JP2002116825A - Pressure controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the excess rotation of a potentiometer. SOLUTION: A pressure controller 11 is constituted of a pressure control valve 14, a pilot valve 16, a pressure setting part 17, and a control circuit 18. The pressure setting part 17 is provided with an excess rotation preventing mechanism 80 for preventing the excess rotation of a potentiometer 56. The excess rotation preventing mechanism 80 is constituted of a moving member 82 engaged with a large diameter gear 64 for transmitting the rotation of a rotary shaft 53 to the potentiometer 56 so as to be movable to an axial direction and a stopper bolt 84 for controlling the movable range of the moving member 82 to the axial direction. The movable range of the moving member 82 is limited to a movement distance corresponding to the detectable angle of the potentiometer 56 by the stopper bolt 84 so that the rotation angle of the rotary shaft 53 can be also limited to not more than the detectable angle of the potentiometer 56 via the large diameter gear 64 engaged with the moving member 82.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control device, and more particularly to a pressure control device having a rotation detector for detecting a rotation angle of a main shaft for driving a pressure setting spring for adjusting a set pressure of a pressure control valve. .

[0002]

2. Description of the Related Art For example, in a pressure control device installed in a line for supplying city gas, a diaphragm operated by using pressure is employed as a driving unit of a pressure control valve, and a pilot valve is operated by a pressure setting device. The pressure (secondary pressure) on the downstream side of the pressure control valve in the gas supply line is set by adjusting the pilot pressure (control pressure) supplied from the pilot valve to the diaphragm chamber of the pressure control valve by operating the valve section of Pressure (target pressure) is set.

A pressure control device of this type includes a pressure control valve for controlling a secondary pressure of a gas supplied to a downstream pipe, and a diaphragm for adjusting a control pressure supplied to an actuator of the pressure control valve. A pressure setting device having a pilot valve provided, a motor for operating a diaphragm so that a secondary pressure becomes a predetermined set pressure, and a potentiometer for detecting a rotation state of the motor, and a control data registered in advance. And a control circuit for controlling the drive of the motor of the pressure setting device so that the secondary pressure becomes a predetermined set pressure.

[0004] The pressure setting device includes a pilot valve and a pressure setting unit. The pilot valve is connected to an actuator for driving the pressure control valve, and the actuator is driven in accordance with the operation of the pilot valve to open and close the pressure control valve. A pressure setting spring is disposed below the diaphragm provided inside the pilot valve.

The pressure setting spring has an upper end portion in contact with the diaphragm of the pilot valve and a lower end portion in contact with the spring receiver. The spring receiver is configured to move up and down by rotation of the main shaft. That is, a male screw portion is formed on the main shaft, a female screw portion is formed on the spring receiver, and each screw portion is screwed together.
Further, the main shaft is connected to a motor provided in the pressure setting section.

Accordingly, the main shaft is rotated by the driving of the motor, and the spring receiver moves up and down accordingly, whereby the amount of compression of the pressure setting spring is increased or decreased. The load applied to the diaphragm by the pressure setting spring increases and decreases as the amount of compression increases and decreases, so that the set pressure of the pilot valve is controlled by a pressure setting device.

As a potentiometer provided in the pressure setting device, a resistance potentiometer that can obtain a stable detection result at low cost is generally used. This potentiometer is connected to the above-mentioned main shaft, and is configured to change the resistance value as the main shaft rotates. Therefore, the rotation state of the motor (ie, the rotation state of the main shaft) can be detected from the output of the potentiometer (change in resistance value).

The pressure setting device having the above configuration operates as follows when the pressure setting is changed.

It is known that the output value of the potentiometer provided in the pressure setting device is proportional to the secondary pressure (pressure downstream of the pressure control valve of the gas supply line) controlled by the pressure control valve. Therefore, the control circuit uses this to set the output value of the potentiometer (set output value) corresponding to the set pressure after the change, and set the motor so that the output value output from the potentiometer becomes the set output value. Drive control. When the output value from the potentiometer matches the set output value, the secondary pressure becomes the set pressure.

[0010]

As described above, in order to set the secondary pressure to the set pressure, drive control of the motor is performed based on the output value output from the potentiometer so that the output value becomes the set pressure. Done. Therefore, in the control processing performed by the pressure setting device and the control circuit, the potentiometer is a very important element. In addition, since the resistance type potentiometer is configured by a variable resistor that detects a rotation angle by sliding a slider (wiper) rotatably supported by a resistor formed in an arc shape, There is a limit (less than 360 degrees) in the detectable range due to the rotation of the slider, and if rotation beyond the detection limit is applied, the slider may be forcibly over-rotated and damaged.

