Expansion bolt

Abstract

To provide an expansion bolt that can firmly fasten machine parts and other components and is resistant to loosening. [Solution] An expandable bolt comprising: a movable sleeve 1 having an internal tooth portion 11 on its inner wall surface and a friction portion 12 on its outer wall surface, and expandable radially outward; a bolt shaft 2 having a tooth portion 22 that engages with the internal tooth portion 11 of the movable sleeve 1, and a male thread portion 21 provided continuously with the tooth portion 22; and a nut 3 that screws onto the male thread portion 21 of the bolt shaft 2. The teeth of the tooth portion 22 of the bolt shaft 2 and the internal tooth portion 11 of the movable sleeve 1 can each be annular. The tooth portion 22 of the bolt shaft 2 may gradually increase in diameter from the open end toward the male thread portion 21, and the internal tooth portion 11 of the movable sleeve 1 may gradually decrease in diameter from the end into which the bolt shaft 2 is inserted toward the other end.

Description

Technical Field

[0001] The present invention relates to an expansion bolt used when connecting machine parts or the like.

Background Art

[0002] A connection structure using bolts is called an "adhesive" for machine parts or the like and is used for fastening machine parts or the like. An expansion bolt is a special screw connector for fixing pipes, suspension structures, brackets, etc. to walls, floors, columns, etc. Existing expansion bolts are composed of a countersunk head bolt, a bulkhead, a flat washer, a spring washer, and a hexagonal nut. When using an expansion bolt, after making a hole with an appropriate size in a fixing body, inserting the bolt and the bulkhead into the hole, and tightening the nut, the bolt, the bulkhead, and the fixture expand and become integrated with the fixing body. However, conventional expansion bolts are likely to loosen with respect to a relatively soft base body, and if the fixing of the bolt is not sufficient, it greatly affects the fixing effect. In addition, existing expansion bolts have few pipe expansion fixing points, resulting in insufficient fixing and the possibility of component detachment problems.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The present invention has been made to solve the problem of insufficient fixing in the above-mentioned conventional expansion bolts, and an object thereof is to provide an expansion bolt that can firmly fix machine parts or the like and is difficult to loosen.

Means for Solving the Problems

[0004] To achieve the above object, an expansion bolt according to the present invention includes a bolt shaft having an internal tooth portion on an inner wall surface and a friction portion on an outer wall surface, a movable sleeve that can expand radially outward, a tooth portion that engages with the internal tooth portion of the movable sleeve, and a male screw portion provided continuously with the tooth portion, and a nut that is screwed onto the male screw portion of the bolt shaft.

[0005] The teeth of the bolt shaft and the internal teeth of the movable sleeve can be made annular, and the teeth of the bolt shaft can be gradually widened from the open end toward the male threaded portion, and the internal teeth of the movable sleeve can be gradually narrowed from the end into which the bolt shaft is inserted toward the other end.

[0006] Furthermore, a striking portion can be provided on the open end face of the male threaded portion of the bolt shaft, and the diameter of the striking portion can be made smaller than the diameter of the male threaded portion.

[0007] Furthermore, the movable sleeve may be made by bending a metal piece into a ring shape, and the friction portion of the movable sleeve can be formed by a plurality of protrusions.

[0008] The thickness of the movable sleeve may be gradually increased from the end into which the bolt shaft is inserted to the other end, and the teeth of the bolt shaft may be gradually increased in thickness from the open end to the male threaded portion.

[0009] Furthermore, teeth can be formed on the bottom surface of the nut, and a spacer having teeth on one side that engage with the teeth on the bottom surface of the nut, and a spring washer that abuts against the opposite side of the spacer's other side, can be provided between the nut and the movable sleeve. [Effects of the Invention]

[0010] According to the present invention, after inserting a movable sleeve into a hole, a bolt shaft is driven into the movable sleeve. The teeth of the bolt shaft push the movable sleeve outward, fixing the movable sleeve in place within the hole. The teeth of the bolt shaft then engage with the internal teeth of the movable sleeve, fixing the bolt shaft and preventing it from loosening. This allows for the firm fastening of machine parts and provides an expandable bolt that is less prone to loosening. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing one embodiment of the expansion bolt according to the present invention. [Figure 2] Figure 1 is a schematic diagram showing the first step in installing the expansion bolt. [Figure 3] Figure 1 is a schematic diagram showing the second step in installing the expansion bolt. [Figure 4] Figure 1 is a schematic diagram showing the movable sleeve of the expansion bolt. [Figure 5] Figure 4 is an exploded view of the movable sleeve. [Figure 6] Figure 4 is a partially broken cross-sectional view of the movable sleeve. [Figure 7] Figure 1 is a schematic diagram showing the bolt axis of the expansion bolt. [Modes for carrying out the invention]

[0012] To make the above-mentioned objectives, features, and advantages of the present invention clearer, embodiments of the present invention will be described with reference to the drawings. The specific details described below represent only some embodiments of the present invention, and the present invention can be realized in many different embodiments from those described herein. Based on the embodiments of the present invention, all other embodiments that can be obtained, unless those skilled in the art perform creative work, fall within the technical scope of the present invention.

