Reduce the concrete pump cylinder reversing impact measures analysis
Concrete pumping concrete pump truck, if the impact force is too large to pumping cylinder system, can produce the following five kinds of hazard: one is the pump truck arm frame jitter, affect the service life; 2 it is to make the boom at the end of the hose swing, easy operation personnel that touch an injury; 3 it is easy to cause the main hydraulic pump suction empty, affect the service life; Four is to make the power loss increase, fuel consumption increase; Fifth, make noise increases, an adverse impact on the environment. To this end, the author from two aspects of hydraulic system and the pump cylinder pump cylinder reversing impact measures to lower it. 1. Pump cylinder in hydraulic system working principle of the concrete pump truck, A and B oil outlet connections are two pumping in and out of the oil cylinder cavity, the main oil pump from A and B alternately mouth for 2 conveying high pressure oil pump cylinder. As shown in figure 1. Right pumping rod cylinder cavity into the high pressure oil, driving the piston rod back, right pumping rodless cylinder cavity pressure oil by pumping rodless cylinder of high pressure oil pipe into the left cavity, drive pump cylinder was left out. When the proximity switch after induction to right pumping cylinder was in place, control system signal commutator. Main pump after receiving the reversing signal, will be left pumping pressure oil cylinder rod cavity connected, make left pump cylinder was back. Left pumping rodless cylinder cavity pressure oil, through high pressure oil pipe into the right pumping rodless cylinder cavity, drive right pumping cylinder piston rod out. Two pump cylinder so alternating movement, can finish concrete pumping work. When the pump cylinder rod chamber into the oil pressure and piston rod will be moved to the rodless cavity end, due to the oil pressure is higher than the rodless cavity, rod cavity pressure oil by pumping holes on the cylinder, the one-way valve, damping hole to rodless cavity fill oil, can make the piston rod to stop moving as soon as possible. On the contrary, in the main pump connecting the two pumping rodless cylinder cavity respectively, two oil pumping rod cylinder cavity of A and B mouth connected. Rodless cavity pressure below a bar cavity, rodless cavity pressure oil by pumping holes on the cylinder to a rod cavity filling oil. 2. Pump cylinder above the reversing impact test principle analysis, the author designed the following four impact test plan: one is set in the pump cylinder diameter 3 to 1. 5 m m damping hole, S N valve in the hydraulic system is not installed, Install the check valve on both sides of main pump servo cylinder) 。 The measured pump cylinder when reversing impact pressure is 24 mpa, low voltage side suction empty time of 100 ms. 2 it is set in the pump cylinder diameter 3 to 1. The damping hole 5 mm, SN valve installed in the hydraulic system. The measured the impact pressure of pump cylinder when reversing to 14 mpa, low voltage side suction empty time of 70 ms. , the third is to pump cylinder three diameter of 1. 5 mm of the damping hole to a damping hole diameter is 2 mm. When measured the reversing impact pressure pump cylinder for 9 mpa, the pressure is greater than zero on the low voltage side of the pump, main pump is not empty. Four is to pump cylinder three diameter of 1. 5 mm of the damping hole to a damping hole diameter of 1 mm. At this time when measured the reversing impact pressure of 7 mpa. Shut down the pump cylinder buffer device, pump cylinder when reversing almost no impact and empty. 3. Measures to improve the above test results, take the following three measures: one is increasing SN valve in pumping hydraulic system, to reduce the impact pressure of the system and reduce the phenomenon of the main pump suction empty; Second is to reduce the pumping oil compensating damping hole diameter on the cylinder, in order to reduce the pump cylinder of the reversing impact; Three is to use pumping rodless cylinder cavity filling method, further reduce the pump cylinder of the reversing impact. After the three improvement measures, pump cylinder reversing impact greatly reduced.