Quantcast
Jump to content
  • 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.  

Recommended Posts

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).

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By 袁春凤 (Tiffany)
      The most important component of the water pump is the pump shell and the inner parts of bearing and the bearing. To improve the pump, the most important thing is to optimize and improve the two parts. The following is a detailed introduction to the improvement of the two parts.
      1. to improve the pump shell. When disassembly the pump to inspect the failure, there are a large number of debris seriously affect the quality of the pump and work efficiency. In this case, we can reduce the two holes used for drainage on the pump shell to one, and remove the drain holes on the upper part of the transmitter. This can greatly reduce the small particles and sundries into the pump, thus greatly reducing the interference of sundries on the pump and the other bad.
      2. to improve the bearing. In the case of the failure of the bearing, we are generally sealed, the lubricating oil used by the bearing, the ball of the bearing and the bearing itself. So we should have a solution to these parts
      3. to improve gasket. The traditional design is to design the sealing test as a double mouth seal, so the advantage of the design is that two ports are all frictional with the bearing, the roughness of the bearing surface is more appropriate and the wear of the lip is relatively slow; but the disadvantage is that a large amount of dust can be directly entered into the middle of the mouth and bearing, so that the plate will be used for a period of time. The interference between the bearing and the bearing decreases, thus losing the original function of the seal. There are two ways to improve it: the first is the sealing week of the bearing with double, and the sealing area is lengthened properly and the thickness of the chip mouth is thickened accordingly. The method is to change the original double mouth into the three form of the seal and seal the seal. The advantage of this structure is that the outer lip and mouth have increased the seal design, which can resist many dust. However, this method also has shortcomings, the mouth and the reverse cap friction, the surface roughness of the surface of the cover is relatively poor, it is very easy to wear and tear seal test, resulting in sealing failure.
      4. to improve the lubricating oil. The bearing of the automobile pump is a more special bearing unit. Its environment is mostly temperature, humidity and dust, and the temperature of the water usually reaches about one thousand degrees, so the lubricating oil of the bearing is required. From our analysis of the fault, the lubricating oil in the bearing of the fault appears discolourable, which means that the grease in the lubricating oil is not enough, so the lubricating oil manufacturer should be required to increase the fat content of the lubricating oil so as to ensure the better protection of the bearing.
      5. to Improve the contact ball of the bearing. Balls in bearing are important parts to ensure normal operation of bearings, but there are more and more damage to rolling balls. When measuring the hardness of the ball, it is found that most of the balls do not meet the required hardness requirements, which makes the bearings greatly wear at high speed and finally breaks down completely. Therefore, we should strictly supervise the production quality of the manufacturers, guarantee the hardness of the ball and pass the quality, so that the fundamental problem of bearing damage can be effectively solved.

    • By 袁春凤 (Tiffany)
      Engine knock
      In a gasoline engine, when the mixture (fully mixed with air and fuel) enters the combustion chamber at the intake stroke, the piston compresses it at the compression stroke. When the spark plug ignites the high-pressure mixture, the pressure generated by the combustion is converted to the power of the engine.
      The right side of the high compression ratio setting, more prone to detonation, so the need to use high octane fuel to avoid detonation.
      It is precisely because the combustion of the engine is very complex, so the need for a fairly accurate design and control, a little control error or abnormal, will cause abnormal combustion, and "detonation" is a kind of abnormal combustion. Simply speaking, knock is abnormal pressure in combustion chamber caused by abnormal combustion.
      Causes of detonation
      Firstly, the mixture burns in the combustion chamber, and the flame is spread around by the ignition point in a "wave", so it takes a short time from ignition to the complete combustion of oil and gas.
      Second, although oil and gas need to be ignited by spark plugs, too high temperature, high pressure environment will also make oil and gas spontaneous combustion.
      Generally, detonation is caused by the fact that the flame has not completely diffused after the ignition of oil and gas in the combustion chamber, and the long-range unburned oil is spontaneously ignited because of high temperature or high pressure. The impact between the flame and the normal burning flame produces great pressure, which makes the engine produce abnormal knock.

