Gear shifting mechanism is a very important man - machine interface in vehicle. Good shift performance will bring customers a strong sense of pleasure driving. The gear shifting force test based on the gear shifting performance evaluation system is mainly tested in dynamic and static modes by measuring the gear shifting force and displacement at the gear shifting handle, which provides an objective test support for the gear shifting performance of the whole vehicle. Thus assist the gearbox engineer to carry on the thorough research to the shift process. Based on the test data and the geometric model of transmission and shift control mechanism, the possible causes and improvement plan are proposed.
I. equipment and composition
1. Fixed device: provide installation platform for gear shifting performance evaluation system.
2. Displacement measurement system: it is composed of three displacement sensors and is responsible for the measurement of shift and shift displacement.
3. Two-dimensional force sensor: it is placed in the shift ball head and is responsible for the measurement of shift force and selection force.
4. Data acquisition system: the data acquisition system supplies power for each sensor and collects signals of each sensor.
5. Upper computer: the upper computer provides power for the whole system, is responsible for data calculation and storage, and provides human-computer interaction platform.
Ii. Product application
The shift displacement and shift force characteristics of the vehicle are tested by the shift performance test instrument. The specific problems in gear shifting performance of test models were determined, and the value range of each main parameter of gear shifting performance was determined.
Stop clearance test
The shift clearance space after each shift is put into gear is measured by the shift clearance test. The shift clearance test aims to reflect the clarity of the car's shift position and analyze the spatial symmetry of each shift position. The definition and spatial symmetry of the baffle are very important for the training of the driver's sense of baffle. In complex road conditions, drivers of vehicles with a clear sense of gear position can judge the current gear position of the vehicle without visual measurement, and the clear gear position can also avoid the phenomenon of entering the wrong gear, thus improving driving safety.
Block selection test
Selection force test, mainly analyzes the selection force symmetry, selection stiffness and selection roughness. The symmetry force of gear selection is generally shown as the difference between low speed gear selection and high speed gear selection. In view of this, the asymmetric force of selection is intended to realize the function of reminding drivers of sensitive stops. The roughness of gear selection is mainly manifested as: blocking sense, shifting particle sense. In the man-machine interaction system of gear shifting, the driver can clearly feel the roughness of gear shifting. Therefore, roughness of gear selection is bound to affect users' evaluation of gear shifting performance.
Static shift test
Shift force test, analysis shift force, shift stiffness, and analysis shift clarity. Good static shift force test performance is necessary to ensure high quality dynamic shift performance. Through the pedal force sensor, the clutch pedal pressure information in the gear shift process was collected and included in the evaluation system. Static shift force analysis, analysis of shift handle through the shift mechanism and ultimately to the transmission fork of the whole transmission system, in the shift process of the comprehensive performance. The gear shifting rigidity and gear shifting curve reflect the definition and smoothness of gear shifting.
Dynamic shift test
Dynamic shift force test: analyze shift force, shift force and shift impact. Dynamic shift test is the comprehensive evaluation of vehicle transmission system, is also shifting visual performance, the performance of the miserable with synchronization performance of the influence factors of shift mechanism and the transmission shift information, combined with dynamic shift test experiment, test and static shift will shift problem disassembling, provide objective test support for shift quality improvement. At the same time, through the pedal force sensor, the information of clutch pedal pressure and accelerator pedal force and brake pedal force collected in the process of gear shifting was integrated into the system for comprehensive analysis.