JPH11285737A - Method for bending cylindrical body and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve bending work of a cylindrical body in high accuracy by executing press work. SOLUTION: A press machine is constituted of a lower die base 1 and a upper die base 5. A cylindrical body 2 is, on one side across a part subjected to bending, interposed and fixed by upper and lower side holding pieces 3, 6 provided on both the bases 1, 2, and on the other side is, in a state that is interposed by upper and lower side bending punches 10, 11 provided on each die base side supported by supporting pins 8, 9 as fulcrums, subjected to bending by swinging and displacing around the supporting pins 8, 9 as fulcrums.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a method and apparatus for bending a cylindrical body such as a cylinder and a square cylinder.

[0002]

2. Description of the Related Art In general, a tubular body (pipe) of this kind is sometimes used by being bent. In such a case, it is proposed to use a dedicated bending device (bender). The apparatus is poor in versatility as a processing apparatus, and as a result, there is a problem that fixed costs are increased. Therefore, it has been proposed to bend using a versatile press device, and such a device is disclosed in, for example, JP-A-2-30328. In this device, a cylindrical body is placed on an arc-shaped holding (fixing) mold, and one end of the cylindrical body is elastically supported, and is swung about a support shaft orthogonal to the axial direction of the cylindrical body. Pressing (pressing) with a freely supported punch causes the punch to swing along the arc surface of the mold, thereby bending the cylindrical body.

[0003]

However, in the prior art, when the cylindrical body is bent, the cylindrical body is arranged along the arc-shaped surface from a state separated from the arc-shaped surface of the presser die. Since the pipe is subjected to bending stress, the binding force on both sides of the bent portion is weak, so that the pipe shape is deformed, and there is a problem that the bending accuracy is unstable. There are issues to be addressed.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been made to solve these problems. In bending the cylindrical body by moving the die base close to each other, the cylindrical body is clamped and fixed by a holding piece provided at one end side on both die base sides with the bending processing portion interposed therebetween, and the other end side is cylindrical. The support shafts that are displaced with respect to the support shafts that have been displaced while holding both bending punches with the support shafts that are displaced so as to be deviated in the axial direction of the body while being clamped by bending punches provided on each die base side so as to swing around the support shaft as a fulcrum The cylindrical body is bent by swinging and displacing. Further, the present invention provides, as a cylindrical body bending apparatus, a fixed die base, a movable die base moving close to the fixed die base, and a bending part of the cylindrical body when the movable die base moves close to the fixed die base. Pressing pieces provided on each die base to clamp and fix one end side, and swinging to each die base to clamp the other end side against the bent part of the cylindrical body when the movable die base moves close to the fixed die base A bending punch provided freely, and the swinging support shaft of each bending punch is displaced in the axial direction of the cylindrical body. The cylindrical body is configured to be bent by swinging and displacing the support shaft shifted in position with respect to a fulcrum while holding the cylindrical body. Further, in this apparatus, the bending displacement of the bending punch is regulated by a torsion piece. According to the present invention, since the tubular body is bent while being restrained on both sides of the bent portion while being pressed, the pipe can be deformed without deformation, and stable bending accuracy can be achieved. By exchanging pieces and bending punches, it is possible to easily cope with a cylindrical body having a different shape and diameter, and to make it more versatile.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawing, reference numeral 1 denotes a lower die base fixed to constitute a press device, and the lower die base 1 is located on one side (left side in the drawing, hereinafter) of the cylindrical portion 2 with a bent portion of a cylindrical body 2 interposed therebetween. , The side end is referred to as “base end” for convenience.
The lower holding piece 3 is provided on the other side (on the right side in the drawing, hereinafter, the side end is referred to as “tip” for convenience). On the upper die base 5 provided to move up and down, an upper holding piece 6 is provided so as to face the lower holding piece 3, and an upper body pushing piece 7 is provided so as to face the lower body pushing piece 4. I have. On the opposing surfaces of the upper and lower pressing pieces 6, 3, semicircular concave grooves 6a, 3a into which the upper and lower halves of the cylindrical body 2 are fitted respectively are formed, and the upper die base 5 is moved downward to hold the upper and lower pressing pieces. The setting is such that when the pieces 6, 3 abut, the tubular body 2 is clamped and fixed from above and below. The upper die base 5 has a positioning pin 5a protruding therefrom, and the lower die base 1 has a positioning hole 1a into which the positioning pin 5a fits.

