Concrete pump was a kind of construction equipment that was very common in many construction units at that time. With the help of concrete pumps, many units were useful to improve the efficiency of construction. However, if you want to maintain an outstanding situation, you should not only pay attention to the concrete pumping situation during the construction process, but also pay attention to the precautions when the concrete pump stops pumping.
Experts point out: In order to ensure the normal operation of concrete pumps during construction, and to prevent the occurrence of problems as much as possible, construction units should pay attention to the pumping of concrete pumps and the suspension of pumping of concrete pumps . However, in daily life, many units only pay attention to pumping, but neglect the maintenance work of stopping the pumping. So what should the concrete pump pay attention to when stopping pumping? Now let's introduce it in detail.
1.Pilot solenoid valve
In the process of stopping the concrete conveying pump, if the external control oil circuit of the solenoid valve pilot valve is connected to the oil return circuit, the pilot valve should be closed immediately, and then the main valve core will be closed. At this moment, the concrete backflow will cause back pressure on the cylinder , So it will be cut off by the main spool. However, because the main valve core of the sequence valve uses a tapered Vert line seal, and its oil inlet and outlet are also at right angles. Therefore, there will always be a useful pressure ring area that opens the main core on the sealing cone surface. When the backflow pressure reaches a certain value, the force exerted on the pressure ring area will be greater than the spring force of the main core tension spring. The main core is opened, and the backflow back pressure overflows to the fuel tank. It can be seen that this structure has a limited height to prevent backflow of concrete and should be improved.
So how can we improve it? The principle is to use the external control sequence valve to control the oil outside of the solenoid valve to block the oil passage to control the one-way valve added to the main oil circuit. The operating principle is that when the concrete pumping is suspended, the solenoid valve The pressure of the pressure-holding circuit of the distribution valve reaches the spring chamber of the one-way valve through this solenoid valve and oil passage, so that the one-way valve is closed. Because the compression area of the spring chamber is much larger than the useful annular compression area of the sealing cone. Therefore, the added check valve can effectively stop the back pressure of the concrete from flowing back to the oil cylinder.
The concrete backflow prevention structure mainly depends on the cartridge valve itself to complete the backflow prevention. And through the introduction and control of the pilot valve of the cartridge valve to the back pressure of the main cylinder, the back pressure can be separated from the tension spring cavity acting on the cartridge element, so that the back pressure of the main cylinder can be isolated from the main system under unloading. If concrete backflow has occurred and it is also confirmed that the (remaining) oil has penetrated into the closed circuit of the main cylinder, you can open the stop valve to adjust the oil quantity in the return line after the concrete pumping operation for a period of time. Or the flow valve can be adjusted to remove excess oil from the valve and it should be closed immediately afterwards.
The pumping suspension of the concrete pump can help the normal operation of the construction, and the construction party should pay attention to this. So what should you pay attention to when the concrete pump stops pumping? With the above introduction, we trust that a wide range of users now understand this issue.