JPH0381166B2 - - Google Patents

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 forces are unbalanced, the diaphragm is displaced, the valve body is operated to adjust the amount of fluid passing, and the pressure on the secondary side is maintained 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.

Therefore, in such cases, automatic control valves are used. An automatic control valve is a system that detects the controlled variable of the controlled object, compares it with a target value, processes judgments and commands based on deviations, etc. in the form of signals, and controls operating parts such as electric motors and fluid actuators that operate the valve body. It is something to do.

When used as a pressure reducing valve, a pressure sensor detects the pressure on the secondary side, compares it with a target value input through a setting mechanism, processes it as a signal, and operates an actuator such as an electric motor to perform proportional operation. Or make it perform differential/integral operations. Therefore, remote control and automatic control are possible.

However, automatic control valves are expensive. This is because the valve body must be operated directly and rapidly in small increments using an actuator such as an electric motor, which requires a high-output actuator and a controller that performs complex signal processing.

Prior Art Therefore, the applicant filed a proposal to solve the above problem as Japanese Patent Application No. 59-207779. This is a pressure reducing valve with a diaphragm structure that is equipped with an actuator that operates a means for adjusting the elastic force of a pressure setting spring, and the detected deviation value between the fluid pressure on the secondary side and the set pressure target value is lower than the deviation reference value. When the detected deviation value is large, the actuator is operated and the actuator is stopped when the detected deviation value becomes almost zero.

Problems to be Solved by the Invention In the structure described above, there is a problem in that as the pressure setting spring is tightened, the generated force increases, resulting in insufficient torque of the actuator.

The technical problem of the present invention is therefore to ensure that tightening of the pressure setting spring does not result in insufficient torque.

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problems is an actuator that operates a means for adjusting the elastic force of a pressure setting spring in a pressure reducing valve having a diaphragm structure. If 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, operate the actuator and stop the actuator when the detected deviation value becomes almost zero. In the automatic setting pressure reducing valve, a magnetic member is fixed to the means for adjusting the elastic force of the pressure setting spring, and the means for adjusting the elastic force of the pressure setting spring is tightened opposite to the magnetic member. A magnetic member is arranged to attract the magnetic member when it is inserted.

Effect 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. When the detected deviation value is larger than the deviation reference value, the detected deviation value becomes almost zero. A signal is sent to the driver to operate the actuator as desired.

The actuator is operated by a screwdriver, and a conventional elastic force adjusting means such as an adjusting screw is rotated to the right or left to advance or retreat, thereby adjusting the elastic force of the pressure setting spring. As a result, the diaphragm is displaced and the valve body is operated, the amount of fluid passing increases or decreases, and the fluid pressure on the secondary side increases or decreases.

A magnetized member is fixed to a means for adjusting the elastic force of the pressure setting spring, and when the means for adjusting the elastic force of the pressure setting spring is tightened to face the magnetic member, the magnetic member is attracted to the magnetic member. Since the members are arranged, as the means for adjusting the elastic force of the pressure setting spring is tightened, the attractive force of the magnetic member increases and absorbs the force generated by the pressure setting spring.

Unique effects The present invention produces the following unique effects.

With a simple structure that attaches a magnetic member and a magnetic member, the force generated by the pressure setting spring can be absorbed, and the actuator will not run out of torque.

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

The automatically set pressure reducing valve of this embodiment is composed of 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 port 7 is opened and closed by the main valve body 6. The main valve body 6 is disposed so as to be biased in the valve closing direction by a spring, and is connected to the 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, the fluid in the inlet 2 is introduced above the piston 8 through the passages 9 and 11, and the main valve body 6 is pushed down by the piston 8 to Valve port 7 is opened and fluid at inlet 2 flows to outlet 3. Furthermore, 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 6 to escape. is pushed up by the spring, and the main valve port 7 is closed.

