame) 107 of the bending apparatus 101. On a top face of the lower table 159, the die setting body 155 (155A, 155B, 155C) are successively connected in the longitudinal direction and extending in the X-axis direction (refer to FIGS. 13 and 15).

Above the die setting body 155 (155A, 155B, 155C), the die 121 (121A, 121B, 121C) is integrally arranged. The dies 121A, 121B, and 121C have the same specifications and are successively connected in the longitudinal direction and extending in the X-axis direction.

At a front upper part of the apparatus base 107, the upper table 119 is arranged. The upper table 119 is movable in the Z-axis direction relative to the apparatus base 107.

Integrally arranged through the punch holder 117 on lower face of the upper table 119 is the punch 115 (115A, 115B, 115C). The punches 115A, 115B, and 115C have the same specifications and are successively connected in the longitudinal direction and extending in the X-axis direction (refer to FIG. 13).

The punches 115A, 115B, and 115C arranged on the upper table 119 face the dies 121A, 121B, and 121C arranged on the lower table 159, respectively.

The bending apparatus 101 (bending apparatus 1) is provided with a controller 161. Under the control of the controller 161, the upper table 119 is moved and positioned in the Z-axis direction by the hydraulic cylinder 163 of the bending driver 113.

With this, the bending part 103 bends the sheet material W, the end face pressing part 105 presses an end face of the sheet material W, and the hemming part 153 hems the sheet material W.

The back gauge 143 is arranged at a central part of the apparatus base 107 in the Z-axis direction and behind the lower table 159 in the Y-axis direction. Under the control of the controller 161, the back gauge 143 is moved and positioned in the X-, Y-, and Z-axis directions with respect to the apparatus base 107.

The die setting body 155A will be explained in detail. The die setting bodies 155B and 155C are configured similar to the die setting body 155A, and therefore, explanations thereof are omitted.

As illustrated in FIGS. 17, 21, and the like, the die setting body 155A has the base frame 123, die holder 125, upper press die 127, cylinder 129, lower press die 135 (press dies 137 and 139), connection member 141, and stopper 145.

The base frame 123 has a thin and long parallelepiped shape. More precisely, a section (a sectional plane orthogonal to the longitudinal direction, i.e., the X-axis direction) of the base frame 123 has a rectangular lower base part 165 and a rectangular upper joint part 167.

A width (a dimension in the Y-axis direction) of the upper joint part 167 is smaller than a width (a dimension in the Y-axis direction) of the lower base part 165. The upper joint part 167 is positioned at an intermediate part of the lower base part 165 in the Y-axis direction and upwardly protrudes from an upper end of the lower base part 165 in the Z-axis direction.

The die holder 125 is formed in a thin and long parallelepiped shape having the same length as the base frame 123 and is positioned at the same location as the base frame 123 in the X-axis direction (longitudinal direction). More precisely, a section (a sectional plane normal to the longitudinal direction) of the die holder 125 has a rectangular upper body part 169 and a rectangular lower protrusion part 171.

A width value (a dimension in the Y-axis direction) of the lower protrusion part 171 is smaller than a width value (a dimension in the Y-axis direction) of the upper body part 169. The lower protrusion part 171 is positioned at a rear end of the upper body part 169 in the Y-axis direction and protrudes from a lower end of the upper body part 169 in the Z-axis direction.

The die holder 125 has a die setting recess (die) setting groove) 173. The die setting recess 173 is formed along the hole length of the die holder 125 in the longitudinal direction (X-axis direction). When the die holder 125 is sectioned, a width value of the die setting recess 173 is smaller than a width value of the upper body part 169 and a depth value (a dimension in the Z-axis direction) thereof is smaller than a height value (a dimension in the Z-axis direction) of the upper body part 169. The die setting recess 173 is positioned at an intermediate part of the upper body part 169 in the Y-axis direction and downwardly recessed in the Z-axis direction from an upper end of the upper body part 169.

A lower part of the die 121 is in the die setting recess 173 so that the die 121 is integrally arranged on the die holder 125. A length (a dimension in the X-axis direction) of the die 121 is equal to the length of the base frame 123 and is positioned at the same location as the base frame 123 in the X-axis direction (longitudinal direction).

