Welcome to Auto Parts Forum
Thanks for visiting our brand new online forum for automotive parts. We are just starting to build content and invite you to join us here in our new online discussion forum for automotive parts topics. Whether you are a veteran automotive parts guru or just someone looking for some quick auto parts advice, register today and start a new topic in our forum. Registration is free and you can even do it with social network platforms such as Facebook, Twitter, Google, and LinkedIn.
By 袁春凤 (Tiffany)
Fatigue life prediction of rubber bushing in vehicle system
1.Response analysis of rubber bushing under random excitation The Monte Carlo method is used to simulate the random excitation spectrum.
2. The fatigue life calculation of rubber bushing under random load can calculate the maximum strain energy density of rubber bushing under different excitation by using the response characteristics of rubber bushing under engine and road excitation obtained previously. The fatigue life of rubber bushing can be calculated under different load conditions. The maximum strain energy density U = 0.5134Nmm2 and the fatigue life N = 771371 were predicted under the excitation of engine speed n = 3000r/min and class B pavement, while U = 0.6893Nmm2, N, = 146774 under the excitation of engine speed n = 3000/min and class D pavement.(Thanks for the help and support of Chongqing Feilong Jiangli Auto Parts technical department.)
3. The test verification of the front sub-frame module is expensive because of the fatigue test of the whole vehicle system. Now the former sub-frame module is the research object, and the calculation results are compared with the test results. The front sub-frame is installed in accordance with its layout in the vehicle, and the six points connected with the body on the sub-frame are restrained. Sinusoidal excitation is carried out at the midpoint of the rear beam, and the maximum frequency which can be reached under the condition of satisfying the amplitude of the force is taken as the test frequency. The amplitude of force is 2.45.2kN. Fatigue failure criteria of rubber bushing: 2mm crack (equivalent to 20% of tensile coefficient).
By 袁春凤 (Tiffany)
Structural form of engine suspension mount
In the design of engine mount, the purpose of mount, such as the quality of support and limited displacement, must be fully considered, and the reasonable shape must be chosen. There are three basic types of mounting: compression, shearing and tilting (see figure below).(Thanks for the help and support of Chongqing Feilong Jiangli Auto Parts technical department)
If the displacement of the power assembly is too large, the total power cost will be caused, or the intake and exhaust system, control mechanism, pipeline, wiring and other peripheral parts will be damaged. At the same time, the mounting cushion is easy to damage. For this reason, suspension stiffness must be limited from overhanging structure 1, plus larger displacement. For example, when a car is accelerating or turning, the inertia force generated by the power assembly may cause a greater displacement of the power assembly. In order to limit the displacement of power assembly, it is necessary to design rigid suspension, that is, large stiffness suspension cushion 2, nonlinear and variable stiffness suspension structure, in order to reduce the vibration caused by small exciting force and limit the large vibration displacement when large exciting force. For example, the engine output torque is small when the car stops idling, or when the car runs at a constant speed. At this time, the lower stiffness of the suspended cushion should be designed to effectively isolate vibration. But in the fast start, the reaction force of the driving torque is very large, which can make the power assembly produce greater vibration. In addition, when the vehicle is running on uneven road surface, with the large ups and downs of the whole vehicle, the dynamic assembly also produces great up and down inertia. At this time, the stiffness of the suspension cushion is increased, which can effectively limit the vibration and position of the power assembly. Shift
By 袁春凤 (Tiffany)
Rubber bushing is mainly used in the position of automobile front and rear suspension and other frequent vibration. It plays a vital role in the whole vehicle NVH (Noise Vibration Harshness), and it will be invalid and will affect the whole vehicle noise and driving stability. The failure mode of rubber bushing is not only its own quality control, but also its working environment is one of the key factors affecting its life. Thanks for the support of the Feilong Jiangli technical department.
Automobile suspension is a component that connects the frame (or body) with the axle (or direct and wheel). Its main functions are: D mitigates and inhibits vibration or shock caused by uneven pavement to ensure the car has good smoothness; 2 (2) rapidly attenuates the vibration of the body and axle (or wheel); 3 (3) transfer function in the wheel and frame (car) Various forces (vertical force, longitudinal force, transverse force) and moments (braking moment and reaction moment) between the body; 4) to ensure the necessary stability of the vehicle.
By Mengjuan Zhu
This power assembly mounting arrangement design uses more mature left, right engine side and transmission side three-point mounting arrangement, are rubber mounting. In the road test of NVH performance of mounting system, one measuring point (three-way sensor) is arranged on the active side (i.e. connecting engine side mounting bracket) and the passive side (i.e. connecting body side mounting bracket) of each mounting. The noise measuring points are located in the driver's right ear, the right ear of the non-left seat and the right ear of the rear left seat respectively. Set up a measuring point.
Under the condition of slow acceleration, the active and passive side brackets of the engine have obvious resonance bands around 260 Hz, and the maximum speed of the engine is about 3860 rpm.
Under the condition of slow acceleration, the sound pressure inside the vehicle has obvious peak value at about 3860rpm of the engine speed.
(Thanks to the engineers from Feilong Jiangli providing information)