English
Español
Portugues
As we all know, shock absorbers are important devices of motorcycles. The role of motorcycle shock absorbers is to alleviate and attenuate the impact and vibration of motorcycles during driving, and to ensure the smoothness and comfort of driving, which is conducive to improving the service life and handling stability of motorcycles. Motorcycles are equipped with shock absorbers. The following article analyzes the classification and selection of motorcycle shock absorbers, For the reference of motorcycle users and fans. Attention: Rongji igniter
Classification of shock absorber:
There are many types of Mo Ruochen shock absorbers. Most motorcycles use cylinder shock absorbers, and only a few use steel plate spring structure. There are many types and varieties of cylinder shock absorbers, mainly divided into front shock absorbers and rear shock absorbers according to the installation position.
(1) According to the direction of attenuation force, there are unidirectional shock absorber and bidirectional shock absorber.
(2) According to the load adjustment type, there are spring initial pressure adjustment type, gas spring type and installation angle adjustment type.
(3) According to the structural form, there are telescopic tube front * hydraulic shock absorber (which is the most commonly used front shock absorber in motorcycles), rocker type shock absorber, rocker lever vertical center shock absorber, and rocker lever inclined center shock absorber.
(4) According to the working position of the oil cylinder, there are inverted shock absorber (i.e. the oil cylinder is located above and the piston rod is located below) and upright shock absorber (the oil cylinder is located below and the piston rod is located above).
(5) According to the working medium, there are spring type shock absorber, spring air damping shock absorber (because the damping force of air is limited, the damping effect is not ideal, and it is generally only used for mopeds with low speed as rear shock absorber), hydraulic damping shock absorber, oil-gas combined front shock absorber, and nitrogen filled hydraulic shock absorber.
Telescopic front hydraulic shock absorber:
(1) The telescopic front * is connected with the front wheel and the frame, which not only supports part of the frame, but also serves as a shock absorber. With the mutual expansion and contraction between the handle tube and the sleeve, the oil in the front * flows through the small hole set in the partition wall.
(2) When the handle tube is compressed, with the movement of the handle tube, the oil in chamber B is pressurized and flows to chamber C through the small hole on the handle tube.
(3) And flows to chamber a through the free valve. When the oil flows, the resistance attenuates the compression force.
(4) When the compression stroke is near the limit, the conical oil seal at the end of the handle tube will be inserted, thus closing the oil passage in chamber B.
(5) At this time, the oil pressure in chamber B rises sharply, making it in a closed state, which limits the stroke of the handle tube and effectively prevents instantaneous mechanical collision between the movable parts on the front plate.
(6) When the handle tube is stretched (i.e. rebounded), the oil in chamber a flows to chamber C through the small hole on the upper part of the front piston (near the piston ring).
(7) At this time, the resistance to oil flow attenuates the tensile force.
(8) When the extension stroke is near the limit, the extension of the rebound spring absorbs the vibration energy, and in this process, the oil is replenished to chamber B through the small hole at the lower part of the front piston, making preparations for the next work.
Hydraulic damping rear shock absorber
(1) The hydraulic shock absorber is the most common shock absorber used by motorcycles at present. The structure of the hydraulic shock absorber is basically similar to that of the suction pump, except that the upper end of the steel body of the hydraulic shock absorber is closed, and there are small holes on the valve.
(2) When the rear wheel is impacted on the convex Road, the cylinder barrel moves upward, and the piston moves relatively downward in the inner cylinder barrel. At this time, the piston valve is flushed upward, and the oil in the lower side of the piston in the inner cylinder barrel flows to the upper side of the piston without any resistance.
(3) At the same time, this part of oil also flows into the oil chamber between the inner and outer cylinders through the small hole on the bottom valve.
(4) This effectively attenuates the impact load of the concave convex Road on the vehicle.
(5) When the wheel falls over the raised ground, the cylinder barrel will also move downward, and the piston will move upward relative to the cylinder barrel.
(6) When the piston moves upward, the oil flows to the inner cylinder through the valve at the bottom, and the oil on the upper side of the piston of the inner cylinder flows to the lower side through the small hole on the piston valve.
(7) At this time, when the oil flows through the small hole, it will be subject to great resistance, which produces a better damping effect and plays the purpose of damping.
Motorcycle manufacturers all over the world have invested a lot in the design of the front suspension device and rear suspension device of motorcycles in the process of competition. They have adopted more novel elastic elements with variable diameter and pitch, such as oil pressure damper, oil-gas regulating device, load regulating device, rocker lever type central shock absorber and other advanced structures.
