JPS6131775A - Valve opening control device of opening and closing valve - Google Patents

Abstract

PURPOSE:To simplify a control device and form the device in a small size, by inputting only the number of pulses as a setting signal and detecting the position of a valve through the number of the pulses. CONSTITUTION:A control device compares in a comparator 13 a valve opening preset value, that is, an output A from a binary counter 11 with the present opening of an opening and closing valve 20, that is, an output B from an up- down counter 12. The device, when the comparison is in a relation where A<B, places the up-down counter 12 in a count up mode turning on a switch in an opening direction circuit till the relation becomes A=B. While the device, when the comparison is in a relation where A>B, places the up-down counter 12 in a count down mode turning on a switch in a closing direction circuit till the relation becomes A=B.

Description

[Detailed Description of the Invention] [Object of the Invention] The present invention relates to a valve opening degree control device for an on-off valve used in a heat medium amount control table of a heat exchanger for an air conditioner installed in a building, factory, etc. It is.

As shown in FIG. 6, the conventional device of this type is composed of a drive section 1, an opening/closing control section 2, and an opening degree setting section 3. The motor 6 is rotated in the forward or reverse direction by passing an unbalanced current of the bridge constituted by the resistor 4 to the balancing relay coil 5 of the opening/closing control section 2. Note that 7 is an AC power source.

By the way, since the above-mentioned conventional device uses a relay coil 5, a potentiometer, and a balancing relay to detect the opening, variations in resistance value and mounting position for each product directly affect control characteristics. Therefore, fine adjustments are required for each product, and when controlling a large number of on-off valves, the same number of setting mechanisms as on-off valves are required on the setting signal output side to maintain the output signal at all times. However, it has the disadvantage of being complicated and expensive.

In view of this point, the present invention simplifies the signal output device and signal system by inputting only the number of pulses input at preset pulse intervals as a setting signal and storing the value. The object of the invention is to simplify the adjustment work by detecting the position of the valve by the number of pulses, and to simplify and downsize the device by configuring the opening/closing control section with a digital circuit. .

[Structure of the Invention] The valve opening control device for an on-off valve of the present invention includes a control signal input section, an opening detection section, an on-off control section, and a drive section for opening and closing the on-off valve. The control signal input section inputs only the pulse signal inputted at the timing set, and stores and outputs the number of pulse trains corresponding to the set opening degree, and the opening degree detection section is connected to the drive section. The number of pulses corresponding to the amount of operation of the drive unit is stored and outputted in conjunction with each other, and the opening/closing control unit compares the output of the control signal input unit and the output of the opening degree detection unit, and determines whether these two outputs are the same. It is characterized by outputting a signal that operates the driving section until the two match.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1 to 5. In Figure 1, 8 is an interval timer, trigger input port 8α, timer set input port 8h.
The output 8C is connected to the NAND gate element 9.

Monomulti 10 inputs the output of WAND gate 9 to 10α
and is connected to the reset terminal 11α of the binary counter 11 via an OR element. The binary counter 11, which is a control signal input section, outputs its output to a comparator 13, which is an opening/closing control section.

This is a 12-enlarged up-down counter, which has a reset terminal 12α and a preset terminal 12b, and which inputs the output of the pulse generation mechanism 14 equipped with a Hall element etc. for detecting the position of the valve and outputs it to the comparator 13. Configures the opening detection section.

Comparator 13 has comparison output terminals 13α, 15A, 13
It compares the output A of the binary counter 11 with the output B of the pull-down counter 12, and outputs it to the comparison output terminal 13α when the value is M>B. Comparison output terminal 13b
is output when A-B, and the comparison output terminal 13C is output when M<B.

The comparison output 15α of the comparator 15 rotates the motor 16 via the relay circuit 15 so that the on-off valve 20 operates in the opening direction, and also sets the counting mode of the up-down counter 12 to the addition mode. The comparison output 13A becomes a signal to stop the motor.

Further, the comparison output 13C rotates the motor 16 via the relay circuit 15 so that the on-off valve 20 operates in the closing direction, and sets the up/down counter 120 count mode to the subtraction mode.

17 is a limit switch that closes the auxiliary contact 171 when the on-off valve 20 is fully closed; 18 is a limit switch that closes the auxiliary contact 171 when the on-off valve 20 is fully closed;
6 is a limit switch that closes the auxiliary contact 18' when the switch is fully open, and together with the relay circuit 15 and the motor 16, these constitute a driving section.

Next, the operation will be explained with reference to FIGS. 2 to 5, centering on FIG. 1.

FIG. 2 is a timing chart showing the operation of the interval timer 8 shown in FIG. 1. When the setting signal 19 is input to the trigger input port 8α of the interval timer 8, the internal interval timer is activated by the first pulse. . Once this timer is started, subsequent pulse inputs to 8a are ignored during basic timer cycle T3. Here, the basic timer cycle T6 and Hi
The signal duration T2 is fixed, and only the Hi signal output start time T1 can be changed by using the externally set input port 8b. Therefore, as shown in FIG. 3, when the setting signal 19 is input, the interval timer 8 is driven by its first pulse, and the external setting input port 8 is driven.
After the period T1 set by b, the output 8C becomes Hi for 12 hours. Therefore, the only pulse signal that can pass through the NAIJD gate 9 is the pulse generated during this period 'r2.

