JPH0140576Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a tube bending device that bends a tube while performing high-frequency heating, and enables small radius bending.

One type of pipe bending equipment that has been used in the past is a three-point bending system that performs bending by supporting three points while performing high-frequency heating. It is provided with fulcrum rollers 2 and 3 for holding both sides, a high frequency heating coil 4 is provided on the distal side of these fulcrum rollers 2 and 3, and a rear chuck 5 for pushing out the tube 1 is provided on the proximal end side. Further, in order to apply bending force to the tube 1, a bending roller 6 is provided on the distal end side of the high frequency heating coil 4, and the bending force is applied via a hydraulic cylinder 7.

When bending a pipe, the fulcrum roller 2,
3 is pushed out through the rear chuck 5, and the bending roller 6 is advanced so that the distance of the bending roller 6 from the bending center O of the tube 1 to a fixed point A set at the tip of the tube is constant. The bending process is performed at a constant radius by controlling the bending process so that

However, in conventional pipe bending equipment, the bending roller 6
The amount of movement is limited by the stroke of the hydraulic cylinder 7 and is small, and the distance between the bending roller 6 and the heating coil 7 cannot be made small, making it impossible to bend a small diameter pipe with a small radius.

The object of the present invention is to eliminate such conventional drawbacks and provide a tube bending device capable of bending with a small radius.
The structure of the present invention that achieves this purpose includes a fulcrum roller that holds the tube, a heating coil that heats the bending part of the tube with high frequency, and a bending roller that applies bending force to the tube, and pushes out the tube from the rear. In a pipe bending device that performs bending, an auxiliary bending roller is provided between the fulcrum roller and the bending roller to work with the bending roller to bend the pipe, and the heating coil is slidable along the longitudinal direction of the pipe. It is characterized by being provided in

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 2 is a schematic configuration diagram of an embodiment of the pipe bending device of the present invention, in which fulcrum rollers 2 and 3 are attached to the main body of the device (not shown) so as to be located on both sides of the middle portion of the pipe 1. A high-frequency heating coil 4 for local heating is provided on the distal side of 2 and 3 so as to be slidable in the feeding direction of the tube 1, and a rear chuck is provided on the proximal side with a pushing mechanism for gripping the tube 1 and pushing it forward. 5 is provided. On the other hand, in order to apply bending force to the tube 1, a sliding guide groove 8 is provided in the main body of the device perpendicular to the feeding direction of the tube 1.
A bending roller 10 is rotatably attached to a sliding table 9 that can slide along the two fulcrum rollers 2 and 3.
They are provided on the outside in the tube bending direction (outside the tube from the bending center O of the tube 1) so as to contact the outer surface of the tube 1 alternately. A hydraulic cylinder 7 is connected to this sliding table 9 to drive the sliding table 9 and apply bending force to the pipe 1 via bending rollers 10. Additionally, an auxiliary sliding table 1 that slides parallel to the bending roller 10 on the main body of the device between the bending roller 10 and the high-frequency heating coil 4 is provided.
1 is slidably attached to the auxiliary guide groove 12, and an auxiliary bending roller 13 that cooperates with the bending roller 10 to apply bending force to the pipe is rotatably attached to the auxiliary slide groove 11. This auxiliary bending roller 1
Reference numeral 3 applies force to the tube 1 from the direction opposite to that of the bending rollers 10, and applies a bending moment to the high frequency heating coil 4 portion. The auxiliary sliding table 11 to which the auxiliary bending roller 13 is attached can be driven by transmitting the driving force from a hydraulic motor and reducer through a chain or wire, or by driving the chain or wire with a hydraulic cylinder. or directly driven by a hydraulic cylinder. Further, the bending roller 10 or the auxiliary bending roller 13 is supported on the sliding table 9 or the auxiliary sliding table 11 by using a cantilever support for the bending roller 10 as shown in FIG. A rolling bearing 14 is interposed between and the sliding table 9, and the rotating shaft of the bending roller 10 is attached via a bearing 15, or rotating shafts are formed at both ends of the bending roller 10 as shown in FIG. A bearing 15 is provided on each of the two ends to form a support structure at both ends.

To explain the case of small radius bending with the pipe bending device configured as described above, first, a straight pipe 1 is held by fulcrum rollers 2 and 3 and attached to the rear chuck 5, and the bending roller 10 and auxiliary The bending rollers 13 are moved and pressed against the tube 1 from opposite directions. Thereafter, the auxiliary bending rollers 13 apply a constant bending force F to the tube 1 depending on the working dimensions, and the bending rollers 10 push the tube 1 forward while applying the bending force, and perform the bending process while applying high-frequency heating. At this time, the position of the bending roller 10 is controlled so that the distance between the bending center O of the tube and the tube tip position A is constant. When the bending process progresses and the bending angle reaches approximately 30 degrees, the auxiliary bending roller 13 is moved back, and the bending process is performed by applying bending force only with the bending roller 10. At the same time, the high-frequency heating coil 4 is moved to the front side (the first position) in the feeding direction of the tube. 2), and at the same time, the bending center O is also moved to perform a small radius bend.

In this way, the bending roller 10 and the auxiliary bending roller 13
By performing pipe bending using
Small radius bending becomes easy. Furthermore, by retracting the auxiliary bending roller 13 during the bending process, it is possible to prevent the distance between the high-frequency heating coil 4 and the auxiliary bending roller 13 from becoming small, and as the bending progresses, the axial component force increases. Therefore, the shear force acting on the bending part can be ignored. Furthermore, in the case of small radius bending, after bending to a predetermined angle with the bending roller 10 and the auxiliary bending roller 13, the high-frequency heating coil 4
By moving the auxiliary bending roller 13 forward in the tube feeding direction and retracting the auxiliary bending roller 13, it is possible to ensure a small radius bending of the tube.

As described above in detail with the embodiments, according to the present invention, in a high-frequency heating type tube bending device, the high-frequency heating coil is made slidable in the tube feeding direction, and is placed between the bending roller and the fulcrum roller. The provision of auxiliary bending rollers that cooperate with the bending rollers to apply bending force to the tube facilitates small radius bends. Moreover, the structure is simple and can be manufactured at low cost.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a conventional pipe bending device;
4 to 4 show an embodiment of the pipe bending device of the present invention, FIG. 2 is a schematic configuration diagram, and FIGS. 3 and 4 are sectional views of a support structure for a bending roller. In the drawing, 1 is a tube, 2 and 3 are fulcrum rollers, 4 is a high-frequency heating coil, 5 is a rear chuck, 8 is a sliding guide groove, 9 is a sliding table, 10 is a bending roller, 11 is an auxiliary sliding table, 12 is an auxiliary guide groove, and 13 is an auxiliary bending roller.

Claims (1)

[Scope of utility model registration request] In a tube bending device that includes a fulcrum roller that holds the tube, a heating coil that heats the bending portion of the tube with high frequency, and a bending roller that applies bending force to the tube, the tube is pushed out from the rear of the tube and bent. A pipe bending device characterized in that an auxiliary bending roller is provided between a roller and the bending roller to work with the bending roller to bend the pipe, and the heating coil is provided slidably along the longitudinal direction of the pipe. .