Expansion pipe

Abstract

The utility model discloses an expansion pipe which comprises an expansion knotting part, a retraction middle part and an expansion head part which are sequentially arranged along the length direction of the expansion pipe, the expansion knotting part comprises an expansion pipe wall and two slender openings which are symmetrically formed in the pipe wall in the length direction of the expansion pipe and penetrate through the pipe wall, and anti-rotation outer teeth are arranged on the side edge, close to one of the slender openings, of the expansion pipe wall; the retraction middle part consists of an expansion pipe wall and a plurality of annular grooves which are distributed on the pipe outer wall at intervals along the length direction of the expansion pipe; the opening head is composed of four opening petals which are evenly distributed in the circumferential direction of the expansion pipe at intervals. According to the expansion pipe, the expansion stress is more uniform, the pipe wall is prevented from rotating during expansion and knotting, and the machining procedure is simple.

Description

Technical Field

[0001] The utility model relates to the technical field of furniture connectors, in particular to an expansion tube. Background Art

[0002] Generally, an expansion tube is used in combination with a screw and is a fastener for connecting or fixing furniture panels. Existing expansion tubes include only tube body expansion and tube body expansion plus knotting. For the expansion tube with only tube body expansion, only part of the tube body of the expansion tube contacts the hole wall of the embedded hole, resulting in a small frictional force between the expansion tube and the hole wall of the embedded hole. For occasions where a large frictional force is required to ensure connection or fixation, the tube body of the expansion tube needs to expand and knot to increase the contact area with the embedded hole and thus increase the frictional force. Existing expansion tubes with expansion and knotting often rotate along the hole wall under the action of inertia during expansion and knotting, affecting the expansion and twisting effects of the expansion tube. There is an expansion tube formed by secondary injection molding, which forms two components. When the expansion tube expands and twists, the two components are partially separated, with one component expanding and the other twisting. However, due to secondary injection molding, first, the processing process is complex, and second, the processing cost is relatively high. Summary of the Utility Model

[0003] The purpose of the utility model is to provide an expansion tube with more uniform expansion force, which can prevent rotation during expansion and knotting, and has a simple processing process, so as to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the utility model adopts the following technical scheme:

[0005] An expansion tube includes an expansion knotting part, a retraction middle part, and an opening head arranged in sequence along the length direction of the expansion tube. The expansion knotting part includes an expansion tube wall, two slender openings penetrating the tube wall symmetrically arranged on the tube wall along the length direction of the expansion tube, and anti-rotation external teeth arranged on one side of the expansion tube wall adjacent to one of the slender openings. The retraction middle part is composed of an expansion tube wall and a plurality of annular grooves distributed at intervals on the outer tube wall along the length direction of the expansion tube; the opening head consists of 4 opening petals evenly distributed at circumferential intervals along the expansion tube.

[0006] Further, 2 anti-rotation external teeth are arranged on the same side of each slender opening, and the 2 anti-rotation external teeth are close to both ends of each slender opening.

[0007] Further, a plurality of reinforcing ribs are arranged on the expansion tube wall of the expansion knotting part.

[0008] Further, a plurality of chevron openings are arranged on the retraction middle part along the length direction of the expansion tube.

[0009] Further, a limiting flange is circumferentially arranged along the wall of the expansion tube at the bottom end of the expansion knotting part.

[0010] Further, a screw decorative cover is arranged outside the bottom end of the expansion knotting part.

[0011] The beneficial effects of the utility model are as follows: when the screw enters the expansion tube and rotates, the tube walls on both sides of the slender opening of the expansion knotting part of the expansion tube expand and rotate to form a knot at the same time. The anti-rotation external teeth on one side of the two slender openings are in contact with the wall of the embedded hole while the tube wall expands, preventing the expansion tube from rotating along the wall of the embedded hole under the action of inertial force during the expansion and knotting of the expansion tube. At the same time, the retracting middle part contracts towards the expansion knotting part during the expansion and knotting, so that the 4 opening petals of the opening head evenly open outwards, making the force on the expansion tube during expansion more uniform. And only one injection molding process is required, and the processing is simple. Description of the Drawings

[0012] The drawings further illustrate the present utility model, but the embodiments in the drawings do not constitute any limitation to the present utility model.

[0013] Figure 1 It is a schematic structural diagram of an expansion tube of the present utility model;

[0014] Figure 2 It is a schematic diagram of an expansion tube of the present utility model;

[0015] Figure 3 It is Figure 2 A-A sectional view of the head schematic diagram;

[0016] Figure 4 It is Figure 2 B-B sectional view of the head schematic diagram;

[0017] Figure 5 It is a schematic diagram of an expansion tube assembling screw of the present utility model. Detailed Embodiments

[0018] To make the objectives, technical solutions and advantages of the present utility model clearer, the technical solutions of the present utility model will be further described clearly and completely below in conjunction with the embodiments of the present utility model. It should be noted that the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0019] It should be understood that the directions or positional relationships indicated by terms such as "upper", "lower", "front", "back", "left", and "right" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0020] like Figures 1-4 As shown, an expansion pipe of the utility model comprises an expansion knotted portion 1, a retracted middle portion 3 and an open head portion 2 which are sequentially arranged along the length direction of the expansion pipe.

