JPH084842B2 - Bending die for metal pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal pipe bending die used in a rotary draw system.

[0002]

2. Description of the Related Art A rotary draw system is generally used for bending a metal pipe such as a circular pipe.

In this system, as shown in FIG. 10, a bending clamp die 2 is fixed to a bending die 1 rotatably attached to a machine base (not shown), and the tip of the bending clamp die 2 is attached to the outer periphery of the bending die. A wrinkle remover 12 is provided.

Reference numeral 3 denotes a clamp type, which is arranged on a slide base so as to be slidable right and left. Reference numeral 5 is a pressure type, and 6 is a cored bar.
When bending a pipe, insert a core metal 6 into the pipe and bend the front end of the pipe to bend the clamp die 2 and the clamp die 3.
The clamp die 3 is moved to the left as indicated by the arrow A (sliding on the slide table) so as to be sandwiched between them and moved to the position indicated by reference numeral 3A. At this time, the pressure die 5 is also moved to the left and brought closer to the wrinkle remover 12.

In this way, the pipe whose tip (front end) is sandwiched between the clamp die 2 and the clamp die 3 is arranged such that the bend die 1 together with the bend clamp die 2 and the clamp die 3 is rotated around the central axis of the bend die. The work (pipe) is bent by rotating in the direction.

The pipe is bent along the outer circumference of the bending mold by sandwiching the shape of the bending clamp mold 2 and the clamp mold 3 that sandwich the pipe, that is, the semi-cylindrical part.

[0007]

SUMMARY OF THE INVENTION In the above conventional technique,
The bending clamp mold 2 and the clamp mold 3 for gripping the pipe are formed in a mold shape in which a circular cross section is divided into two along the diameter, and when clamping a workpiece, a mold clamp mechanism or a pressure mold is used. Due to the mechanical play of the slide mechanism,
Relative to the clamp-type 3 bending clamp type 2, caused a relatively center displacement as shown by the arrow B in FIG. 6, significantly reduces the appearance quality of the product, as shown in FIG.

In FIG. 7 , 7 is a product, and 8 and 9 are scratches due to the center shift. Further, when shifted in the direction alignment of the clamp type longitudinal (vertical direction in FIG. 5), as indicated by reference numeral 10 in FIG. 8, the bending R results in a circumferential direction of the wound as folded are separated.

Therefore, it is an object of the present invention to provide a bending die for a metal tube, which can prevent these scratches from occurring and improve the appearance quality of the product.

[0010]

In order to achieve the above object, a metal pipe bending die of the present invention is a semi-circular pipe holding groove in a metal bending die used in a rotary draw system.
On either side of (12, 12a), the corresponding taper part or bend
Forming a mating surface (2a, 3a) having a surface portion, and the mating surface
Insert the inner end of (2a, 3a) in contact with the pipe gripping groove
It is characterized in that it is located at both ends of the semicircle of the grip groove.
It

[0011]

[0012]

[0013]

[0014]

[Action] In this invention, at the time of processing, the first and eliminates the deviation of the second fitting part and (2a) (3a) and are mutually fitted vertically center the two-piece circular cross section is automatically It suits

[0015]

[0016] In the invention Matako both fitting portions (2b) (3
b) regulates the displacement of both clamp types (2) and (3) in the front-rear direction. In yet invention this, both the fitting portion (2c) (3c)
Adjusts the centers of both clamp types (2) and (3) and regulates the front-back direction at the same time.

[0017]

Example of the Embodiment] FIGS. 1-4, in different embodiments corresponding to this invention, both, the bending mating surface of the clamp type 2 and the clamp die 3, two divided circular cross-section of both clamped Also has a taper part that fits each other so that the centers of
Tsu and a first fitting portion 2a and a second fitting portion 3a is provided, respectively.

In both cases, the shape of the fitting portion is different, but the action of centering is the same. In addition to these, the first
Various shapes of the first and second fitting portions are conceivable. For example, the taper of the first and second fitting portions 2a and 3a in FIG. 1 may be opposite to each other.

[0019] Figure 1 is adapted to tape path which first and second fitting portions to perform each other center alignment. In addition, FIG. 2, tape
As shown in FIG.
Has a thread-shaped projection and groove on the mating surface, but the number of threads may be plural.

In FIG. 4, the mating surfaces are formed by R-shaped concave and convex lines.

[0021]

[0022]

[0023]

As described above, the bending die for a metal pipe of the present invention is as described above.
Compatible with both sides of the semicircular pipe grip groove (12, 12a)
The fitting surface (2a, 3
a) is formed, and the pipe grip of the fitting surface (2a, 3a) is formed.
Position the inner ends that contact the holding groove on both ends of the semicircular shape of the pipe holding groove.
Since it is placed, the mating of both molds does not depend on the taper or curved surface.
It can be easily and surely made to be slip-in type, and it can be fitted
The inner edges of the faces are located at the ends of the semicircle of the pipe grip groove.
Therefore, center alignment is reliably performed , and scratches are prevented from occurring during bending, improving product quality.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention.

FIG. 2 is a front view of the embodiment of the present invention.

FIG. 3 is a front view of an embodiment of the present invention.

FIG. 4 is a front view of the embodiment of the present invention.

FIG. 5 is a plan view of a main part of a conventional bending machine.

FIG. 6 is a front view of a conventional technique.

FIG. 7 is a perspective view of a product processed by a conventional technique.

FIG. 8 is a perspective view of a product processed by a conventional technique.

[Explanation of symbols]

 2 Bending clamp type 2a 1st fitting part 3 Clamping type 3a 2nd fitting part

Claims (1)

[Claims] 1. A semi-circular pipe holding groove (12, 12a) in a metal bending die used in a rotary draw system.
Fitting with corresponding taper or curved surface on both sides of
The surfaces (2a, 3a) are formed, and the mating surfaces (2a, 3a)
The inner end that touches the pipe grip groove is a semicircle of the pipe grip groove.
Bending dies for metal pipes , characterized by being located at both ends of the shape .