JP2669693B2 - Hemming mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a hemming die used for hemming in which an edge portion of a work is bent and then crushed.

(Prior Art) For the safety and reinforcement of a plate-shaped work, a hemming process in which an edge portion is bent at an acute angle and then crushed is known. Conventionally, in order to perform this hemming process, two molds, a mold for a bending process and a mold for a crushing process, are manufactured, and these molds are attached to two press brakes, respectively. Hemming was performed in the process. Alternatively, hemming is performed in two steps by alternately attaching two dies to one press brake.

(Problems to be Solved by the Invention) However, according to the above-described conventional technique, two types of dies for a bending process and a crushing process have to be prepared as dies, which causes a problem of high cost. It was When hemming is performed by attaching two dies to two press brakes, the press brake is
A table is required, and the work must be attached to and detached from the press brake for each process, which has the disadvantage of increasing man-hours.

On the other hand, when performing two-step hemming by exchanging two dies using one press brake, only one press brake is required, but many man-hours are required for exchanging the dies ( There is a problem in that it takes time and labor) and the work must be attached and detached for each process as in the case described above, which further increases the number of steps.

The present invention has been made in view of the above circumstances, and
An object of the present invention is to provide a die for hemming, which can perform hemming in one step (one stroke) using a table bending machine.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a hemming die for performing hemming on a work by cooperation of an upper die and a lower die. The upper die has a punch body, a crushing punch and a cam plate fixed to the punch body, a material pressing means attached to the punch body so as to be retractable upward, and a material pressing means. And a punch for bending that is removably attached to the die main body, and the lower die is attached to the die main body so as to be movable in the lateral direction. And a die block provided with a pressing portion for bending a work, and the die block is provided so as to be movable laterally by elevating and lowering the cam plate to form a hemming die.

(Operation) By adopting the hemming die of the present invention, the work is interposed between the upper die and the lower die, and the bending punch and the lower die attached to the work are attached to the upper die. Bending is performed in cooperation with the die body attached to the die, and then the bending punch is retracted from the work. In this state, the crushing punch fixed to the punch main body is lowered, and the bent work is clamped and pressed between the lower work and the lower die to perform the crushing work.

Hemming is performed while one of the upper mold and the lower mold is moved up and down by one stroke with respect to the other mold.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, an upper table 1 which is moved up and down by, for example, a driving unit (not shown) is provided at an upper portion of the front surface of a press brake main body (not shown), and a lower table 3 is fixed to a lower portion of the front surface. On the upper table 1, a punch body 5 forming a part of an upper mold is provided with a fixture 7.
Attached through. Moreover, the punch body 5 is attached to the fixture 7 with the bolts 9, and the die body 11 forming a part of the lower die is fixed on the lower table 3.

A substantially rectangular plate-shaped punch 17 for punching and a cam plate 19 are attached to the punch main body 5 in parallel downward by bolts 13 and 15, respectively. The crushing punch 17 and the cam plate 19 are fixed by bolts 23 via fixing blocks 21.

Further, a plurality of blind holes 5a are formed in the up-down direction along the longitudinal direction on one side of the punch body 5 on which the crushing punch 17 is attached. Bolts 25 are vertically inserted into these blind holes 5a so as to penetrate the punch body 5. Further, the cam plate 19 of the punch body 5
A plurality of guide holes 5b are formed vertically in one side of the side on which the is mounted, and a guide bolt 27 described later is inserted through these guide holes 5b.

A material pressing block 29 is attached to the lower end of the bolt 25, and a first spring 31 is provided along the bolt 25 between the material pressing block 29 and the punch body 5.
Is provided, and the head of the bolt 25 is urged in a direction in which it contacts the bottom of the blind hole 5a. A fluid cylinder 33 is attached to the material pressing block 29, and a bending punch 37 mounted coaxially on the material pressing block 29 is fixed to the tip of a piston rod 35 of the fluid cylinder 33. .

Here, the piston rod 35 and the bending punch 37
Forms an angle of, for example, about 45 degrees with the lower surface of the material pressing block 29, and the tip of the bending punch 37 is parallel to the lower surface of the material pressing block 29. Moreover, the inner side surface of the material holding block is in sliding contact with the outer side surface of the crushing punch 17.

