High-strength anti-loosening screw for wheelchair and fitness equipment

Abstract

A high-strength anti-loosening screw for a wheelchair and fitness equipment comprises a nut and a screw rod which are sequentially arranged, the screw rod comprises a first external thread and a second external thread which are continuously arranged, the first external thread is a round thread, the second external thread is a metro common thread, and the first external thread and the second external thread are consistent in tooth height and thread pitch; wherein the thread angle of the first external thread is 30 degrees, the thread angle of the second external thread is 60 degrees, a chamfer is formed from the initial first thread to the initial second thread of the first external thread, and the crest diameter of the first external thread is smaller than that of the other chamfer-free round threads on the rear side; the screw cap and the screw rod are made of SCM435 alloy steel subjected to heat treatment, and chromium-free coatings are arranged on the screw cap and the screw rod. According to the high-strength locking screw for the wheelchairs and the fitness equipment, the round threads are arranged on the front sides of the meter-made common threads, so that the locking torque during nut installation is increased, and the installation firmness is improved; and the SCM435 alloy steel subjected to heat treatment is matched with the chromium-free coating, so that the strength and durability of the screw are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of anti-loosening screws, in particular to a high-strength anti-loosening screw for wheelchairs and fitness equipment. Background Art

[0002] Screws are a representative product among fasteners and are widely used in industry and daily life. The basic principle is to use the physical and mathematical principles of the circular rotation of the inclined surface of an object and the friction force to gradually fasten objects, usually used in conjunction with the corresponding internal thread.

[0003] At present, a large number of fasteners, especially high-strength anti-loosening screws, are needed in the manufacture of wheelchairs and fitness equipment. As the market's requirements for the structural installation space, safety of use, and aesthetic durability of these equipment and facilities continue to increase, the performance of traditional anti-loosening screws can no longer meet market demand.

[0004] Therefore, in view of the shortcomings of the prior art, it is necessary to design a high-strength anti-loosening screw for wheelchairs and fitness equipment to solve the above problems.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solution of the utility model and facilitating the understanding of those skilled in the art. It cannot be considered that the above contents are well known to those skilled in the art simply because they are explained in the background technology of the utility model. Utility Model Content

[0006] In order to overcome the above-mentioned deficiencies in the prior art, the utility model aims to disclose a high-strength anti-loosening screw for wheelchairs and fitness equipment, which is used to improve the installation reliability and durability of the anti-loosening screw.

[0007] The utility model discloses a high-strength anti-loosening screw for wheelchairs and fitness equipment, comprising a nut and a screw arranged in sequence, the screw comprising a first external thread and a second external thread arranged continuously, the first external thread being a round thread, the second external thread being a metric common thread, the first external thread and the second external thread having the same tooth height and pitch. The round thread has a thicker tooth top width, and when matched with a nylon insert nut, a greater extrusion force is generated; the anti-loosening torque is increased, and a better anti-loosening effect is achieved. At the same time, the easy-to-process metric common thread is matched with the anti-loosening while reducing the processing difficulty and cost.

[0008] Preferred technical solution: the tooth angle of the first external thread is 30°, and the tooth angle of the second external thread is 60°. When assembling the nut, the volume of the round thread squeezed into the nylon ring is larger than the volume of the mechanical tooth, and the corresponding anti-loosening torque is increased, so as to achieve a better anti-loosening effect.

[0009] Preferred technical solution: The first external thread is provided with at least three teeth to ensure the connection strength between the first external thread and the nut.

[0010] Optimal technical solution: The first external thread has a chamfer from the initial first tooth to the second tooth, and its crest diameter is smaller than the crest diameter of the remaining non-chamfered round threads on the rear side, which facilitates the installation and introduction of the nut.

[0011] The preferred technical solution is that a non-threaded rod is provided on one side of the screw rod close to the nut for assembly.

[0012] Preferred technical solution: The material of the nut and the screw is heat-treated SCM435 alloy steel, which can meet the technical requirements of metric 10.9 and American Gr.8.

[0013] Optimal technical solution: Both the nut and the screw are provided with a chrome-free coating, which can ensure both high corrosion resistance of the product and stable appearance of the product.

[0014] Preferred technical solution: The chromium-free coating is a chromium-free zinc-aluminum-rich coating, and the processing technology does not involve pickling, which effectively avoids the risk of brittle fracture of screws caused by hydrogen embrittlement.

[0015] Preferred technical solution: The thickness of the chromium-free coating is greater than 10um to avoid failure due to wear and tear and ensure its service life.

[0016] The preferred technical solution is that the screw is equipped with a nylon insert nut, which has an anti-loosening function, and a matching or double-threaded screw is used to achieve a better anti-loosening effect.

