JPS61165109A - Fluid flow rate control device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a titled device, and also to increase its response speed by connecting plural solenoid opening and closing valves for receiving a digital control signal, in parallel to a flow passage. CONSTITUTION:A flow rate of a fluid which becomes a control object flowing between gates a-a' of a flow passage A is measured by a flow rate sensor 1 interposed in its flow passage A, and this flow rate measuring signal 2 is led to a comparing operation controller 3. It is brought to a comparing operation processing with a flow rate setting signal which is inputted separately by this comparing operation controller 3. On the other hand, to the flow passage A which becomes the other side of this flow rate sensor 1, plural solenoid opening and closing valves 6-13 which have an orifice having an appropriate flow rate coefficient, respectively are connected in parallel, to which a digital control signal 5 generated from the comparing operation controller 3 is led. The solenoid opening and closing valves 6-13 are set to a flow rate coefficient corresponding to a bit pattern of the digital control signal 5 of 8 bits, and control the flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a fluid flow rate control device used in automatic control systems for various processes or equipment in steel, chemical plans, etc.

<Prior art> Conventionally, a widely used method for automatically controlling the flow rate of fluid is to change the flow rate coefficient of the orifice of an electric needle valve or air-operated valve arranged in the flow path using an external control signal. . In this case, when using an electric needle valve, the valve's rotating shaft is rotated by an electric motor, so it has the disadvantage that the response speed from when the 11 control signal is input manually until the required flow coefficient is reached is slow. . In addition, when using an air-operated valve, the required flow coefficient can be obtained by displacing the diaphragm with changes in air pressure, so the response speed is fast. 1 NO is essential, which has the disadvantage that the entire flow control device becomes large and complicated. Of course, in any of these cases, in order to increase the set viscosity of the flow rate coefficient, a device called a hodgepodge that detects the flow rate coefficient itself is required.

<Problems to be Solved by the Invention> In view of the above-mentioned circumstances, the present invention aims to provide a fluid flow rate control device that has a simple configuration, has a fast response speed, and has extremely high flow rate coefficient setting accuracy for control signals. This is what I did.

<Means for Solving the Problems> The fluid flow rate control device of the present invention includes a plurality of solenoid valves each having an orifice that can be opened and closed independently according to a control signal.
The valves are connected in parallel in the middle of the flow path, and a digital control signal calculated in the same month as the J flow rate sensor 1 NO signal and the flow mll setting is sent to each solenoid valve in the flow path.

<Function> Because of the above configuration, the flow coefficient between the inlet and outlet of a fluid flow path in which multiple orifices are connected in parallel can be changed depending on the combination of opening and closing of the individual orifices. ,ru. Therefore, if each orifice is configured to open and close using a solenoid valve that has a fast response speed and can be controlled by a binary signal that performs 0N10FF operation, it is possible to open and close each orifice using a binary signal that overlaps each orifice. The flow coefficient can be changed by changing the combination of . That is, when the number of orifices connected in parallel with piping is n,
Using a positioner with a flow coefficient using a digital signal of n pi 1~ as a control signal, it is easy to use a positioner with a high il'l'1 degree.
If the setting is changed quickly, it will be 11L in January.

<Example> The present invention will be described below based on the drawings of an actual 71-hour example.

FIG. 1 shows a fluid flow rate feedback constant value control device using a fluid flow rate control device according to the present invention. The flow rate of the fluid to be controlled flowing between the inlet and outlet a-a' of the flow path A is measured by a flow rate sensor 1 no 1 interposed in the flow path A,
This flow rate h11 signal 2 is guided to the comparison calculation adjustment 13. This comparison calculation adjustment! + 3 is configured to perform comparison calculations and processing with the flow rate setting signal 4, which is manually input separately.

On the other hand, a plurality of electromagnetic on-off valves 6, 7, 8, 9, 10, 11, 12, 13 each having an orifice with an appropriate flow rate coefficient of 4 is installed in the flow path A which is the destination of this flow rate sensor 1 no 1. They are connected in parallel and the digital control signal 5 generated from the comparison calculation adjustment h13 is guided thereto, and the whole constitutes a fluid flow rate control device.

That is, in this control system, the flow M open side signal 2 of the flow rate sensor υ-1 and the flow M setting signal 4 are comparatively adjusted by the comparison calculation adjustment iL 3, and the flow rate coefficient is set to give the required flow rate. It emits digital control signals 5 for 8 pins 1~ (in this case, 8 pins 1~ are electromagnetic on-off valves, as shown in the figure, and are eight in number). Comparison calculation adjustment it
The electromagnetic on-off valves 6, 7, 8, 9, 10; 11.12° 13, which receive the digital control signal 5 sent from 3, are set to flow coefficients corresponding to the patterns 1 to 13, and -a' substantially controls the fluid flow rate. The electromagnetic on-off valves, etc., which are the main components of this fluid flow control device, may be a single unit and piped in parallel externally, or they may be integrated in a manifold and piped internally in parallel. be. Further, the number of electromagnetic on-off valves connected in parallel is not limited to eight.