    • By 袁春凤 (Tiffany)
      China's shortcuts in automobile manufacturing industry
      Over the past nine years, China has become the world's largest automobile market and producer, with annual production and sales exceeding 25 million vehicles. China's automotive industry has also been the world's largest automotive industry in just a few years, driven by the huge domestic demand of the Chinese market. But there is not a strong enough component system to support the development of China's automobile industry. In March this year, the 2017 Top 100 list of global auto parts suppliers was officially unveiled. Unsurprisingly, Germany's Bosch Group continued to rank first with more than $46 billion in revenue, while German gearbox supplier Zeiff rose to second. From the third to the tenth ranking of parts companies are Magna, electronics, mainland, Aixin, modern Mobius, Virginia, Lear.
      In this ranking, China's highest ranking of parts companies is Yanfeng automotive interior system, followed by CITIC Deka ranked 71. And the selected parts enterprises are mainly single components. Feilong Jiangli supply water pumps for car plants.
      In contrast, there is no comprehensive automobile parts supplier in China's automobile industry.

    • By 袁春凤 (Tiffany)
      Inspection rules for rubber parts for automobiles
      1.rubber hardness
      Test method of indentation hardness based on GBT531.1-2008 rubber pocket hardness tester
      contents and requirements
      Instruments and equipment: Shahr hardness tester (type A, D)
      Environmental conditions: the laboratory temperature is 23 C + + 2 C, the relative humidity is 60%~70231
      Test method: the specimen thickness is at least 6mm. If the thickness of the sample is less than 6 mm, it can be stacked with no more than 3 layers of smooth, parallel samples with each layer thickness not less than 2 mm. The specimen must have enough area to make the needle and specimen contact position at least 12mm from the edge.
      Place the specimen on a solid plane, hold the hardness tester, press the pin at least mm from the edge of the specimen, press the pin smoothly on the specimen, and read it within 3 seconds after the full contact of the pin with the specimen.
      Results: the hardness values were measured 5 times at different locations of 6mm, and the median was taken.
      Feilong Jiangli will update the more inspection rules for automobile rubber parts

    • By 袁春凤 (Tiffany)
      The phenomenon that two objects move relative to each other to produce motion resistance between their contact surfaces is called friction, which is called friction. The existence of friction not only increases the power consumption, but also causes the wear of parts' contact surfaces. Therefore, lubricating oil is usually used between the relative moving surfaces of automobile parts to reduce friction. Failure of automotive parts 75% is caused by friction.
      Friction can be divided into dry friction, liquid friction, boundary friction and mixed friction according to the lubrication state of the parts.
      (1) dry friction
      The friction between the frictional surfaces without any lubricating medium is called dry friction.
      When the parts are in the state of dry friction, the surface of the parts is abraded sharply, so the surface of the moving parts of the automobile should avoid the occurrence of dry friction as far as possible.
      Dry friction and boundary friction are the main friction between the upper part of cylinder wall and piston ring. Dry friction will occur when the journal and bearing are subjected to impact load in the working process.
      (2) liquid friction
      Two the friction of the friction surface when the lubricant is completely separated is called liquid friction.
      In liquid friction, the two friction surfaces are completely separated by a layer of lubricating oil film with a thickness of 1.5-2.0um, which avoids direct contact between the working surfaces of the two parts. Friction only occurs between the lubricating fluid molecules, so the friction resistance is very small, and the wear of the parts is very slight.
      Most of the relative motion parts of a car are carried out under the condition of liquid friction (for example, crankshaft and bearing).
      (3) boundary friction
      Two friction surface separated by a very thin boundary film is called boundary friction.
      The oil film thickness is usually below 0.1um. Friction only occurs between the outer molecules of the boundary film, reducing the friction and wear of the parts. But its thickness is very small, and it is easy to be destroyed by impact and high temperature, so it is not as reliable as liquid friction.
      For example: between cylinder wall and piston ring; if the work crankshaft and journal between the insufficient supply of lubricant, easy to produce boundary friction.
      (4) Mixed friction
      The friction between two friction surfaces in the presence of dry friction, liquid friction and boundary friction is called mixed friction.
      In the actual working state, the parts usually work under the mixed friction state, and the friction state varies with the working conditions.

×

Copyright © 2018 AutoPartsForum.com Powered by Invision Community