How to deal with the valve body oil seepage of German Ha Wei’s multi-channel valve
HAWE Ha Wei PSL and PSV series proportion multi-channel reversal valve differentiate the stepless speed adjustment of applicable fixed displacement pump system and hydraulic power element of the variable displacement pump system, regulate the function and have nothing to do with system load. A plurality of power elements can work at the same time and independently. HAWE Ha Wei PSL and valve in the PSV series proportion multi-channel reversal valve form are mainly applied to walking in the mechanical hydraulic power system (for example: Hoisting machinery, the rig, the engineering machinery,etc.) . Pass and choose the power element A, B oral and respectively different flowrate, and choose to use the valve of all kinds of additional functions
Valve body seepage oil of Ha Wei’s multi-channel valve
There is one to enter the oil port to connect with job pump of the system to enter the oil valve, the return port of the return valve is connected with return port of the system, relief valve( Overflow valve) Control and overflow the oil duct. Should pay attention to some items of following German hawe Ha Wei’s multi-channel valve in dismantling and maintaining:
1.The mounting plate should level, the screw is tightened, strength wants evenly, can’t make the valve body twist.
2.Install drive lever, should guarantee slide valve sport too flexible to there is not stagnat phenomenon of Carlosing.
3.Don’t strike and damage the exposure part of the valve plug while carrying and installing, preserving, the paint does not need japanning on the valve plug hour.
4,The fluid of job should be cleaned, the cleaning degree of fluid and system is not lower than 250440619/16 grades or NA1638 11 grades.
5.Push away, check, use the hydraulic oil N32 ‘ Winter) . N46 (summer) .
6.The rigorous return port connects the high pressure, the back pressure of return port can’t exceed 25 kilograms / one centimetre of German hawe Ha Wei’s multi-channel valves and maintain attentive matters and operating principle
Leak multi-channel reversal valve leak take place, inside, the intersection of job and oil duct and answer oil duct or overflow in the oil duct Xiang Tong, hydraulic oil flow back to directly fuel tank is unable to finish, operate, lead to the fact, get up, rise hydraulic cylinder get up, rise unable or can’t get up rise, the intersection of fork and glide and the intersection of lane and the intersection of person who lean forward and trouble by oneself by oneself
Valve stem and sealing of the valve body are realized by the seal ring of the Model O, if the seal ring is worn out or damaged, the hydraulic oil will be flowed out along the valve stem under the function of systemic pressure, cause the valve body seepage oil. It only needs to change the seal ring of the O-shape to get rid of this trouble.
What the forklift truck adopted is to divide the multi-channel valve of the chip type, the structure of the multi-channel valve of this type is complicated, precision great, this valve includes the outer cover, gets up to promote the valve stem, slopes parts such as valve stem, reset spring, relief valve and cone valve,etc., until inside form, enter oil duct, work oil duct, go back oil duct, overflow oil duct and go back oil duct always, make the hydraulic oil flow in every oil duct under different operating conditions, achieve different working purposes.
Inner leaky reason and exclusion method are: Leak the phenomenon inside
1)Abrade most over No. reversal valves of interval and get up to rise and have three ditch grooves respectively on the tilted valve stem between valve stem and valve body, the cannelure can put through or cut off the oil passage, change the operating mode to cooperate with the oil duct. The interval between valve stem and valve body of the good distributing valve is very small, the oil seepage is few, so the hydraulic cylinder drops or solp is very small, do not influence the work. When but it is too big to abrade the interval, the hydraulic oil is at the pressure that the job pump produces, will cause oil of job in the oil duct and answer oil duct or overflow in the oil duct Xiang Tong, get back to the fuel tank automatically. The reason emerges mainly, because distributing valve long term administration or fluid is unclean,etc. to accelerate the abrasion of the valve stem and valve body, destroy and cooperate with the sealing surface, cause the oil seepage. While repairing if the valve stem abrades lighter, can plate the chrome to polish the valve stem; If the valve stem is abraded seriously, need changing.
( 2) Between the valve body the intersection of oil seepage and oil duct because of job, go back oil duct, overflow oil duct run through between 3 one piece valve bodies, so the leak tightness between the valve bodies requires very, after installing the seal ring of the O-shape between valve body and valve body oil duct, use valve body a Lai of bolt joint, achieve the sealed goal. If firm force moments of the bolt are different, may cause the warping of the valve body. The seal ring fails, leak in producing; If the valve body surface is damaged now or the O-shape ring is worn out or damaged while installing, under the function of oil pressure, easy to leak when happen between the valve bodies. While repairing, if the valve body damages and needs to grind, change the seal ring of the O-shape, and tighten the bolt with the force moment requirement sequentially.
( 3) The safety valve spring invalid relief valve is used in the work of the governing system? ? ? Strength, enable pressure maintenance within the range of suring, prevent damage to the limiting position or other reason and every spare part of hydraulic power system caused of hydraulic cylinder piston, because overloadsing. The relief valve is mainly pressed the steel ball at the valve position and achieves the goal of making, closing by the spring force. When the oil pressure that the hydraulic pump outputted exceeded the fixed number value, the pressure of the high pressure oil was overcome some high pressure oil to overflow in the oil duct by the relief valve and return to the fuel tank. When the oil pressure reaches the specified value, the spring is under the action of force of one’s own preloading, cramp the steel ball at the valve position, the relief valve is closed.
If the safety valve spring fails, the hydraulic oil can force the steel ball to leave the valve position and flow into and overflow the oil duct under the authorised pressure of below system, leak while causing, enable system disappointment. Must change spring repair, then utilize, adjust the screw adjusting spring from pressure to specified 14 Mpa. Load 7.5t goods according to the demand from the loaded centre 600mm while adjusting, is lock when the goods are like not getting up with the locking nut, the pressure at this moment is the pressures needed adjusting.
( 4) The multi-channel communtation valve stem can’t reset the reset spring of valve stem to install at the lower end of the valve stem, whether the valve stem can make the spring compressed in the epistasis or in the downstream, while there is no epigene action, because the elasticity of the spring makes the valve stem return to the original position rapidly. If the valve stem can’t be reset, the ditch groove communicates with oil duct, leak when will emerge. First, because the valve stem reset spring is out of shape or damages, the spring force is lowered but can’t make the valve stem get back to the normal position, must change the spring while repairing; Second, unclean among valve body and valve stem, produce greater resistance, make the valve stem reset the difficulty, the inside that must wash the multi-channel reversal valve while repairing, dispel resistance.
( 5) The conical valve abrades the conical valve and is used for preventing fluid backflow. If the conical valve is abraded, it is not tight to close the group the oil duct, will make the hydraulic oil reflux, enable system disappointment. While repairing, reply it enters to grind or change. Dispel return current.