The upper press die 127 has a thin and long parallelepiped shape having the same length as the base frame 123 and is positioned at the same location as the base frame 123 in the X-axis direction (longitudinal direction). More precisely, a section (a sectional plane orthogonal to the longitudinal direction) of the upper press die 127 has a rectangular upper recess 175 and a triangular lower chamfered part 177 to generally form an L-shape.

The upper recess 175 and lower chamfered part 177 extend along the hole length of the upper press die 127 in the longitudinal direction (X-axis direction). When the upper press die 127 is sectioned, a width value of the upper recess 175 is smaller than a width value of the upper press die 127 and a depth value (a dimension in the Z-axis direction) thereof is smaller than a height value (a dimension in the Z-axis direction) of the upper press die 127. The upper recess 175 is arranged at a rear upper corner of the upper press die 127. The lower chamfered part 177 is arranged at a front lower corner of the upper press die 127.

Two faces (sides) of the upper press die 127 that form a front lower corner of the upper body part 169 of the die holder 125 are in the upper recess 175. The two faces of the upper recess 175, i.e., a plain spreading in the X- and Y-axis directions and a plain spreading in the X- and Z-axis directions are in face-to-face contact with front and lower faces of the upper body part 169, respectively. In this way, the upper press die 127 is integrated with the die holder 125.

The die holder 125 and the upper press die 127 arranged thereon define a thin and long parallelepiped groove 179 at a lower central part thereof.

This groove 179 receives the upper joint part 167 of the base frame 123 so that the base frame 123 engages with the die holder 125 and upper press die 127. With this, the base frame 123 and the die holder 125 and upper press die 127 form a sliding pair so that the die holder 125 and upper press die 127 move in the Z-axis direction relative to the base frame 123.

A width (a dimension in the Y-axis direction) of the groove 179 is set to be slightly larger than a width (a dimension in the Y-axis direction) of the upper joint part 167 of the base frame 123.

The base frame 123 incorporates the cylinder 129. The cylinder 129 has a cylinder body 181, a piston 183, and a piston rod 185.

The cylinder 129 is at a central part of the base frame 123 in the Y-axis direction. In the Z-axis direction, the cylinder body 181 and piston 183 are positioned at a lower part and the piston rod 185 upwardly protrudes. A front end of the piston rod 185 protrudes from an upper end of the base frame 123 (the upper joint part 167) and integrally engages with the upper body part 169 of the die holder 125. The cylinder body 181 is integral with the base frame 123.

When the upper cylinder chamber of the piston 183 is opened to the atmosphere and compressed air is fed into the lower cylinder chamber of the piston 183, the die holder 125, upper press die 127, and die 121 are positioned to a lifted end as illustrated in FIGS. 17, 18, 21, and 22.

When the upper and lower cylinder chambers of the piston 183 are opened to the atmosphere, the die holder 125, upper press die 127, and die 121 descend due to, for example, their own weights (refer to FIGS. 19, 20, 24, and the like).

The press die 137 (137A) of the lower press die 135 has a thin and long parallelepiped shape. More precisely, as illustrated in FIG. 17, a sectional shape (a sectional plane normal to the longitudinal direction) of the press die 137 is substantially rectangular having an upper front cut 187.

At a front upper part of the lower base part 165 of the base frame 123, there is a recess 189. In a sectional shape of the base frame 123, the recess 189 is rectangular as illustrated in FIG. 17 and is formed at a front upper corner of the lower base part 165 of the base frame 123.

The press die 137 is in the recess 189. A lower face of the press die 137 and a bottom face of the recess 189 are in face-to-face contact with each other. The press die 137 is moved by an actuator such as a pneumatic cylinder (not illustrated) in the Y-axis direction relative to the base frame 123.

In FIGS. 17, 19, 22, 23, and 24, the press die 137 is at a front movable end, and in FIG. 20, the press die 137 is at a rear movable end.

