The lifting ring screw should be made of 20 or 25 steel (GB699). The lifting ring screw must be forged as a whole. The forgings should be normalized and the oxide scale should be removed. The grain size of the finished product should not be lower than grade 5 (YB27-77). There must be over-burning, crack defects.
3. Friction coefficient The friction angle is an important factor affecting the torque, and the existence of friction is the basis for the normal operation of the lock nut. When the lock nut is working, the contact surface has pressure and friction under the action of the elastic restoring force of the thread piece. During the repeated use, the rough position and edges and corners of the contact surface are ground and smoothed under the action of cyclic friction. The coefficient of friction becomes smaller, which in turn reduces the maximum unscrewing torque of the nut.
It is suitable for plates of various thicknesses, with a minimum thickness of 0.8mm. When using, the tail number Z corresponding to size A must be determined according to the thickness of the plate and the specification of the nut. The user selects samples and orders according to the tail number in the table according to the thickness of the plate; Accurate control, processing according to the tolerance size of 0-+0.075mm, is punching, and the nut should generally be installed from the broken surface of the plate. The installation process is generally achieved through press riveting operations, and must not be impacted and knocked in.
In steelmaking plants, the wheels of metallurgical casting crane trolleys used for hanging liquid metal are connected with cardan shafts through flanges. Usually, a keyway is set in the radial direction of the connecting flange, and the keyway is a through groove. The B-type flat key is set in the keyway to transmit torque. During the frequent forward and reverse motion of the wheel, the flange connection bolts are easily loosened. Since the keyway is a through groove, the B-type flat key is easily caused when the flange connection bolts are loosened. It falls off from the keyway of the connecting flange and cannot transmit the torque, which seriously affects the working efficiency of the locomotive. In addition, because the B-type flat key falls off and cannot transmit the torque, the locomotive can only rely on the connecting bolt to transmit the torque when it continues to work. Poor, it is easy to damage and scrap the connecting bolts, and then damage the connecting flanges, requiring frequent replacement and maintenance, high cost, and difficult maintenance.
The fixing screw proposed by Guangdong Yueluo Hardware Industry Co., Ltd. has a screw body 1, and the axial surface of the screw body 1 is formed with extending screw teeth 6, and the axial surface is a column along the central axis direction of the cylinder of the screw body 1. The body surface has a hemispherical screw tail 7 at the bottom, and a screw head 2 at the top. The upper surface of the screw head 2 is provided with a slot (not shown). The screw body 1 is composed of the upper tapered rod 4 and the lower cylindrical screw 5. The tapered rod 4 is an inverted cone, the diameter of its circular upper surface and the diameter of the screw mounting hole 10. equal. The fixing screw also has a washer 3, the washer 3 is arranged between the screw head 2 and the screw body 1, the lower surface of the cylindrical washer 3 has a number of teeth 8, the teeth 8 are along the The upper surface of the inverted cone of the tapered rod 4 and the edge of the washer 3 are connected to form a straight convex strip 15 extending outward; the convex strip 15 can also be designed in an arc shape. The fixing screws for installation proposed by Guangdong Yueluo Hardware Industry Co., Ltd. can be made of metal materials in one piece. As shown in Figure 3, it is a schematic diagram of the installation of Guangdong Yueluo Hardware Industry Co., Ltd. for PCB board fixing. When installing, first pass the screw body 1 of the fixing screw through the mounting hole 10 and the copper column 11 provided on the PCB board 9, so that the tail 7 of the screw reaches the mounting hole 13 on the casing 12, and then use the tightening tool 14 to insert the screw At the notch on the top of the head, forcefully press the inverted cone design taper rod 4 of the screw body 1 into the mounting hole 10, so that the tail 7 passes through the mounting hole 13. Due to the outer diameter D at the bottom of the taper rod and the screw mounting hole The aperture size of 10 is equal, and the fixing screws are pressed and fixed, so that the PCB board 9 can be automatically corrected in the process of fixing its front, back, left and right deflections, and the accuracy of the installation position of the PCB board 9 can be ensured. As shown in Figure 4, after the fixing screw is screwed into the casing, the washer 3 is fully contacted and pressed on the PCB board 9, and the PCB board 9, the copper column 11 and the casing 12 are firmly connected together without sliding. . The teeth 8 on the washer 3 are in full contact with the surface of the PCB board 9, so that a ground wire path is set up between the PCB board 9 and the casing 13 by the metal fixing screw 1, thereby ensuring that the PCB board 9 is fully grounded , the design of the teeth 18 on the washer 3 also has a non-slip function. The fixing screws for installation designed by Guangdong Yueluo Hardware Industry Co., Ltd. make use of the cooperation, friction and electrical conductivity in the mechanical connection, which fully guarantees the firm installation of the PCB board and the chassis and the good grounding of the PCB board. Moreover, the ellipsoid tail of the fixing screw The surface is relatively smooth, even if the mounting holes are exposed, it will not cause scratches on the hands and desktop. The above is only the embodiment of Guangdong Yueluo Hardware Industry Co., Ltd., and does not limit the scope of Guangdong Yueluo Hardware Industry Co., Ltd., any equivalent structure made by using the contents of the description and drawings of Guangdong Yueluo Hardware Industry Co., Ltd. or etc. Effective process transformation, or direct or indirect application in other related technical fields, are also included in the protection scope of Guangdong Yueluo Hardware Industry Co., Ltd.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: GBT897 stud bolts, raw copper posts, mechanical tools and inspection tools for handle trimming, 8.8-grade fine-toothed high-strength hexagonal nuts and other products, we can Provide you with the right fastener solution for you.
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