On the other hand, up-and-down bending punches 10 and 11 that swing about support shafts 8 and 9 in a direction orthogonal to the axis of the cylindrical body 2 are supported by the upper and lower body abutting pieces 7 and 4, Of the support shafts 8 and 9, the lower bending punch 11 has a positional relationship (deviation) toward the holding pieces 3, 6 or the base end side with respect to the upper bending punch 10. ing. Further, the upper end surface 10a of the upper bending punch 10 has its base end side provided on the upper torsion piece 7 so as to be vertically movable,
Pressing pin 12 pressed downward by a bullet 12a
Urged downward. When the upper die base 5 is in the upward movement posture (non-pressing posture), the upper bending punch 10 has the leading edge 10b having the upper body pushing piece 7.
The guide piece 13 provided so as to protrude downward from the leading edge of the armature comes into surface contact with the urging force of the bullet 12a, and in this state,
A lower end surface 10c in which a semicircular concave groove 10d is formed to fit the upper half portion of the tubular body 2 is formed in a horizontal shape flush with the lower end surface 6b of the upper holding piece 6, and End face 10
a is an inclined surface which becomes lower toward the base end side, and the inclination angle is an angle corresponding to the bending angle of the tubular body.

Further, the support shaft 8 of the upper bending punch 10 is connected to the lower end face 7a of the body thrust piece 7 and the base end face 13 of the guide piece 13.
a is set to be equidistant from each other, and the upper corner portion on the tip end side of the upper bending punch 10 is formed on an arc surface 10 e having the support shaft 8 as an axis and having the radius as the distance, thereby forming the upper side. When the bending punch 10 is moved downward (press operation) as described below, the arcuate surface 10e is brought into contact with the lower end surface 7a of the torso piece and the base end surface 13a of the guide piece in a guided state, and the upper end face 10a of the punch is torsion piece. It is set so that it swings upward against the bullet 12a until it comes into surface contact with the lower end surface 7a. In addition, the upper bending punch 1
The base surface 10f of 0 is set to be separated from the distal end surface of the upper holding piece 6 to allow the upward swing.

The lower end surface 11a of the lower bending punch 11
The front end of the armature is provided on the lower body abutting piece 4 so as to be vertically movable, and is urged upward by a pressing pin 14 which is pressed upward by an elastic machine 14a. When the lower bending punch 11 is in the non-pressing posture, the base end face 11 b has a distal end face 3 b of the lower holding piece 3 and a distal edge of a guide piece 15 provided below the lower holding piece 3. 15a is brought into surface contact with the urging force of the ram 14a, and in this state, the upper end surface 11c in which the semicircular concave groove 11d is formed to fit the lower half of the cylindrical pair 2 is located on the lower side. The upper end surface 3c of the presser piece 3 is formed in a horizontal shape flush with the upper end surface 3c, and the lower end surface 11a is an inclined surface which becomes higher toward the front end side.
This inclination angle is an angle corresponding to the bending angle of the cylindrical body.

Further, as in the case of the upper bending punch 10, the support shaft 9 of the lower bending punch 11 is set so as to be located at the same distance from the upper end surface 4a of the body abutting piece 4 and the distal end face 15a of the guide piece 15, respectively. The lower corner portion of the lower bending punch 11 is formed on an arcuate surface 11e having the support shaft 9 as an axis and having the radius as the distance, thereby forming the lower bending punch 11 as described later. When the pressing force is applied, the circular arc surface 11e becomes
In the guide state in which the punch lower end surface 11a is in contact with the guide piece front end face 15a, the punch lower end face 11a is set to swing downward against the punch 14a until the punch lower end face 11a comes into surface contact with the body end piece 4a. . In addition, the front end face 11f of the lower bending punch 11
Is provided with a positioning projection 11g for abutting the tip of the tubular body 2 to position the bending portion.
The base end portion of the concave groove 11d formed in the lower bending punch 11 has an R shape so as to be along a bending line when the cylindrical body 2 is bent.

The cylindrical body 2 is bent as follows. In other words, the cylindrical body 2 is fitted and set in the lower bending punch 11 and the concave grooves 11 d and 3 a of the lower holding piece 3 in a state where the tip abuts on the positioning projection 16. In this state, the upper die base 5 is moved downward by pressing to bend the cylindrical body 2. In this case, the cylindrical body 2 has upper and lower pressing pieces 6, 3 on the base end side of the bent portion. The upper and lower bending punches 10 and 11 are supported by the upper and lower torsion pieces 7 and 4, respectively. The cylindrical body 2 is bent by swinging up and down with the support shafts 8 and 9 as fulcrums. As a result, the cylindrical body 2 receives bending stress in a state where both sides of the base end side and the front end side with respect to the bent portion are securely restrained in the vertical direction, respectively. While performing bending using a processing apparatus, highly accurate bending can be performed. Moreover, in this device, since the up-down bending punches 10 and 11 are supported by the body abutting pieces 7 and 4, the swing support shafts 8 of the bending punches 10 and 11 are used.
9 is not as strong as the one where the overall press strength works here.

