JPH0454500Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> The present invention relates to a pressure regulating device that adjusts the primary or secondary pressure of a self-regulating valve to a set pressure. It relates to things that can detect abnormal conditions in advance.

<Prior Art> Conventionally, as the above-mentioned pressure regulating device, there is one disclosed, for example, in Japanese Patent Application Laid-open No. 84715/1983. This pressure regulating device adjusts the set pressure of a pressure reducing valve. A set pressure is set, and the pressure reducing valve is configured to automatically adjust the secondary pressure to a pressure corresponding to this set pressure.

In this pressure regulator, the secondary pressure of the pressure reducing valve is detected by a pressure sensor and is supplied to a comparison regulator. The comparison regulator is also supplied with the set pressure target value from the set pressure target value setter, and the comparison regulator calculates the deviation between the secondary pressure detected by the pressure sensor and the set pressure target value, and calculates the deviation between the secondary pressure detected by the pressure sensor and the set pressure target value. The deviation is compared with a predetermined deviation reference value, and when the deviation exceeds the deviation reference value, an operation signal is sent to the driver so that the deviation becomes zero. The driver drives the electric motor, and when the deviation becomes zero, the electric motor is stopped.

<Problem to be solved by the invention> By the way, the above-mentioned pressure reducing valve uses a pilot valve, a piston, etc., although not explained in detail, in order to self-adjust the secondary pressure. Dust may adhere to the product. If this kind of dust is left unattended, the pilot valve will eventually become damaged.
Pistons etc. no longer operate normally, and the pressure reducing valve begins to operate abnormally. Further, when a pressure reducing valve is used for many years, the pressure regulating spring described above deteriorates over time, its spring constant decreases, and it also begins to operate abnormally. However, with the above-mentioned pressure reducing valve, it is not until it starts to operate abnormally that it becomes clear that the pressure regulating spring has reached the end of its lifespan, or that dirt, etc. has adhered to it, and it is not possible to check this in advance. There was a problem that an accident could occur.

<Means for solving the problem> The present invention is designed to set the secondary pressure of the pressure reducing valve to the target value of the set pressure under normal conditions when dust etc. adhere or the pressure adjustment spring begins to deteriorate over time. The above problem was solved by focusing on the fact that a different amount of movement than the amount of movement of the adjustment screw is required.

That is, the present invention provides a means for adjusting the set pressure of a self-regulating valve that automatically adjusts the pressure to the set pressure by moving it, a means for driving the adjusting means to move it, and a self-regulating valve that automatically adjusts the pressure to the set pressure. A pressure detection means detects the pressure of the regulating valve and generates a pressure signal representing the detected pressure, a setting section generates a set pressure signal representing the set pressure, and the pressure signal and the set pressure signal are inputted, and the pressure and control means for causing the drive means to move the regulating means until the signal becomes approximately equal to the set pressure signal, representing the allowable amount of movement of the regulating means at various set pressure signals. Means for generating an allowable movement amount signal compares the allowable movement amount signal in the set pressure signal when the pressure signal becomes approximately equal to the set pressure signal with the movement amount of the adjustment means, The apparatus further includes comparison means for generating a notification signal when the amount of movement deviates from the amount of movement.

<Operation> According to the present invention, when a set pressure signal is given to the control means, the control means moves the adjusting means via the driving means, and sets the pressure of the self-adjusting valve to the set pressure. Here, if the adjusting means has deteriorated over time or if there is dust attached to the inside of the self-regulating valve, the amount of movement of the adjusting means necessary to achieve the set pressure under normal conditions, that is, the allowable movement amount The set pressure will be achieved when the amount of movement is large or small. Therefore, the comparison means that compares the amount of movement of the moving means when the set pressure is reached with the allowable amount of movement for that set pressure,
When the notification signal is generated, it is found that the amount of movement deviates from this allowable amount of movement, and it is found that the self-adjusting valve is about to enter an abnormal state.

<Example> In this example, the present invention is applied to a pressure setting device provided for a pressure reducing valve as shown in FIG.

This pressure reducing valve transmits the rotation of a motor 4 provided in the upper part of the main body 2 to an adjusting screw 10 via a speed reducer 6 and a spline shaft 8. In addition, the spline shaft 8
is spline-fitted into a spline hole formed by a hole provided in the adjustment screw 10, a retainer 12 provided in the hole, and a ball 14. The male thread 16 cut at the tip of the adjustment screw 10 is screwed into the female thread 18 fixedly provided in the main body 2, so the adjustment screw 10 descends and comes into contact with the tip of the adjustment screw 10. One end of the pressure adjustment spring 24 is compressed via the ball 20 and the spring receiver 22. As a result, the diaphragm 28 is compressed via the spring receiver 26 provided at the other end of the pressure adjustment spring 24, the pilot guide 30 is lowered, and the pilot valve 32 is moved against the force of the coil spring 34. Push down.

In this state, when primary pressure fluid, for example primary pressure steam, is introduced from the inlet 36, a part of this primary pressure steam enters the chamber below the pilot valve 32 via the first passage 38 and is opened. The pilot valve 32 is connected to the piston 4 via the second passage 40.
Enter the room above 2. As a result, the piston 42 descends against the force of the coil spring 44 and opens the main valve body 46. Most of the primary pressure steam introduced from the inlet 36 is sent out from the outlet 48 as secondary pressure steam via the opened main valve body 46.

A portion of this secondary pressure steam is sent into the chamber below the diaphragm 28 via the third passage 50. When the secondary pressure steam is higher than the pressure set by the pressure adjustment spring 24, the diaphragm 28 is pushed up against the acting force of the coil spring 24, reducing the opening degree of the pilot valve 32, and thus opening the main valve body 46.
Reduce the opening degree and reduce the secondary pressure to maintain the set pressure.

On the other hand, if the secondary pressure is lower than the set pressure, the secondary pressure is increased and maintained at the set pressure by the operation opposite to the above. Therefore, the pressure adjustment spring 24 is controlled by the motor 4.
Steam at a secondary pressure equal to the set pressure set by compressing the steam is always sent out from the delivery port 48. Furthermore, 52
is a cylinder for sliding the main valve body rod 54 of the main valve body 46, and is directed to a cylindrical body 56 provided within the main body 2.

The pressure regulating device of this embodiment adjusts the degree of compression of the pressure regulating spring 24 by moving the regulating screw 10 of the pressure reducing valve up and down, and adjusts the set pressure.
As shown in the figure, it has a microcomputer 60 that controls the motor 4. The microcomputer 60 is supplied with a set pressure signal TP representing the set pressure from a setting unit 61, and the pressure signal TP from the pressure sensor 62 representing the secondary pressure of the pressure reducing valve is sent to the A/D converter 64. A digital pressure signal digitized by is also input.

The microcomputer 60 outputs a set pressure signal.
When TP is given, the screw position of the adjustment screw 10 (the amount of screw movement from the state where the pressure adjustment spring 24 is not compressed at all, that is, the reference state) is adjusted by the motor so that the digital pressure signal becomes equal to the set pressure signal TP. 4. There is a functional relationship between this screw position and the set pressure. For example, if it is experimentally determined that there is a functional relationship of A·TP (A is a coefficient) as shown by the solid line in Fig. 2, When the set pressure is applied, the screw position is calculated according to the above functional relationship, and if the motor 4 is controlled in accordance with this, the pressure reducing valve should be able to be set to the set pressure.

However, there are cases where the functional relationship is not completely as described above, and a slight deviation may occur.
Further, as described above, if the pressure adjustment spring 24 deteriorates over time and the spring constant becomes small, the set pressure may not be achieved unless the screw is moved more than the calculated screw position. Furthermore, if dirt adheres to the piston 42 or the cylinder 52, the set pressure may not be achieved unless the screw is moved less than the calculated screw position. In such a case, the microcomputer 60 controls the motor 4 so as to make the deviation between the digital pressure signal and the set pressure signal TP zero.

Microcomputer 60 also has a lookup table. As schematically shown in FIG. 4, a plurality of sets of set pressures and corresponding upper and lower screw positions are stored in the memory. When a set pressure is applied to this table, the upper limit screw position and lower limit screw position of the same set as the applied set pressure are read out. This upper limit screw position is, for example, the pressure adjustment spring 2
4 is the screw position when deterioration over time begins to occur, and the lower limit spring position is the screw position when the piston 42 and cylinder 5
This is the screw position when dust started to adhere to 2. The upper limit screw position and the lower limit screw position are each determined experimentally.

When the pressure reducing valve is set to a set pressure, the microcomputer 60 reads the upper and lower limit screw positions corresponding to the set pressure from the lookup table, compares them with the screw positions at that time, and determines that the screw position at that time is the upper limit. If it is larger than the screw position or smaller than the lower limit screw position, an alarm output signal is generated and the alarm device 66 is activated to notify that there is an abnormality in the pressure reducing valve.

