JPS61201972A - Motor-driven governor valve - Google Patents

Abstract

PURPOSE:To enable the intensity of electric input signal to an electric motor and the variation of valve seat opening area of a movable valve body to change proportionally, by providing an electric motor which drives the movable valve body by electric input. CONSTITUTION:A rotary rotor 15 of an electric motor is turned by receiving an electric input, and as the turning shaft 17 turns a valve spindle 18 in which rotation is restrained is driven up and down to be controlled via a screw connection part in accordance with the pitch of thread. When the electric input is interrupted due to power failure, etc., a valve body 2 is energized to be pressed in the closing direction by the force of a spring 5, enabling failsafe fluid control. Furthermore, the up-and-down vibration of the valve body 2 caused by the effect of fluid force can be prevented, because the valve body 2 is connected with the electric motor 4 via the screw connection part.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a proportional control valve that proportionally controls fluid flow rate in a combustor such as a water heater according to load.

``Prior Art'' Conventionally, an electromagnetic governor valve has been known as a device of this type. For example, as disclosed in Japanese Unexamined Patent Publication No. 58-217877, a diaphragm is provided in the valve body and the diaphragm is connected to the diaphragm. It consists of winding an electromagnetic coil and connecting the valve rod of the valve body around the coil bobbin.According to this, the valve body is pushed in the closing direction by the pressure of the gas acting on the diaphragm, and the current value applied to the coil is The amount of displacement of the valve body was determined by However, since the valve body is driven by an electromagnet, analog control of the input current is required, and when connecting a digital computer, a digital-to-analog converter is required, resulting in an expensive microcomputer control system. In addition, since the electromagnet controls the position of the movable iron core, which moves in the same axial direction as the valve body's moving direction, the valve body changes due to gas pressure changes and fluid pressure, causing irregular combustion due to changes in gas flow rate. was there. Furthermore, the amount of axial movement of the valve body and the amount of change in the fluid flow path opening area of the valve were not made to correspond proportionally, and the shape of the valve body was not determined in this way, so the amount of change in the movable core of the electromagnet was and the fluid flow rate did not necessarily change proportionally correspondingly.

``Problems to be Solved by the Invention'' The present invention was created in view of these points, and allows for digital control by a microcomputer, eliminates the movement of the valve body due to fluid pressure, and allows the valve to move in response to the amount of electrical input. An object of the present invention is to provide an electric governor valve that allows proportional control of fluid flow rate and has a fail-safe structure.

``Means for Solving the Problems''``Operation'' The electric governor valve of the present invention includes a fixed valve seat disposed in a fluid flow path passing through the valve body, and a fixed valve seat corresponding to the valve seat. In a governor valve equipped with a movable valve body that controls opening and closing, and a pressure receiving body that is connected to the movable valve body and biases the movable valve body in a closing direction in response to fluid pressure, an electric motor drives the movable valve body by electric input. The system is designed to proportionally change the amount of electrical input signal to the motor and the amount of change in the valve seat opening area of the movable valve body, and as a fail-safe structure, it is equipped with a spring that always presses and biases the valve body in the closed direction. The rotating shaft of the electric motor and the valve rod shaft of the valve body are screwed together.

Therefore, the electric motor drives the valve body with a rotational torque that is stronger than that of an electromagnet, and proportionally controls the valve seat opening area of the valve according to the amount of electrical input signal to the electric motor.

"Embodiment" Hereinafter, one embodiment of the electric governor valve according to the present invention will be described with reference to the drawings. A fixed valve seat 1 is disposed in the fluid flow path passing through the inside of the valve body 10 from the inlet 11 to the inlet 12, and the valve is fixed to a pressure receiving body 3 such as a diaphragm held between the valve cover 13 and the valve body 10. A movable valve body 2 is disposed at the lower end of the rod 14 in correspondence with a fixed valve seat, and a spring 5 is compressed between the movable valve body and the valve body to constantly urge the valve body 2 upward. A rotating rotor 15 and a fixed stator coil 1 are mounted on the upper part of the valve cover 13.
An electric motor 4 consisting of
17 and the valve rod shaft 18 of the valve rod are screwed together. Fluid flows from arrow A to arrow B, but the gap between the valve body 2 and the valve seat 1, that is, the opening area of the fluid flow path, changes in proportion to the axial (vertical) stroke of the valve body. The shape of body 2 is determined.

That is, the shape of the quadratic curved surface 19 of the valve body 2 is determined so that the opening area of the fluid flow path (the annular area in terms of length) changes in proportion to the axial stroke h of the valve body 2. That is, the sentences determined by D and d are made to be proportional to each stroke h.

In other words, intersection 2 = (D-d)" + h2, and the opening area of the flow path is proportional to (D-d)2 + h2, so (D-d)
Make 2+h2 proportional to h.

Since D is a known number, the value of d is determined so as to vary proportionally with h, and the shape of the quadratic surface 19 is determined. And the opening area A of the annular orifice is determined by looking at it.
The flow rate Q passing through the niorifice is expressed by the linear formula % %: 1 However, the flow rate of fluid passing through the niorifice Q is expressed by the pressure difference before and after the niorifice, and the flow rate is Since the coefficient C is considered to be approximately constant, the formula shows that if the pressure difference ΔP is constant, the flow rate Q is proportional to the opening surface MIA. The valve opening area is proportional to the stroke h of the valve body, and the amount of movement of the valve body is proportional to the rotation angle of the rotor via the threaded part, so as shown in Figure 3, the rotation angle of the rotor is is proportional to the opening area of the valve. Therefore, the flow rate can be proportionally controlled by the amount of electrical signal input to the motor.

Next, to explain its operation, the rotating rotor 15 of the electric motor rotates in response to electric input, and as the rotation shaft 17 rotates, the valve rod shaft 18, whose rotation is restricted, is screwed through the threaded part. The drive is controlled up and down depending on the pitch. When electrical input is cut off, such as during a power outage, the valve body is urged in the closing direction by the force of the spring 5, allowing fail-safe fluid control. Further, since the electric motor and the valve body are connected through the threaded portion, the valve body is prevented from moving up and down due to the influence of fluid force. Furthermore, by using a pulse motor as the electric motor, digital control becomes possible, allowing direct control with a microcomputer.

"Effects of the Invention" As described above, according to the electric governor valve of the present invention, the governor valve body can be stably driven and controlled by the large driving force of the electric motor, and the flow rate can be controlled proportionally to the amount of electrical input signal. . In addition, the valve automatically closes in the event of a power outage, etc.
Fail-safe fluid control is possible, the valve body does not move up and down due to the influence of fluid force, and direct microcomputer control is possible by adopting a pulse motor that can be controlled by digital signals.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the electric governor valve of the present invention, FIG. 2 is a partial sectional view showing the valve shown in FIG. 1 when it is open, and FIG. FIG. 3 is a diagram showing the relationship between the opening area and rotor rotation angle. 100. Valve seat, 2. ,, valve body, 300. pressure receiving body,
400. Electric motor, 500. spring garden

Claims (1)

[Claims] 1. A fixed valve seat disposed in a fluid flow path penetrating the valve body, a movable valve body that controls the opening and closing of the fixed valve seat in response to the valve seat, and a movable valve body connected to the movable valve body. and a pressure-receiving body that biases the movable valve body in a closing direction in response to fluid pressure;
An electric governor valve that proportionally changes the amount of electrical input signal to the motor and the amount of change in the valve seat opening area of the movable valve body. 2. A fixed valve seat disposed in a fluid flow path penetrating the valve body, a movable valve body that controls opening and closing of the fixed valve seat corresponding to the valve seat, and a movable valve body connected to the movable valve body to control fluid pressure. In a governor valve equipped with a pressure receiving body that receives pressure and urges the movable valve body in a closing direction, an electric motor is provided that drives the movable valve body by electric input,
An electric governor valve that proportionally changes the amount of an electrical input signal to an electric motor and the amount of change in the valve seat opening area of a movable valve body, and is provided with a spring that biases the valve body in the closing direction. 3. A fixed valve seat disposed in a fluid flow path penetrating the valve body, a movable valve body that controls opening and closing of the fixed valve seat corresponding to the valve seat, and a movable valve body connected to the movable valve body and receiving fluid pressure. In the governor valve, the governor valve includes a pressure receiving body that biases the movable valve body in the closing direction, and an electric motor that drives the movable valve body by electric input is provided,
An electric governor valve that proportionally changes the amount of electrical input signal to the electric motor and the amount of change in the valve seat opening area of the movable valve body, and that the rotating shaft of the electric motor and the valve rod shaft of the valve body are screwed together.