As illustrated in FIG. 18, the press die 139 (139A, 139B) of the lower press die 135 has a sectional shape (a sectional plane normal to the X-axis direction) of L having a lower horizontal part 191 and an upper upright part 193.

A height dimension (a dimension in the Z-axis direction) of the lower horizontal part 191 is equal to a height dimension of the press die 137. Formed at a front upper part of the lower horizontal part 191 is a cut 195 that is similar to the cut 187.

Formed at an upper part of the lower base part 165 and a lower part of the upper joint part 167 of the base frame 123 is a through hole 197 passing through the base frame 123 in the front-rear direction. A height position of a bottom face of the through hole 197 agrees with a height position of a bottom face of the recess 189.

The press die 139 arranged in the through hole 197 has a lower face that is in face-to-face contact with the bottom face of the through hole 197 to form a sliding pair.

Accordingly, when the press dies 137 and 139 are arranged on the base frame 123, the position of an upper face 203 of the press die 137 agrees in the Z-axis direction with the position of an upper face 201 of the lower horizontal part 191 of the press die 139.

The upper upright part 193 of the press die 139 is integrally engaged with the back gauge 143, and therefore, the press die 139 is able to be moved and positioned in the Y-axis direction.

The lower horizontal part 191 of the press die 139 is provided with the stopper 145. The stopper 145 is vertically movable with respect to the lower horizontal part 191 and is able to appear and disappear from the upper face 201 of the lower horizontal part 191.

The stopper 145 is upwardly biased by the compression coil spring 151. If no external force is applied, the stopper 145 protrudes from the upper face 201 of the lower horizontal part 191 (refer to FIG. 18). When the punch 115 is lowered, the stopper 145 is pushed by the upper press die 127 and is downwardly moved (refer to FIG. 19 and the like).

To press the sheet material W to reduce a boat warp or to bend the sheet material W, the press die 139 (139A to 139F) is positioned in the Y-axis direction as illustrated in FIG. 18. Namely, the stopper 145 is backwardly spaced by a proper dimension L1 from a front end of a lower face 199 of the upper press die 127. The dimension L1 is a pressing width of the sheet material W.

To carry out a hemming process, the press die 139 is positioned at a rear end as illustrated in FIG. 21. At this time, the stopper 145 is in the through hole 197 of the base frame 123.

In each of the cases illustrated in FIGS. 18 and 21, the upper face 201 of the lower horizontal part 191 of the press die 139 partly holds and presses the sheet material W, and therefore, faces the lower face 199 of the upper press die 127.

In the die setting body 155A, the press dies 137A, 139A, 137A, 139B, and 137A are arranged in this order from the left to the right in the X-axis direction.

As illustrated in FIG. 13, the die setting bodies 155A, 155B, and 155C are arranged in this order from the left to the right in the X-axis direction. Then, from the left to the right, the press dies 137A, 139A, 137A, 139B, 137A, 137B, 139C, 137B, 139D, 137B, 137C, 139E, 137C, 139F, and 137C are arranged in this order (refer to FIG. 15).

Illustrated with a reference numeral 205 in FIG. 17 is a guide plate for guiding the sheet material W. The guide plate 205 is integrally arranged with the base frame 123 through the connection member 141.

Protruding from a lower end of the base frame 123 is an engagement pin 207. With the engagement pin 207 and fastening tools such as bolts, the base frame 123 (the die setting body 155) is integrally installed on the upper face of the lower table 159.

As is already understood, the punch 115 and the die 121 set on the die setting body 155 form the bending part 103. The upper press die 127 (lower face 199) of the die setting body 155 and the lower press die 135 (upper faces 201 and 203) of the die setting body 155 form the end face pressing part 105 and hemming part 153.

Operation of the bending apparatus 101 will be explained.

The length in the X-axis direction of the die setting bodies 155A, 155B, and 155C is supposed to be 1500 mm (500 mm×3). This means that the die 121 and punch 115 are able to bend the sheet material W at one time for a length of 1500 mm at the maximum. The length of a bend line of the sheet material W is supposed to be slightly shorter than 1500 mm.

