JPS6371710A - Automatic set reducing valve - Google Patents

Abstract

PURPOSE:To perform the control of quick responsiveness by providing an actuator, which operates a means which controls the elastic force of a pressure set spring, for a reducing valve having a diaphragm structure. CONSTITUTION:The absolute position in the axial direction of an adjusting screw which controls the elastic force of a pressure set spring 16, namely, relations between displacement in the axial direction of a disk 24 and a set pressure target value are stored in a computer in a controller; and when a desired set pressure target value is inputted through a controller 32, a set signal as the position signal of the adjusting screw is operated and is sent to a comparing controller 31. The comparing controller compares the signal from a position detecting sensor 26 with said signal; and if the deviation detection value is larger than a deviation reference value, the signal which operates the actuator is sent to a driver 30 so that the deviation detection value is about zero. In this case, the actuator is stopped if the deviation detection value does not become zero in a certain time though the actuator is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a valve for controlling the pressure of a fluid, and relates to an automatically setting pressure reducing valve that reduces the pressure of a fluid on the primary side so as to maintain a constant pressure on the secondary side. .

What is generally referred to as a pressure reducing valve has a structure in which a main valve, such as a piston valve, is operated directly by displacing a diaphragm, or indirectly by operating a pilot valve.

The fluid pressure on the secondary side is applied to one side of the diaphragm, and the elastic force of a pressure setting spring is applied to the other side. If the two blades are unbalanced, the diaphragm is displaced, and the valve body is operated to adjust the amount of fluid passing, maintaining the pressure on the secondary side at a value corresponding to the elastic force of the pressure setting spring.

To set the fluid pressure on the downstream side to a desired value, while checking the pressure on the downstream side with a pressure gauge, manually operate the adjusting screw screwed into the valve casing to adjust the elastic force of the pressure setting spring. Adjust so the pressure gauge points to the desired pressure value. Therefore, it is extremely inconvenient when changing the set pressure frequently. Additionally, remote control and automatic control are not possible.

Prior art Therefore, in the past, the applicant of the present application
As proposed in this issue, a motor-driven actuator is attached to the means for adjusting the elastic force of the pressure setting spring of the pressure reducing valve, and the deviation between the fluid pressure on the secondary side and the set pressure target value is detected and the deviation is calculated. is larger than the standard deviation value, the motor is driven and the adjusting screw is operated so that the detected deviation value becomes zero. There is also an automatic pressure reducing valve that stops the motor when the pressure reaches almost zero.

Compared to general automatic control valves, this control valve is inexpensive, does not require complicated control, and has quick response.

Problems to be Solved by the Invention As a flow rate characteristic of a pressure reducing valve, there is a phenomenon in which as the flow m increases, the set pressure decreases. To compensate for this, the automatic setting pressure reducing valve drives the motor and tightens the adjustment screw so that the deviation between the secondary fluid pressure and the set pressure target value becomes zero.
The main valve port is further opened to increase the flow rate and operate to increase the pressure.

However, there is a limit to the degree of opening of the main valve port, and once the main valve port is fully open, no matter how much the adjustment screw is tightened, the pressure will no longer increase and will only continue to decrease.

Normally, when the flow rate decreases, the pressure will recover and rise, but in this situation, if the adjustment screw is tightened more than necessary, the flow rate will decrease. ,
This time, on the contrary, the secondary pressure becomes too high than the set target value. From this state, the motor is driven again toward the set target value to return the pressure to its original value. In this way, the control returns to its original state by an excessive amount, resulting in control with poor responsiveness.

Means for Solving the Problems The technical means of the present invention taken to solve the above-mentioned technical problems is to attach an actuator for operating a means for adjusting the elastic force of a pressure setting spring to a pressure reducing valve having a diaphragm structure. , When the detected deviation value is larger than @difference standard 1st shift (
This is characterized by having control for stopping the actuator if the detected deviation value does not become approximately zero within a certain period of time even if the actuator operates.

action The operation of the above technical means is as follows.