On the other hand, the shaft of the potentiometer is connected to the main shaft through a gear, and the main shaft is driven by a motor. Therefore, if the motor excessively rotates, the main shaft may rotate beyond the detection limit of the potentiometer. Alternatively, the gear connecting the main shaft and the shaft of the potentiometer may be disengaged and the rotation of the main shaft may not be transmitted to the potentiometer.

As described above, when the main shaft rotates beyond the detection limit of the potentiometer and the potentiometer is damaged, the slider is deformed, or the gear connecting the main shaft and the shaft of the potentiometer comes off. As a result, an accurate detection value cannot be obtained, and accordingly, there arises a problem that proper drive control of the pressure control valve cannot be performed.

In the case where a potentiometer having a built-in stopper mechanism for preventing the shaft of the potentiometer from rotating excessively beyond the detection limit is employed,
A problem that the gear connected to the shaft of the potentiometer is disconnected from the shaft of the potentiometer, which is prevented from rotating by the stopper mechanism, makes it impossible to perform appropriate drive control of the pressure control valve as in the case without the above-described stopper mechanism. was there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a pressure control device that improves reliability by preventing rotation exceeding a detection limit from being transmitted to a potentiometer. I do.

[0015]

In order to solve the above problems, the present invention has the following features.

According to the present invention, there is provided a transmission path for transmitting rotation to a potentiometer for detecting a rotation angle of a main shaft for moving and biasing a spring receiver of a pressure setting spring for adjusting a set pressure of a pressure control valve, and for rotating the main shaft. And a regulating member that regulates the moving range of the moving member according to the rotation angle that can be detected by the potentiometer. The potentiometer is damaged or broken by preventing the potentiometer from rotating excessively. Or the gear connecting the main shaft and the potentiometer shaft comes off,
Even in the case of a potentiometer having a built-in stopper mechanism for preventing over-rotation, it is possible to prevent the shaft that is prevented from rotating by the stopper mechanism from being disconnected from the gear that transmits rotation to the shaft.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of one embodiment of a pressure control device according to the present invention.

As shown in FIG. 1, a pressure setting device 10
Is disposed between an upstream pipe 12 for supplying city gas and a downstream pipe 13.
The pressure control device 11 includes a pressure control valve 14 for controlling a secondary pressure of gas supplied to the downstream pipe 13, and a pilot valve 16 for adjusting a pilot pressure supplied to an actuator 15 of the pressure control valve 14. A pressure setting unit 17 that operates the valve unit of the pilot valve 16 so that the secondary pressure becomes a predetermined set pressure value, and a secondary pressure based on control data stored in the pressure setting unit 17 and registered in advance. And a control circuit 18 for controlling the pressure setting unit 17 so that the pressure value becomes a set pressure value for each time zone.

The pressure setting device 10 includes a pilot valve 1
6 and a pressure setting unit 17 incorporating a control circuit 18.

Actuator section 15 of pressure control valve 14
The upper diaphragm chamber 20 and the lower diaphragm chamber 21 defined by the diaphragm 19 are formed, and the upper diaphragm chamber 20 is provided with a pressure setting spring 22 that presses the diaphragm 19 in the valve closing direction. I have.

The pilot valve 16 has a primary pressure introducing line 23 connected to the upstream line 12, a secondary pressure introducing line 24 connected to the downstream line 13, and a lower diaphragm chamber 21. And a secondary pressure introduction line 26 connected to the upper diaphragm chamber 20.
Is connected.

In the pilot valve 16, the amount of compression of the pressure setting spring 36 is increased or decreased by the operation of the pressure setting section 17, and the load of the pressure setting spring 36 is increased or decreased by the increase or decrease of the amount of compression. The set pressure Ps of the pilot valve 16 is determined by the load of the pressure setting spring 36 and the secondary pressure P ₂ applied to the diaphragm 32.
The force due to become a secondary pressure P ₂ at the time of balance.