[0013] In this specification, "attached" to another component includes both direct placement on the other component and placement via yet another component. Furthermore, "connected" to another component includes both direct and indirect connection via another component. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not indicate that they represent only a limited number of embodiments.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art. Terms used herein are solely for the purpose of describing specific embodiments and are not intended to limit the invention.

[0015] One embodiment of the present invention will be described with reference to Figures 1 to 7. The present invention relates to an expansion bolt, which comprises a movable sleeve 1, a bolt shaft 2, and a nut 3.

[0016] As shown in Figure 7, one end of the bolt shaft 2 is provided with a male threaded portion 21 that screws onto the nut 3, and the other end of the bolt shaft 2 is provided with teeth 22.

[0017] As shown in Figures 1 to 4, the movable sleeve 1 expands radially outward when pressed, and the inner wall of the movable sleeve 1 is provided with internal teeth 11 that engage with the teeth 22 of the bolt shaft 2, and the outer wall of the movable sleeve 1 is provided with friction parts 12 to increase the frictional force.

[0018] This invention provides teeth 22 on the outer wall surface of the bolt shaft 2 of the expansion bolt, internal teeth 11 on the inner wall surface of the movable sleeve 1, and friction parts 12 on the outer wall surface, thereby significantly improving the fastening effect of the expansion bolt and preventing it from coming loose from the fixed frame, etc. When in use, the movable sleeve 1 is first inserted into the hole, and then the bolt shaft 2 is driven into the movable sleeve 1. The bolt shaft 2 presses against the movable sleeve 1 with its teeth 22, pushing the movable sleeve 1 outward and fixing the movable sleeve 1 in the hole, and at the same time, the interaction between the teeth 22 of the bolt shaft 2 and the internal teeth 11 of the movable sleeve 1 fixes the bolt shaft 2 to the fixed frame, etc., and prevents the bolt shaft 2 from loosening.

[0019] As shown in Figures 4 to 7, the teeth 22 of the bolt shaft 2 and the internal teeth 11 of the movable sleeve 1 are both annular. The teeth 22 of the bolt shaft 2 gradually increase in diameter from the open end toward the male threaded portion 21, while the internal teeth 11 of the movable sleeve 1 gradually decrease in diameter from the end into which the bolt shaft 2 is inserted toward the other end.

[0020] The ring-shaped tooth structure is easy to process, and the inclined tooth part is easy to insert into the movable sleeve 1 of the bolt shaft 2. After the fixation is completed, it can also prevent the loosening of the bolt shaft 2 and come out of the movable sleeve 1, greatly improving the convenience and stability of the bolt assembly.

[0021] As shown in FIG. 7, a convex knocking portion 23 is provided on one end surface of the bolt shaft 2, and the diameter of the knocking portion 23 is smaller than the diameter of the male thread portion 21 of the bolt shaft 2. Specifically, this knocking portion 23 is in the shape of a truncated cone that gradually reduces in diameter along the axial direction of the bolt shaft 2.

[0022] When the bolt shaft 2 is installed, it needs to be knocked and inserted into the movable sleeve 1. Since the end surface of the bolt shaft 2 may be deformed when knocked, in this embodiment, this reduced-diameter knocking portion 23 is provided on the end surface to prevent the deformation of the end surface of the bolt shaft 2.

[0023] Furthermore, as shown in FIG. 4, the movable sleeve 1 is made by bending a metal piece into a ring shape, and a plurality of protrusions are evenly provided on the outer wall of the movable sleeve 1 as the friction portion 12. For the purpose of enhancing the anchor effect, various shapes and position distributions of these convex portions can be adopted and are not limited to this embodiment.

[0024] The movable sleeve 1 made by bending a metal piece into a ring shape is easy to expand radially outward when pushed by the bolt shaft 2 and is functional. The movable sleeve 1 can be formed of iron, steel, or other materials.

[0025] During use, the movable sleeve 1 expands, and the protrusions of the friction portion 12 are pushed into the wall, forming a plurality of fixing points, greatly enhancing the fixing effect of the expansion bolt, avoiding the problem of bolt loosening due to a single fixing point, and ensuring the stability of the product.

[0026] The thickness of the movable sleeve 1 gradually increases from the end into which the bolt shaft 2 is inserted to the other end. This structure allows the movable sleeve 1 to gradually expand as it is pressed against the outer wall during the process of the bolt shaft 2 being driven into it. This structure enhances the fixing effect and prevents loosening. Other structures may be used as long as they can expand the movable sleeve 1, and the present invention is not limited to this.

