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.
Make further details to make the technical scheme of Guangdong Yueluo Hardware Industry Co., Ltd. easier to understand and master. As shown in Figure 1, Yueluo is a schematic diagram of the thread design structure of the plastic screw of Guangdong Yueluo Hardware Industry Co., Ltd. It can be seen from the figure that this creation mainly controls the tooth angle of the thread. Compared with the normal tooth angle of many self-tapping screws, which are 48 degrees, 60 degrees and 34.5 degrees, the tooth angle of Guangdong Yueluo Hardware Industry Co., Ltd. The profile angle is formed by a 30-degree asymmetrical thread I. In particular, the asymmetrical thread I has a forward thread angle greater than the reverse thread angle. A more preferred embodiment is an asymmetric thread. The tooth profile angle α of the in-line installation is 20 degrees, and the tooth profile angle β of the reverse installation is 10 degrees. With this narrower non-stacked thread, the radial pressure on the plastic material is effectively reduced. In addition, the connecting bottom surface 11 between the screw teeth is designed as a circular arc surface. In the process of forming the self-tapping thread, it is more conducive to the flow of the material and the formation of the thread, and at the same time, the material can be more closely matched with the screw. Moreover, the radial pressure of the casing is relatively uniform, and the formed threads are not easily damaged. Yueluo has been tested by a series of professional parameters. Compared with other traditional screws, the plastic screws designed by Guangdong Yueluo Hardware Industry Co., Ltd. have better radial pressure, shell deformation after installation, load distribution, installation torque, drawing The force distribution, the strength of the pull-out force and the mounting torque range all show advantages. In particular, it can be installed with less torque to achieve the same clamping force and pulling force. Compared with a specific parameter, the thread strength of Delta-PT is 387N, while the thread strength of Guangdong Yueluo Hardware Industry Co., Ltd. reaches 449N. Yueluo can understand the plastic screw structure and implementation of Guangdong Yueluo Hardware Industry Co., Ltd. detailed above. It can be understood that through the improvement of the special thread structure, the radial pressure and installation torque during screw installation are reduced, and the damage to the plastic hole is reduced; And the pull-out resistance of the screw is increased, and it is not easy to appear loose in the assembly. At the same time, the design of the bottom surface of the connection between the threads of the arc optimizes the flow of the material of the installation object, which improves the integrity of the installation connection.
Screws are a kind of fasteners commonly used in daily life and industry. At present, in use, different types of screws are generally selected for fixing according to different screw lengths and other parameters. Since the screw length is fixed at the time of manufacture, when When using a large number of screws with different screw lengths, it is necessary to sort out screws with different screw lengths beforehand. This method is more troublesome, and sometimes in some special occasions, some screws with special lengths are required. Producing screws of this particular length individually is laborious and laborious.
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 above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