Therefore, the pilot valve 16 increases or decreases the set pressure Ps by increasing or decreasing the spring load of the pressure setting spring 36 by the operation of the pressure setting section 17. Here, for example, 2
When the next pressure P ₂ lower than the set pressure Ps, because the direction of the spring load of the pressure setting spring 36 is greater than the force by the secondary pressure P ₂ applied to the diaphragm 32, the diaphragm 3
2 is displaced upward. As a result, the valve portion of the pilot valve 16 opens to increase the pilot pressure.

On the other hand, a pilot pressure is introduced into the lower diaphragm chamber 21 from the pilot valve 16 through a pilot pressure introduction pipe 25, and the upper diaphragm chamber 20
To the secondary pressure P ₂ via the secondary pressure introduction pipes 24 and 26.
Has been introduced. Therefore, as the pilot pressure increases, the lower diaphragm chamber 21 and the upper diaphragm chamber 20
The diaphragm 19 is displaced upward with respect to the load of the pressure setting spring 22 due to the pressure difference.

[0026] Thus, the valve portion of the pressure control valve 14 to increase the secondary pressure P ₂ by opening operation valve set pressure Ps. Further, when the secondary pressure P ₂ rises above the set pressure Ps, because the direction of the spring load of the pressure setting spring 36 is smaller than the force due to secondary pressure P ₂ applied to the diaphragm 32, the diaphragm 32 is displaced downward.

As a result, the valve portion of the pilot valve 16 performs a valve closing operation to lower the pilot pressure. Accordingly, the pilot pressure is reduced, and the pressure difference between the lower diaphragm chamber 21 and the upper diaphragm chamber 20 is reduced. This allows
The valve portion of the pressure control valve 14 to step down the secondary pressure P ₂ operates the valve closed to the set pressure Ps.

[0028] Thus, the secondary pressure when the P ₂ is varied by a change in the amount of gas used downstream, the diaphragm 19 of the pressure control valve 14 as described above is displaced secondary pressure P ₂ is the set pressure value Pressure control is performed so as to maintain Ps.

Here, the pressure setting device 10 will be described.

FIG. 2 is an enlarged longitudinal sectional view showing the internal structure of the pressure setting device 10. As shown in FIG.

As shown in FIG. 2, the pressure setting device 10
The pressure setting part 17 is detachably attached to the lower part of the pilot valve 16. The housing 31 of the pilot valve 16 is integrally fastened by bolts 30 with the upper part 31a, the middle part 31b, and the lower part 31c overlapped. The interior of the housing 31 is defined by an upper diaphragm 32 and a lower diaphragm 33 as an upper chamber 34a, a middle chamber 34b, and a lower chamber 34c.

The lower chamber 34c is provided with a pressure setting spring 36 for pressing the lower diaphragm 33 upward. The lower end of the pressure setting spring 36 abuts against a disk-shaped spring receiver 37 abutting on the upper end of the adjusting screw 55, and the upper end abuts on a spring receiver 38 fixed to the lower surface of the lower diaphragm 33. The pressure setting spring 36 sets a set pressure value Ps by adjusting a spring force by a motor driving force as described later.

The housing 31 of the pilot valve 16
An explosion-proof case 46 having a pressure-resistant explosion-proof structure of the pressure setting unit 17 is detachably attached to the lower part of the pressure setting unit 17 by fastening bolts 47. This explosion-proof case 46 is used for the upper case 4
8 and the lower case 49 are combined, and are fixed to each other by fastening bolts 50.

Inside the explosion-proof case 46, an electric motor (drive means) 51 for adjusting the spring force of the pressure setting spring 36, a transmission path 52 for transmitting the rotation of the electric motor 51, and a transmission path 52 A rotation shaft (main shaft) 53 to which the rotation of the shaft is transmitted, and an upper end of the rotation shaft 53 and a coupling 54
An adjusting screw 55 coaxially connected through a rotary shaft 5
3, a potentiometer 56 composed of a variable resistor for measuring the rotational position, an auxiliary battery 57, an over-rotation prevention mechanism 80 for preventing transmission of rotation exceeding the detection range to the potentiometer 56, and a measurement value from the potentiometer 56. A control circuit 18 for driving and controlling the electric motor 51 is accommodated.