First, a pressing operation for relaxing a boat warp of the sheet material W and a bending operation for bending the sheet material W will be explained.

In an initial state illustrated in FIGS. 17 and 18, the punch 115 is lifted, the die holder 125 and upper press die 127 are positioned at a lifted end, the press die 139 of the die setting body 155A, the press die 139 of the die setting body 155B, and the press die 139 of the die setting body 155C are positioned as illustrated in FIG. 18, the press die 137A of the die setting body 155A is forwardly positioned as illustrated in FIG. 17, and the press die 137B of the die setting body 155B and the press die 137C of the die setting body 155C are backwardly positioned as illustrated in FIG. 20.

In this initial state, the sheet material W is set on the die setting body 155 (155A to 155C). In this state, the die setting body 155 (155A to 155C) and sheet material W positionally agree with each other in the X-axis direction. As illustrated in FIGS. 17 and 18, the sheet material W is in contact with the stoppers 145 and is thereby positioned in the Y-axis direction.

The punch 115 is lowered so that the upper press die 127 of the die setting body 155A and the lower press die 135 (the press dies 137A, 139A, and 139B) of the die setting body 155A press a longitudinal end of the sheet material W for a width L1 (refer to FIG. 19).

At this time, the upper press die 127 of the die setting body 155B and the press dies 139C and 139D of the die setting body 155B, as well as the upper press die 127 of the die setting body 155C and the press dies 139E and 139F of the die setting body 155C press the sheet material W similarly.

Thereafter, the punch 115, die holder 125, and upper press die 127 are positioned to a lifted end, the press die 137A of the die setting body 155A is positioned rearward as illustrated in FIG. 20, and the press die 137B of the die setting body 155B is positioned forward as illustrated in FIG. 19.

Thereafter, the punch 115 is lowered so that the upper press die 127 of the die setting body 155B and the lower press die 135 (the press dies 137B, 139C, and 139D) of the die setting body 155B press a longitudinal central part of the sheet material W for the width L1 (refer to FIG. 19).

At this time, the upper press die 127 of the die setting body 155A and the press dies 139A and 139B of the die setting body 155A, as well as the upper press die 127 of the die setting body 155C and the press dies 139E and 139F of the die setting body 155C press the sheet material W similarly.

Thereafter, the punch 115, die holder 125, and upper press die 127 are positioned to the lifted end, the press die 137 of the die setting body 155B is positioned rearward as illustrated in FIG. 20, and the press die 137 of the die setting body 155C is positioned forward as illustrated in FIG. 19.

Thereafter, the punch 115 is lowered so that the upper press die 127 of the die setting body 155C and the lower press die 135 (the press dies 137C, 139E, and 139F) of the die setting body 155C press the other longitudinal end of the sheet material W for the width L1 (refer to FIG. 19).

At this time, the upper press die 127 of the die setting body 155A and the press dies 139A and 139B of the die setting body 155A, as well as the upper press die 127 of the die setting body 155B and the press dies 139C and 139D of the die setting body 155B press the sheet material W similarly.

This completes the pressing of the sheet material W for the full length of 1500 mm, i.e. for relaxing a boat warp of the sheet material W.

Thereafter, the punch 115, die holder 125, and upper press die 127 are positioned to the lifted end, the sheet material W is taken out of the die setting body 155, and the die holder 125 and upper press die 127 are positioned to a lowered end as illustrated in FIG. 24. When the die holder 125 and upper press die 127 are at the lowered end, a gap between the lower face 199 of the upper press die 127 and the upper faces 201 and 203 of the lower press die 135 is very small (about 0.2 mm) as illustrated in FIG. 25.

This prevents foreign matter such as dust from entering between the lower face 199 of the upper press die 127 and the upper faces 201 and 203 of the lower press die 135, so that the sheet material W is precisely bent.

When the die holder 125 and upper press die 127 are positioned at the lowered end, an upper face of the upper joint part 167 of the base frame 123 and a lower face of the upper body part 169 of the die holder 125 are in face-to-face contact with each other.

Thereafter, the sheet material W is set on the die 121 and the punch 115 is lowered to bend the sheet material W for nearly the whole length of 1500 mm at one time.

