JPH044255Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a device for automatically setting pressure in a self-regulating valve such as a pressure reducing valve.

<Prior Art> Conventionally, as the above-mentioned pressure reducing valve 1, there has been one as shown in FIG. 4, for example. This transmits the rotational force of the motor 2 via the reducer 4 to the male screw 6 that is spline-fitted thereto, lowers the male screw 6, and releases the pressure setting spring via the ball 8 and the spring receiver 10. 12 and this pressure setting spring 12
The compressive force is transmitted to the pilot guide 18 via the diaphragm receiver 14 and diaphragm 16 to lower it, and the pilot valve 20 is opened. When primary pressure fluid, for example primary pressure steam, is introduced from the inlet 22 in this state, a portion of this primary pressure steam enters the chamber below the pilot valve 20 via the first passage 24. Open pilot valve 20, second passage 2
6 into the chamber above the piston 28. This causes the piston 28 to descend and open the main valve body 30. The primary pressure steam enters the secondary side via the main valve body 30, and most of it is sent out from the outlet 32 as secondary side steam, and a part of it is sent from the third passage 34 to the lower part of the diaphragm 16. Enter the room. At this time, if the secondary pressure steam is higher than the pressure set by the pressure setting spring 12, the diaphragm 16 is pushed up against the acting force of the pressure setting spring 12.
The opening degree of the pilot valve 20 is reduced, thereby reducing the opening degree of the main valve body 30, and the secondary side pressure is maintained at the set pressure. Conversely, if the secondary pressure is lower than the set pressure, the secondary pressure is maintained at the set pressure by the operation opposite to the above.

By the way, in such a pressure reducing valve, the relationship between the two can be calculated by taking advantage of the fact that the amount by which the pressure setting spring 12 is pushed in from a certain reference position and the set pressure are roughly proportional, as shown in FIG. is stored in a control unit composed of a microcomputer, etc., and when a set pressure is instructed, the control unit controls the motor 2 to push in the pressure setting spring 12 by the corresponding pushing amount, thereby increasing the pressure. Settings were being made.

<Problems to be Solved by the Invention> However, in such pressure reducing valves, the relationship between the pushing amount of the pressure setting spring 12 and the set pressure differs from one pressure reducing valve to another, as shown in FIG. this is,
This is due to differences in the spring constants of the pressure setting springs 12, differences in the pushing amount and compression force characteristics, and differences in the initial overall lengths of the pressure setting springs. Therefore, the pressure cannot be set accurately unless the relationship between the set pressure and the pushing amount of the pressure setting spring 12 is measured for each pressure reducing valve and stored in the control unit. The problem was that a dedicated control unit had to be manufactured, which was cumbersome to manufacture. In addition, if the relationship between the push-in amount and the set pressure is used in this way, even if the relationship between the set pressure and push-in amount is memorized for each pressure reducing valve as described above, it will deteriorate over time. However, if the spring constant of the pressure setting spring changes, the above relationship deviates and the pressure cannot be set properly. The above-mentioned problems would not occur if the quality of each pressure setting spring could be standardized and deterioration over time could be suppressed, but this would be extremely difficult and virtually impossible to achieve.

<Means for solving the problems> This invention was made to solve each of the above problems, and instead of controlling using the relationship between the pushing amount and the set pressure, it uses a pressure setting spring. The pressure is set using the relationship between the compression force and the setting force. That is, this invention is a self-regulating valve in which the pressure is set according to the compressive force applied to the pressure setting spring by the drive part, and a detection part that detects the compressive force of the pressure setting spring, and an attempt to set the pressure. a setting section that generates a compression force signal corresponding to the pressure to be applied; and a setting section that inputs the compression force signal from the setting section and the detection signal from the detection section, and operates the driving section until the detection signal becomes equal to the compression force signal. and a control unit that operates the control unit.

