What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
As an important connecting part in the automobile assembly process, the screw plays a vital role in the safety performance of the automobile. The assembly of each component of the vehicle cannot be separated from the function of the screw. In the connection of the automobile assembly and its parts, the screw connection As well as simple structure, easy maintenance and disassembly, it is widely used. There may be thousands of screws on a car. The screw connection of each part has its own function and function. Once one or some screw connections fail, it will be It will lead to the loosening or even separation of the connected parts. If the car is running, it is likely to cause some parts to fail or break away. The light ones will cause the main functions of the car such as steering and braking to fail, potentially affecting driving safety. If it is not found in time, it will lead to major safety accidents and even endanger the lives of people. The failure of the car screws will cause the safety hazard of the whole vehicle, and will also cause customers to worry and complain, thus affecting the reputation of the company and endangering the life of the company. cycle.
1. Standards for fastener product dimensions: specify the content of the basic dimensions of the product; threaded products also include the basic dimensions of the thread, thread end, shoulder distance, undercut and chamfer, and the end of externally threaded parts size, etc. 2. Standards for technical conditions of fastener products. It mainly includes product tolerances, mechanical properties, surface defects, surface treatment, product testing standards and corresponding specific provisions. 3. Standards for screw product acceptance inspection, marking and packaging: specify the qualified quality level and sampling plan of random inspection items during product acceptance inspection, as well as product marking methods and packaging requirements. 4. Marking method standards for standard parts, fasteners, screws and screws: specify the content of the complete marking method and simplified marking method of the product. 5. Standards for other aspects of fasteners: such as standards for fastener terminology, standards for fastener product weight, etc.
Pins are widely used. In the connection of the rotating mechanism of two moving components, such as the crank mechanism, the turning mechanism, the connection between the hydraulic cylinder and the moving parts, the pins are used. kind. In order to ensure the normal use of the running equipment and prevent the cylindrical pin from slipping out and falling off during use, some anti-falling methods are usually used at the head of the pin, such as 1. Drill holes and insert cotter pins to prevent the pins from slipping out; 2. The external thread is tightened with a nut to prevent the pin from slipping out; 3. The slot is clamped with a circlip to prevent it from slipping out, etc. These measures make the cylindrical pin very practical in the case of infrequent disassembly and assembly, but in the actual use of the field, in order to prevent the collision of some equipment during each troubleshooting or maintenance, the pin needs to be pulled out and turned up, etc. After the failure or maintenance is completed, put down and then insert the pin to restore, this process will bring trouble to the actual operator. For example, special tools must be brought with you every time you disassemble and assemble the pin, and the split pin or the circlip is easily damaged after repeated disassembly and assembly. , In order to save trouble, the operator sometimes uses iron wire to thread or fasten it instead, and even does not remove the pin for the sake of speed and convenience, which is easy to cause damage to the equipment when dealing with faults.
When using a rivet nut, drill a hole corresponding to the outer diameter of the rivet nut on the thin wall, then place the rivet nut on the bolt of the special rivet gun, push the handle to screw in the rivet nut, and put it into the drilled hole. In the workpiece, squeeze the handle, the rivet nut expands, and the deformed skirt bulges and deforms. At this time, the workpiece is tightened. After riveting, the handle is pulled out, the bolt is released from the rivet nut, and the corresponding screw is screwed into the rivet nut threaded hole. , forming a tight riveted body.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
