If we want to use hydraulic seal, then we must be the right choice. Or choose a half-day hydraulic seal is wrong only a waste of time,
1.first convincing the location of the movement of the seal, the Family Use Oil Press Machine is reciprocating motion, rotating motion, still spiral or fixed.
2.to determine the flow point is the inner diameter of the piston rod seal is still in the outer diameter of the piston seal.
3.Family Use Oil Press Machine from the original use of imitation to identify or according to the actual situation to assess the working temperature, which determines the required seal material.
4.From the original use of imitation to identify or by observing the original seal of the hardness and structure of the judge for the maintenance of the use of seals, the manpower should be from the following aspects. Mechanical working pressure rating.
5.Determine the dimensions of the seal. Most users will use the old samples used to buy. But the seal after a period of use, will be affected by temperature, press and wear and other factors to change the original size, therefore, according to the sample size can only be used as a reference, the best way is the amount of seal The location of the metal trench size, the accuracy will be greatly improved.
Hydraulic valve relief valve, refers to the upper part of the main valve core small diameter cylindrical surface, the central large diameter cylindrical and lower cone three parts, must be with the bonnet hole, valve body hole and valve cone to maintain concentric, known as the three (Or three) concentric. The relief valve to ensure that the three parts of the concentricity, processing difficult to become larger; assembly is not good, a little easy to cover the valve seat hole stuck to the main spool, resulting in poor operation of the overflow valve failure; The As the overflow valve than the two concentric valve early appearance, the market share.
The so-called two concentric relief valve, the main spool of the cylindrical surface and cone two must be concentric, difficult to become smaller processing. At the same time with the emergence of cartridge valve, you can use the cartridge valve plug unit, versatility, changeability and good maintenance; valve stability is also good.
Hydraulic valve relief valve function
The hydraulic relief valve has direct acting type (direct acting type) and pilot type. The relief valve is used to ensure that the pressure in the hydraulic system is a certain value and the system is overloaded, Limiting pressure. In the hydraulic system, the function of the relief valve is:
① stable quantitative pump output pressure: in the quantitative pump pump source hydraulic system, the relief valve 2 from the pressure, pressure, overflow effect
② to prevent system overload: variable pump for power In the hydraulic system of the source, the flow rate of the pump 1 is generally variable with the load, and there is no excess flow. When the pressure exceeds a pre-set pressure, the relief valve 2 opens the overflow so that the system force does not rise High, to prevent the system pressure overload from the role of security protection, then the relief valve will be called safety valve
③ to pump unloading: from the relief valve 2 remote pressure port connected two two normally closed electromagnetic valve 3, When the electromagnet is de-energized, the valve 3 is in the open position, the remote control port is closed and the relief valve 2 acts as a normal overflow. When the electromagnet is energized, the valve 3 is in the path position, the remote control port and the fuel tank connected to the overflow valve 2 in the unloading state
④ remote voltage regulator: the remote regulator valve inlet and the main relief valve 2 remote control port Connected to the main relief valve set within the pressure range to achieve remote regulation [Figure
⑤ multi-level control: the main relief valve remote control port with three four-way solenoid valve and two different opening pressure into a remote pressure Valve 4,5 connection, you can achieve high and low pressure three pressure control
⑥ for hydraulic motor brake.
The working principle of oil pressure relief valve
In the high-pressure and high-flow hydraulic system, when the electromagnetic relief valve is switched from the loaded high-pressure state to the unloaded state of the load, the electromagnet is only a few tens of milliseconds Short time from high pressure drop to low pressure, the rapid release of energy, resulting in a large pressure shock, vibration and noise. This shock, vibration and noise in the case of high pressure and high flow often have a heavy barrier. In order to prevent this from happening, an electromagnetic spill valve with a buffer valve can be used. The buffer valve can extend the time from high pressure to pressure relief process so that the pressure is steadily reduced to prevent shock, vibration and noise generation.
Adjust the adjustment screw, you can change the spool stroke and spring preload force, you can change the unloading time, adjust the screw loose, the throttle opening and spring preload force is the smallest, the longest unloading time; The shortest, basically can not afford to unload the buffer effect.
