JPH03238509A - Pressure regulator for self-operated regulating valve - Google Patents

Abstract

PURPOSE:To improve the set precision by performing the regulation to an actual screw position corresponding to a logical screw position based on relations between the logical set screw position and the actual screw position. CONSTITUTION:When a set pressure as the target is inputted, the extent of adjustment of the logical screw position is operated. Since relations between the logical set screw position for the set pressure and the screw position actually measured at the same pressure as the set pressure are stored, the actual screw position corresponding to the logical screw position is immediately operated based on these relations, and an regulation means 40 is driven to attain the actual screw position. Thus, compatibility between a controller 40 and a reduction valve 30 is given, and the error from the target of pressure setting is reduced, and immediate setting is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a self-regulating valve that self-adjusts a secondary pressure or secondary pressure to a set pressure.

<Conventional technology> Conventionally, examples of self-regulating valves include pressure reducing valves.

In this pressure reducing valve, the set pressure is adjusted by adjusting the adjusting screw that compresses the pressure setting spring to change the degree of compression of the pressure setting spring. It is conceivable to remotely control the adjustment of the set pressure by changing the degree of compression of the pressure setting spring using a motor.

An example of a configuration in such a case is shown in FIG. 5. In the figure, reference numeral 2 denotes a pressure setting spring, and a spring receiver 4 that contacts a diaphragm (not shown) is attached to one end of the spring, and a spring receiver 6 is attached to the other end.

The spring receiver 6 is in contact with the tip of the adjusting screw 10 via the ball 8. A male thread 12 is formed at the lower end of this pressure adjusting screw 10, and is screwed into a fixedly provided female thread member 14.

The drive unit consists of a motor 16, a potentiometer 18, a speed reducer 20, and a printed circuit board 22 with electronic components for controlling the motor. An output shaft 24 from the speed reducer 20 is splined to the pressure adjusting screw 10.

This spline fitting part is connected to the peripheral side of the output shaft 24 by the roller 2.
The upper part of the pressure adjusting screw 10 is formed into a cylindrical shape, and a groove 28 is formed in the cylindrical part, and the rollers 26a and 26b are fitted into the groove.

Therefore, when the output shaft 20 rotates left and right, the rollers 26ab
, and the groove 28 are engaged with each other to transmit the rotation to the pressure adjustment screw 10, and the male thread 12 of the pressure adjustment screw 10 is connected to the female thread member 1.
Due to the screw connection with 4, the pressure setting spring 2 is displaced in the axial direction.
Change the biasing force to.

A value indicating how far the tip of the adjusting screw 10 is from the reference position (screw position), the degree of compression of the pressure setting spring,
Furthermore, there is a functional relationship between the set pressure and the motor 1
A predetermined set pressure can be set by rotating the adjusting screw 6 and causing the adjusting screw 10 to take a predetermined screw position. Incidentally, as a method of controlling the adjusting screw 10 so that it takes a predetermined screw position, for example, a screw position detection device such as the aforementioned potentiometer is provided, and the motor is operated until the output generates a signal indicating that the predetermined screw position is detected. Alternatively, a stepping motor for which it is known how many times it will rotate when one pulse is supplied is used as the motor 16, and the number of pulses supplied to the stepping motor is controlled. can.

As mentioned above, there is a functional relationship between the screw position and the set pressure, so store this relational expression in the microcomputer in the controller, input the set pressure to the microcomputer, and calculate the screw position. , the microcomputer controls the motor 16 so that the adjusting screw 10 takes this screw position.

<Problem to be solved by the invention> In order to make the pressure reducing valve and the controller compatible, the relationship between the screw position of each pressure reducing valve and the set pressure must match the relational expression stored in the controller. be done.

The relational expression within the controller generally uses a linear expression as shown in FIG. However, the relationship between the screw position and set pressure differs slightly for each pressure reducing valve due to the dimensional tolerance of the mechanical part of each pressure reducing valve, and when the relationship between the actual screw position and set pressure is measured, it is shown in Figure 3. As shown in the figure, various results can be obtained that cannot be strictly expressed using a linear equation. Therefore, when one controller is used in combination with a pressure reducing valve, the actual downstream pressure immediately becomes the set pressure, resulting in good controllability, but when used in combination with another pressure reducing valve, In this case, the secondary pressure does not reach the target pressure and an error occurs.

To solve these problems, the screw position (0 to 100%) relative to the set pressure calculated by the controller is input as an analog signal (4 to 20 mA) to the conversion circuit of the driver board of the drive unit. Actual screw position signal 1~
5V (this is the signal for comparison with the signal 1-5V from the potentiometer that detects the actual screw position 0-100%), performs zero adjustment and gain adjustment, and adjusts the actual value of the pressure reducing valve. The relational expression was approximated to the theoretical relational expression shown in FIG.

However, in reality, the relationship between the screw position and the set pressure is not perfect in the linear equation shown in Fig. 2, even if zero adjustment and gain adjustment are performed with high precision to draw various curves as shown in Fig. 3. The problem remains that the setting accuracy is poor in the pressure range that is not approximated by the actual pressure setting.

The technical problem of the present invention is therefore to provide a pressure regulating device for a self-regulating valve which solves the above-mentioned problems.

Means for solving the above problems> The technical means of the present invention taken to solve the above problems are as follows:
A self-adjusting valve, means for adjusting the set pressure of the self-adjusting valve, means for driving the adjusting means, and means for storing a theoretical relationship between the set pressure of the self-adjusting valve and the adjustment amount of the adjusting means. and means for calculating the adjustment amount of the adjustment means based on the theoretical relational expression by inputting the set pressure of the self-adjustment valve; means for actually measuring the relationship and storing the relationship between the theoretical adjustment amount of the adjustment means and the actually measured adjustment amount in correspondence when the set pressure and the actual measurement pressure are the same, and based on the stored relationship; and means for calculating an actual control signal to be supplied to the driving means from the calculated theoretical adjustment amount of the adjusting means.