On the other hand, below the material pressing block 29 on the die body 11, a plurality of cylindrical spring receivers 39 are fixed, and at the center position of these spring receivers 39,
A stepped hole 11a is formed in the die body 11 in the vertical direction.
A bolt 41 is inserted into each of the stepped holes 11a so as to project upward, and an ejector plate 43 is attached to the upper end of the bolt 41 so as to face the material pressing block 29. In the spring receiver 39, a second spring is provided between the ejector plate 43 and the die body 11.
45 is attached, and the head of the bolt 41 is biased in the direction in which it is locked to the step of the step hole 11a.

Further, a die block 47 is provided substantially in the center of the die body 11 so as to be movable in the direction of arrow AB, and the upper surface of the die block 47 is located on the same plane as the upper surface of the ejector plate 43 at the upper limit. ing. Then, at a predetermined position on the upper surface of the die block 47, the ejector plate 43
An abutment member 49 for positioning the work W placed on the workpiece W is fixed by bolts 51. Further, a pressing portion 47a having a tapered lower surface is provided at the end of the upper surface of the die block 47 facing the ejector plate 43, and the lower surface of the cam plate 19 is provided on the opposite surface. A projecting cam plate 47b is provided to engage with the cam plate 19a formed in a mountain shape.

Further, the lower portion of the die block 47 is provided with a leg portion 47c extending in a direction opposite to the spring receiver 39, and the leg portion is attached to a stopper member 55 attached to the side surface of the die block 11 with a bolt 53. The end of 47c comes into contact. By adjusting the position of the stopper 55 with the bolt 53, the bending length of the work W can be adjusted.

Further, a cam guide block 5 having a guide surface 57a which is in sliding contact with the outer surface of the cam plate 19 is provided at the end of the die body 11 opposite to the side where the spring receiver 39 is attached.
7 is installed. A bolt 59 is attached to the cam guide block 57 so as to be movable in the direction of arrow AB, and the tip of the bolt 59 is attached to the die block 47.
It is fixed to. In addition, the blind hole 57b formed concentrically with the bolt 59 on the cam guide block 57 from the outside,
The third spring 61 is mounted, and the die block 47 is urged in the direction of arrow B by the third spring 61 to press the end of the leg 47 c of the die block 47 against the stopper member 55. .

The base end of the guide bolt 27 is fixed to the upper part of the cam guide block 57, and the head of the guide bolt 27 is fixed.
27a can be inserted into a guide hole 5b formed in the punch body 5. Furthermore, with the upper surface of the cam guide block 57,
A fourth spring 65 is mounted between the guide bolt 27 and the washer 63 locked to the head 27a of the guide bolt 27, and biases the washer 63 in a direction of pressing the washer 63 against the lower surface of the head 27a of the bolt 27. There is.

Next, the operation of the hemming die according to this embodiment will be described.

FIG. 1 shows the setting of a plate-shaped work W before processing, FIG. 2 shows the completion of a right-angle bending process, and FIG. 3 shows the completion of an acute-angle bending process.
FIG. 4 is a vertical cross-sectional view showing the completion of the crushing step.

In FIG. 1, the upper table 1 is separated from the lower table 3 at a predetermined interval, and the material pressing block 29 is at the lower limit position by the urging force of the first spring 31. The ejector plate 43 is also connected to the second spring 45.
It is at the upper limit position due to the urging force, and in this state, a gap of a predetermined distance is formed between the lower surface of the material pressing block 29 and the upper surface of the ejector plate 43. Also,
The piston rod 35 of the fluid cylinder 33 is in a protruding state, and the taper surface of the lower end of the bending punch 37 and the lower surface of the material pressing block 29 are substantially flush with each other. Further, the upper surface of the ejector plate 43 and the upper surface of the die block 47 are substantially flush with each other.

On the other hand, the die block 47 is moved in the arrow B direction by the urging force of the third spring 61, the ends of the leg portions 47c of the die block 47 are in contact with the stopper 55, and the pressing portion 47a of the die block 47 is in contact. Is slightly separated from the inner side surface of the ejector plate 43. Also, the cam surface of the cam plate 19
19a is separated from the cam surface 47b of the die block 47, and the head 27a of the guide bolt 27 is also separated from the guide hole 5b of the punch body 5. Further, the butting member 49 and the stopper member
Reference numeral 55 is set so that the dimension of the bent portion of the work W becomes a predetermined length.

