Vehicle main reducing gear pre-tighten device and pre-tighten method

Abstract

The invention relates to a pre-tightening device of the automobile main reducer and a pre-tightening method of the same. The device is characterized in that a working platform is arranged for suspending the main reducer. A rotatable bearing pre-tightening torque measurement mechanism is arranged under the platform. The method is characterized in that the pre-tightening torque of a main gear bearing and the tightening torque of a main gear nut are measured while the main gear nut is tightened by a nut tightening mechanism and a main reducing bearing seat is rotated by the bearing pre-tightening torque measurement mechanism. When the pre-tightening torque of the main gear bearing and the tightening torque of the main gear nut both reach within the area of the setting value, the pre-tightening of the automobile main reducer is completed. The method can effectively improve the qualification rate of products and increase the working efficiency.

Description

technical field [0001] The invention relates to a pre-tightening device and a pre-tightening method for the main decelerator of an automobile used in the assembling process of the main decelerator of the automobile. Background technique [0002] In the existing assembly process of the main reducer for light trucks, it is necessary to preload a pair of main tooth bearings (ie, a pair of tapered roller bearings) in the final reducer to achieve a certain rotational resistance torque. If the resistance torque is too small, the rigidity of the main reducer will be insufficient and noise will easily occur; if the resistance torque is too large, burning will easily occur when the main reducer rotates at high speed. Therefore, it is very important to control the preload torque of the main tooth bearing. [0003] The qualified value of the pretightening torque of the main tooth bearing is a set range value A1~A2. In light trucks, the A1~A2 set by the final drive is usually 1~2Nm. T...

AI Technical Summary

Problems solved by technology

As for the detection of the pre-tightening torque of the main tooth bearing, the assembly worker generally turns the main reduction bearing seat of the main reducer manually, and judges whether the pre-tightening torque is within the acceptable range by hand feel and experience. The detection of tightening torque is affected by the worker's operating proficiency, physical condition and emotion; there is also a way to manually pull the main reduction bearing seat with a spring balance to rotate the main reduction bearing seat, and then observe the magnitude of the pulling force, multiply the force by The force arm obtains the pre-tightening torque. The problem with this measurement method is that manually pulling the spring scale cannot make the main reducer bearing seat rotate at a constant speed. The line of action cannot be perpendicular to the radius of rotation at the point of action, so the size of the preload torque can only be roughly measured, and the bearing preload torque cannot be accurately measured, which brings difficulties to determine whether the preload torque falls within the qualified range

[0006] In fact, according to the existing method, if the measured pre-tightening torque falls within the set qualified range, but whether it is the real pre-tightening torque; if it is less than the lower limit A1 of the pre-tightening torque, that is, the measured value is less than A1, whether to continue Tighten the main tooth nut, if you continue, it is impossible to predict how much to tighten; if it is greater than the upper limit A2 of the pre-tightening torque, that is, the measured value is greater than A2, it is impossible to know whether the pre-tightening torque really exceeds the upper limit

As a result, there is a situation where the preload of the main reducer bearing is too large or too small, resulting in unstable product quality

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