JPH0244890Y2 - - Google Patents

Description

[Detailed Description of the Invention] - Industrial Application Field - The present invention relates to a bending machine for bending metal pipes, and in particular to an improvement of a bending cylinder device for reciprocating a bending piece.

-Prior Art- As is well known, in a conventional bending machine as shown in FIG.
The metal pipe X is locally bent by placing a clamp cylinder device B and a bending cylinder device C facing the reference stand A which has a guide groove a on the side surface that can support the metal pipe. That is, the clamp cylinder device B has a clamp D at the tip of the piston rod b that presses and fixes the metal pipe It consists of a hydraulic cylinder that reciprocates in the bending direction, but since a large bending moment acts on the bending cylinder device C when the metal pipe X is bent by the bending piece E, it is necessary to The same bending mode is applied to piston rod c.
It is simply impossible to burden the ment.

For this reason, in the past, a sturdy fixed base G was installed on the base F, and the dovetail groove H of this fixed base G (Fig. 6)
A piston rod c of a bending cylinder device C is coupled to a movable base I that can move along the curve, and a bending piece E is supported on the movable base I.

-Problems to be solved by the invention- However, in such a structure, the movable base I
Since the bending cylinder device C is configured to indirectly reciprocate the bending piece E through the bending cylinder device C, the device not only becomes larger, but also requires support for supporting the bending piece E every time the bending specification of the metal pipe X is changed. It was necessary to rearrange the relationship between the members and the movable base I, and there was a problem in that it was not possible to respond quickly to changes in specifications.

The purpose of the present invention is to provide a bending cylinder device for a bending machine that can miniaturize the entire device and quickly respond to changes in bending usage, taking into account the problems of conventional bending machines as described above. be.

-Means for solving the problem- In order to achieve this object, the present invention provides a bending cylinder device for a bending machine that bends a metal pipe into a predetermined shape by reciprocating a bending piece. The present invention proposes that a cylindrical block whose position can be adjusted in the angular direction is accommodated, a piston rod having a rectangular cross section to which the bending piece is attached at the tip, and the piston rod slidably penetrates a square hole in the center of the cylindrical block. be.

-Embodiment- Hereinafter, details of an embodiment of the present invention will be explained with reference to FIGS. 1 to 4.

FIG. 2 shows the entire bending machine according to the present invention, and this bending machine is equipped with a reference stand 2 placed on a base 1, a clamp/cylinder device 3, and a bending cylinder device 4. That is, the reference stand 2 has a guide groove 2a on the side surface that can guide the metal pipe X;
A clamping cylinder device 3 is oriented at right angles to. This clamp cylinder device 3 is a conventional cylinder device composed of a pneumatic cylinder, and its piston rod 3
There is a metal pipe X between the tip of a and the reference stand 2.
A clamp 3b that can clamp the is fixed.

The bending cylinder device 4, shown in detail in FIGS. 1 and 3, has a pair of fixed brackets 5 at both ends.
It has a cylindrical cylinder 4a that is firmly fixed to the base 1 by A and 5B, and an air chamber 4b of this cylinder 4a is filled with compressed air from ports 4c and 4d in the length direction of the cylinder 4a. A piston 4e that is reciprocated is housed therein. A support member 7 that supports the bending piece 6 is fixed using a mounting nut 8 to the tip of the piston rod 4f whose base is fixed to the piston 4e. As shown enlarged in Fig. 3, this piston rod 4f
is a rod-shaped member with high bending rigidity manufactured in a rectangular cross section with a width dimension W larger than a height dimension H,
The intermediate portion of the piston rod 4f is connected to a square hole 9a of a cylindrical block 9 arranged in a longitudinally adjacent side chamber of the pneumatic chamber so as to be adjustable in position in the angular direction.
is slidably penetrated.

As shown in FIG. 3, an arcuate index groove 11 is formed on the circumferential surface of the cylindrical block 9 to receive a tip 10a of a fixing screw 10 screwed into the cylinder 4a in the radial direction. A plurality of fixing holes 11a into which the tips 10a of the fixing screws 10 can be inserted are formed at the bottom of the index groove 11 at different positions in the circumferential direction of the cylinder 4a.

Returning to FIG. 1, a rubber seal 13 is seated in pressure contact with the right end surface of the cylindrical block 9. As shown in an enlarged view in FIG. 4, this rubber seal 13 has an inner ring 13b formed with an inner hole 13a having a rectangular cross section that can tightly fit around the circumferential surface of the piston rod 4f so as to rotate together with the piston rod 4f. An outer ring 13c is integrally formed on the outer periphery of the inner ring 13b. Since this outer ring 13c has an annular lip 13d that presses against the inner peripheral surface of the cylinder 4a,
The pressure in the pneumatic chamber brings the annular lip 13d into pressure contact with the inner surface of the cylinder 4a, preventing leakage of compressed air.

Since the illustrated embodiment has the above structure,
After fixing the metal pipe X to the base 1 with the clamp 3b of the clamp cylinder device 3, compressed air is sent to the bending cylinder device 4 to bend the piston rod 4.
By reciprocating the bending piece 6 supported at the point f, the intermediate portion of the metal pipe X is bent into the state shown by the imaginary line in FIG. This bending process is repeated.
A large bending moment acts on the piston rod 4f, and the section modulus Z of the piston rod 4f is a large value such as Z=W・H ² /6, and the piston rod 4f has a large bending moment.
Since the intermediate portion of f is supported by the highly rigid cylindrical block 9, the bending moment can be borne with almost no deformation.

To change the bending direction of the metal pipe X, loosen the fixing screw 10, and the cylindrical block 9 can freely move in the circumferential direction relative to the cylinder 4a. Therefore, when the cylindrical block 9 is adjusted to the required inclination by operating the piston rod 4f and the fixing screw 10 is tightened again, the tip 10a of the fixing screw 10 enters the fixing hole 11a and is pressed against the cylinder 4a. Since the reference stand 2 is completely fixed, it can be easily adjusted. Even in this adjusted state, the relationship between the direction of the bending moment acting on the piston rod 4f and the cross section of the piston rod 4f does not change, so the piston rod 4f
exhibits sufficient bending rigidity.

- Effects of the invention - As is clear from the above explanation, according to the invention, the bending piece can be directly attached to the piston rod, so the entire bending machine can be downsized, and the cylindrical block of the bending cylinder device can be made smaller. The bending direction of the metal pipe can be changed simply by adjusting the position in the angular direction with respect to the cylinder, which has the effect of easily meeting bending specifications.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a bending cylinder device according to the present invention, Fig. 2 is an overall perspective view of a bending machine using the same bending cylinder device, Fig. 3 is an enlarged sectional view taken along the - line in Fig. 1, Figure 4 is an enlarged sectional view of the rubber seal used in the bending cylinder device, Figure 5 is an overall perspective view of a conventional bending machine, and Figure 6 is an enlarged sectional view of the rubber seal used in the bending cylinder device.
The figure is a sectional view taken along the - line in FIG. 5. X...Metal pipe, 4...Bending cylinder device,
4f...Piston rod, 6...Bending piece, 9...
...Cylindrical block, 9a...Square hole.

Claims (1)

[Scope of utility model registration request] In a bending cylinder device for a bending machine that bends a metal pipe into a predetermined shape by reciprocating a bending piece, a piston rod that houses a cylindrical block whose position can be adjusted in the angular direction inside a cylindrical cylinder and attaches the bending piece to the tip. A bending cylinder device for a bending machine, characterized in that the cylinder block has a rectangular cross section, and the piston rod slidably penetrates a square hole in the center of the cylindrical block.