The adjusting screw 55 is provided in the screw hole 31 of the base 31 d held between the housing 31 and the upper case 48.
When the rotation of the electric motor 51 is transmitted via the coupling 54, the motor 51 moves in the axial direction (vertical direction) while rotating. Therefore, the spring receiver 37 abutting on the upper end of the adjustment screw 55 moves in the axial direction by a distance proportional to the rotation angle of the adjustment screw 55 and moves to a position where the spring force of the pressure setting spring 36 is adjusted. The upper end of the adjusting screw 55 is formed in the conical recess 3 formed on the lower surface of the spring receiver 37.
A shaft portion 55a that comes into contact with the upper end 7a and protrudes from the upper end of the adjusting screw 55 is inserted into a central hole 37b that passes through the spring receiver 37.

FIG. 3 is an enlarged longitudinal sectional view showing the structure of the transmission mechanism such as the transmission path 52, the rotating shaft 53, the coupling 54, and the adjusting screw 55.

As shown in FIG. 3, the drive shaft 59 of the electric motor 51 has a drive gear 60 fitted and fixed at an end thereof, and the drive gear 60 has a large diameter fitted and fixed to the rotary shaft 53. The gear 61 is engaged. The small-diameter gear 62 fitted to the rotary shaft 53 below the large-diameter gear 61 is slidably meshed with a large-diameter gear 64 fitted and fixed to a shaft 63 of a potentiometer 56. Therefore, the rotation amount of the rotating shaft 53 driven by the electric motor 51 is controlled by the potentiometer 5.
6 and is detected as a voltage value accompanying a change in resistance value according to the rotation amount.

The large-diameter gear 61 is fitted so as to be slidable in the axial direction along the rotation shaft 53.
5 is urged to the position where it meshes with the drive gear 60 by the spring force of No. 5. The upper end of the clutch spring 65 is in contact with a spring receiver 66 that rotatably contacts the inner wall of the upper case 48 of the explosion-proof case 46.

The upper end of the rotating shaft 53 projecting upward from the explosion-proof case 46 is connected by a connecting pin 67 fitted with a coupling 54 and inserted in a direction perpendicular to the axial direction. Further, at the upper end of the coupling 54,
The lower end portion of the adjusting screw 55 is inserted, and the engaging groove 69 is formed to extend in the axial direction. This engagement groove 69
The connecting pin 68, which is inserted in the horizontal direction at the lower end of the adjusting screw 55, is slidably fitted.

For this reason, the coupling 54 is
9 can be moved in the axial direction while the engagement between the connector pin 9 and the connecting pin 68 is maintained. On the outer periphery of the coupling 54, a handle 70 for manual operation protruding in the lateral direction is provided.

Therefore, the rotation of the rotating shaft 53 driven by the electric motor 51 is controlled by the coupling 54 and the connecting pin 6.
It is transmitted to the adjusting screw 55 via the switches 7 and 68. And
The adjusting screw 55 is inserted into the housing 31 of the pilot valve 16 described above, and is screwed into the central hole 37 a of the disc-shaped spring receiver 37 of the pressure setting spring 36. Further, since the rotation of the spring receiver 37 in the circumferential direction is restricted by the stopper 71, the spring receiver 37 moves up and down in the axial direction according to the rotation direction of the adjusting screw 55, and moves in the axial direction by an amount corresponding to the rotation angle. . Therefore, when the adjusting screw 55 is driven by the electric motor 51 and rotates, the axial position of the spring receiver 37 is adjusted. As a result, the compression length of the pressure setting spring 36 changes, the spring force is adjusted to an arbitrary value, and the set pressure value Ps is set.

FIG. 4 is a diagram showing an operation method when adjusting the spring force of the pressure setting spring 36 by manual operation.

As shown in FIG. 4, when adjusting the spring force of the pressure setting spring 36 by manual operation, first, the handle 70 for manual operation is pulled up. Accordingly, the rotating shaft 53 connected via the coupling 54 and the connecting pin 67 moves upward, and the large-diameter gear 61 and the small-diameter gear 62 fitted and fixed to the rotating shaft 53 also move in the same direction. As a result, the large-diameter gear 61 is separated from the drive gear 60 driven by the electric motor 51 and becomes free, and the small-diameter gear 6
2 is extended in the axial direction, so that the potentiometer 56
And a large-diameter gear 64 fitted and fixed to the shaft 63.

The engagement groove 69 of the coupling 54 is
It moves upward while engaging with the connecting pin 68 provided at the lower end of the adjusting screw 55. When the handle 70 for manual operation is rotated in this state, the adjusting screw 55 screwed into the spring receiver 37 is rotated around the axis, and the axial position of the spring receiver 37 is adjusted. Therefore, the compression length of the pressure setting spring 36 changes, and the spring force is adjusted to an arbitrary value.

When adjusting the spring force of the pressure setting spring 36 by manual operation, the amount of rotation of the rotary shaft 53 is transmitted to the potentiometer 56 and a voltage value corresponding to the compression length of the pressure setting spring 36 is measured. .

FIG. 5 is an enlarged longitudinal sectional view of the over-rotation prevention mechanism 80.

As shown in FIG. 5, the over-rotation prevention mechanism 8
0 meshes with a large-diameter gear 64 for transmitting the rotation of the rotary shaft 53 to the potentiometer 56 and is axially (up and down)
Moving member 82 movably provided on the moving member 82
And a stopper bolt (restriction member) 84 for restricting the axial movement range. The moving member 82 has a lower guide shaft 90 extending downward and an upper guide shaft 96 extending upward. Also, on the outer periphery of the moving member 82,
The gear portion 82a that meshes with the large-diameter gear 64 is formed to extend in the axial direction. Even when the moving member 82 moves in the axial direction, the state in which the gear portion 82a meshes with the large-diameter gear 64 can be maintained.

The lower guide shaft 90 is connected to the potentiometer 5
6 has a screw portion 90a screwed into a screw hole 88a of a bearing member 88 attached to a lower support plate 86 that supports the screw 6; Therefore, when the rotation of the rotating shaft 53 is transmitted through the large-diameter gear 64, the moving member 82 moves the screw portion 90 a of the lower guide shaft 90 in the axial direction with respect to the screw hole 88 a of the bearing member 88. Can be.

The upper guide shaft 96 is supported by a central hole 94 a of a bearing member 94 attached to the upper support plate 92.
It is slidably supported in the axial direction. Further, the upper guide shaft 96 has a concave portion 94b into which the moving member 82 is inserted, and the concave portion 94b provides an extra distance for moving the moving member 82 upward.

In FIG. 5, since the lower end of the moving member 82 is in contact with the bearing member 88, the moving member 82 is at the lower limit position.
Therefore, the bearing member 88 also functions as a stopper member for regulating the lower limit position of the moving member 82.

The bearing member 94 has an insertion hole 94c into which the lower end of the stopper bolt 84 is inserted from above. The stopper bolt 84 is used for the explosion-proof case 46.
Is screwed into a screw hole 96 a of a bearing member 96 attached to the upper case 48. And the stopper bolt 8
Reference numeral 4 is locked at a predetermined height position by a lock nut 98. When adjusting the regulation position, the lock nut 98 is loosened to adjust the length of the protrusion into the upper case 48.

A scale (not shown) for reading the rotational position of the stopper bolt 84 is provided on the upper surface of the upper case 48 from which the head of the stopper bolt 84 projects. Therefore, when adjusting the position of the stopper bolt 84, it is possible to confirm the axial length of the stopper bolt 84 from the rotation position of the stopper bolt 84 with respect to the scale provided on the upper surface of the upper case 48.

FIG. 6 is a longitudinal sectional view showing a state where the moving member 82 has moved to the upper limit position.

As shown in FIG. 6, the stopper bolt 8
In a state where the tip 84b of the fourth member 84 does not protrude downward from the insertion hole 94c of the bearing member 94, the upper limit position of the moving member 82 is a position in contact with the concave portion 94b of the bearing member 94.

The length of the protrusion of the stopper bolt 84 is determined by the moving member 82 corresponding to the detectable angle of the potentiometer 56.
Is determined by the distance traveled. That is, the large-diameter gear 64 fitted to the shaft 63 of the potentiometer 56 and the moving member 8
The protrusion of the stopper bolt 84 is limited by the gear ratio with the second gear portion 82a and the movement distance of the movement member 82 obtained by the lead (movement distance per rotation) of the screw portion 90a of the lower guide shaft 90. Adjust the length.

FIG. 7 is a longitudinal sectional view showing a state in which the projecting length of the stopper bolt 84 is adjusted.

As shown in FIG. 7, when the protrusion length of the stopper bolt 84 is adjusted in accordance with the detectable angle of the potentiometer 56, the upper limit position of the moving member 82 regulated by the stopper bolt 84 is adjusted.