FIG. 2 shows an example of controlling a liquid level at a fixed value of 1'' as a typical example of general process control.

That is, the liquid level at the liquid level 15 due to the fluctuation of the flow rate flowing out from the drain port 14 of the tank 1B is detected by flows 1 to 16, and the liquid level h-1 becomes 17, and the comparison calculation adjustment 1 is performed. -13, is subjected to comparison calculation adjustment with the flow rate setting signal 4 by the comparison calculation controller 3, and is sent as a digital control signal 5 to the fluid flow rate control unit 19, and is sent to the flow path A of the fluid flow rate control unit 19. Parallel arrangement of electromagnetic on-off valves 20.21. ...Control as appropriate, turret 1
8).

Of course, the flow rate coefficient for realizing this predetermined flow rate is set depending on the target height of flows 1 to 16.

In the embodiments shown in FIGS. 1 and 2 above, the number of orifices that can be opened and closed independently is set to n, and each orifice is set to Vl. , 2°...Vl, the flow coefficient of Vl is S, and V2. V3.・The flow coefficient of vn is 23.4S.

...2n-13, the bit pattern of the digital signal to n pin 1 that controls the opening and closing of the orifice and the overall flow rate coefficient have a one-to-one relationship, and pin 1
~ Once the pattern is determined, the overall flow coefficient is determined as -F=. For example, when 8 orifices are connected in parallel as shown in Fig. 3, the control signals of 8 pits 1 to 1 are set to the minimum value o.
ooooo.

00J, by changing it up to the maximum value 11111111, the overall flow coefficient is over a range of approximately 256S from O, with the minimum single change vl being S, and the ε3 bit 11 control signal pitch 1 to pattern expression. It is possible to maintain a nearly direct proportional relationship with the 1 value and to avoid continuous and smooth changes. Therefore, since the flow rate coefficient is uniquely determined by the control pitch pattern rather than the accuracy, the controller is not required, and the overall structure of the fluid flow rate control device is simplified.

Furthermore, as shown in the embodiments shown in FIGS. 1 and 2, by using an electromagnetic on-off valve or the like to open and close the orifice, it is possible to achieve an extremely fast response speed. This is a great advantage for improving control accuracy especially in a process control system with large disturbances, and is extremely adaptable not only to constant value control but also to additional value control.

Furthermore, in recent years, from the point of view of reliability, many comparative calculation controllers are of the digital type, mainly based on microprocessors, and even in this case, the fluid flow rate control system of the present invention uses control signals. Since it is used as a digital signal, the interface is extremely easy.

<Effects of the Invention> As described above, the fluid flow control device of the present invention has a simple (II has made it possible to realize fast and highly accurate fluid flow control.Furthermore,
Easy to interface with digital equipment and highly reliable.

Improve the control performance and reliability of process control systems and equipment, including these activities and various fluid flow rate controls-1
``It has the effect of reducing the cost of 1 item = 1 item.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a system diagram of fluid flow rate control that is feedback constant value control, FIG. 2 is a system diagram of liquid level constant value control, and FIG. ~
This is a graph showing the relationship with digital control signals. 1...Flow rate measurement signal 2...Flow rate measurement signal, 3.
...Comparison calculation controller, 4...Flow rate setting signal, 5...
Digital control signal, 6.7, 8.9, 10, 11°12
．． 13.20.21...Solenoid on-off valve, A...Flow path. Patent Applicant Sanyo Electric Co., Ltd.] ij Omata Yumen Araki Tomonosuke -〇 - Figure 1 Figure 2 Figure 3 000QOOO1ff 11++
No. 1111 + UPIE No. 1, Fut I, March 15, 1985, 1985 Patent Application No. 66z2 No. 2, Invention Name Flow Section 1 [Owner] Device 3, Person Making Amendment Case Relationship with Patent Applicant Address (Residence) Keihan, Moriguchi City, Osaka Prefecture; J Te-dori 2-12 Name (18δ) Sanyo ゛tun 1hoi;::jq Kaito 4; Agent 〒104 Address Room 709, National Fuel Center, 8-12-15, Ginza, Chuo-ku, Tokyo Name (6704) Patent attorney's shoes, legs broken (
1 person) Phone: Tokyo 03 (543) 0036 (main)
6. Contents of correction (1) In the description section, page 7, line 13, 1, the word ``positioner'' has been corrected to ``positive job.'' (2) The phrase ``to be used as a digital signal'' in pages 6 to 71-1 of page 8 has been corrected to read ``because it is a W digital signal''. that's all

Claims (1)

[Claims] 1. A plurality of orifices that can be opened independently by electromagnetic valves are connected in parallel in the middle of the flow path, and the flow coefficient between the fluid inlet and outlet of the flow path is 1:1 with the combination of opening and closing of each orifice. A fluid flow rate control device characterized by adjusting the relationship such that: