In the process of using the concrete pump truck, the oil temperature of the pumping hydraulic system may be too high, which will adversely affect the hydraulic system and even damage the system, resulting in huge economic losses. Therefore, it is necessary to solve the problem of high oil temperature in the hydraulic system of the concrete pump truck.
1. The reason why the temperature of the oil in the hydraulic system of the concrete pump truck is too high
1. Improper adjustment of pressure
The concrete pump truck pumping hydraulic system involves a relatively wide range and complicated assembly. In the hydraulic system, there are more than ten hydraulic valves that need to be checked and adjusted frequently. If the inspection and adjustment work of the staff is not in place, it will As a result, the pressure of the hydraulic valve does not meet the standard. As long as one of the hydraulic valve pressure is not adjusted properly, the entire hydraulic system will have problems, which will cause the temperature of the oil temperature to rise instantaneously, which will adversely affect the operation of the entire system. The normal pressure of the relief valve is 28Mpa. If the pressure of the hydraulic valve exceeds this value, the concrete pump truck will encounter a large load during the pumping process. When the load is too large, the pressure will be excessive. High and rising oil temperature [1]. The normal pressure value of the sequence valve is 10.5Mpa. When the worker adjusts its pressure, if the adjustment is too high, the pressure of the hydraulic valve of the pumping hydraulic system of the concrete pump truck will increase, and the oil temperature will increase, especially It is in summer that the increase in oil temperature will be very obvious. The normal pressure value of the overflow valve of the oil return system is 0.15Mpa. If the adjusted pressure exceeds the normal value, heat will be generated, thus affecting the normal operation of the system.
2. Improper adjustment of cooling system pressure
The reason why the oil temperature of the hydraulic system of the concrete pump truck is too high is also the improper adjustment of the cooling system pressure. When the staff adjusts the pressure of the cooling system, if the pressure is adjusted below the normal value, the running speed of the cooling motor, that is, the speed will be reduced, which will lead to a reduction in work efficiency, the cooling result will be affected, the oil temperature The temperature will be higher [2]. In addition, the cooling system is also easily blocked during operation, which will also reduce its working efficiency, resulting in an ineffective cooling effect.
3. The viscosity of hydraulic oil is relatively large
In the concrete pump truck pumping hydraulic oil system, if the viscosity of the hydraulic oil is relatively large, it will cause greater resistance during the flow of the hydraulic oil, and at the same time, the pressure loss will also become larger, resulting in greater The heat will increase the temperature. If you choose a hydraulic oil with a relatively low viscosity, its viscosity-temperature characteristics will not meet the standard [3]. The lubrication of the combined valve block needs to be completed by hydraulic oil. It is difficult for hydraulic oil with low viscosity to form an oil film, which will lead to a decrease in the lubrication effect, thereby increasing the resistance of the valve body during operation.
4. Internal leakage of hydraulic system
During the normal operation of the hydraulic system, a certain part of the internal leakage may occur. If this occurs, the pressure loss of the hydraulic system will increase, which will increase the temperature of the oil temperature. In general, this phenomenon often occurs in the main hydraulic cylinder or the spool hydraulic cylinder. The main characteristics of this phenomenon are as follows [4]: The speed of oil temperature rise will become faster. If the manual operation valve is closed, the oil pressure will rise. The speed can be effectively controlled. At this time, the hydraulic oil will emulsify, and a small amount of bubbles will appear while emulsifying. The probability of hydraulic system leakage occurring at the construction site is relatively frequent.
Second, the solution of excessively high oil temperature in the hydraulic system of the concrete pump truck
1. Timely check the pressure of the hydraulic valve in the hydraulic system
The main reason for the high oil temperature in the hydraulic oil system of the concrete pump truck is that the pressure of the hydraulic valve does not meet the standard. Therefore, the staff should detect the pressure of the hydraulic valve in a timely manner. If the pressure of the hydraulic valve does not meet the standard pressure specified in the manual, it should be adjusted in time to ensure that the pressure of the hydraulic valve is normal. Only by strictly supervising and testing in this way can problems be discovered and resolved within the first time, and the hydraulic system can be damaged and cannot be used normally due to unresolved problems, resulting in huge economic losses.
2. When the hydraulic system is running normally, some non-working components need to be unloaded
During the normal operation of the hydraulic system, it is not necessary for all hydraulic pumps to work at the same time. When individual hydraulic pumps are not used, they must be unloaded and the hydraulic pump is at rest, so as to avoid excessive oil temperature. Appearance. The concrete pump truck has four hydraulic pumps, which are the main hydraulic pump, water pump, boom hydraulic pump and mixing hydraulic pump [5]. These four hydraulic pumps do not need to work at the same time in daily operations. During normal pumping of concrete, the pump and boom are not involved in this work. At this time, they need to be unloaded. One of them is not unloaded, and the oil temperature will increase when the hydraulic system works normally.
3. Strengthen the management of hydraulic oil
Hydraulic oil is also one of the reasons for the increase in oil temperature. Therefore, in order to prevent the phenomenon of excessive oil temperature in the hydraulic system of the concrete pump truck, the management of hydraulic oil must be strengthened. Before using hydraulic oil, the hydraulic oil with appropriate viscosity must be selected according to the actual situation, so as to reduce the probability of oil temperature rise caused by unsuitable viscosity. In addition, the management of its entry and exit should also be strengthened. When purchasing hydraulic oil, the purchaser must purchase it according to the requirements. During the purchase process, the quality of the hydraulic oil should also be checked to ensure that there is no problem with the quality before buying in large quantities. Before the hydraulic oil is put into storage, the relevant personnel must conduct a test on it. During the test, the viscosity should be determined according to the changes of the seasons, and the storage can only be carried out after the test results meet the standards. After the hydraulic oil is stored in the warehouse, it cannot be placed randomly. It needs to be placed in an orderly manner according to the category. When the hydraulic oil is out of the warehouse, the staff should also conduct a test to ensure that its quality has not changed before it can be put into use. It is strictly forbidden to put the hydraulic oil with changed quality into the construction site for use.
4. Improve system design
During the use of the hydraulic system, there will be a phenomenon of increased oil temperature. This phenomenon is related to the design of the system. Therefore, if you want to avoid the rise of oil temperature, you can improve the design of the system, mainly to improve the design of the oil tank, oil pipe and radiator. If the designed oil pipe is curved and thin and long, it will increase the resistance of hydraulic oil flow and increase the oil temperature during use. In view of this situation, its design should be improved, the diameter of the oil pipe should be enlarged, and the length should be shortened, so as to ensure the smooth transmission of hydraulic oil in the oil pipe. If the volume of the oil tank is relatively small and the radiator function is not strong, the oil temperature will also increase. In order to solve this problem, the volume of the oil tank can be expanded appropriately, and a cooler can be configured when necessary to achieve the goal of controlling the oil temperature.