Enter the desired set pressure through the controller. The fluid pressure on the secondary side is constantly or periodically measured by a pressure sensor. The comparison regulator detects the deviation between the fluid pressure on the secondary side and the set pressure target value, and compares it with a predetermined deviation reference value. @If the detected difference value is larger than the B difference reference value, the detected deviation value is approximately A signal is sent to the driver to operate the actuator so that the value becomes zero.

A signal is sent to the driver, the actuator is operated, and the secondary pressure increases and attempts to approach the set target value, but the main valve port is fully open and the secondary pressure does not change within a certain period of time. If this occurs, a dry drive stop signal is sent to prevent the adjustment screw from being tightened more than necessary.

Unique effects The present invention produces the following unique effects.

The adjustment screw no longer moves too far, and there is no need to return it to its original position, allowing for quick-response control.

Also, the motor does not operate more than necessary, so it takes 7 hours.
The durability of the parts is good, the power consumption is low, and the lifespan is long.

Embodiment An embodiment illustrating a specific example of the above technical means will be described (see FIG. 1).

The automatic setting pressure reducing valve of this embodiment has a mechanical pressure reducing valve section 1.
, an electric motor section, and a control section.

The pressure reducing valve section 1 is similar to the conventional one. Fluid inlet 2 and outlet 3 are connected and attached to primary passage 4 and secondary passage 5, respectively. The main valve lower is opened and closed by the main valve body 6. The main valve body 6 is biased in the valve closing direction by a spring, and is connected to a piston 8 via a valve stem.

The fluid pressure on the outlet 3 side acts on the lower surface of the piston 8, and the fluid pressure on the inlet 2 side is introduced into the upper surface through passages 9 and 11 while being controlled by the pilot valve body 12. The pilot valve element 12 is biased by a spring in the valve closing direction, contacts the lower surface of the diaphragm 13 via the valve stem, and receives an operating force in the valve opening direction due to its displacement.

Therefore, when the diaphragm 13 is displaced downward, the pilot valve body 12 is pushed down, and the fluid in the inlet 2 is transferred to the passage 9.
1 and above the piston 8 , the main valve body 6 is pushed down by the piston 8 to open the main valve lower, and the fluid at the inlet 2 flows to the outlet 3 . Further, when the diaphragm 13 is displaced upward, the pilot valve body 12 is pushed up by the spring, the passage 9 is closed, and the fluid above the piston 8 escapes to the outlet 3 through the orifice 50, causing the piston 8 and the main valve body is pushed up by the spring, blocking the main valve lower.

The upper part of the diaphragm 13 is connected to the outside air through the pores 14, and the outside air pressure is maintained at a constant level. Further, the lower end of the pressure setting spring 16 comes into contact with the upper surface of the diaphragm 13, and an elastic force acts thereon. The lower end of the adjusting screw 17 is in contact with the upper end of the pressure setting spring 16 via a spring support member, and the amount of compression of the constant pressure g2 spring is adjusted by advancing and retreating as the adjusting screw 17 rotates.
The elastic force acting on the diaphragm 13 can be adjusted. The adjusting screw 17 is threadedly connected to an internally threaded member attached to the spring receiving case 15, which forms part of the valve casing.

The electric motor section and yoke member 18 are attached to the spring housing case 15. At this time, the adjusting screw 17 and the output shaft 20 are aligned on the same axis, and the hexagonal head 42 and the lower end of the output shaft 20 are connected.

The output shaft 20G forms the axis of the ball spline 21, and a locking member 23 is provided at the upper end. A cylindrical connecting member 22 is fixed to one of the outer peripheral members of the ball spline 21. A disk 24 is formed at the bottom of the output shaft 20. A position detection sensor 26 is attached to the bottom surface of the mounting base 25, and the detection rod 3
3 is arranged so as to resemble the side surface of the disk 24.