Accordingly, the moving range of the moving member 82 is limited by the stopper bolt 84 so as to have a moving distance corresponding to the detectable angle of the potentiometer 56. The rotation angle of the rotation shaft 53 is also limited so as not to exceed the detectable angle of the potentiometer 56. Therefore, the electric motor 5
Even when the first drive shaft 59 rotates excessively, the moving member 82 abuts on the distal end 84b of the stopper bolt 84 and cannot move further upward. Thus, the rotation of the shaft 63 and the rotating shaft 53 of the potentiometer 56 and the driving shaft 59 of the electric motor 51 are stopped to prevent over-rotation. as a result,
The potentiometer 56 is prevented from being damaged or broken due to excessive rotation, or the large-diameter gear 64 connecting the rotary shaft 53 and the shaft 63 of the potentiometer 56 is prevented from coming off. Therefore, in the pressure control device 11, the reliability of the pressure control operation is improved by the over-rotation prevention mechanism 80.

The stopper bolt 84 has a head 84a.
Project above the upper case 48, and the upper case 4
When the lock nut 98 on the upper surface of the moving member 8 is loosened, the moving member 8
2 can be adjusted, the moving range of the moving member 82 can be adjusted to a moving distance corresponding to the detectable range of the potentiometer 56 by a relatively simple operation. Therefore, when adjusting the protrusion length of the stopper bolt 84, it is not necessary to remove the upper case 48, so that the maintenance work is improved and the adjustment work can be performed in a short time.

Further, the stopper bolt 84 is rotated by using a tool such as a spanner so that the movable member 82 is rotated.
Can be finely adjusted.

In this embodiment, the potentiometer 5
6 does not have a stopper mechanism for preventing over-rotation, but even in the case of a potentiometer having a built-in stopper mechanism, the shaft whose rotation is prevented by the stopper mechanism by the action of the over-rotation prevention mechanism 80 and the shaft Can be prevented from being disengaged from the gear transmitting the rotation.

FIG. 8 is a block diagram of each electronic device housed in the explosion-proof case 46.

As shown in FIG. 8, the control circuit 18
It is housed in the same explosion-proof case 46 as the electric motor 51 and has a compact configuration. Therefore, the signal cable 72 for electrically connecting the control circuit 18 and the electric motor 51 and the control circuit 18 and the potentiometer 56
It is not necessary to draw out a signal cable 73 for electrically connecting the control circuit 18 and a cable 74 for electrically connecting the control circuit 18 and the auxiliary battery 57 to the outside.
It is not necessary to insert 2 to 74 through an explosion-proof pipe or the like.

The auxiliary battery 57 is a backup power supply for supplying power to the control circuit 18 and the electric motor 51 in the event of a power failure. Therefore, pressure control can be performed continuously even during a power failure.

[0065] The control circuit 18 includes a memory 78 in which the control amount and the CPU77 for calculating a secondary pressure P ₂ of the set pressure control pattern by the pressure control valve 14 is stored in the pressure setting section 17 as described later . Further, the CPU 77 performs the second control based on the set pressure control pattern stored in the memory 78.
Controls the driving of the electric motor 51 so that the pressure at which the next pressure P ₂ corresponding to the set pressure control pattern.

The control circuit 18 is connected to a connector 75 connected to an external device or a power supply. In the present embodiment, the connector 75 is provided with terminals H and G for AC 100 V, a terminal E for grounding, a terminal for alarm output, and terminals for communication.

The memory 78 has a control program for calculating a control amount of the pressure setting unit 17 based on each signal and a spring of the pressure setting spring 36 so as to maintain a set pressure value Ps corresponding to a change in gas usage amount per day. A data table of control data in which the rotational position of the rotating shaft 53 for adjusting the force is determined for each time zone is stored.

FIG. 9 is a graph showing an example of the valve opening of the pressure control valve 14 corresponding to each time.

As shown in FIG. 9, the set valve opening signal is calculated by the pressure rise control program or the pressure drop control program based on the valve opening corresponding to a predetermined set pressure value set for each time. Is done. Also, a predetermined value P
Since different values are set depending on conditions such as the pipeline diameter and the characteristics of the pressure control valve 14, a value calculated in advance based on data obtained by experiments is set as a threshold value.

Further, in the above embodiment, the case where the gas is provided on the line to which city gas is supplied has been described as an example. However, the present invention is not limited to this, and the pressure control of the pipe for supplying other gas or liquid is not limited to this. Of course, it can be applied to

In the above embodiment, the rotation of the large-diameter gear 64 fitted and fixed to the shaft 63 of the potentiometer 56 is transmitted to the over-rotation preventing mechanism 80 to prevent the rotation of the potentiometer 56 as an example. However, the present invention is not limited to this. For example, the large-diameter gear 6 meshed with the drive gear 60 may be used.
Of course, one rotation may be transmitted to the over-rotation prevention mechanism 80.

