Research On The Stability Of The Whole Machine And The Force Characteristics Of The Outrigger Of The Concrete Pump Truck Based On Parametric Modeling

Concrete pump truck is a kind of vehicle equipment with strong mobility,strong adaptability,high efficiency and high quality pouring concrete slurry.With the development of the city,the floors are constantly elevated,and the concrete pump truck makes it easy for the concrete slurry to be sent to the designated position and height.The stability of the whole machine of the concrete pump truck is a very important safety performance index,which is related to the operation safety and personal safety.This paper studies the stability of the whole machine and the stress characteristics of the outriggers of the concrete pump truck in combination with the horizontal cooperation project of the enterprise.Firstly,the structure of the concrete pump truck is analyzed,the threedimensional coordinate system is established,and the structure of the concrete pump truck is parameterized.The functional relationship between the length of the luffing cylinder and the angle between the boom and other components is derived by analytical method,and the parametric dynamic adjustment of the boom attitude is realized.The coordinates of the center of gravity of the concrete pump truck boom,luffing cylinder,connecting rod,rocker arm,outrigger,turntable and other components are parameterized.Then,the influencing factors of the stability of the concrete pump truck are analyzed,and the stability coefficient of the stability evaluation index of the whole machine is given and the calculation formula of the stability coefficient is given.The stability of the vehicle is reflected by analyzing the stability coefficient and the change of the center of gravity position of the vehicle in any pose within the 360 ° full rotation angle.The results show that in the case of full support of four outriggers,the boom is horizontal and the large bow pumping attitude,any angle of 360 ° rotation is safe,and the stability of the large bow attitude is better than that of the horizontal attitude.The stability of unilateral support is not as good as that of full support,and the working area is limited.With the help of finite element method,the outrigger reaction force analysis model is established.The element stiffness matrix is obtained by deriving the moment of inertia of beam elements with different cross sections.According to the transformation matrix,the element stiffness in the local coordinate system is transformed into the stiffness matrix in the global coordinate system,and the different element stiffness matrices of the same node are superimposed to form the overall stiffness matrix.The gravity and external load are equivalent to the node by using the common equivalent node load formula of beam element.According to the stiffness matrix equation formula,the overall stiffness matrix equation is written.The boundary conditions are introduced and the boundary conditions are processed by the ’ 1’method to solve the stiffness matrix equation,so as to obtain the force of the outrigger.The force characteristics of the Outrigger under the horizontal attitude of a certain type of concrete pump truck are analyzed.The results show that when the azimuth angle is 60 °,the force of the right rear outrigger reaches the maximum 308.9 k N.When the azimuth angle is 120 °,the force of the right front outrigger reaches the maximum 305.6 k N.When the azimuth angle is 210 °,the force of the left front outrigger reaches the maximum 305.6 k N.When the azimuth angle is 300 °,the force of the left rear outrigger reaches the maximum 308.9 k N.Finally,the influence of boom parameters on vehicle stability under full support and unilateral support is analyzed.By changing the thickness of the upper and lower cover plates and side plates of each arm frame by 1mm,under the condition of full support,the stability of the whole vehicle is improved after the increase of one arm,and the stability of the whole vehicle is reduced after the increase of the second arm to the sixth arm.The change of plate thickness of three arms,four arms and five arms has a great influence on the stability of the whole vehicle.In the case of unilateral support,the stability of the whole vehicle is improved after the increase of one arm.The stability of the whole vehicle decreases after the increase of the two arms to the six arms.The change of the thickness of the four arms and the five arms has a great influence on the stability of the whole vehicle when the concrete pump truck is supported by the unilateral outrigger.The change of the thickness of the six arms has little effect on the stability of the whole vehicle.The influence of the change of the length of the adjacent boom on the stability of the vehicle is analyzed.The stability of the vehicle will be increased when the length of the arm with small section size is increased and the length of the arm with large section size is decreased.