JPH0227410A - Automatic setting constant flow valve - Google Patents

Abstract

PURPOSE:To obtain an automatic back pressure regulating valve which is fast in responsibility and inexpensive by inputting a desired setting flow quantity from a setting input means, operating the optimum valve body position or the energizing force of a spring with a controller and driving a driving means. CONSTITUTION:The title valve provides a spring 20 in which one edge is fixed in a valve casing and other edge is provided so as to energize a valve seat 14 in an inlet 6 direction. A driving means 4 to change the position of a valve body 26 or the energizing force of the spring 20 is fitted to a valve casing and the setting flow quantity, the displacement quantity of the valve 26 or the relation of the energizing force of the spring 20 are stored in a controller 62 to provide a setting input means 64. The desired setting flow quantity is inputted from the setting input means 64, the position of the optimum valve body 26 or the energizing force of the spring 20 is operated by the controller 62 and only for the adjusting quantity, the driving means 4 is driven. Thus, the driving part is operated by a necessary quantity at a stroke toward the target value, the valve is mechanically and quickly operated, the control with a quick responsibility can be controlled and the setting flow quantity can be also changed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a valve for controlling the amount of fluid flowing in a pipe, and particularly to a constant flow valve used to maintain a constant flow rate regardless of pressure fluctuations.

<Prior Art> In general, a constant flow valve self-adjusts the flow of fluid through the valve by grasping the pressure difference before and after the valve and opening/closing the valve to achieve the set flow rate.

When setting the flow rate to a desired value, various spring forces that bias the valve seat and valve body are selected in order to obtain a valve that allows the desired flow rate to flow. Therefore, it is extremely inconvenient when changing the setting flow m frequently. Additionally, remote control and automatic control are not possible.

Conventionally, automatic control valves have been used in such cases. An automatic control valve detects the controlled variable of the controlled object, compares it with the target value, disconnects < 71 based on the deviation, processes commands, etc. in the form of a signal, and controls the operating part of the electric motor or fluid actuator that operates the valve body. Weakened by things that control us.

When used as a constant flow f-valve, a flowmeter that outputs an electrical signal detects diversion in the pipe, compares it with a target value input through a setting mechanism, processes it signally, and controls the actuator 11- of an electric motor, etc. Proportional, differential, and integral operations, so-called PID control, are performed throughout the day.

<Problems to be Solved by the Invention> However, when performing the above-mentioned PID control, P for determining the valve operation amount, 1. It is difficult to determine each constant of D, and high skill and experience are required. In addition, in this control method, the valve is operated while comparing the actual measured value so that it approaches the target value, so the response is very poor, and it takes a long time to reach the set temperature, or the temperature goes too far. This is because the pressure is not controlled by the pressure, but by adjusting the valve opening, so there is no linear relationship between the amount of operation given to the valve by the operating part such as the actuator and the pressure. This is because control becomes complicated.

Further, the automatic control valve described above is expensive and necessary. This is because the valve body must be operated directly and rapidly in small increments using a seven-wheel drive unit such as an electric motor, which requires a high-output actuator and control equipment that performs complex signal processing.

Therefore, the technical problem of the present invention is to provide an automatic back pressure regulating valve that can be controlled remotely or automatically, and whose set pressure can be easily changed, with a simple control method, quick response, and low cost. There is a particular thing.

<Means for Solving the Problems> The technical means of the present invention taken to solve the above problems is to provide a conical valve body that temporarily expands toward the outlet side in a valve casing that forms an inlet and an outlet. An annular valve seat that surrounds the valve body and opens in the direction of fluid flow is arranged inside the valve cushion, and a spring that has one end fixed within the valve cushion and a narrow end that biases the valve seat toward the inlet direction. In a constant flow valve, a driving means for changing the position of the means for changing the position of the valve body or the biasing force of the spring is attached to the valve casing, and the drive means for changing the position of the means for changing the position of the valve body or the biasing force of the spring is attached to the valve casing, and the set flow rate and the amount of displacement of the valve body or the biasing force of the spring are adjusted. By storing the relationship in a controller equipped with a setting input means, and inputting a desired set flow rate from the setting input means, the controller calculates the optimal valve body position or spring biasing force, and calculates the optimal valve position or spring biasing force. The driving means is driven by the calculated adjustment amount.

