Virtual Design of Pump Valve of High Pressure Reciprocating Pump

Introduction The average flow rate pump valve is an important component of the high pressure reciprocating pump, and it is also one of the most important wearing parts of the reciprocating pump. Its design has a direct impact on the pump's working performance and service life. The traditional pump valve design method is mainly based on manual design. The design cycle is long, the efficiency is low, and the design level has limitations. Virtual design technology is an emerging comprehensive discipline. Although it has not been around for a long time, it has been widely recognized for its low energy consumption, high efficiency and high integration. This paper uses VB6.0 to write the main control program of the pump valve design, complete the size design calculation of the valve, strength check, combined with AutoCAD and SolidWorks to complete the virtual model of the reciprocating pump valve and virtual assembly process.

1 The main design parameters of the pump valve The pump valve type generally has flat valves and conical valves, among which the flat valve is adopted by many reciprocating pumps because of its relatively simple structure, convenient processing, and low cost. Flat valves are used here. The entire pump valve consists of a suction valve and a discharge valve. It consists of a valve seat, a valve plate, a valve guide rod, and a spring.

The seat diameter dk can be empirically determined initially based on the valve seat hole maximum flow rate Vkmax (1) When a single-acting pump passes through a valve (suction or discharge valve) theory in each cylinder (working chamber), suction valve or discharge Valve number; plunger sectional area, m; plunger stroke, m; plunger reciprocating number of minutes, spm. (2) valve plate thickness S according to formula (3) initial determination, and then the strength check.

When the valve seat diameter dk, the seal width b has been determined, the valve plate diameter (1) allows the closure speed to be determined because the pump valve is working under frequent opening and closing, and the frequency is high.

Therefore, the pump valve must not only satisfy the static pressure strength check but also pay special attention to the closing speed. Therefore, one of the important control conditions of the spring valve design is to control the allowable closing speed, that is k adolph test coefficient, 7kgms, K3 = after designing the main parameters, then the strength check, that is, the valve plate and the valve seat The sealing surface is checked for the pressure check and the bending strength of the valve plate. For details, see relevant information.

2 virtual design of the pump valve First of all, write the main control program code and human-computer interaction interface in the VB6.0 IDE; use Access to establish the system's parameter library; use AutoCAD to use its embedded VBA to write the plane parametric drawing program; SolidWorks APIs to create 3D solid maps; virtual assembly in SolidWorks to finalize the virtual design of the pump valve. The system is mainly composed of six modules: calculation coefficient, pump valve design, spring design, strength check, parametric drawing, and virtual assembly. A software flow chart for a virtual design of a pump valve.

The parameters used to determine the design of the pump valve include: the maximum instantaneous flow rate Vkm of the valve bore, the Adolph test coefficient, the calculation of the valve plate thickness S1 and the medium weight Y. The range of values ​​is Vkmax=1 to 4m/s, Vkmax- According to experience selection: excessive flow rate, large resistance loss, affect the suction performance of the pump, the flow rate selection is too small, the pump valve size is too large, the pump valve quality increases; Adolph test coefficient range is K3 = 1.26 ~ 1.35; valve plate Thickness S is calculated in the range of Ki = 0.14 to 0.4; Medium Severity Y is in the range of Y = 5X103~20XlrfN/n3. Spring steel covers are stainless steel, high-strength steel, ultrahigh-strength steel; The materials are stainless steel, high-strength steel, and ultra high-strength steel. Different types of materials can be selected according to actual needs. Component design parameters such as the allowable stress of the torsion of the spring, the allowable pressure of the sealing surface material, the allowable bending stress of the valve plate, etc., are set according to the specific material type selected.

The pump valve design module will determine the 11 important parameters in the design of the pump valve based on the data for determining and inputting the calculated parameters. They are the valve seat diameter dk, the maximum lift hmax, the contact surface contact width b, and the spring initial installation force. F., valve plate diameter df, spring stiffness C Valve plate thickness The maximum working force of the spring F1, the weight of the valve plate Gf, the maximum load on the valve Fmax, and the allowable closing speed, etc., are all automatically completed by the program.

The spring design module will determine the 8 important parameters of the spring, they are the spring diameter Dm, the spring pitch t, ​​the spring wire diameter dh, the free height H spring working circle i, the installation height H0, the total number of springs i1 and the spring Steel wire length L and so on. The number of revolutions or the total number of revolutions of the pump valve spring can be calculated by the formula, but the calculated number of revolutions may be a decimal number, and rounding must be performed, ie, the number of spring turns is rounded or halved. In the preparation of the rounding program, set i to calculate the number of turns, and then set two conversion variables. When the number of decimal places for calculating the number of turns i is between 0 and 0.15 and greater than 0.75, it can be rounded to an integer number of turns. When the number of decimal places for the calculation of the number of revolutions i is between 0.15 and 0.75, it can be rounded to the integer number of the number of revolutions plus 0.5, which is half.

The strength check module is mainly implemented by: automatically calculating the bending strength of the valve plate and the valve seat sealing surface than the pressure check and the valve plate and determining whether the checked strength value meets the requirements by the program, so as to decide whether to re-calculate the calculation parameters.

The biggest advantage of using parametric drawing is to improve drawing efficiency and avoid the cumbersomeness of manual drawing. In addition to using VBA for 2D parametric drawing, by controlling the application API interface of 3D drawing software SolidWorks, 3D entities can be realized more effectively. Parametric modeling. Based on the dimensional parameters of the previous module design, parts such as valve plates, valve seats, and springs can be quickly built.

The parts assembly is based on the interconnection between the parts. SolidWorks provides various assembly relationships such as fixing, face matching, surface alignment, insertion, and connection. In this module, two types of manual assembly and automatic assembly can be used. the way. Manual assembly is the assembly model where the user calls each component model to construct the pump valve. The user must be familiar with the relative positions of the components. Solid Works automatically records the dimensional definition during the modeling process and records the features of the entire modeling process. This enables the design of a new type of electromechanical and hydraulic tension winch. Zhang Yang, Hou Youfu, Meng Qingrui (China University of Mining and Technology, Mechatronics) School of Engineering, Xuzhou 221008, Jiangsu, China) Partially adopting PLC technology can meet both dynamic and steady-state conditions, and the tension can be adjusted, the reaction is sensitive, and the action is rapid. At the same time, soft start is achieved.

In the foreword direction, its parts and components are also moving towards the high-performance, long-life, low-energy belt conveyor is one of the main equipment for the transport of bulk materials, the direction of development. During the start-up and shutdown of the belt conveyor and the normal operation of the equipment, the elastic deformation of the conveyor belt and the change of the delivery volume are now being made into large-volume, long-distance, large-angle and strong adaptability. The left API interface feeds back the operations recorded in the process to the designer, uses VB to generate assembly files for SolidWorks, and then generates corresponding matrices by recording its various assembly paths. Finally, through the optimization of the matrix, a most reasonable assembly route is found in the assembly tree containing multiple assembly sequences, so as to achieve automatic assembly. After the assembly is completed, a static interference check is required to determine the rationality of the component design. For components with interference, the dimension calculation and modeling are repeated until all components can pass the static interference check. Such as high pressure reciprocating pump valve assembly diagram.

3 Conclusion In this paper, the virtual design of high-pressure reciprocating pump valves based on AutoCAD and Solid Works secondary development technology using VB programming is a useful attempt to apply virtual manufacturing technology to the design of reciprocating pump valves. The whole process of concept design from valve to virtual assembly is realized on the computer. The actual use proof can effectively reduce the research cost of the reciprocating pump valve, shorten the research and development cycle and improve the design level, and has certain practical value.