JP2551286B2 - Gas pressure regulator for gas combustor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas pressure adjusting device for a gas combustor such as a water heater.

[0002]

2. Description of the Related Art A conventional gas pressure adjusting device for a gas combustor (2)
One example will be described with reference to FIGS. 4 and 5. First, in the first example, as shown in FIG. 4, a maximum gas pressure setting means 10 for determining a maximum gas pressure value, a minimum gas pressure setting means 7 for determining a minimum gas pressure value, a set hot water temperature, an outgoing hot water temperature, and a water entering temperature. There is provided a proportional control calculation unit 2 that executes a predetermined calculation from data 1 such as temperature and hot water discharge amount to determine an output value. The output of the proportional control calculating unit 2 is input to the adding unit 8 via the amplifying unit 5, is added to the minimum gas pressure output output from the minimum gas pressure setting unit 7 via the minimum gas pressure setting unit 6, and is maximum. It is output to the gas pressure setting unit 9. The maximum gas pressure setting unit 9 limits the output of the adding unit 8 to the output value set by the maximum gas pressure setting unit 10 or less and outputs it to the proportional valve drive unit 11, and the proportional valve 12
It is designed to control the current value supplied to the device (see Japanese Utility Model Laid-Open Nos. 58-58248 and 58-148455).

Next, in the second example, as shown in FIG. 5, when the minimum gas pressure is adjusted, the minimum output command means 3 is turned on,
The minimum output is output from the proportional control calculation unit 2. If this minimum output is set to 0, the output of the amplifier 5 is also 0, and the output of the maximum gas pressure setting unit 9 is 0 regardless of the set value of the maximum gas pressure setting means 10. When the set value of the minimum gas pressure setting means 7 is adjusted in this state, the control value corresponding to the minimum gas pressure output from the adder 8 is determined. Next, when the maximum gas pressure is set, the maximum output command means 4 is turned on, and the maximum output is output from the proportional control calculation unit 2. If the maximum gas pressure setting means 10 is adjusted in this state, a voltage corresponding to the maximum output can be obtained from the maximum gas pressure setting unit 9, and the output of the minimum gas pressure setting unit 6 is added by the addition unit 8. As a result, the output corresponding to the maximum gas pressure is finally output to the proportional valve drive unit 11 (see Japanese Utility Model Laid-Open No. 63-122801).

[0004]

However, in the first example of the prior art described above, for example, when the maximum gas pressure setting means 10 is set and then the minimum gas pressure setting means 7 is adjusted,
The adjustment value of the maximum gas pressure setting means 10 is changed by the adjustment of the minimum gas pressure setting means 7, and when the maximum gas pressure setting means 10 is readjusted next, the minimum gas pressure setting means 7 is reversed.
The output of the maximum gas pressure setting means 10 corresponding to the set value of is changed. As a result, in this conventional example, it is necessary to repeat the adjustment of the minimum gas pressure setting means 7 and the adjustment of the maximum gas pressure setting means 10 alternately many times, and it is necessary to perform mass production adjustment of the gas combustor and maintenance after delivery. There is a problem that the adjustment work is sometimes very troublesome.

In the second example of the prior art, which has improved the problems of the first example of the prior art, the minimum gas pressure setting means 7 and the maximum gas pressure setting means are adjusted at the time of adjusting the gas pressure.
The gas pressure adjustment can be completed by adjusting each of 10 and 10 once, but in the second example as well, the minimum gas pressure setting means 7 is provided in the circuit of the gas pressure adjusting device of the gas combustor. And the maximum gas pressure setting means 10 are provided with two gas pressure adjusting volumes, and the addition section 8 is required because these two gas pressure adjusting volumes are present. In the gas pressure adjusting device of the gas combustor which is used only at the time of factory shipment and at the time of service, it is necessary to provide the above-mentioned two volumes and the addition section 8 from the viewpoint of cost. This is also a big problem in terms of having to prepare a space for.

Therefore, the present invention solves the above-mentioned drawbacks of the prior art, one volume for gas pressure adjustment can be omitted, the addition section is not required, and the gas pressure adjustment is performed only once. An object of the present invention is to provide a gas pressure adjusting device for a gas combustor that requires only one maximum gas pressure adjustment.

[0007]

In order to achieve the above object, a gas pressure regulator for a gas combustor according to the present invention comprises a proportional valve for continuously changing the gas pressure of the gas combustor, and a proportional valve driven by the proportional valve. A gas pressure adjusting device for a gas combustor comprising a proportional control calculating section for outputting a signal, wherein the proportional control calculating section outputs a minimum output of the minimum output command means.
Maximum output command means for outputting the maximum output, and a single gas pressure adjusting volume for generating the minimum gas pressure setting voltage under the minimum output command and the maximum gas pressure setting voltage under the maximum output command. And the proportional control calculation unit is A /
Built-in D converter, microcomputer and PWM
The D conversion unit inputs the gas pressure setting voltage from the gas pressure adjusting volume and transfers the A / D conversion value to the PWM unit via the microcomputer unit, and the PWM unit outputs the A / D conversion value according to the control signal of the microcomputer. The / D conversion value is converted into a PWM pulse having a predetermined duty factor and output as a drive signal to the proportional valve.