The upper part of the diaphragm 13 is connected to the outside air through the pores 14, and is maintained at a substantially constant outside pressure. In addition, a pressure setting spring 1 is provided on the upper surface of the diaphragm 13.
The lower end of 6 hits and an elastic force acts on it. The lower end of the adjusting screw 17 is in contact with the upper end of the pressure setting spring 16 via a spring receiving member, and the amount of compression of the pressure setting spring is adjusted by moving the adjusting screw 17 forward and backward as it rotates, thereby reducing the elastic force acting on the diaphragm 13. It is adjustable. 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 part and the yoke member 18 are placed in the spring housing case 1.
Attach to 5. At this time, the adjusting screw 17 and the output shaft 20 are aligned on the same axis, and the hexagonal head 43 and the lower end of the output shaft 20 are connected.

The output shaft 20 forms the shaft of a ball spline 21, and a locking member 23 is provided at the upper end. A cylindrical connecting member 2 is attached to the outer peripheral member 19 of the ball spline 21.
Fix 2. A disk 24 is formed at the bottom of the output shaft 20. A position detection sensor 26 is attached to the lower surface of the mounting base 25, and its detection rod 33 is arranged so as to touch the side surface of the disk 24.

An electric motor 29 and a speed reducer 28 are fixed to a mounting base 25, and an output shaft 27 thereof is inserted and fixed to a connecting member 22.

Therefore, when the electric motor 29 is rotated, the reducer 28
The output shaft 27 rotates, the outer peripheral member 19 of the spline 21 rotates together with the connecting member 22, and depending on the direction of rotation, the output shaft 20 rotates while moving up and down, and 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 the amount of movement is captured as a position signal.

Place the driver 30 next to the electric motor 29,
It is covered with a cover 36 to take dust-proof and moisture-proof measures. The illustration of the power line and its inlet is simplified.

The control section includes the above-mentioned position detection sensor 26, comparison regulator 31, regulator 32 for inputting the set pressure target value, and pressure sensor 4 attached to the secondary passage.
Consists of 0. Reference number 34 is a terminal block, which is connected to the motor driver 30 and the sensor 26. Connect the terminal block 34 and comparison controller 31 to the signal line 3
At 7, the pressure sensor 40 is connected to the comparator regulator 31 by a signal line 39 and the regulator 32 is also connected to the comparator regulator 31 by 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 inside the controller has a pressure setting spring 1.
The absolute position in the axial direction of the adjusting screw 17 for adjusting the elastic force of the disk 24, that is, the relationship between the axial displacement of the disk 24 and the set pressure target value is stored, and the desired set pressure target value is adjusted through the controller 32. Once input, a setting signal as a position signal of the adjusting 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 almost zero. It will be done. Thereafter, the electric motor 29 is operated to displace the adjusting screw 17 to the target value all at once.

When the detected deviation value becomes almost zero, that is, when the detected deviation value falls within the range of another predetermined minute deviation reference value that is sufficiently smaller than the above-mentioned deviation reference value,
An operation signal to stop the electric motor 29 is sent to the driver 30. The comparison loop at this time is the comparison regulator,
Loop the driver, electric motor, position detection sensor, and comparison regulator 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 amount of movement of the adjustment screw, and calculations are performed to determine how much the adjustment screw should be displaced. The signal is sent to the comparator and fine-tuned.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an electric pressure reducing valve according to an embodiment of the present invention, with a block diagram of a control section superimposed thereon. DESCRIPTION OF SYMBOLS 1...Pressure reducing valve part, 5...Secondary side passage, 6...Main valve body, 8...Piston, 12...Pilot valve body, 13...Diaphragm, 15...Spring housing case, 16...Pressure Setting spring, 17... Adjustment screw, 20... Output shaft, 21... Spline, 26
... Position detection sensor, 27 ... Output shaft of reducer, 29 ... Electric motor, 30 ... Driver, 31
... Comparison regulator, 32 ... Controller, 40 ... Pressure sensor, 41 ... Magnetic member, 42 ... Magnetized member.

Claims (1)

[Claims] 1 Attach an actuator that operates the means for adjusting the elastic force of the pressure setting spring to the diaphragm structure pressure reducing valve, and check that 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. Sometimes, in an automatic setting pressure reducing valve that operates the actuator and stops the actuator when the detected deviation value becomes almost zero, a magnetic member is sometimes used as a means for adjusting the elastic force of the pressure setting spring. An automatic setting pressure reducing valve is provided with a fixed magnetic member that attracts a magnetized member when a means for adjusting the elastic force of a pressure setting spring is tightened to face the magnetized member.