FIG. 1 is a flowchart showing the operation of the microcomputer 60 for performing such control. First, the microcomputer 60 reads the set pressure signal TP from the setting section 61 (step S2), and sets the A. Calculate TP and set screw position SL
is calculated (step S4). The position of the adjustment screw 10 is adjusted based on this calculated SL (step S6). Subsequently, the digital pressure signal CP representing the current actual secondary pressure is read from the A/D converter 64 (step S8), and CP is subtracted from TP to calculate ΔP (step S10). It is determined whether ΔP is within the allowable range (step S12). If the answer is no, that is, if it is not within the allowable range, it is determined whether ΔP is positive (step S14). If the answer is yes, that is, if it is positive, the current
A predetermined ΔSL is added to the SL to calculate a new SL (step S16). Also, if the answer to step S14 is no, that is, if ΔP is negative, the current
A new SL is calculated by subtracting ΔSL from the SL (step S18). Following step S16 or step S18, return to step S6 and repeat the steps from step S6 until the answer to step S12 is yes.
Repeat the loop up to S16 or the loop from step S6 to step S18. By this,
The secondary pressure of the pressure reducing valve becomes the set pressure.

If the answer in step S12 is YES, the upper limit screw position and lower limit screw position corresponding to the set pressure at that time are read from the lookup table (step S20), and if the current screw position is smaller than the upper limit screw position, the lower limit screw position corresponds to the set pressure at that time. It is determined whether it is larger than the position (step S22). If the answer is no,
That is, if the current screw position is outside the allowable range defined by the upper limit screw position and the lower limit screw position, the alarm device 66 is activated to notify that there is an abnormal state (step S24), and the process is stopped. Further, if the answer to step S22 is YES, that is, if the current screw position is within the above-mentioned allowable range, the process stops.

As described above, according to this embodiment, after the secondary pressure is adjusted to the set pressure, the screw position after that adjustment is compared with the upper limit screw position and the lower limit screw position, so that the occurrence of abnormal conditions which may lead to a major accident can be checked before they occur.

In the above embodiment, if the secondary pressure cannot be adjusted to the set pressure based on the calculated screw position, ΔSL is added or subtracted in step S16 or step S18 to adjust the pressure to the set pressure. , instead of the above steps, a value obtained by multiplying the current ΔP by a coefficient A may be added or subtracted.

Furthermore, when calculating the screw position, A.
TP was calculated, but instead of this, we stored various set pressures and corresponding screw positions in a lookup table, and when the set pressure was given, the corresponding screw position was read out. You can.

In addition, the upper limit screw position and the lower limit screw position were stored in the lookup table, but as shown by the dotted line in Figure 2, there is a functional relationship between the upper limit screw position and the lower limit screw position. The upper limit screw position and the lower limit screw position may be calculated by storing constants and calculating them every time the set pressure is input.

In the embodiments described above, the present invention is applied to a pressure reducing valve, but it goes without saying that it can be applied to other self-regulating valves, such as primary pressure regulating valves, vacuum regulating valves, differential pressure valves, relief valves, etc.

<Effects of the invention> As described above, in the present invention, when the adjusting means is moved so that the pressure signal representing the pressure of the self-regulating valve is approximately equal to the set pressure signal, the amount of movement thereof is It is configured to determine whether or not the amount of movement is outside the allowable travel amount for the set pressure at the time, and if it is, a notification signal will be generated. You can tell when the means have started to deteriorate over time,
It is possible to prevent major accidents from occurring.

[Brief explanation of the drawing]

Fig. 1 is a flowchart of one embodiment of the pressure regulating device according to the present invention, Fig. 2 is a diagram showing the relationship between pressure and screw position in the same embodiment, Fig. 3 is a block diagram of the same embodiment, and Fig. 4 is a diagram showing the relationship between pressure and screw position in the same embodiment. The figure shows a look-up table used in the same embodiment, and FIG. 5 is a partially omitted vertical cross-sectional view of a pressure reducing valve used in conjunction with the same embodiment. 4...Motor (driving means), 10...Adjusting screw (adjusting means), 60...Microcomputer (controlling means, comparison means), 61...Setting section, 62...
Pressure sensor (pressure detection means).

Claims (1)

[Claims for Utility Model Registration] Means 10 for adjusting the set pressure by moving the self-regulating valve that automatically adjusts the pressure to the set pressure, and driving this adjusting means 10 to move it. a pressure detection means 62 for detecting the pressure of the self-regulating valve and generating a pressure signal representing the detected pressure; a setting unit 61 for generating a set pressure signal representing the set pressure; control means S2, S4, S6, S8, S10, S12, S for causing the driving means 4 to move the adjusting means 10 until the pressure signal and the set pressure signal are inputted and the pressure signal becomes approximately equal to the set pressure signal;
14, S16, and S18, the adjusting means 10 at various set pressure signals.
means S20 for generating an allowable movement amount signal representing the allowable movement amount of the adjustment means 10; and the amount of movement of the adjustment means 10 and the allowable movement amount signal in the set pressure signal when the pressure signal becomes approximately equal to the set pressure signal. A pressure regulating device for a self-regulating valve, characterized in that it comprises a comparing means S22 for comparing the amount of movement with the amount of movement and generating a notification signal when the amount of movement deviates from the amount of allowable movement.