[0017] Due to the application of the above technical solution, the high-strength anti-loosening screws for wheelchairs and fitness equipment of the utility model have the following beneficial effects:

[0018] (1) By setting a round thread in front of the metric ordinary thread, the anti-loosening torque during nut installation is increased, thereby improving the firmness of the installation;

[0019] (2) Heat-treated SCM435 alloy steel with chromium-free coating is used to increase the strength and durability of the screws. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a high-strength anti-loosening screw for a wheelchair and fitness equipment of the utility model;

[0021] Figure 2 It is a structural schematic diagram of the screw in the utility model.

[0022] In the above drawings, 1, nut; 2, screw rod; 21, first external thread; 22, second external thread; 23, bare rod. DETAILED DESCRIPTION

[0023] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0024] In the description of the present utility model, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, terms such as "horizontal", "vertical", and "overhanging" do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Example:

[0027] like Figure 1 As shown, a high-strength anti-loosening screw for wheelchairs and fitness equipment disclosed in the utility model includes a nut 1 and a screw rod 2 arranged in sequence. The main components of the utility model are described in detail below:

[0028] like Figure 1 and Figure 2As shown, the screw 2 includes a first external thread 21 and a second external thread 22 which are arranged continuously. The first external thread 21 is a round thread with a tooth angle of 30°, and the second external thread 22 is a metric common thread with a tooth angle of 60°. The tooth height and pitch of the first external thread 21 and the second external thread 22 are consistent. The first external thread 21 has a chamfer from the first tooth to the second tooth, and its crest diameter is smaller than the crest diameter of the remaining non-chamfered round threads on the rear side. The first external thread 21 has two teeth without chamfers. It should be noted that the above structure is only exemplary and not restrictive. In this embodiment, the first external thread 21 has two teeth without chamfers; but in other embodiments, the first external thread 21 can have three or more teeth without chamfers.

[0029] like Figure 1 and Figure 2 As shown, a non-threaded polished rod 23 is provided on one side of the screw rod 2 close to the nut 1. It should be noted that in this embodiment, a non-threaded polished rod 23 is provided; however, in other embodiments, the polished rod 23 may be partially provided as a full-threaded structure when there is no matching requirement.

[0030] like Figure 1 and Figure 2 As shown, the material of the nut 1 and the screw 2 is heat-treated SCM435 alloy steel, and the nut 1 and the screw 2 are both provided with a chromium-free coating, which is a chromium-free zinc-rich aluminum coating; the thickness of the chromium-free coating is greater than 10um.

[0031] like Figure 1 and Figure 2 As shown, the screw rod 2 is provided with a nylon insert nut, which has an anti-loosening function, and a matching or double-threaded screw rod is used to achieve a better anti-loosening effect.

[0032] refer to Figure 1 and Figure 2 As shown, the principle and use method of the high-strength anti-loosening screws for wheelchairs and fitness equipment of the utility model are as follows:

[0033] Anti-loosening structure design: Screw 2 is composed of continuously set round threads and metric ordinary threads. The round threads have a thicker crest width, which will produce a greater extrusion force when combined with the nylon insert nut; the anti-loosening torque is increased to achieve a better anti-loosening effect.

[0034] High-strength and high-corrosion-resistant design: The screw material is heat-treated SCM435 alloy steel, and the surface is treated to add a chromium-free zinc-rich aluminum coating. The process does not involve pickling, which increases the strength and corrosion resistance of the screw while avoiding the risk of brittle fracture caused by hydrogen embrittlement. At the same time, to ensure the durability of the chromium-free coating, its thickness is greater than 10um. It should be noted here that the thread parameters before coating need to be pre-designed to meet the specific accuracy requirements of the thread.

[0035] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A high-strength anti-loosening screw for a wheelchair or fitness equipment, comprising a nut (1) and a screw (2) arranged in sequence, characterized in that: The screw rod (2) comprises a first external thread (21) and a second external thread (22) which are arranged continuously, the first external thread (21) being a round thread, the second external thread (22) being a metric common thread, and the first external thread (21) and the second external thread (22) having the same thread height and pitch.

2. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 1, characterized in that: The tooth profile angle of the first external thread (21) is 30°, and the tooth profile angle of the second external thread (22) is 60°.

3. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 1, characterized in that: The first external thread (21) is provided with at least three threads.

4. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 3, characterized in that: The first external thread (21) has a chamfer from the initial first thread to the second thread, and its crest diameter is smaller than the crest diameter of the remaining non-chamfered circular threads at the rear side.

5. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 1, characterized in that: A threadless bare rod (23) is provided on one side of the screw rod (2) close to the nut (1).

6. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 1, characterized in that: The nut (1) and the screw (2) are made of heat-treated SCM435 alloy steel.

7. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 6, characterized in that: The nut (1) and the screw (2) are both provided with a chrome-free coating.

8. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 7, characterized in that: The chromium-free coating is a chromium-free zinc-aluminum-rich coating.

9. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 8, characterized in that: The thickness of the chromium-free coating is greater than 10 um.

10. The high-strength anti-loosening screw for wheelchairs and fitness equipment according to claim 1, characterized in that: The screw rod (2) is provided with a nylon insert nut.

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