Sliding block type section full-supporting core rod structure with diameter changed through ratchet wheel inverse stop rotation

Abstract

The invention discloses a sliding block type section full-supporting core rod structure with a diameter changed through ratchet wheel inverse rotation. The structure comprises a core rod movable jointand a straight handle, wherein the core rod movable joint and the straight handle are connected through a quick-dismounting universal joint; a rotating shaft of the core rod movable joint is successively provided with a connecting rod mounting disc, a ratchet wheel, a reverse ratchet wheel, a bearing and a limiting clamping ring, a bearing outer ring is provided with a pawl mounting frame, the connecting rod mounting disc and the pawl mounting frame are hinged to a long connecting rod and a short connecting rod respectively, and the long connecting rod and the short connecting rod are hingedto an outer ring sliding block component; a connecting rod mechanism is driven to move through the relative rotation of the pawl mounting frame and the rotating shaft, the sliding block component is pushed to move to change the diameter, and the diameter is limited to being small during use through the ratchet wheel device; and the sliding block component is of a Z-shaped structure composed of twolayers of arc-shaped blocks, a sliding block positioning pin is arranged on the one layer, and a sliding block positioning pin sliding groove is formed in the other layer. According to the structure,the diameter of the core rod can be adjusted to meet machining requirements of circular-section pipes with different sizes, the adjusting process is simple and rapid, the production cost can be saved, and meanwhile, the efficiency can be improved.

Description

technical field [0001] The invention belongs to the technical field of preventing wrinkling and cross-section flattening distortion defects of a circular cross-section tube, and in particular relates to a slider-type cross-section full-support mandrel structure with a ratchet backstop rotation and diameter reduction. Background technique [0002] Circular cross-section elbow has the characteristics of hollow cross-section, light weight, low consumption and high efficiency, etc., and is widely used in aerospace, shipbuilding and automobile industries. The forming process of complex bent pipes (such as thin wall, large diameter, large bending angle, etc.) often has defects such as wrinkling, cross-section flattening and distortion, etc. Inserting a mandrel into the billet to be bent can effectively reduce the wrinkling in the forming process of the bent pipe and cross-section flattening distortion, so the study of the structure and performance of the mandrel has great signific...

AI Technical Summary

Problems solved by technology

[0004] The existing mandrels mainly have the following deficiencies: (1) The mandrels used in actual production have a fixed radial size. If pipe fittings with different diameters need to be bent, mandrels with corresponding sizes are required, resulting in the production cost of the bent pipe, the mandrel storage costs are high

(2) In response to the problems mentioned in (1), many people have proposed schemes to realize mandrel diameter reduction. These schemes generally have two problems. The outer contour of the mandrel is no longer a complete circle, but there is a gap, which weakens the support effect of the mandrel; second, the process of diameter adjustment and fixing is complicated, and the joints need to be removed one by one for adjustment. Re-install and disassemble the limit lock nut, collar and other components, which reduces the use efficiency of the mandrel

(3) The joints of multi-section flexible mandrels are often connected by hinges or ball joints. A hinge with only one degree of freedom will limit the direction of use of the mandrel, resulting in uneven wear of the mandrel and shortening the service life; the assembly of the ball joint and It is difficult to disassemble, and it is extremely inconvenient to add or remove joints according to changing bending parameters

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