JPS63130221A - Metal die for radius bending - Google Patents

Abstract

PURPOSE:To obtain the radius bending die causing no multistep breakdown nor flaw on a plate stock by providing a pair of punches whose tip part is the curved surface of about the same radius of curvature and whose sectional shape is symmetrical and making the punches adjustable freely in their moving in the front and back directions for the punch main body respectively. CONSTITUTION:A die bending machine is equipped with the die 7 for radius bending consisting of a punch main body 21 and punch 23 as the upper part die. The punch 23 makes a front side punch 23F and rear side punch 23B a couple, forms almost symmetrically the sectional shape of each punch 23F, 23B and provides the curved faces 25, 27 at the tip in about the same radii R1, R2 of curvature. In case of bending each clamp member 37, 39 are moved along the inclined face 21F, 21B of the V-groove 21G of the main body 21 and the punches 23F, 23B are subjected to positional adjustment at both sides of a center line CL according to the shape of a die 15. The plate stock is thereafter subjected to a radius bending by the die 15 and die 7. An uniform radius bending is thus performed without giving a multistep breakdown nor flaw on the plate stock.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a mold for R-bending, and more particularly, to a mold for R-bending a plate material using a bending machine. This invention relates to an R-bending mold for obtaining an R-bending product.

(Prior art) Conventionally, a bending machine such as a press brake is used to bend a plate material once.
An ordinary mold is used to perform R bending by performing obtuse angle processing many times instead of performing bending.

(Problems to be Solved by the Invention) However, in the conventional R-bending process described above, an ordinary die is used, so when the R-bending process is performed, the contact point of the tip of the punch, which is a die, is attached to the plate material. is small, and the pressure per unit area is large. As a result, there is a problem in that the plate material is easily damaged, resulting in an R-bent product with multiple folds. Furthermore, there is also the disadvantage that the pitch during R machining is small, and the machining time is long because it must be repeated many times.

The purpose of the present invention was proposed in order to improve the problem in view of the above-mentioned circumstances, and it is possible to obtain a uniform R-bent product that does not damage the plate material or cause multi-stage bending, and also to shorten the processing time with a large processing pitch. An object of the present invention is to provide a mold for R bending.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention provides a front punch whose tip portion has a curved surface having approximately the same radius of curvature and whose cross-sectional shape is approximately symmetrical. A die for R bending is constructed by providing a punch paired with a rear punch, and providing the front punch and rear punch of the punch so as to be movable and adjustable in the front and rear directions with respect to the punch body.

(Function) By employing the R-bending mold of the present invention, it is possible to obtain an R-bending product that is free from scratches and multi-step folding. Furthermore, since the pitch can be increased during the R bending process, the machining time can be shortened compared to the conventional method.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Referring to FIG. 1, a plate-shaped upper table 5 is fixed to the upper part of a side frame 3 of a press brake 1 as a bending machine, for example.

An R-bending die 7 serving as an upper die is fixed to the lower end of the upper table 5 via a presser plate 9 with bolts 11 or the like.

Further, a lower table 13 is provided at the lower part of the side frame 3 at a position facing the upper table 5 so as to be movable up and down, and at the upper end of the lower table 13, a die 15 as a lower mold is mounted on a presser plate 17. It is fixed with bolts 19 through.

The plate material W is placed on the die 15 attached to the upper part of the lower table 13, and the lower table 13 is placed on the R bending die 7 as an upper die attached to the lower part of the upper table 5. The die 15 is moved up and down by vertical movement to form the plate material W.
1. :R bending process is performed.

A specific structure of the R-bending mold 7 as an upper mold for the die 15 is shown in FIG. In Figure 2,
The R-bending mold 7 is composed of a punch body 21 and a punch 23. The lower part of the punch body 21 has a V-shape with inclined surfaces 21F and 21B centered on the center line CL, and a groove 21G is bored in the lower part along the V-shape. The punch body 21 is symmetrical in the front and rear views in FIG. 2 with respect to the center line OL.