<Effect> The operation of the above technical means is as follows.

In general, the amount of fluid passing through a valve is determined by the valve opening area (
This is determined by the fluid passage area) and the differential pressure before and after the constant flow valve.In this case, when fluid flows due to an arbitrary pressure difference between the front and rear of the constant flow valve, the fluid will push the valve seat against the spring due to the flow resistance. It is displaced toward the exit against the force and stops when it balances the spring force. At this time, a certain amount of fluid passes through the valve opening area formed between the valve seat and the valve body.

Next, if the pressure on the inlet side of the valve increases and the differential pressure across the valve increases, the flow rate passing through the valve port will increase, but due to the increase in flow resistance that accompanies the increase in flow, the valve seat will also be affected. It is further displaced toward the exit side. When the valve seat is displaced, the distance from the conical valve body becomes shorter, and the area of the valve opening becomes smaller. Therefore, even if the differential pressure increases, the valve opening area decreases accordingly, so the flow Φ does not increase and remains constant.

To change the set flow rate, the distance between the valve seat and the valve body can be changed by changing the displacement of the valve body or the spring force that biases the valve seat, and the flow rate can be varied even with the same differential pressure. Therefore, the adjustment amount of the valve body (
By storing the relationship between the position (position) and the set flow rate in the memory device in the controller, and inputting the desired settings from the setting input means, the controller's arithmetic unit calculates the optimal adjustment amount for the valve body based on the above relationship. Calculate. A control signal based on the calculated adjustment amount is sent to the drive unit to operate the valve, and the valve body moves to a desired value and then stops. In order to move the drive means by the calculated adjustment amount and then stop, a position detection means such as a potentiometer is used, or a stepping motor is used to control the position of the valve body or the operating shaft of the drive means itself.

Alternatively, a means for changing the biasing force of the spring may be provided, and the relationship between the adjustment (position) of the means and the set pressure may be stored and controlled in the same manner as described above.

<Effect of the invention> The present invention produces the following unique effects.

The automatic back pressure regulating valve of the present invention includes P, 1. Control is simple because there is no need to determine the constant of D, and since the control method does not operate the valve opening degree via the drive unit while comparing the target value and the actual value, it can quickly move toward the target value. The drive unit is operated as required, and the valve is mechanically operated quickly as in the past, allowing control with quick response, and the set flow rate can be easily changed.

Furthermore, once the initial setting is completed, the drive section does not have a chance to operate until the set pressure is changed next time, and the operating time is short, so the lifespan is longer than that of an automatic control valve.

<Example> An example showing a specific example of the above technical means will be described. (
(See FIG. 1) This embodiment consists of a constant flow valve section 2 and a drive section 4.

A cylindrical valve chamber 12 is provided in a main body 10 that forms an inlet 6 and an outlet 8, and a cylindrical valve seat 14 is accommodated in the main body 10 so as to be movable.
A spring 20 is arranged between the protrusion 18 at the rear of the valve 2 and the valve seat 14 to constantly bias the valve seat 14 toward the inlet side. It is then locked with a ring 16 to restrict its movement.

A bellows chamber 22 is provided in the upper part of the main body 10, and a bellows 24 is housed therein. The lower end surface of the bellows 24 is formed integrally with a valve body 26 having a conical tip, and its valve shaft 28 is guided by a bearing 30 and slides, so that the valve body 26 moves in the direction in which fluid flows within the valve chamber 12. It is displaced as the bellows 24 expands and contracts. The bellows 24 is always urged upward by a bellows 34 interposed between it and the bearing portion 32 below.

On the other hand, the seventh flange 36 of the drive section 4 and the upper seven flange portion of the bellows chamber 22 are attached with bolts, sandwiching the heat insulating material 38, the internally threaded member 40, and the seventh flange 42 of the bellows 24. The drive unit 4 includes a motor 44. Potentiometer 46. Reducer 4
8 and an electronic component for driving the motor (not shown).