[0027] The teeth 22 of the bolt shaft 2 gradually widen from the open end towards the male threaded portion 21. During the process of driving the bolt shaft 2 into the movable sleeve 1, the movable sleeve 1 is pushed by the bolt shaft 2 and gradually expands, and is fixed by being pressed against the outer wall. This structure provides a strong fixing effect and prevents the bolt shaft 2 from coming loose.

[0028] A spring washer 4 and a spacer 5 are provided in this order between the movable sleeve 1 and the nut 3, and the nut 3 is a self-locking nut.

[0029] The above structure increases the tightness of the connection between the nut 3 and the bolt shaft 2, preventing the nut 3 from loosening and improving the fixing effect. The anti-loosening nut 3 may also be a mechanical, frictional, or structural anti-loosening device, and is not limited to this embodiment.

[0030] It can also be used as a fastening unit that performs fixing and fastening work using the expansion bolt and related mating parts as described above.

[0031] When using this expansion bolt, insert the movable sleeve 1 corresponding to the drilled hole, insert the bolt shaft 2, and strike the tip of the bolt shaft 2 with a heavy object such as a hammer so that the outer width of the movable sleeve 1 fits smaller into the bolt shaft 2. The bolt shaft 2 is inserted into the movable sleeve 1 by striking it. Align the teeth of the movable sleeve 1 and the bolt shaft 2 to ensure that the bolt shaft 2 and the movable sleeve 1 are tightly fitted together. At the same time, open the movable sleeve 1 while striking it, and press the movable sleeve 1 against the wall. Because there is a friction part 12 with rough protrusions on the outside of the movable sleeve 1, the friction force with the wall is increased. As the protrusions fit into the wall and tighten further, multiple fixing points are formed, and loosening due to a single fixing point of conventional expansion bolts is avoided. This invention not only solves the problem of expansion bolts being prone to loosening, but is also suitable for locations with relatively softer foundations than conventional expansion bolts. After attaching the movable sleeve 1 and the bolt shaft 2, assemble and fix the workpiece, and then attach the elastic sheet 6, the spacer 5 for loosening prevention, and the anti-loosening nut 3 in that order.

[0032] The technical features of the above embodiments can be combined in any way, and for the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as these combinations of technical features are not contradictory, they should be considered to fall within the scope described herein.

[0033] The embodiments described above only illustrate some of the embodiments of the present invention, and while a more specific and detailed description is available, this does not limit the technical scope of the invention. Furthermore, those skilled in the art can make several modifications, substitutions, and improvements without departing from the spirit of the present invention, and these should be included within the technical scope of the invention. [Explanation of Symbols]

[0034] 1. Movable sleeve 11 Internal teeth 12 Friction part 2 Bolt shaft 21 Male threaded section 22 Teeth 23. Percussion section 3 nuts 4. Spring washer 5 Spacers 6 Elastic Sheet

Claims

1. A movable sleeve having an internal tooth portion on its inner wall surface and a friction portion on its outer wall surface, and which is expandable radially outward, A bolt shaft having teeth that engage with the internal teeth of the movable sleeve, and a male threaded portion provided continuously with the teeth, An expansion bolt characterized by comprising a nut that screws onto the male threaded portion of the bolt shaft.

2. The expansion bolt according to claim 1, characterized in that the teeth of the bolt shaft and the teeth of the internal teeth of the movable sleeve are annular in shape.

3. The expanding bolt according to claim 1, characterized in that the teeth of the bolt shaft gradually increase in diameter from the open end toward the male threaded portion, and the internal teeth of the movable sleeve gradually decrease in diameter from the end into which the bolt shaft is inserted toward the other end.

4. The expansion bolt according to claim 1, characterized in that a striking portion is provided on the open end face of the male threaded portion of the bolt shaft, and the diameter of the striking portion is smaller than the diameter of the male threaded portion.

5. The expansion bolt according to claim 1, characterized in that the movable sleeve is made by bending a metal piece into a ring shape.

6. The expansion bolt according to claim 1, characterized in that the friction portion of the movable sleeve consists of a plurality of protrusions.

7. The expansion bolt according to any one of claims 1 to 6, characterized in that the thickness of the movable sleeve gradually increases from the end into which the bolt shaft is inserted to the other end.

8. The expansion bolt according to any one of claims 1 to 6, characterized in that the teeth of the bolt shaft gradually become thicker from the open end toward the male threaded portion.

9. The expansion bolt according to any one of claims 1 to 6, characterized in that teeth are formed on the bottom surface of the nut, and between the nut and the movable sleeve, there is a spacer having teeth on one side that engage with the teeth on the bottom surface of the nut, and a spring washer that abuts against the opposite side of the one side of the spacer.

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