In one embodiment, the storage means, calculation means, etc. are realized by a microcomputer as described below.

<Operation> When the target set pressure is input, the theoretical adjustment amount of the screw position is first calculated. Here, according to the means of the present invention, since the relationship between the theoretical set screw position for the set pressure and the actually measured screw position under the same pressure as the set pressure is stored, the above-mentioned The actual screw position corresponding to the theoretical screw position is immediately calculated and the adjusting means is driven to the actual screw position.

<Example> An example showing a specific example of the above technical means will be described.

(See Figures 1 to 5) In Figure 1, 30 is a pressure reducing valve, 32 is an adjusting means, and 34 is a driving means. The pressure setting spring 2, ball 8, adjustment screw 10, etc. shown in FIG. 5 correspond to the adjustment means 32. In addition, the drive element @34 also has a motor 16 shown in FIG.
, a speed reducer 20, a potentiometer 18, and a board 22 on which control electronic equipment is arranged.

The microcomputer in the controller stores a relational expression between set pressure and theoretical screw position as shown in FIG. In Figure 2, the horizontal axis is pressure and the vertical axis is screw position from 0 to 10.
Displayed as 0%. The controller 40 is also supplied with a set pressure signal representing the required set pressure from the setting section 42 . Therefore, when a set pressure is input from the setting section 42, the corresponding theoretical screw position is calculated (%) from the above relational expression, converted into an analog signal of 4 to 20 mA corresponding to the value, and sent to the drive section 34.

On the other hand, the electronic device 22 for controlling the drive unit 34 also has a built-in microcomputer 1-1, and a correction table as shown in FIG. 4 is configured in the memory of this microcomputer. In this correction table, the theoretical setting screw position (%) 44 mentioned above and the actual measured pressure on the downstream side of the pressure reducing valve and the screw position (%) as shown in Fig. 3 are used to calculate the setting pressure and the actual measured pressure. Corresponding actual screw position under the same condition (%)
46 data are stored. The number of data is 0°10.20 as shown in Figure 4. . . . are stored at regular intervals. It is preferable that the interval be small.

The actual screw position 46 is also expressed as 0 to 100%, but in this case (%) is for confirming the actual screw position with the potentiometer 18, and is converted into 1 to 5 volts.

The analog signal @4 to 20 mA sent from the controller 40 is converted into A10 in the drive unit 34, and the signal is set as a set screw position (%) in a table in the microcomputer shown in FIG. 4. When the set screw position (%) is set in the table, the corresponding measured screw position (%) is read out, and as mentioned above, the value is the measured screw position 1 to 5.
It is converted to v. At the same time, a drive signal is sent from the microcomputer in the drive section 34 to the motor 16, and the motor rotates in a predetermined direction. As the output shaft 24 rotates, its displacement is detected by the potentiometer 18 and output as a position signal (1 to 5 V). If this output signal matches the actually measured screw position signal calculated above, the microcomputer issues a motor drive stop signal. In this way, the pressure setting spring is applied with a compression force suitable for each pressure reducing valve, so that the pressure on the secondary side becomes the set pressure immediately.

In the above embodiment, if the set screw position is between 10 (%) and 20 (%) in the correction table shown in FIG. 4, for example, the actual screw position is determined by proportional distribution therebetween. Therefore, as described above, it is better to have a large number of data at small intervals.

If more precise control is required here, the secondary pressure can also be detected and fed back. That is, the pressure sensor 36 detects the pressure on the secondary side of the pressure reducing valve 30 and generates a pressure signal representing the detected pressure. This pressure signal is converted into A10 in a converter 38 and supplied to a controller 40 having a microcomputer. The set pressure and the actual measurement value are compared in the controller 40, and if a deviation occurs, a correction signal is sent from the controller 40 to the drive section 34 again.

<Effects of the Invention> According to the present invention, the controller and the pressure reducing valve can be made compatible, the error with the target pressure setting is extremely small, and the pressure can be set immediately. Further, since the measurement of the actual screw position can be automated using a device such as a computer, the above correction table can be easily created.

[Brief explanation of drawings]

Figure 1 is a block diagram of an embodiment of the present invention, Figure 2 is a graph showing the relationship between theoretical set pressure and screw position, and Figure 3 is a graph showing the relationship between actually measured outlet pressure and screw position. graph,
FIG. 4 is a diagram schematically showing a memory map of a microcomputer in a drive unit according to an embodiment of the present invention, and FIG. 5 is a partially omitted vertical sectional view of a pressure reducing valve used in the embodiment. 2: Pressure setting spring 10: Adjusting screw 16: Motor 30: Pressure reducing valve 40: Controller 18: Potentiometer 34: Drive section

Claims (1)

[Claims] 1. Memorize a self-adjusting valve, a means for adjusting the set pressure of the self-adjusting valve, a means for driving the adjusting means, and a theoretical relationship between the set pressure of the self-adjusting valve and the adjustment amount of the adjusting means. means for calculating the adjustment amount of the adjustment means based on the theoretical relational expression by inputting the set pressure of the self-adjustment valve; and the control target pressure of the self-adjustment valve and the adjustment amount of the adjustment means. means for actually measuring the relationship between the set pressure and the measured pressure, and storing the relationship between the theoretical adjustment amount of the adjustment means and the actually measured adjustment amount in correspondence with each other when the set pressure and the actual measurement pressure are the same; and means for calculating an actual control signal to be supplied to the drive means from the theoretical adjustment amount of the adjustment means calculated based on the above.