The electric motor 29 and the reduction gear tJ 28 are fixed to the mounting base 25, and the output shaft 27 thereof is inserted and fixed to the connecting member 22.

Therefore, when the two electric VJ machines are rotated, the output shaft 27 of the reducer 28 rotates, the outer peripheral member 19 of the spline 21 rotates together with the connecting member 22, and the output shaft 20 moves up and down depending on the direction of rotation. The adjustment screw 17 rotates to the right or left.

At the same time, the detection rod 33 of the sensor 26 moves up and down following the up and down movement of the disk 24, and captures the moving foot as a position signal.

Place the screwdriver 30 next to the electric motor 29 and remove the cover 3.
6, and take measures to prevent dust and moisture. The illustration of the power line and its inlet is simplified.

The control section includes the above-mentioned position detection sensor 26 and comparison regulator 3.
A controller 32 for inputting a set pressure target value, and a pressure sensor 40 attached to the secondary passage. Reference number 34 is a terminal block, which is connected to the motor driver 30 and the sensor 26. Terminal block 34 and comparison controller 3
1 with signal wire 37, pressure sensor 40 with three signal wires,
The controller 32 is also connected to the comparator controller 31 via a signal line. The comparator 31 may be placed at the terminal block 34.

The fluid pressure in the secondary passage 5 is detected by a pressure sensor 40 and sent to the controller 32 either constantly or at relatively short intervals.

The computer in the controller stores the absolute position in the axial direction of the adjusting screw 17 that adjusts the elastic force of the pressure setting spring 16, that is, the relationship between the axial displacement of the disk 24 and the set pressure target value. When a desired set pressure target value is inputted through the meter 32, a setting signal as a position signal of the adjustment screw is calculated and sent to the comparator controller 31. The comparison controller compares the signal from the position detection sensor 26 with the above signal, and when the detected deviation value is larger than the deviation reference value, a signal is sent to the driver 30 to operate the actuator so that the detected deviation value becomes approximately zero. It will be done. Thereafter, the electric embroidery 29 is operated to displace the adjusting screw 17 to the target value all at once.

An operation signal for stopping the electric motor 29 when the detected deviation value becomes almost zero, that is, when the detected deviation value enters a range of another predetermined minute deviation reference value that is sufficiently smaller than the above-mentioned deviation reference value. is sent to driver 3Q. At this time, the comparison loop loops through the comparison controller, the driver, the electric motor, the position detection sensor, and the comparison controller again.

In order to make even more accurate settings, the signal from the pressure sensor 40 is compared with the relationship between the set pressure stored in the controller and the movement of the adjustment screw, and the calculation is processed to calculate how much the adjustment screw should be displaced. The signal is sent to the comparator and fine-tuned.

When the flow rate increases and the set pressure begins to decrease, the pressure sensor immediately detects this and sends a signal to move the actuator to increase the pressure. However, there is a limit to the opening degree of the main valve, and if the pressure does not increase even if the adjusting screw is tightened further, the motor will stop after a certain period of time, and the adjusting screw will change when the pressure no longer increases. The motor rotates in reverse to return to normal condition.

If the flow rate decreases this time, the adjustment screw has not been tightened too much, so even if the secondary pressure starts to rise, you can take immediate action and stabilize it at the target value.

Further, even when the secondary pressure changes due to temporary pressure or load fluctuation, the signal from the pressure sensor 40 is always input, compared, calculated, and finely adjusted.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electric pressure reducing valve according to an embodiment of the present invention and a block diagram of a control section superimposed thereon.

Claims (1)

[Claims] 1. An actuator that operates the means for adjusting the elastic force of the pressure setting spring is attached to the diaphragm structure pressure reducing valve, and when the detected deviation value between the fluid pressure on the secondary side and the set pressure target value is larger than the deviation reference value. , the actuator is operated to stop the actuator when the detected deviation value becomes almost zero, and when the detected deviation value does not become almost zero within a certain period of time, the actuator is stopped. Automatic setting pressure reducing valve.