Service HotlineIn order to achieve the above purpose, Guangdong Yueluo Hardware Industry Co., Ltd. provides the following technical solutions: an anti-drop screw structure, including a connecting bolt and a fastening screw, the connecting bolt includes a connecting screw and a connecting nut, one end of the connecting screw It is integrally connected with the connecting nut, the surface of the connecting screw is provided with an external thread, the connecting bolt is movably mounted with a matching nut, the matching nut and the connecting bolt are connected by thread, and the interior of the connecting screw is provided There is a screw hole along the axis of the connecting screw. The connecting screw is provided with a number of slots along the axis. The slot extends into the screw hole. The screw hole is provided with an internal thread, and the screw hole is movable in the screw hole. A tightening screw is installed, the tightening screw includes a tightening screw and a tightening nut, one end of the tightening screw is integrally connected with the tightening nut, and the tightening screw is connected to the tightening nut through a screw hole Bolted thread connection.
In view of the deficiencies of the prior art, Guangdong Yueluo Hardware Industry Co., Ltd. provides a relatively simple screw that can be manually disassembled. In order to achieve the above purpose, Guangdong Yueluo Hardware Industry Co., Ltd. provides the following technical scheme: a screw that can be disassembled manually, including a stud and a nut, and the axial direction of the screw is provided with a screw extending from the nut to the stud. A groove, a control column that is slidably matched with the groove is arranged in the groove, a through groove is opened on the circumferential side wall of the control column, and a circumferential side wall of the control column is provided with a parallel to the axis of the control column. A limit bar, the side wall of the groove is provided with a limit groove that cooperates with the limit bar, the control column is provided with a accommodating groove, and the accommodating groove is provided with a rotating rod that cooperates with the through groove, so The accommodating groove and the rotating rod are arranged separately. Further, a accommodating groove is opened at the corresponding groove on the nut, a baffle is hinged on the side wall of the accommodating groove, and a torsion spring is provided at the hinged joint between the baffle and the accommodating groove.
This clearance determines how much the bone fragment fixed by means of the locking screw in the corresponding locking hole can move relative to the nail and thus also relative to other bone fragments fixed by the same nail due to the rigidity of the nail. Together with the flexibility of the material and the overall device this can build up to a size that prevents or decisively delays effective healing. In order to ensure the applicability of the locking device to the surgeon, this gap, although unavoidable, is clinically undesirable in some indications (eg in the case of metaphyseal fragments). Even a screw with a full cross-section, which can have an internal thread in the locking hole, is not gapless. This internal thread only prevents possible axial movement of the screw on the locking screw.
total of 13 domestic automotive fastener companies were interviewed and investigated in this survey, and all the companies under investigation have passed the TS16949 system certification. An average car has about 1500 fasteners, and the total bolt assembly time for each car is about 2.5~3.2h. It can be seen that the variety and quality of fasteners have an important impact on the level of the main engine and the quality of the vehicle. This article analyzes the localization of high-strength threaded fasteners and the management of supply quality from the perspective of the production process of high-strength threaded fasteners. Product flow of high-strength threaded fasteners The production process of high-strength threaded fasteners is raw material transformation → cold heading forming → thread processing (thread rolling or thread rolling) → heat treatment → surface treatment → sorting and packaging, generally used above grade 10.9 Thread rolling process after heat treatment. The steel grades commonly used for high-strength bolts of automotive fastener materials are 35 steel, 45 steel, and ML35 steel for grade 8.8 bolts; 35CrMo for grade 10.9 bolts; 40Cr; 35CrMo, 42CrMo, and SCM435 for grade 12.9 bolts. The raw materials for domestic fasteners are basically in the hot-rolled state, while the steel for fasteners produced in Japan and other countries is basically in the state of direct cold heading. Users do not need pretreatment, which can reduce costs from the link. Common failure modes of fastener failure are assembly elongation, fatigue fracture, and delayed fracture. In addition to the material, the quality of cold heading forming and thread processing (thread rolling or thread rolling, tapping) threaded fasteners, forming equipment and thread processing equipment and molds (production process and equipment) are the key factors to ensure their quality. Especially in the state of large-scale and multi-variety supply, automotive fasteners that require high machining accuracy, how to ensure product consistency and defect prevention is one of the problems faced by fastener production. For the cold heading equipment and thread processing equipment of the investigated companies, domestic equipment accounts for about 40%, Taiwan equipment accounts for 50%, and imported (Europe, America, Japan) equipment accounts for about 10%; Partial folding, thread streamline upsetting, tooth wrinkles and cracks, etc. Domestic fastener factories are limited by capital or other reasons, and most of them use domestic equipment and Taiwan equipment to produce fasteners for automobiles. To ensure the dimensional tolerance and geometric tolerance of large-scale production of high-end fastener products, online monitoring should be increased. Means and mold making level. Eliminate unqualified products in production, so as to ensure the assembly quality of OEMs and OEMs. [1] About 80% of the surveyed fastener enterprises have heat treatment equipment, and most of them use Taiwan heat treatment process lines; the process line equipment is a continuous mesh belt furnace with atmosphere protection, and the atmosphere, temperature and process parameters are controlled by a computer. The high-strength fastener industry is a relatively competitive industry. If we want to have a thorough and objective analysis of the technology and market of the high-strength fastener industry, we need to start from the following aspects: domestic high-strength fasteners Industry and Enterprise Competition Pattern High-strength Fastener Industry Industrial Policy High-strength Fastener Product Technical Standards and Regulations my country's High-strength Fastener Product Technology Competition Pattern Dynamics Regarding these six aspects, many domestic research institutions have conducted in-depth research and research, and many institutions have long been engaged in research and research in this industry.
Pre-embedded channels are often used in rail transit. There are usually U-shaped channels and C-shaped channels. There are also various widths of openings on one side. The T-bolts used in their connection are generally non-standard parts, which need to be The actual project needs to be customized, mostly for the overall stamping production, the mold cycle is long, the number of mold openings is large, and the production cost is high. Moreover, when assembling and connecting, it is sometimes found that the size of the originally designed t-bolts does not match, and it is necessary to replace t-bolts of different sizes, then it is necessary to redesign and produce non-standard t-bolts, which slows down the entire equipment. processing cycle. Customized T-bolts are often not wide enough in size range, and only a few can be selected for specific assembly and connection, which is difficult to meet the diverse requirements of the production site for bolts.
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