Service HotlineThe flat gasket product is an accessory on the high-speed rail backing plate. The product requires two planes to be flat, the shape and size of the inner hole are accurate, and there are no casting defects (such as air holes, shrinkage holes, sand holes, etc.), and the casting material requires GB/T450-10 . Due to the light weight and large demand of flat gaskets, if they are produced by ordinary sand casting process, the castings are prone to deformation, sand holes, air holes and other casting defects, and the molding area is large, the production efficiency is low, and the production tasks are difficult to complete.
There are two typical pin shearing fixture tooling, among which the traditional fixture shown in Fig. 1 is more complicated and consists of fixture, spacer, washer and shearing block guide post, hardened bushing, shearing block and so on. The cylindrical pin is installed in the hardened bushing, and the axial load is applied through the shear block to complete the shear test. The fixture is complicated in manufacture and has many consumables, because the size of the hardened bushing is similar to that of the cylindrical pin. , and to keep the notch of the cylindrical pin upward, it is difficult to install before the test, and the broken cylindrical pin after the test remains in the hardened bushing and is difficult to remove.
The material of the rubber gasket is NBR nitrile rubber, which is the most commonly used and has the highest cost performance. The use of FFKM perfluoroelastomer gaskets is generally in the more advanced fields, such as the field of aerospace rockets. Because its price is quite expensive, but its performance is excellent and can exceed many metal materials. For specific material information, please refer to the following: Material Name Chemical Description English Abbreviation English Alias Nitrile Butadiene Rubber Acrylonitrile-Butadiene Rubber Ethylene-Propylene-Diene Rubber EPDM EP,EPT,EPR Neoprene Neoprene CR Neoprene Silicone Silicone Rubber WMQ PVMQ Fluorosilicone Fluorosilicone Rubber FVMQ FVMQ Acrylate Acrylate Rubber ACM ACM Ethylene Acrylate Vinyl -Acrylic Rubber AEM Vamac Styrene-Butadiene Styrene-Butadiene Rubber SBR SBR Polyurethane Polyester/Polyether Urethane AU/Eu AU/EU Natural Rubber Natural Rubber NR NR
At present, when using the existing screwdriver to install the screw, it is necessary to fix the screw with the left hand and turn the screwdriver with the right hand. However, in some places where the installation space is small and the installation is difficult, there are many areas that cannot be accessed by hands, and the installation is very difficult. For example, on an airplane, when installing with a common screwdriver, it is very difficult to install the screws and the installation efficiency is low because the screws cannot be positioned; in addition, when installing screws on the aircraft wing or fuselage, the combination between the screwdriver and the screw is easy to slip, The blade of the screwdriver slipped out and could easily bruise the hand and damage the aluminum skin of the aircraft.
The most important link in the development and design of fasteners is quality control. There are several major points from the feed to the finished product shipment, and these major points have different inspection methods. First of all, the feed is related to appearance, size, elements, performance, detection of harmful substances, etc.; the process is more about appearance, size, percussion test, forging flow line; heat treatment is more about appearance, hardness, torque, tension , metallography, etc.; the surface treatment is more about some hydrogen embrittlement tests, coatings, salt spray, etc., including a detection of harmful substances in shipments. In size and appearance inspection, the common ones are quadratic element, contour measuring instrument, three-coordinate measuring instrument, image sorting machine (this is a full selection machine); in mechanical and chemical inspection, there are mainly hardness machines (Rockwell and Vickers). ), tensile machine, metallographic microscope; in material testing, there is a spectrum analyzer and a salt spray testing machine.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: screw screw link nut, 10.9 grade nut, GB848A grade small flat washer, large cap nail countersunk head rivet and other products, we can provide you Provide the right fastener solution for you.