<Function> In a self-regulating valve, the pressure is maintained at the set pressure by the compression force of the pressure setting spring (in the case of the pressure reducing valve 1 in Fig. 4, the diaphragm 16 of the pressure setting spring 12
presser foot load) and the pressure to be maintained at the set pressure (secondary pressure in the case of pressure reducing valve 1 in Fig. 4)
(In the case of the pressure reducing valve 1 shown in FIG. 4, the force caused by the secondary pressure pushing up the diaphragm 16 from below) is balanced. Therefore, there is a proportional relationship between the compression force and the set pressure as shown in FIG. In the case of the pressure reducing valve 1 in Fig. 4, this proportionality coefficient is
This is the area of the diaphragm 12. This proportional relationship is not related to the spring constant of the pressure setting spring, and is not affected by deterioration over time. Therefore,
In this invention, the compression force detected by the compression force detection unit is compressed until the compression force corresponds to the set pressure.
The drive unit is controlled by the control unit, and the compression force of the pressure setting spring corresponds to the set pressure.

<Effects> As described above, according to this invention, the pressure is not set based on the relationship between the pushing amount of the pressure setting spring and the set pressure, but rather on the proportional relationship between the compression force of the pressure setting spring and the set pressure. It is based on This proportional relationship remains unchanged even if the pressure setting springs are different, and is not affected by aging and is permanent. Therefore, a control section in which this relationship is stored can be used for any self-regulating valve as long as it is of the same type, which simplifies the manufacture of the control section and adds versatility to the control section. You can have it.

<Example> One example is shown in FIGS. 1 and 2. In this embodiment, this invention is applied to a pressure reducing valve similar to that shown in FIG. 4, and as shown in FIG. 2, a load meter 36 is provided in place of the spring receiver 10. The output signal of this load cell 36 is inputted to a control device 38 consisting of a microcomputer or the like, as shown in FIG.

This control device 38 is also supplied with a pressure setting signal from a pressure setting section 40 . This pressure setting signal is converted into a conversion means 38a provided in the control device 38.
Based on the relationship shown in FIG. 3, it is converted into the presser load on the diaphragm 16 required to bring the secondary pressure to the set pressure. This conversion means 38a
For example, there is a lookup table method in which each set pressure and the corresponding presser load are stored in a memory as a set, and when the set pressure is applied, the corresponding presser load is read out.

The presser foot load signal from the conversion means 38a is supplied to the comparison means 38b within the control device 38. This comparing means 38b is also supplied with an output signal from the load cell 36, and this comparing means 38b converts the output signal of the load cell 36 (presser load applied to the diaphragm 16 by the pressure setting spring 12) into a converting means. 38a
motor 2 until it becomes equal to the presser foot load signal from
to compress the pressure setting spring 12.

Thereby, the load applied to the diaphragm 16 by the pressure setting spring 12 corresponds to the set pressure.

In the embodiments described above, this invention was applied to a pressure reducing valve, but this invention can also be applied to self-regulating valves other than pressure reducing valves, such as primary pressure regulating valves, vacuum regulating valves, differential pressure valves, etc.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the automatic pressure setting device for a self-regulating valve according to this invention, Fig. 2 is a partially omitted vertical cross-sectional view of the pressure reducing valve used in the same embodiment, and Fig. 3 is the presser load and settings. FIG. 4 is a longitudinal sectional view of an example of a conventional pressure reducing valve, and FIG. 5 is a diagram showing the relationship between the pushing amount of the pressure setting spring and the set pressure. 12... Pressure setting spring, 36... Load meter (detection section), 38... Control section, 40... Setting section.

Claims (1)

[Scope of utility model registration request] In a self-regulating valve in which the pressure is set according to the compression force applied to the pressure setting spring by the drive section, there is provided a detection section that detects the compression force of the pressure setting spring, and a compression force that corresponds to the pressure to be set. a setting section that generates a force signal; a control section that receives a compression force signal from the setting section and a detection signal from the detection section and operates the drive section until the detection signal becomes equal to the compression force signal; A self-regulating valve pressure automatic setting device comprising: