JPH01135122U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is an action diagram showing the insertion position of the small-diameter mandrel during bending into the small-diameter portion of the pipe, and Fig. 2 is an action diagram showing the insertion position of the large-diameter mandrel during bending into the large-diameter part of the pipe. Figure 3 is a longitudinal sectional view showing the arrangement of the clamping die and pressing die when the clamping die has rotated to the bending end point, Figure 4 is a plan view of the bending mechanism, and Figure 5A shows the arrangement of the bar-shaped material. A side view of the bending mechanism showing the state before it is clamped, FIG. Figure 8 (a) shows the inconvenience when working with a large curvature when the insertion length of the core metal is short, and Figure 8 (b) shows the inconvenience when working with a small curvature when the insertion length of the core metal is long. It is an action diagram showing a state. 2...Pipe supply mechanism, 21...Curved shape, 23...
...Tightening mold, 31... Core bar, P... Pipe, 34...
...Core position changing device, b...Rotation start point.

Claims (1)

[Scope of utility model registration request] A pipe supply mechanism 2 that clamps the rear end of the bending pipe P and supplies it to the bending section is provided, and a bending die 21 that selectively sets a plurality of bending curvatures to the bending section cooperates with the bending die 21. A clamping die 23 is provided which clamps the pipe P and rotates around the center of curvature of the curved shape, and a core bar 31 is provided which is inserted from the rear end of the pipe P and whose tip is located near the bending start point b. This pipe bending machine is equipped with a core position changing device 34 that moves the tip of the core bar 31 closer to the starting point b as the bending curvature of the pipe P becomes smaller.