In this case, by changing the upper and lower pressing pieces and the bending punch, the cylindrical body can be changed to one corresponding to the shape and diameter of the cylindrical body. The shape and diameter of can be processed. Also, upper and lower end surfaces 10a, 11 of the bending punch
By changing the inclination angle of a, the bending angle of the cylindrical body can be changed, and the versatility can be increased.

It should be noted that the present invention is not limited to the above-described embodiment, and may be configured as in the second embodiment shown in FIG. 3 are the same as those in FIG. In the second embodiment, the up-down bending punch 1 is oscillated by support shafts 8 and 9.
6 and 17 are pivotally supported.
6 and 17, the edges 16b and 17b are brought into contact with the guide pieces 13 and 15 by the pressing pins 12 and 14 in the non-pressing posture,
The upper end surfaces 16a and 17a are in a steeply inclined state. The press device is provided with punch supporting pieces 18 and 19 for slidingly supporting the arcuate surfaces 16e and 17e corresponding to the support shafts 8 and 9 of the vertical bending punches 16 and 17, respectively, and presses the upper die base 5 down. By doing so, the vertical bending punch 16,
Reference numeral 17 denotes a pressing force by the punch supporting pieces 18 and 19,
Bending is performed by swinging the upper end surfaces 16a, 17a or the gently inclined side after being received at the nine positions, and in the first embodiment, the upper and lower bending punches are formed by the torsion pieces 4, 7. The vertical displacement of the press device (the downward movement of the upper die base 5 in the present embodiment) is changed to the cylindrical body 2 without restricting the amount of swing displacement of 10 and 11. The press bending may be performed by selectively setting (the stroke setting can be adjusted by a control device provided in the press device) the amount set as the bending angle of (the amount corresponding to the bending angle of the tubular body 2). In addition to being able to perform high-precision bending, it is also possible to freely set the bending angle and shorten the time required for setup changes such as changing the bending angle and changing the diameter of the cylindrical body. The performance is also improved. In addition, 16c and 17c are end faces on the side pressing the cylindrical body 2 of the up-down bending punch. Further, the arrangement of the up-down bending punch may be configured such that the one in the above embodiment is upside down so that the bending punch swings upward when pressed. It is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a press device showing a state of a non-press posture.

FIG. 2 is a cross-sectional side view of the press device showing a state in the middle of a press posture.

FIG. 3 is a cross-sectional side view of the press device showing a state of a press posture.

FIG. 4 is a cross-sectional side view showing a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower die base 2 Cylindrical body 3 Lower holding piece 4 Lower tongue piece 5 Upper die base 6 Upper holding piece 7 Upper torsion piece 8 Support shaft 9 Support shaft 10 Upper bending punch 11 Lower bending punch 13 Guide piece 15 Guide piece

Claims (3)

[Claims] When a movable die base is moved close to a fixed die base to bend a tubular body, the tubular body is clamped and fixed by a holding piece having one end provided on both die bases with a bent portion interposed therebetween. Then, the other end side is pinched by bending punches provided on each die base side so as to swing about a support shaft that is displaced so as to be deviated in the axial direction of the cylindrical body as a fulcrum. A method for bending a tubular body, wherein the displaced support shaft is pivotally displaced to a fulcrum to bend the tubular body. 2. A fixed die base, a movable die base moving close to the fixed die base, and each die base fixed to one end side with respect to a bent portion of the cylindrical body when the movable die base moves close to the fixed die base. Each die base is provided with a holding piece provided and a bending punch which is swingably provided on each die base so as to hold the other end side with respect to the bent portion of the cylindrical body when the movable die base moves close to the fixed die base. And the pivot shafts of the bending punches are arranged so as to be deviated in the axial direction of the cylindrical body, and the vertical bending punch is displaced while clamping the cylindrical body. A cylindrical body bending device configured to perform a bending process on a cylindrical body by swinging displacement about a support shaft. 3. The bending apparatus according to claim 2, wherein the bending punch is controlled to swing by a body abutting piece.