A hemming operation of the sheet material W will be explained.

In an initial state illustrated in FIG. 21, the punch 115 is lifted, the die holder 125 and upper press die 127 are positioned to the lifted end, the press die 139 of the die setting body 155A, the press die 139 of the die setting body 155B, and the press die 139 of the die setting body 155C are positioned to the rear end, and the press die 137A of the die setting body 155A, the press die 137B of the die setting body 155B, and the press die 137C of the die setting body 155C are positioned forward.

In this initial state, the punch 115 is lowered to bend the sheet material W as illustrated in FIG. 24. This bending is carried out at once for the length of about 1500 mm. An angle of the bending is about 30 degrees.

Thereafter, the punch 115 is lifted, the die holder 125 and upper press die 127 are positioned to the lifted end, and the part of the sheet material W bent by about 30 degrees is set between the upper press die 127 and the lower press die 135 (refer to FIG. 22).

Thereafter, the punch 115 is lowered so that the upper press die 127 and lower press die 135 hold the part of the sheet material W bent by about 30 degrees and the hemming process is carried out (refer to FIG. 23).

When hemming the sheet material W, the state illustrated in FIG. 22 and the state illustrated in FIG. 23 have the left end of the sheet material W set at the same position. To reduce moment generated on the die setting body 155, the position of the stopper 145 may properly be changed to change the left end position of the sheet material W that is brought into contact with the stopper 145 (refer to, for example, Japanese Unexamined Patent Application Publication No. 2003-181546).

In the above explanation, the three punches 115 have the same specifications and the three dies 121 also have the same specifications. The punches 115 and dies 121 may have different specifications. However, the heights of the dies (a pass line of the sheet material W) must be equal to one another.

Each die setting body 155 may differently process the sheet material W.

For example, the die setting body 155A hems the sheet material W and the die setting bodies 155B and 155C press and bend the sheet material W.

This enables the sheet material W to be differently processed, for example, bent, hemmed, and the like without changing arrangements.

According to the bending apparatus 101, the press dies 137 and 139 are able to selectively press the sheet material W so that, without increasing the maximum pressing force of the bending driver 113, a sufficient pressing force is applicable to the sheet material W and a boat warp occurring on the sheet material W during bending can easily be contained within an allowable range. Accordingly, without using a large bending apparatus having a maximum thrust required, a sufficient pressing force is applicable to the sheet material W.

The bending apparatus 101 realizes such selective pressing by individually moving the press dies 137 and 139 in the front-rear direction to achieve the selective pressing. This configuration is simple to select proper ones from among the press dies and press a sheet material.

According to the bending apparatus 101, the simple structure using the back gauge 143 can set an area (a width, i.e., the dimension L1 in FIGS. 18 and 19) of the sheet material W to press without using separate mechanisms or actuators.

According to the bending apparatus 101, the hemming part 153 is made of the end face pressing part 105, and therefore, is able to hem the sheet material W with a simple configuration without preparing a separate hemming part.

Third Embodiment

A bending apparatus (a brake press; a sheet material processing apparatus) 301 according to the third embodiment differs from the bending apparatus 1 of the first embodiment or the bending apparatus 101 of the second embodiment in that the third embodiment employs a press die 303, which is not used for bending a sheet material W, to (i) press an end part of the sheet material W for such as adjusting residual stress caused when cutting the sheet material W or reducing a warp to be caused when bending the sheet material W and to (ii) hem (if required) the end part of the sheet material W. The other parts of the bending apparatus 301 are configured similar to the bending apparatuses 1 and 101, to provide similar operations and similar effects.

The sheet material processing apparatus (processing apparatus) 301 according to the third embodiment has an apparatus base 302 (refer to FIG. 30(b)) similar to, for example, the apparatus base 107 illustrated in FIG. 14. It also has a pressurizing part (pressurizing means) 305 for pressurizing the sheet material W and a supporting part (receiving means) 307 for supporting the sheet material W pressurized by the pressurizing part 305 (refer to FIGS. 26, 27, 29, and the like).

