What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Guangdong Yueluo Hardware Industry Co., Ltd. provides a screw positioning pin, which is composed of a main body part and an insert part. The main body part is a circular boss structure, and the bottom of the circular boss structure is provided with a rectangular groove. The inserting part is fixed on the middle part of the upper surface of the main body part, the lower part of the inserting part and the contact section of the main body part are in a circular truncated structure, the upper part of the inserting part is a cylindrical structure, and the outer surface of the cylindrical structure is provided with threads; the screw positioning pin , The structure is simple and the design is ingenious. The special structural design of the main part and the insert part can be positioned between the punch and the die in the first processing process, effectively reducing the gap formed during the processing between the punch and the die. Firmly fixed, suitable for the needs of large-scale industrial production.
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 12 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.
(+): Cross slot (-): Slotted slot (T): Chrysanthemum slot (H): Hexagon socket (PZ): Bevel slot (+-): +- slot (Y): Y-shaped slot (H) : H-groove (L): Back-stop tooth (WIS): Single-moving spring washer (WIF): Single-moving flat washer (WIT): Single-moving external tooth washer (W2SF): Double-moving flat washer (W=6mm ): Washer outer diameter equal to 6mm (SUS): Stainless steel (Cu): Brass (Br): Red copper (8.8): Grade 8.8 screw (10.9): Grade 10.9 screw (12.9): Grade 12.9 screw (R): Other Notes
Lock washers feature easy installation. 1. Just place the helical tooth surfaces on the inner side of the two washers against each other and place them between the nut and the connecting material; 2. After the nut is tightened, the radially convex surface on the outer side of the lock washer and the contact surfaces at both ends are in an engaged state, and The angle of the slope angle of the helical tooth surface on the inner side of the washer is greater than the thread angle of the bolt; 3. When the bolt is elongated due to mechanical vibration, the nut will rotate and loosen accordingly. Because the frictional force of the outer radial convex surface of the lock washer is greater than the frictional force between the inner helical tooth surfaces. In this state, only the relative dislocation between the inner helical tooth surfaces is allowed to generate a certain lifting tension; 4. When the bolt shrinks, the helical tooth surface of the washer will make the nut return to its original position. So as to achieve 100% anti-loose and tightening effect; 5. Washers are suitable for relatively flat and smooth surfaces; 6. If the connecting material is non-metallic material, a metal plate can be fixed on the connecting material, so that the Use the lock washer; 7. There is no need to use a torque wrench when installing the lock washer; 8. You can choose to use an air tool when installing or removing the lock washer.
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