Furthermore, the first pulse that passes through the NAND gate 9 activates the monomulti 1o, resulting in an output 10b. Therefore, only the first pulse is input to the reset terminal 11cL of the pinary counter 11, and the subsequent pulse train excluding the first pulse is input to the clock terminal 11b. On the other hand, in order to know the current opening position of the on-off valve 2o,
Generating mechanism 14 that generates pulses in conjunction with the operation of the on-off valve
Input the pulse emitted by.

In this case, the drive motor 16 does not need to be a pulse motor or the like, and in order to obtain the necessary number of pulses by rotation, the disk may be rotated at a necessary gear ratio and detected by a Hall element or the like.

Valve opening setting value, that is, output A of the binary counter 11
The comparator 13 compares the current opening degree of the on-off valve 2o, that is, the output B of the up/down counter 12.

When A<B(D), the comparator 15 turns on the open circuit of the motor 16 of the 1Jv circuit 15, sets the up/down counter 12 to countdown mode, and keeps the open circuit open until A-B. Turn on the switch. When A>B, the comparator 13 turns on the closing direction circuit switch 2 of the motor 16 of the relay circuit 1-5, puts the up/down counter 12 in countdown mode, and keeps the closing direction circuit switch turned on until A=B. turn on.

By adopting the above method, the signals required for setting can be sent intermittently, and a sample and hold circuit is not required. Additionally, all initial adjustments and positioning are performed through signal lines as described below.

When performing initial adjustment, a setting signal is input to the input clock 11A of the binary counter 11 so that the number of pulses exceeding the 11 maximum count amount by one is input.

At this time, the output of the binary counter 11 becomes 0, and the carry signal 11c presets the up/down counter 12, which serves as an opening detection section.

The preset value is the number of pulses generated by the pulse generating mechanism 14 from fully closed to fully open.

In this way, no matter where the pulp opening is,
The pulp operates fully closed. When the fully closed position is reached, the limit switch 17 operates and the contact 171 closes.
The up/down counter 12 is reset and the initial adjustment is completed.

Furthermore, if a limit switch 18 that operates in the fully open position is installed, the contact 18 closes when the limit switch 18 is fully open, so that the preset value is input to the value of the up/down counter. In this way, even in normal operating conditions, alignment is performed in the fully closed and fully open positions.

FIG. 4 shows a system for controlling a plurality of (5) on-off valves in which the valve opening control device described in FIGS. 1 to 3 is integrated into the upper part of the valve body. In this case, as shown in the timing chart of FIG. 5, the setting signal to the external setting input port 8h of the interval timer 8 of the valve opening control device in FIG. By setting the Hi timings so that they do not overlap with each other, it is possible to share the setting signal input system and give unique setting values to each on-off valve. In this way, since the number of signal input systems can be reduced to one, the control circuits for a large number of on-off valves can be simplified. Note that although the above embodiments are constructed using digital circuits, it is also easy to realize a similar construction using a microcomputer.

[Effects of the Invention] As described above, the device of the present invention can be configured with a digital circuit or a microcomputer, so it does not suffer from drifts that occur in analog circuits or variations in component characteristics during manufacturing. This eliminates the need for fine-tuning cropping, significantly improving productivity. Furthermore, since the control circuit is simplified, the entire device can be made smaller, more compact, and less expensive.

Furthermore, since the setting signal can be input in the form of pulses through a common setting signal input system line to many on-off valves, the circuit can be simplified when creating the setting signal with a microcomputer or digital circuit. Moreover, it has the excellent effect of making it easy to control a large number of on-off valves.

[Brief explanation of the drawing]

1N: A block diagram showing the configuration of an embodiment of the valve opening control device of the present invention.I2: A timing chart showing the operation of the interval timer 8 shown in M1.FIG. 3: Setting signal 19 and interval timer 8 shown in FIG.
Timing chart of output signal 8C1, Nanano Multi 100 input signal 10α, output signal 10b1, reset signal jMZ of binary counter 11, and clock signal 11A. FIG. 4: Device of the present invention when controlling a plurality of (5) on-off valves Control system according to Fig. 5: To each on-off valve (1) in the control system shown in Fig. 4 (
5) Operation timing chart Figure 6: Configuration explanatory diagram of conventional valve opening control device 8...Interval timer, 9...NAND)y''-) Element, 10...Monomulti, 11. - Binary counter, 12... Up/down counter, 13... Comparator, 14... Pulse generator 1 [, 15... Relay circuit, 16... Motor, 17.18... Limit switch, 19...Setting signal, 2o...Opening/closing valve Fig. 2 Fig. 4 Fig. 6 3' EIE year - dimension 0

Claims (1)

[Claims] It consists of a control signal input section, an opening degree detection section, an opening/closing control section, and a drive section that opens and closes the on-off valve, and the control signal input section only receives pulse signals input at timings set in advance in the control signal input section. is input, the number of pulse trains corresponding to the set opening degree is stored and outputted, and the opening degree detection section is linked to the drive section and stores the number of pulses corresponding to the amount of operation of the drive section. The opening/closing control section compares the output of the control signal input section and the output of the opening degree detection section, and outputs a signal for operating the drive section until both outputs match. Valve opening control device for on-off valves