[0021] Among them, Figure 1 , Figure 3 As shown, the expansion knotting portion 1 includes an expansion tube wall 11 and two elongated openings 4 symmetrically arranged on the tube wall along the length direction of the expansion tube and penetrating the tube wall, and an anti-rotation outer tooth 5 is arranged on one side of the expansion tube wall 11 adjacent to one of the elongated openings 4; the retracted middle portion 3 is composed of an expansion tube wall 31 and a plurality of annular grooves 32 spaced apart on the outer wall of the tube along the length direction of the expansion tube; Figure 2 The open head 2 shown is composed of four open petals 21 distributed at even intervals along the circumference of the expansion tube.

[0022] The expansion tube of the utility model is formed by one-step injection molding through mold opening, and the processing procedure is simple.

[0023] Preferably, if Figure 1 As shown, two anti-rotation external teeth 5 are provided on the same side of each slender opening 4 , and the two anti-rotation external teeth 5 are close to the two ends of each slender opening, so as to prevent the expansion tube wall along the length section of the slender opening 4 from rotating.

[0024] Preferably, if Figure 3 As shown, a plurality of reinforcing ribs 12 are provided on the expansion tube wall 11 of the expansion knotting portion 1, which can enhance the strength of the expansion tube wall when it is expanded and knotted.

[0025] Preferably, if Figure 3 As shown, the retracted middle portion 3 is provided with a plurality of herringbone openings 7 along the length direction of the expansion tube, which ensures the effective retraction of the retracted middle portion and disperses the retraction stress.

[0026] Preferably, if Figure 1 As shown, a limiting flange 6 is provided at the bottom end of the expansion knotting part 1 along the circumference of the expansion tube wall, and the limiting flange abuts against the embedded hole to prevent the expansion tube from sinking into the embedded hole as a whole when the screw enters the expansion tube and rotates, thereby affecting the screw entry depth and the expansion knotting degree of the expansion tube.

[0027] Preferably, if Figure 5As shown in the figure, a screw decorative cover 9 is provided on the outer side of the bottom end of the expansion knotting part. After the screw 8 extends into the expansion tube for connection and fixation, the screw head is covered by the screw decorative cover to prevent the screw head from being exposed.

[0028] In a kind of expansion tube of the utility model, when the screw enters the expansion tube and rotates, the tube walls on both sides of the slender opening of the expansion knotting part of the expansion tube expand and rotate to form a knot at the same time. The anti-rotation external teeth on one side of the two slender openings abut against the wall of the embedded hole while the tube wall expands, preventing the expansion tube from rotating along the wall of the embedded hole under the action of inertial force during the expansion and knotting of the expansion tube. At the same time, the retracting middle part contracts towards the expansion knotting part during the expansion and knotting, so that the 4 opening petals of the opening head evenly open outwards, making the expansion force of the expansion tube more uniform. And only one injection molding process is required, and the processing is simple.

[0029] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

Claims

1. An expandable tube, characterized in that, It includes an expansion knotting part, a retraction middle part, and an opening head arranged in sequence along the length direction of the expansion tube. The expansion knotting part includes an expansion tube wall, two elongated openings penetrating the tube wall symmetrically arranged on the tube wall along the length direction of the expansion tube, and anti-rotation external teeth arranged on one side of the expansion tube wall adjacent to one of the elongated openings. The retraction middle part is composed of an expansion tube wall and a number of annular grooves distributed at intervals on the outer wall of the tube along the length direction of the expansion tube; the opening head consists of 4 opening petals evenly distributed with gaps along the circumferential direction of the expansion tube.

2. An expandable tube according to claim 1, wherein, Two anti-rotation external teeth are arranged on the same side of each elongated opening, and the two anti-rotation external teeth are close to both ends of each elongated opening.

3. An expandable tube according to claim 2, wherein, A number of reinforcing ribs are arranged on the expansion tube wall of the expansion knotting part.

4. An expandable tube according to claim 1, characterized in that, The retraction middle part is provided with a plurality of chevron-shaped openings along the length direction of the expansion tube.

5. An expandable tube according to claim 1, characterized in that, A limiting flange is arranged circumferentially along the expansion tube wall at the bottom end of the expansion knotting part.

6. A expandable tube according to any one of claims 1-5, characterized in that, A screw decorative cover is arranged outside the bottom end of the expansion knotting part.

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