Swing type control valve

Abstract

The invention discloses a swing type control valve. The swing type control valve comprises a swing reversing mechanism and a valve body sealing cover which are arranged in a mounting cavity, wherein the valve body sealing cover is arranged at the air outlet end of a valve body; the swing reversing mechanism comprises a speed reduction steering gear set; an input shaft of the speed reduction steering gear set is connected with a driving mechanism; an output shaft of the speed reduction steering gear set is in transmission connection with the valve body sealing cover and drives the valve body sealing cover to be opened and closed; a pilot pressure relief hole is formed in the valve body sealing cover; a pilot sealing cover matched with the pilot pressure relief hole is arranged on the valve body sealing cover; and when the control valve is opened, the swing reversing mechanism firstly opens the pilot sealing cover and then opens the valve body sealing cover. According to the swing type control valve, the valve body sealing cover can be quickly opened and closed, and a sealing surface of the valve body sealing cover and a valve body sealing opening are free of friction in the opening and closing process, so that the circumstance of damage of the sealing surface, leakage and venting are reduced, and the service life of the valve is prolonged; and pilot pressure relief is carried out through the pilot sealing cover, so that the torque required during opening is reduced, and the explosion-proof safety of a product is improved.

Description

technical field [0001] The invention relates to the technical field of metering control, in particular to a swing control valve. Background technique [0002] As people pay more attention to environmental protection issues and the continuous improvement of environmental protection awareness, natural gas as an emerging environmentally friendly energy source has received more and more attention and use. Control becomes an important issue. The special control valve for intelligent controller takes on the important role of executor in the entire gas metering system. Its performance not only directly affects the accuracy of metering control, but also directly relates to the safety of natural gas use. At present, the control valves equipped with smart gas flow meters usually use general-purpose DC geared motors to drive the opening and closing parts to make linear or rotary motions to complete the opening and closing of the valves. The reliability of the work is not high, the in...

AI Technical Summary

Problems solved by technology

The bonnet of the control valve adopts a lift-up opening structure, which can realize lift-up opening and closing from the structural principle, which ensures the smooth flow of the gas path to a certain extent, but in actual use, it cannot meet the requirements of stability and reliability. The following defects:

[0004] 1. Through the transmission of two straight-toothed bevel (bevel) gears, the opening and closing parts are driven to open, and the large bevel gear and the pressure rod are fixed as a whole. Although the valve cover can be lifted with the rotation of the large gear, the pressure rod and the gear The shaft is in single-point contact, which is not conducive to the smooth transmission of torque, resulting in a large torque required for the opening and closing of the valve. It is necessary to increase the power of the motor to increase the torque, which will inevitably increase the power consumption of the product and shorten the battery life of the controller. service life, reducing electrical safety reliability

[0005] 2. The control valve is decelerated through two bevel gears, one large and one small. The reduction ratio is limited, and it does not have any adjustability and scalability. At the same time, the transmission accuracy is poor, the instantaneous transmission ratio is inaccurate, and the straight toothed cone (umbrella) The gear structure is only suitable for general steering transmission. For mechanisms with loose speed and transmission ratio requirements, the control valve with this structure cannot guarantee complete, stable and reliable opening or closing within the working pressure range required by gas metering equipment.

[0006] 3. When the bevel gear meshes and drives, there is a large tangential relative sliding velocity along the tooth length direction, which will not only cause greater wear, but also the two tooth profiles are in a point contact state, which will increase the contact stress value and increase drive burden

[0007] 4. Bevel gears (bevel gears) are used as transmission components. The process is complicated, and the manufacturing and installation precision requirements are high. If the product precision is high, it will inevitably increase the production cost. If the product precision is low, it will bring vibration and noise. And it is not suitable for many problems such as transmission with a large distance between shafts. At the same time, bevel gears also have limitations such as not being suitable for the promotion and application of large-diameter valves.

[0008] 5. The opening and closing parts of the control valve cannot be adjusted relative to the center of the flow channel of the valve body during installation, which will greatly improve the processing accuracy requirements of product parts. At the same time, the valve bodies of the above-mentioned control valves are all cast products. Due to structural limitations, the inner cavity of the valve cannot be machined

Therefore, the control valve cannot ensure that the sealed opening and closing part cover is pressed smoothly and centered or is separated from the sealing port, and the phenomenon of eccentricity and inclination of the opening and closing part will occur to a large extent, which will lead to the situation that the valve is not tightly sealed or even cannot be sealed.

[0009] 6. In the above-mentioned control valve, the cylindrical surface of the small sealing cover is cut with a rectangular hole consistent with the cut surface of the pressure rod, and the pressure rod is installed in the rectangular hole of the small sealing cover (the four sides should leave a gap of 0.1mm to 1mm) , and install the positioning nail, the positioning nail head and the small sealing cover also need a gap of 0.1mm to 1mm, but in actual production, this kind of small gap design that cannot be accurately quantified is difficult to achieve stable product quality and consistency of product parts , and the four-sided clearance fit of this rectangular hole cannot realize the effect that the small sealing cover described in the article can swing 360 degrees around the stress point and automatically align itself, and the practicability is not strong

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