The punch 23 includes a front punch 23F and a rear punch 23B as a pair. Furthermore, the front punch 23F and the rear punch 23B are formed to have substantially symmetrical cross-sectional shapes. Further, the curved surfaces 25 and 27 at the tip of the front punch 23F and the rear punch 23B each have a radius of curvature R+
, R2, and the radius of curvature R1 is approximately the same.

The rear end portions of the front punch 23F and the rear punch 23B are inclined so as to move along the V-shaped inclined surfaces 21F and 21B of the punch body 21. Furthermore, holes 29 and 31, each having an old screw thread in its inner circumferential portion, are bored approximately at the center of the rear end portions of the front punch 23F and the rear punch 23B.

Furthermore, grooves 33.degree. 35 parallel to the inclined surfaces 21F and 21B of the punch body 21 are formed on the outer surfaces of the rear parts of the front punch 23F and the rear punch 238, respectively. The hole 29 and the groove 33 and the hole 31 and the groove 35 communicate with each other to form a single-shaped groove.

A clamp bolt 41.4 having a clamp member 37.39 provided at its tip in the V-shaped groove 21G of the punch body 21 and the T-shaped grooves of the front punch 23F and rear punch 23B.
3 is inset. V-shaped groove 21 of punch body 21
The clamp members 37, 39 are fitted into the groove 21G, and are now movable within the groove 21G.

With the above configuration, the front punch 23F and the rear punch 23B
are the clamp bolts 4 for the punch body 21, respectively.
1.43, the clamp member 37
．． 39 are brought into contact with the grooves 21G of the punch body 21 and are tightened and clamped.

When moving the front punch 23F and the rear punch 23B to the center line CL side, which is the center of the punch body 21, loosen the clamp bolts 41, 43 and move the front punch 23F and the rear punch 23 relative to the punch body 21.
This can be done with B in an unclamped state.

Front punch 23F, rear punch BS'l? When distributing the data, all you need to do is use a scale or the like to read the scale value from the center line CL and adjust it.
It can be set at an appropriate position. For example, for the die 15 shown by the dotted line, the front punch 23F1 and the rear punch 23
When using B, adjust it and set it to the position indicated by the dotted line. Also, the front punch 23F is connected to the die 15 shown by the solid line.
, when using the rear punch 23B, adjust it and set it to the position indicated by the solid line. In this way, the pitch between the front punch 23F and the rear punch 23B can be increased.

FIG. 3 shows a state in which a plate material W placed on the die 15 is subjected to R-bending using the punch 23 of the R-bending mold consisting of a front punch 23F and a rear punch 23B. . When R-bending is performed on the plate material W, pressure is first applied to the pressing position ~v1 of the plate material W on the center line CL as shown in (A> in Fig. 3), and R-bending is performed. As the R bending progresses, pressure is applied to pressurized positions W2 and W3 as shown in FIG. 3(B).Finally, pressure is applied to pressurized positions W4 as shown in FIG. . Pressure is applied to W5 to complete the R-bending process. In this way, the pressure position changes and the R-bending process is completed.
A uniform R-bent product can be produced without causing scratches on the surface of the plate material W and preventing multi-stage bending.

Next, another embodiment of the R-bending mold 7 is shown in FIG. In explaining FIG. 4, the same reference numerals are used for the same parts as those explained in FIG. 2.

In FIG. 4, grooves 4, 5, and 47 extending in the front-back direction are bored in the front and back of the lower part of the punch body 21.

The front punch 23F and the rear punch 23B are engaged with the grooves 45 and 47 from the outside, respectively, so that the front punch 23F and the rear punch 23B are in contact with each other at the center line CL. The cross-sectional shape of the front punch 23F and the rear punch 23B when they are in contact with each other is approximately U-shaped. Each slope of the U-shaped part has a groove of 49°5.
1 is perforated.

A sliding member 53 projecting downward is provided in the center of the punch body 21 so as to be movable up and down, and a lower outer portion of the sliding member 53 has an inclined portion 53F.