The output shaft 50 of the speed reducer 48 is connected to an adjusting screw 56 by a spline. This spline joint portion 52 includes rollers 54a and b provided on a roller shaft passing through the output shaft 50 in the radial direction.
On the other hand, the upper part of the adjustment screw 56 is formed into a cylindrical shape, and the cylindrical part has a groove 56a in the axial direction.

b, and the rollers 54a and 54b are fitted into the grooves. In addition, the adjustment screw 56 and the female thread member 40
and screw them together. Therefore, when the output shaft 50 rotates left and right, the rollers 54a and b engage with the grooves 56a and b, thereby transmitting the rotation to the adjustment screw 56. The adjustment screw 56 is screwed to the female threaded member 710 so that its rotation is displaced in the axial direction, and the displacement is caused by sliding in the grooves 55a and 55b. Part numbers 58 and 60 are thrust bearings. Adjustment screw 56
When the lower end of the bellows 24 comes into contact with the inner lower end of the bellows 24, the displacement is transmitted to the valve body 26.

The operation of the constant flow valve section 2 is as follows. When fluid is flowing at an arbitrary pressure difference between the inlet and the outlet, the flow resistance causes the valve seat 14 to be displaced to the position shown in FIG.
At that time, the flow rate is determined by the opening area determined by the distance X from the valve body 26. Next, when the inlet pressure increases and the differential pressure across the valve port becomes large, the flow rate tends to increase, but the flow resistance also increases, causing the valve seat 14 to further displace. When the valve seat 14 is displaced, since the valve body 26 is conical, its distance 1i1tY becomes smaller, that is, the opening area becomes smaller, and as a result, even if the differential pressure increases, the flow rate does not increase and is kept constant.

Here, if you want to change the set flow rate, you can move the valve body 26, adjust the distance from the valve seat 14, and change the opening area arbitrarily. Therefore, the relationship between the displacement of the valve body 26 and the set flow rate can be determined by experiment. You can do what you want.

The computer in the controller 60 stores the relationship between the set flow rate and the adjustment amount (position) of the valve body 26.

Therefore, when the set flow rate is input from the setting input device 64, the adjustment amount of the valve body 26 is calculated from the above-mentioned stored relationship in the adjustment 5162, and the motor 44 is driven by the control signal based on the calculated adjustment value to make the adjustment. The screw moves the valve body 26 through the bellows 24. The displacement of the adjusting screw 56 is detected by the potentiometer 46, and if this signal matches the calculated control signal, the motor 44 is stopped. In this way, simply by manually adjusting an arbitrary set flow rate, a constant flow of fluid can be easily flowed without complicated control.

If even more precise control is required, the flow rate in the pipe can be detected using a flow fLH4 that can be electrically output, and if a deviation occurs by constantly comparing it with the standard value, the pressure difference can be determined from the above relationship. The correction operation can be performed by recalculating the adjustment φ of the valve body corresponding to .

In the above embodiment, the set flow rate was varied by displacing the valve body, or
By moving the protrusion 18 that fixes the spring 20 back and forth, the biasing force applied to the valve seat can be changed and the set flow rate can be varied. In this case, the protrusion 18 is constructed to be movable and operated using the adjustment screw 56.

2: Constant flow valve part 6: Entrance 11: Valve seat 26: Valve body 62: Controller

Claims (1)

[Claims] 1. Inside the valve casing that forms the inlet and outlet, there is a conical valve body that expands slightly towards the outlet, and an annular valve seat that surrounds the valve body and slides in the fluid flow direction inside the valve casing. and a means for changing the position of the valve body or the biasing force of the spring in a constant flow valve equipped with a spring having one end fixed in the valve casing and the other end biasing the valve seat toward the inlet. A driving means for changing the position of is attached to the valve casing, the relationship between the set flow rate and the displacement amount of the valve body or the biasing force of the spring is stored in a controller equipped with a setting input means, and the desired setting is made from the setting input means. When a flow rate is input, the controller calculates the optimal valve body position or spring biasing force, and the automatic setting constant flow valve is configured to drive the driving means by the calculated adjustment amount.