The popularization of these new technologies can quickly attenuate the impact and vibration caused by the change of vehicle speed, load and various road conditions, automatically adjust the vibration resistance to the best technical state, greatly improve the shock absorption performance of motorcycles, and improve the adaptability, comfort, stability and safety of motorcycles to varying degrees.
Performance and selection of shock absorber oil
The length of motorcycle use and the ambient temperature during use are different. Therefore, in order to adapt to various climatic conditions in the motorcycle running area, most shock absorbers absorb impact and vibration energy through the flow damping force of oil, and then convert it into oil heat for dissipation. Therefore, the damping force is closely related to the viscosity of oil, which varies with temperature. The following technical requirements are put forward for shock absorber oil:
(1) Shock absorber oil must have good anti rust and anti-wear effects;
(2) Shock absorber oil should have as little vaporization loss as possible in all the use ranges of motorcycles (including high-speed, full load, overload and other special cases), that is, the so-called small vaporization performance;
(3) When the shock absorber oil contacts the air, it must have anti-oxidation stability and anti oil gas mixing stability, that is, good working stability;
(4) The condensation point of shock absorber oil used in China shall not be lower than - 40 ℃. In other words, when the temperature drops to 0 ℃ ~ - 40 ℃ in the cold winter, the oil should not lose its fluidity;
(5) Because the shock absorber oil containing impurities will scratch the piston rod or cause the oil seal edge to be incomplete during the driving of the motorcycle, resulting in oil leakage. Therefore, the shock absorber oil must be kept absolutely clean;
(6) Shock absorber oil should not only have good viscosity temperature performance and high viscosity viscosity index, but also have low freezing point. When the ambient temperature changes or the temperature of the shock absorber oil changes with the extension of the working time, the viscosity change of the oil should be small. Precautions for selection and use of shock absorber oi
l
To sum up, the viscosity of the shock absorber oil has a great impact on the performance of the shock absorber. If the oil is too viscous, the soft shock absorber will become hard. If the oil is too thin, the hard shock absorber will become soft. In order to change the shock absorption performance of the shock absorber, the brand of the shock absorber oil can be changed, but the amount of oil added must not be increased or decreased at will. At present, there is no special shock absorber oil for sale in China's motorcycle oil product stores, motorcycle Monopoly points and maintenance markets, which can only be solved by self mixing. Now we recommend several methods to prepare shock absorber oil for reference.
(1) In order to avoid the immersion of moisture and impurities as much as possible, the replacement of shock absorber oil should be carried out in a sunny day with high temperature, low humidity and less sand and dust, and it is better to operate in a relatively clean environment. The used shock absorber oil shall not be reused. After the shock absorber oil is prepared, it should be used in time, and should not be stored for too long, so as to avoid oxidation and deterioration of the shock absorber oil and affect its performance.
(2) For motorcycles with low speed and low load (refer to vehicles below 50ml), gasoline engine oil of grade l-eoc and brand 5W / 30 can be purchased directly;
(3) In order to improve the shock absorption performance of the shock absorber, the brand of the shock absorber oil can be changed, but the amount of oil added must not be increased or decreased at will, and the amount of oil added must be accurate. For this reason, it is recommended to fill with a measuring cup. If the conditions are not met, the oil can also be sucked and injected with the help of a 50ml medical syringe (with the ML scale on it as the measurement unit). It is worth pointing out that the oil volume in the two front * shock absorption cylinders must be consistent. Otherwise, it will bring inconvenience to the normal operation of the motorcycle. Please pay special attention to it. (4) When changing the shock absorber oil, remove the steering handle, front wheel, fender and brake caliper in sequence, unscrew the fixing screws of the upper coupling plate and the steering column, rotate the handle tube from left to right, and slowly pull out the handle tube. For motorcycles equipped with front * dust shield, first remove the dust shield and front * cover bolts (the front * cover bolts may spring out under the action of springs, which should be noted). If it is an air pressurized type, press the valve core before loosening the bolt to exhaust the air. Remove the spring pad, spring guide tube and front * spring in sequence, move the handle tube, and pour out the shock absorber oil in the front *. Then inject the recommended front shock absorber oil according to the specified oil quantity, and then slowly pull the handle tube for two or three times to remove the mixed air. Finally, assemble it in sequence. Here is a brief introduction to the oil volume of the front shock absorber of some motorcycles (single):
(5) Mixed oil is selected for preparation, which is usually prepared according to the following three proportions:
a. Mix 22 turbine oil and transformer oil in 50% proportion respectively;
b. Mix 40% of No. 22 turbine oil and 60% of transformer oil;
c. Mix 60% of No. 22 turbine oil and 40% of transformer oil.