53B. The inclined parts 53F and 53B are
Groove 4 of the front punch 23F and rear punch 23B, respectively.
9.51 is engaged.

For example, an inclined surface 55 inclined diagonally to the right is formed at the upper end of the sliding member 53, and projects into a space 57 provided within the punch body 21. Five wedge members engaged with the inclined surface 55 are provided in the space 57 and extend rightward in FIG. 4. A nut member 61 is provided on the outside of the right side of the wedge member 59.
1 is threaded with a bolt 63, and the tip of the bolt 63 is engaged with the right side of the five wedge members. Note that the sliding member 53 is supported by a plurality of spring-loaded bolts 65 with respect to the punch body 21. In addition, the front punch 2
3F, the rear punch 23B is also supported by spring-loaded bolts 71 and 73 via support members 67 and 69 attached to the lower part of the punch body 21.

With the above configuration, when the bolt 63 is rotated, for example, clockwise in the state shown in FIG. 4, the wedge member 59 is engaged with the bolt 63, so the wedge member 59 slides to the left. When the wedge member 59 moves to the left, since the wedge member 59 is engaged with the inclined surface of the sliding member 53, the sliding member 53
slides downward. When the sliding member 53 slides downward, the lower outer portion 53F of the sliding member 53.

53B is the groove 49 of the front punch 23F and the rear punch 23B.
．． 51, the front punch 23F and the rear punch 23B are moved simultaneously in the front and rear directions.

Further, when the bolt 63 is rotated counterclockwise, for example, the wedge member 59 returns to the right, and the bolt 63 with a spring
．． Due to the biasing forces of 71 and 73, the front punch 23F
, the rear bunch 23B simultaneously moves to the center line CL side,
The sliding member 53 will return upward.

Therefore, the front punch 23F and the rear punch 23B are simultaneously centered from the center line CL, and the pitch between the front punch 23F and the rear punch 23B is adjusted appropriately.

The shapes of the lower end portions of the front punch 23F and the rear punch 23B are curved surfaces having substantially the same radius of curvature, as shown in FIG.

Note that the present invention is not limited to the embodiments described above, and can be implemented in other embodiments by making appropriate changes.

[Effects of the Invention] As can be understood from the description of the embodiments described above, according to the present invention, the front punch and the rear punch have curved surfaces at their tip portions having approximately the same radius of curvature and whose cross-sectional shapes are approximately symmetrical. A punch with a pair of side bunches was provided, and the front punch and rear bunch of the punch were each made into an R-bending mold that could be adjusted to move forward and backward relative to the punch body, so R-bending was performed on the plate material. The effect is that a uniform R-bent product can be obtained without causing any scratches or multi-step folding.

In addition, since the front punch and rear bunch can be moved and adjusted in the front-back direction, the pitch between the front pinch and rear bunch can be changed greatly, reducing the processing time for R-bending the plate material. Improved machining efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a press brake according to an embodiment of the present invention. FIG. 2 is an enlarged view of the part shown by the arrow ■ in FIG. (A), (B), and (C) of FIG. 3 are explanatory diagrams for explaining the operation of this embodiment. FIG. 4 is an enlarged cross-sectional view of an embodiment that replaces FIG. 2. [Explanation of the symbols representing the main parts of the drawing...Press brake 7...R bending mold 15...Die
21...Punch body 23...Punch 2
3F...Front punch 23B...Back punch 25.
27...Curved surface agent Patent attorney Tamotsu Miyoshi Ogo 1 Figure 3 (A), CL Kan 30 (B)

Claims (2)

[Claims] (1) A pair of punches, each consisting of a front punch and a rear punch, whose curved surfaces at the tips have approximately the same radius of curvature and whose cross-sectional shapes are approximately symmetrical, is provided, and each of the front punch and rear punch of the punch is A mold for R bending, characterized in that it is provided so as to be movable and adjustable in the front and rear directions with respect to the punch body. (2) The R-bending mold according to claim 1, wherein the front punch and the rear punch are adjusted to move simultaneously in the front-rear direction from the center of the punch body.