[0072]

As described above, according to the present invention, the transmission for transmitting the rotation to the potentiometer for detecting the rotation angle of the main shaft for moving and biasing the spring receiver of the pressure setting spring for adjusting the set pressure of the pressure control valve. The main shaft is provided with a moving member that is provided on the path and moves in conjunction with the rotation of the main shaft, and a regulating member that restricts the moving range of the moving member according to the detectable rotation angle of the potentiometer. The moving member that moves in conjunction with the rotation of the main shaft even if it tries to rotate beyond the possible range is restricted by the restricting member, preventing the rotation of the potentiometer, damaging or destroying the potentiometer, or preventing the potentiometer from rotating. The gear coupling with the shaft can be prevented from coming off. Further, even in the case of a potentiometer having a built-in stopper mechanism for preventing over-rotation, it is possible to prevent the shaft that is prevented from rotating by the stopper mechanism from being disengaged from the gear that transmits rotation to the shaft.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a pressure control device according to the present invention.

FIG. 2 is an enlarged longitudinal sectional view showing an internal configuration of the pressure setting device 10.

FIG. 3 shows a transmission path 52, a rotating shaft 53, and a coupling 5;
FIG. 4 is an enlarged longitudinal sectional view showing a configuration of a transmission mechanism such as an adjustment screw 55.

FIG. 4 is a diagram showing an operation method when adjusting the spring force of a pressure setting spring by manual operation.

FIG. 5 is an enlarged longitudinal sectional view of an over-rotation prevention mechanism 80.

FIG. 6 is a longitudinal sectional view showing a state in which a moving member 82 has moved to an upper limit position.

FIG. 7 is a longitudinal sectional view showing a state in which the length of protrusion of a stopper bolt 84 is adjusted.

8 is a block diagram of each electronic device housed in an explosion-proof case 46. FIG.

FIG. 9 is a diagram illustrating a set pressure value Ps according to a change in gas usage amount per day.
FIG. 7 is a diagram showing control data in which the valve opening degree of the pressure control valve is determined for each time period so as to maintain.

[Explanation of symbols]

 Reference Signs List 10 pressure setting device 11 pressure control device 14 pressure control valve 15 actuator unit 16 pilot valve 17 pressure setting unit 18 control circuit 19 diaphragm 22 pressure setting spring 31 housing 32 upper diaphragm 33 lower diaphragm 36 pressure setting spring 40 nozzle 43 valve unit 45 Valve body 46 Explosion-proof case 48 Upper case 49 Lower case 51 Electric motor 52 Transmission path 53 Rotating shaft 54 Coupling 55 Adjustment screw 56 Potentiometer 80 Over-rotation prevention mechanism 82 Moving member 84 Stopper bolt 88, 94 Bearing member 90 Lower guide shaft 96 Upper Guide shaft 98 Lock nut

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kazuhiro Yonezawa 13 Tanyo, Kakegawa-shi, Shizuoka Tokiko Corporation Shizuoka Plant (72) Inventor Shizuo Kaneko 13 Tanyo, Kakegawa-shi, Shizuoka Prefecture Tokiko Corporation Shizuoka Plant F-term (reference) 5H316 AA11 BB01 DD18 EE02 EE10 EE12 FF01 FF36 GG06 HH04 HH15 JJ04 JJ13 KK02

Claims (1)

[Claims] 1. A pressure control valve for controlling a secondary pressure supplied downstream, a pressure setting spring for adjusting a set pressure of the pressure control valve, and a compression amount of the pressure setting spring. A spindle for moving and urging a spring receiver of the pressure setting spring with the rotation; a drive unit for rotating the spindle; a potentiometer for detecting a rotation angle of the spindle rotated by the drive unit; and the potentiometer. A control means for controlling the rotation of the driving means based on the rotation angle of the main shaft detected in the step (a), and controlling the set pressure of the pressure control valve, wherein the rotation is transmitted to the potentiometer. A moving member that is provided on the transmission path and moves in conjunction with the rotation of the main shaft, and restricts a moving range of the moving member according to a detectable rotation angle of the potentiometer. Pressure setting apparatus characterized in that it comprises a control member.