The processing apparatus 301 also has an end face pressing upper press die 309, an end face pressing lower press die 311, an end face pressing part 313, and an end face pressing width adjusting part (end face pressing width adjusting mechanism) 315.

The end face pressing upper press die 309 is configured to receive pressurizing force from the pressurizing part 305. The pressurizing part 305 is made of an actuator such as a hydraulic cylinder (similar to the hydraulic cylinder 163 of the processing apparatus 101 of the second embodiment illustrated in, for example, FIG. 13) arranged on an upper side of the apparatus base 302. The supporting part 307 is formed by a lower part of the apparatus base 302.

The end face pressing lower press die 311 is arranged on the supporting part 307 side (lower side) and faces the end face pressing upper press die 309. Between the end face pressing lower press die 311 and the end face pressing upper press die 309, an end face of the sheet material W is inserted.

In the end face pressing part 313, the pressurizing part 305 provides a pressurizing force to move the end face pressing upper press die 309 toward the end face pressing lower press die 311. When the end face pressing upper press die 309 is lowered, one end face 319 of the sheet material W to be processed (to be bent) is pressed (pressurized) along a bend line of the she t material V (refer to FIGS. 27, 30, and the like). Namely, between the end face pressing upper press die 309 and the end face pressing lower press die 311, i.e., between the pressurizing part 305 and the supporting part 307 in the end face pressing part 313, the sheet material W is held by the end face pressing upper press die 309 and end face pressing lower press die 311 so that the end of the sheet material W is pressed in a thickness direction.

When the sheet material W is pressed by the end face pressing part 313, the end face pressing width adjusting part 315 sets a pressing width (a dimension in the Y-axis direction) at the end face 319 of the sheet material W. With this, the contact face (stopped face) 319 of the sheet material W is positioned in front of (opposite to the C-shaped apparatus base 302) a pressurizing center (pressing center) 317 of the pressurizing force applied by the pressurizing part 305 to the end face pressing upper press die 309, in terms of an insertion direction (a left-to-right direction in FIG. 30, i.e., a front-to-rear direction in the Y-axis direction) in which the sheet material W is inserted into between the end face pressing upper press die 309 and the end face pressing lower press die 311 (refer to FIG. 30(b)). Namely, the stopped face 319 of the sheet material W is slightly in front of the pressurizing center 317 in the Y-axis direction and the whole of the sheet material W is positioned in front of the stopped face 319 in the Y-axis direction.

Similar to the processing apparatus 101 of the second embodiment, the end face pressing lower press die 311 is divided in the X-axis direction into a plurality of press dies 321 (321A to 321I) that are able to press the end of the sheet material W against the end face pressing upper press die 309 (refer to FIG. 26 and the like).

These divided press dies 321 are configured to be selectively used (to realize selective press) when pressing the end face 319 of the sheet material W.

To achieve such selection, each of the press dies 321 is moved in a direction (Y-axis direction) intersecting with a driving direction (Z-axis direction) in which the end face pressing upper press die 309 is driven toward the end face pressing lower press die 311.

The end face pressing width adjusting part 315 is a press die (321B, 321D, 321F, 321H) among the press dies 321, is moved and positioned in the above-mentioned intersecting direction (Y-axis direction) by a back gauge (not illustrated in FIGS. 26 to 30) of the processing apparatus 301, and is provided with a stopper (contact bar) 323 which is arranged on the press die and to which the sheet material W is pushed.

The press dies 321A, 321C, 321E, 321G, and 321I are moved in the Y-axis direction by an actuator such as a pneumatic cylinder (not illustrated).

Similar to the processing apparatus 101 of the second embodiment, the stopper 323 is biased upward by a compression coil spring 325 (refer to FIG. 29).

The processing apparatus 301 also has a hemming part 327 (refer to FIG. 28) for hemming an end of the sheet material W. The hemming part 327 is included by the end face pressing part 313.

As is already understood, the end face pressing upper press die 309, end face pressing lower press die 311, end face pressing part 313, and end face pressing width adjusting part 315 form the press die 303 that is arranged on and used by the processing apparatus (for example, press brake) 301.

