Manufacturing process and installation for the thin bolt with spanner pilot hole and hexangular socket head

Abstract

The present invention is the machining method and equipment for thin screw with spanner guiding hole and hexagonal socket head. Four pairs of punch die and forging die of different shapes and including male die and female die are used, and one bar is made to enter the female dies for being punched and forged by the male dies successively. During the machining process, the first blank with spindly end, the second blank with cylindrical end and central conic hole, the third blank with hexagonal hole, cylindrical hole and conic hole successively inwards from the end and the fourth blank with hexagonal hole and guide hole are formed successively in the same forming machine to complete the job before rolling thread. Without need of turning, the machining process is convenient and saving.

Description

【Technical field】 [0001] The invention relates to a screw manufacturing method and a manufacturing device thereof, in particular to a manufacturing method and a device of a thin hexagonal socket head screw with a wrench guide hole. 【Background technique】 [0002] Such as figure 1 and figure 2 As shown, the conventional screw forming machine 1 has a machine platform 11, a first female mold 12 installed on the machine platform 11, a second female mold 13 and a third female mold 14, and the corresponding positions of the female molds 12-14. The first male mold 15, the second male mold 16, and the third male mold 17, which are forward and can be punched back and forth relative to the female molds 12-14, are located behind the female molds 12-14 and wear correspondingly. The jacking out device 18 extending in the female molds 12-14, and three sets of clamping devices (not shown) that reciprocate synchronously in front of the female molds 12. During manufacture, the wire 19 is...

AI Technical Summary

Problems solved by technology

[0005] When the guide hole 211 of the above-mentioned blank is drilled, the processing personnel must use the above-mentioned large number of forged parts to cooperate with the drilling machine to drill them into the screw 2 with the guide hole 211 in a semi-manual way. Waste of manpower and man-hours

In addition, in the drilling process of the above-mentioned screw 2, it is easy to cause the guide hole to be formed due to factors such as the drill bit of the drilling machine located at the tail end of the drill lip trimming angle is not correct, or the drill axis of the drill bit is not straight, or the processing personnel do not operate properly. 211 Absence of poor alignment of the center

At present, in the screw manufacturing industry, the tolerance of the guide hole 211 is very small, which is 0.06-0.09mm. Therefore, the accuracy of manufacturing the guide hole 211 must be relatively improved. However, if the center of the guide hole 211 is skewed, Or when the hole size error of the pilot hole 211 is large due to drilling processing factors, the screw 2 becomes a defective product that cannot be used. Therefore, the previous manufacturing method has the defects of high defect rate and high cost.

[0006] like Figure 4 As shown, in order to avoid the above-mentioned problems in the processing of the guide hole 211, some manufacturers have considered that if the shape of the third punch 171 is changed, a section of pointed column 172 protrudes from the rear end of the third punch 171, A multi-layer step-shaped punch can directly punch and forge the inner hexagonal hole 221 and the guide hole 211 on the third blank 25. In addition to solving the above-mentioned defects, the manufacturing process can be reduced, but the cross-section is The difference in area between the hexagonal third punch 171 and the pointed column rod 172 with a circular cross section is too large, resulting in the concentration of applied stress at the junction between them, and in actual forging, because the third punch 171 And the pointed column rod 172 is protruding into the blank, and is pushed by the deformed blank while punching the blank, and is extruded by the active force of the blank, so that the third punch 171 and the pointed column rod 172 are not deformed. The gap is filled and buried deeply and clamped in the blank, so that the transition of the multi-layer punch will be subject to greater compressive stress during this forming, so when the punching and forging is completed and the male mold 17 moves forward , the third punch 171 and the pointed column rod 172 will be pulled and broken, and cannot be produced at all, so there are still difficulties in the production of one-time punching and forging

[0007] In addition, in the above-mentioned forging process, the third male mold 17 and the third female mold 14 are relatively in contact, and the third blank 25 is located between the third punch 171 and the third die opening 141 and is sealed. In the third mold cavity, from a microscopic point of view, while punching and forging, the third blank 25 will be deformed by the impact force, and the flow of material will be limited in the third mold cavity. However, due to the third male mold 17 is not fixed on the third female mold 14, so when punching and forging, the third male mold 17 will also be relatively subjected to the reaction force of the third blank 25, and move forward slightly away from the third female mold 14, so that the third female mold 17 The third blank 25 has a margin for forward deformation, but is not completely limited in the third mold cavity, so the end of the third blank 25 faces the end edge corner 251 of the shaft, and cannot be relatively filled. At the rear edge of the front section of the third die opening 141, that is, at the corner of the third die cavity, the corner 251 of the end edge of the third blank 25 forms an arc, which is difficult to form flat surface and vertical angle

This will affect the usability of the screw in the future and reduce the use effect

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