What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
However, Yueluo still feels that there should be room for improvement for the screw improvement and screw that integrates stability, labor, fast and multi-function in the above two cases; for example, No. 556784 screw improvement Although the rod has the function of cutting and collecting chips, when the screw starts to screw into the object such as wood, it is hindered by the hardness of the object's tissue, so the staff still needs to exert considerable force, resulting in the lock. In the solid operation, there is still a lack of difficulty in screw-in operation; another example, new cases such as No. 289417 screw that integrates locking, stability, labor-saving, fast and multi-function, although the rod has the structural function of cutting and chip removal, it is The rod part is screwed into the middle section to the rear section of the object. Since the debris cannot be discharged, the rod part pushes the outer part of the object to the surrounding tissue of the object, so that the object expands outwards and even seriously damages the appearance of the object.
Axle card is a kind of hole-to-hole movement installed on a slotted shaft and used as a fixed component. The inner diameter of this type of retaining ring is slightly smaller than the diameter of the assembly shaft. Application No. 201621153710.9 discloses a shaft card assembly device, including a feeding mechanism, a material distribution mechanism, a material reclaiming mechanism and an assembling mechanism. The feeding mechanism is connected with the feeding mechanism. The reclaiming mechanism includes a reclaiming tool and a servo system for driving the movement of the reclaiming tool. One end of the reclaiming tool is provided with a c-shaped opening, and an incision connected with the c-shaped opening is provided. The assembling mechanism includes a carrier for fixing the parts to be loaded and a turntable, and the carrier is mounted on the turntable. In the above shaft card assembly device, after the feeding mechanism completes the feeding, the material distribution mechanism separates the shaft card to a specific position with a fixed attitude, and then the private server drives the reclaiming tool to clamp the shaft card and assemble it to the pre-fixed by the assembly mechanism. on the fitting. During the assembly process, the manual workload is small, the efficiency is high, and the labor intensity is small. At the same time, the c-shaped opening and the cutout at the end of the reclaiming tool are designed to effectively form an elastic force to clamp the clamping shaft card and absorb the assembly process. The resulting outward deformation force avoids the plastic deformation of the shaft card due to the large external force.
Referring to Figure 1, one end of the existing insert nut 1' is embedded in the injection molded part 2', and the other end is exposed to the injection molded part 2'. The insert nut 1' has opposite lower and upper end surfaces in the axial direction. The end face of one end of the insert injection molded part 2' is the lower end face. In order to reduce the resistance during hot pressing, the connection between the inner wall surface and the lower end surface of the insert nut 1 ′ is provided with an inclined surface. However, when the embedded nut 1' of this structure is hot-pressed, the hot melted glue will generate a shunt that rises along the slope, and then a convex peak is formed in the screw hole of the embedded nut 1', and the convex peak occupies the screw. The space in the hole prevents the screw 5' from being completely screwed in; at the same time, due to the shunting of the hot solder, the knurling of the inner nut 1' near the upper end face cannot be filled with the solder, which makes the inner nut 1' and the inner nut 1' and The injection part 2' is not firmly embedded. Therefore, the locking strength of the existing insert nut 1 ′ and the screw 5 ′ after being hot-pressed is relatively low.
In order to achieve this purpose, the rivet nut is cold extruded from low carbon steel, the brim is cold forged, the deformed skirt is extruded in the die, and the threaded hole is extruded at the lower end of the deformed skirt. It is characterized in that it consists of a brim, a deformed skirt and a threaded hole. There are fish teeth below the brim; the outer side of the lower end of the threaded hole has a lead angle; the cross section of the thread on the inner wall of the threaded hole is an isosceles trapezoid, and the upper bottom of the trapezoid is a concave arc. Thus, the riveted object is tightly connected with the rivet nut.
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