The processing apparatus 301 employs a punch, a die, and the pressurizing part 305 to bend the sheet material W. When the press die 303 is used to press the sheet material W without bending the sheet material W, the punch and die are not used. Instead, the end face pressing upper press die 309 having a flat lower face is used for the punch and the end face pressing lower press die 311 having a flat upper face is used for the die, as illustrated in FIG. 26.

As mentioned above, the end face pressing lower press die 311 of the press die 303 is divided in the X-axis direction into the plurality of press dies 321 (321A to 321I). When pressing the end face 319 of the sheet material W along a bend line, the divided press dies 321 are selectively used. Each of the press dies 321 is movable in the Y-axis direction to realize such selection. Among the press dies 321, those provided with the stoppers 323 are moved and positioned in the Y-axis direction by the back gauge of the processing apparatus 301.

The press die 303 also has the hemming part 327 that is formed by the end face pressing part 313.

According to the processing apparatus 301, the end face pressing part 313 presses the sheet material W. At this time, the end face 319 of the sheet material W and the whole of the sheet material W are positioned opposite to the C-shaped apparatus base 302 (refer to FIG. 30). Accordingly, the sheet material W is surely pressed to reduce a warp to be caused when the sheet material W is bent.

As illustrated in FIG. 30(a), the end face 319 of the sheet material is pressed. At this time, the sheet material W is positioned opposite to the C-shaped apparatus base 302 with respect to the pressing center 317. The apparatus base 302 and the like are not perfect rigid bodies. Due to this, moment (refer to an arrow MT in FIG. 30) occurs on the end face pressing upper press die 309 (end face pressing lower press die 311), to cause a slight resilient deformation (deflection) on the apparatus base 302 and the like, thereby slightly inclining the end face pressing upper press die 309 (end face pressing lower press die 311) (refer to FIG. 30(b)). In FIG. 30(b), the inclination of the end face press die 309 is exaggerated.

Due to the slight inclination caused by the moment MT, the end 319 of the sheet material W receives a maximum press force larger than that applied to the remaining part of the sheet material W. This correctly and surely presses the sheet material W and surely reduces a boat warp to be caused when the sheet material W is bent.

The stopper 323 provided for each of the press dies 321B, 321D, 321F, and 321H may be integrally formed on the press die so that the stopper 323 is immovable in the Z-axis direction, the heights of the stoppers 323 being equalized with one another.

In this case, the end face pressing upper press die 309 is provided with a recess (not illustrated) to receive the stopper 222 to prevent the stopper 323 from interfering with the end face pressing upper press die 309 when the press die 309 is lowered.

If the thickness of the sheet material W is larger than the protruding height of the stopper 323, the end face pressing upper press die 309 may not be provided with such a recess to receive the stopper 323.

In addition, the press dies 321B, 321D, 321F, and 321H may be fixed in the Y-axis direction.

At least one of the die setting bodies 121A, 121B, and 121C illustrated in FIG. 13 may be replaced with the press die 303. In this case, pass lines (die heights) of them all must be equalized.

According to a technical aspect of the present invention, a sheet material is correctly pressed to reduce a warp to be caused when the sheet material is bent.

According to another technical aspect of the present invention, a bending part for bending a sheet material and an end face pressing part for pressing an end face of the sheet material to suppress a warp of the sheet material are arranged on a single apparatus. The single apparatus, therefore, is capable of carrying out both the end face pressing and bending of a sheet material, thereby realizing the easy handling of the sheet material and improving workability.

(United States Designation)

In connection with United States designation, this international patent application claims the benefit of priority under 35 U.S.C. 119(a) to Japanese Patent Application No. 2011-242501 filed on Nov. 4, 2011 and Japanese Patent Application No. 2012-226724 filed on Oct. 12, 2012, disclosed contents thereof being cited herein.

Number	Date	Country	Kind
2011-242501	Nov 2011	JP	national
2012-226724	Oct 2012	JP	national

SHEET MATERIAL PROCESSING APPARATUS, PRESS DIE, AND DIE SETTING BODY

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CPC

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