After the die is set in such a state, the work W is bent at right angles in a first step. First, the work W is placed on the upper surfaces of the ejector plate 43 and the die block 47, and one end is abutted against the abutting member 49 to perform positioning.

Next, the press brake is driven to lower the upper table 1, for example, and the lower surfaces of the material pressing block 29 and the bending punch are brought into contact with the upper surface of the work W. When the upper table 1 is further lowered, the material pressing block 29 and the bending punch 37 press the work W against the ejector plate 43 as shown in FIG. As a result, the second spring
45 is compressed, the ejector plate 43 is lowered, and the tip of the workpiece W is in contact with the tip of the bending punch 37 and the die block.
It is clamped between the 47 pressing portions 47a and bent upward at a substantially right angle. At this time, if the first spring 31 has a stronger spring force than the second spring 45, the first spring 31 is not compressed. Further, in this state, the cam surface 19a of the cam plate 19 does not press the cam plate 47b of the die block 47.

Next, in the second step, when the upper table 1 is further lowered, the lower surface of the ejector plate 43 contacts the upper surface of the spring receiver 39 as shown in FIG. At the same time, the cam plate 19 descends along the guide surface 57a of the cam guide block 57, the cam surface 19a engages with the cam surface 47b of the die block 47, compresses the third spring 61, and moves the die block 47 in the arrow direction. Move in A direction. As a result, the work W is held between the pressing portion 47a of the die block 47 and the bending punch 37, and is bent into an acute angle.

Next, in the third step, as shown in FIG. 4, the fluid cylinder 33 is actuated by the action of a limit switch or the like to retract the bending punch 37 via the piston rod 35, and the crushing punch 17 is moved. Remove from stroke range. Then lower the upper table 1 further,
The ridge of the cam surface 19a of 19 exceeds the ridge of the cam surface 47b of the die block 47, the die block 47 retreats in the direction of arrow B by the urging force of the third spring 61, and the pressing portion 47a separates from the workpiece W. To do.

Next, when the upper table 1 is further lowered, the front end of the work W whose lower end of the crushing punch 17 is bent at an acute angle is pinched and pressed between the work W and the ejector plate 43 to crush flat. At this time, the punch body 5 is guided by the head 27a of the guide bolt 27 via the guide hole 5b and descends.

When the hemming process in each of the bending and crushing steps is completed as described above, the upper table 1 is moved up and the bending punch 37 is returned to the initial position shown in FIG. 1 by the operation of the fluid cylinder 33. . At the same time, material holding block 29, ejector plate 43, die block
The 47 and washer 63 also return to their initial positions by the biasing forces of the first, second, third and fourth springs 31, 45, 61, 65, respectively.

According to this embodiment, the bending process and the crushing process can be continuously performed in one process (one stroke) without replacing the mold on one press brake. While reducing costs,
Processing man-hours can be significantly reduced.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. For example, in the above embodiment, the case where the bending punch 37 is driven by the fluid cylinder 33 has been described, but the driving means is not limited to the above configuration, and for example, a cam mechanism may be used.

[Effects of the Invention] As described in detail above, according to the present invention, each process of bending and crushing a plate-shaped work is performed by one stroke up and down movement by the upper die and the lower die. Since the process is continuously performed during the period, the cost of the mold and the number of processing steps can be significantly reduced.

[Brief description of the drawings]

1, FIG. 2, FIG. 3, and FIG. 4 are longitudinal cross sections showing a hemming die according to an embodiment of the present invention at the time of setting, right-angle bending, acute-angle bending, and crushing, respectively. It is a side view. 1 Upper table, 3 Lower table 5 Punch body, 11 Die body 17 Punch for crushing work 19 Cam plate 29 Material holding means 33 Fluid cylinder 37 Bending Processing punch 47 …… die block, 47a …… pressing part

Claims (1)

(57) [Claims] 1. A hemming die for hemming a work by cooperation of an upper die and a lower die, wherein the upper die has a punch body and a crushing work fixed to the punch body. And a cam plate, a material pressing means attached to the punch body so as to be able to withdraw upward, and a bending punch attached to the material holding means so as to be able to withdraw. It comprises a die main body and a die block movably mounted on the die main body and provided at its tip end with a pressing portion that cooperates with the bending punch to bend the work. A die for hemming, wherein the die block is provided so as to be movable in a horizontal direction by raising and lowering the cam plate.