Electric wrench is mainly used for fastening high-strength bolts. Its purpose is to destroy the plum head of the high-strength torsional shear bolt. In order to understand the electric torque shear wrench, we must first understand the torque shear type high strength bolt.

　　高強螺栓按施工工藝分為:扭剪型高強螺栓和大六角高強螺栓。高強度扭剪螺栓一端為花鍵端，螺栓螺母一般為圓形(不需要用扳手固定)。

　　According to the construction technology, high-strength bolts are divided into: torsional shear type high-strength bolts and large hexagon high-strength bolts. One end of the high-strength torsional shear bolt is spline end, and the bolt and nut are generally round (no spanner is needed to fix them).

　　扭剪式高強度螺栓(TCB)的加捻過程:(理解“緊固軸力”)

　　Twisting process of torsional shear high strength bolt (TCB): (understand "tightening axial force")

　　削弱斷面的剪切過程

　　Shear process of weakened section

　　同時將扭矩施加于被組裝材料的內部拉應力，使其達到設計值(“拉緊軸力”)，材料相應的抗剪強度剛好使桿頭截面弱化和扭轉。

　　At the same time, the torque is applied to the internal tensile stress of the assembled material to make it reach the design value ("tension shaft force"), and the corresponding shear strength of the material just makes the cross section of the rod head weaken and twist.

　　分析表明，即使是扭轉剪切螺栓也不是直接反饋螺桿內的預緊力值，而是由抗剪強度代替。測試項仍然不是直接項，并且存在替換錯誤。

　　The analysis shows that even the torsional shear bolt does not directly feedback the preload value in the screw, but is replaced by the shear strength. The test item is still not a direct item and there are replacement errors.

　　因此，為了保證扭剪螺栓的施工質量，有必要對螺栓切割時的“緊固軸力”進行測量。該值應符合預緊力的設計值。

　　Therefore, in order to ensure the construction quality of the torsional shear bolt, it is necessary to measure the "fastening axial force" when the bolt is cut. This value shall be in accordance with the design value of preload.

　　根據(jù)gb jgj-82 6.1.1的規(guī)定，在高強度螺栓連接副中，扭轉-剪切高強度螺栓應具有一個墊片和一個母片。在接受扭剪式TCB時，注意桿頭擰合合格。

　　According to 6.1.1 of GB jgj-826.1, the torsional shear high strength bolt should have a gasket and a mother plate. When accepting the torsional shear TCB, pay attention to the qualified screw in of the rod head.

　　扭剪作為大型六角升級版，其有點貴，施工、檢驗相對簡單，優(yōu)點明顯。但國產產品受國標產品標準型號限制(僅10.9級，尺寸24M)。理解其核心原理的關鍵是掌握“扭矩系數(shù)”和“緊固軸力”兩個概念。

　　As a large-scale hexagon upgraded version, torsion shear is a little expensive, relatively simple in construction and inspection, with obvious advantages. However, the domestic products are limited by the national standard product model (only 10.9 grade, the maximum size is 24m). The key to understand its core principle is to master the concepts of "torque coefficient" and "tightening shaft force".

　　扭剪式螺栓采用電扭剪式扳手結構，其根部采用前后扭桿直接通過“桿頭”夾緊螺釘本身，因此在扭轉時不會出現(xiàn)共轉現(xiàn)象。本產品的設計思路是:當螺桿達到預緊值時，材料能承受相應的剪切力，設計并弱化梅花頭根部截面，達到切割的目的。

　　The torsion shear bolt adopts the structure of electric torsion shear wrench, and its root adopts the front and rear torsion bars to directly pass through the "rod head" to clamp the screw itself, so there is no co rotation phenomenon during torsion. The design idea of the product is: when the screw reaches the pre tightening value, the material can bear the corresponding shear force, design and weaken the cross section of the root of the plum head, so as to achieve the purpose of cutting.