As a common electric tool, electric wrench is frequently used. Among them, a kind of electric wrench which can complete the output of constant torque is also called constant torque electric wrench. The existing constant torque electric wrench comprises a shell, the shell is provided with a motor, that is, a power source, and the front end of the shell is provided with a sleeve rod which is connected with the motor through a transmission organization, and the sleeve rod is used as a torque output structure to output torque outwards.

為了能夠完成定扭矩的輸出，電動(dòng)扳手具有扭矩檢測部分，扭矩檢測部分檢測扭矩輸出結(jié)構(gòu)的輸出扭矩，然后完成到達(dá)指定扭矩時(shí)中止動(dòng)力輸出，現(xiàn)有定扭矩電動(dòng)扳手的扭矩檢測部分根本都是經(jīng)過檢測電動(dòng)扳手的電流來完成的。

In order to complete the output of constant torque, the electric wrench has a torque detection part. The torque detection part detects the output torque of the torque output structure, and then stops the power output when reaching the specified torque. The torque detection part of the existing constant torque electric wrench is basically completed by detecting the current of the electric wrench.

當(dāng)電動(dòng)扳手施加扭矩必定程度后，套桿的滾動(dòng)會(huì)受阻，這會(huì)影響電動(dòng)扳手的電流輸出，然后判斷扭矩輸出結(jié)構(gòu)處的輸出扭矩，電流畢竟與輸出扭矩只是有對應(yīng)聯(lián)系，而沒有換算聯(lián)系，這種經(jīng)過檢測電流來判斷輸出扭矩的形式存在的問題就是丈量精度差，無法完成在高精度領(lǐng)域中運(yùn)用。

When the torque of the electric wrench is applied to a certain extent, the rolling of the sleeve rod will be blocked, which will affect the current output of the electric wrench, and then judge the output torque of the torque output structure. After all, the current is only related to the output torque, but not converted. The problem of judging the output torque by detecting the current is poor measurement accuracy, It can not be used in high precision field.

此外現(xiàn)有技能中的，為了豐富電動(dòng)扳手的功用，電動(dòng)扳手往往還具有大扭矩和小扭矩輸出才能，但是其為了完成大扭矩、小扭矩輸出之間的轉(zhuǎn)化，其也是經(jīng)過雜亂的傳動(dòng)變速組織來完成的，不只結(jié)構(gòu)雜亂，而且因?yàn)檎麄€(gè)傳動(dòng)路徑上減速傳動(dòng)過多，大扭矩輸出時(shí)的套桿轉(zhuǎn)速極地，電動(dòng)扳手的作業(yè)效率較差。

In addition, among the existing skills, in order to enrich the function of the electric wrench, the electric wrench often has the ability of large torque and small torque output. However, in order to complete the transformation between the large torque and small torque output, it is also completed through the disordered transmission speed organization, not only the structure is disordered, but also because there are too many decelerations in the whole transmission path, When the torque output is high, the working efficiency of the electric wrench is poor.