[0008]

According to the features of the gas pressure adjusting device for the gas combustor of the present invention, the minimum (then maximum) output command means is set to the command state, and the single gas pressure adjusting volume is changed to the proportional control calculating section. When the minimum (then maximum) gas pressure setting voltage is input, the input is processed in the proportional control operation unit according to the control signal of the microcomputer unit in the operation unit, and the PWM having a duty factor corresponding to the desired combustion heat quantity is generated.
It is converted into a pulse and is output as a drive signal to the proportional valve, and the proportional valve operates to set the minimum (then maximum) gas pressure, but by performing the adjustment operation shown above only once, The gas pressure adjustment of the gas combustor can be completed accurately.

[0009]

Embodiments of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. 1 is a circuit diagram showing an embodiment, and FIG. 2 is a correspondence between an output of an A / D conversion unit (hereinafter abbreviated as A / D conversion value) and an output of a PWM unit (hereinafter abbreviated as PWM-Duty) in a proportional control calculation unit. Explanatory diagram showing the relationship, FIG. 3 shows PWM-Dut
y is the vertical axis, and the number of combustion heat quantity of the gas combustor (however, the number is the unit of the combustion heat quantity required to raise the temperature of 1 liter of hot water for heating by 25 ° C per minute) is a graph with the horizontal axis. is there.

In the gas pressure adjusting device for a gas combustor according to the present invention, the MIN adjusting switch 107 which is the minimum output command means shown in FIG.
It is given to the central processing unit (hereinafter abbreviated as CPU) 111 of the microcomputer unit 100 in 1 through the digital input unit 109. In this state, when the gas pressure adjusting volume 114 is turned to a predetermined position for setting the minimum gas pressure, the voltage of the reference power supply 115 of the proportional control computing unit 101 becomes the minimum gas pressure setting voltage 129 via the volume 114. Then, it is input to the A / D conversion unit 112 in the proportional control calculation unit 101, passes through the A / D conversion unit 112, becomes the A / D conversion value 130, is input to the CPU 111, and further passes through the CPU 111, and then the PWM The A / D conversion value 130 is input to the CP 113 in the PWM unit 113.
Control signal from U111 (ie A / D conversion and P shown in FIG. 2)
Under the control signal based on the program created by the correspondence relationship of WM-Duty, the desired combustion heat quantity (for example, 2
No.) pulse with a duty factor of 132 (for example, a pulse with a duty factor of 18/255 becomes PW).
The PWM pulse 132 is output from the M section output terminal 104 (as an output of the proportional control calculation section 101), and further, the PWM pulse 132 passes through the buffer circuit 116 and the integration circuit 117, and then the PWM integrated value 133.
(However, in this case, since it is under the minimum condition, the main PWM integrated value 133 is the minimum value 0V) and is input to the voltage amplification amplifier 118. Then, the PWM integral value 133 is amplified by the amplifier 118 and then input to the proportional valve 120 (as the valve drive current 135) which changes the gas pressure of the gas combustor steplessly via the constant current circuit 119, and the proportional value is supplied. Valve 120
According to the program in the microcomputer unit 100, the desired minimum gas pressure for producing the desired combustion heat quantity corresponding to the A / D converted value 130, and accordingly the PWM pulse 132 is generated. If the proportional valve 120 does not produce the desired minimum gas pressure at this time, the volume 114 is finely adjusted to cause the proportional valve 120 to produce the desired minimum gas pressure. However, during the above, firstly, the amplifier 118 is
3, that is, having a sufficient amplification degree such that its output can supply a sufficient drive current 135 to the proportional valve 120 through the constant current circuit 119 even when the minimum value 0V of the PWM pulse integrated value is input. And Further, during the above period, secondly, the CPU 11
1 is the input value to the CPU 111 when the minimum gas pressure by the proportional valve 120 is achieved and confirmed as described above, that is, the fixed value of the A / D conversion value 130, and the microcomputer unit 100
It is stored in the storage device 110 of.

Next, the MAX output switch 108, which is the maximum output command shown in FIG. 1, is pressed, and the maximum output command is given to the CPU 111 of the microcomputer unit 100 in the proportional control calculation unit 101 via the digital input unit 109. In this state, when the gas pressure adjusting volume 114 is turned to the predetermined position for maximum gas pressure setting, the voltage of the reference power supply 115 of the proportional control computing unit 101 becomes the maximum gas pressure setting voltage 139 via the volume 114. , Is input to the A / D conversion unit 112 in the proportional control calculation unit 101, passes through the A / D conversion 112, becomes the A / D conversion value 140, is input to the CPU 111, and further passes through the CPU 111 to the PWM unit 113. In the PWM section 113, the A / D conversion value 140 is controlled by a control signal from the CPU 111 (that is, based on a program created by the correspondence between the A / D conversion value and the PWM-Duty shown in FIG. 2). signal) PWM pulse 142 duty factor corresponding to the desired amount of combustion heat (e.g. 16 No.) under (e.g. duty factor
203/255 pulse), and the PWM output terminal 104
(As the output of the proportional control calculation unit 101), the PWM pulse 142 further passes through the buffer circuit 116 and the integration circuit 117, and then the PWM integrated value 143 (However, in this case, the maximum PWM condition is satisfied. Integral value 143 is maximum value 5
V) and is input to the voltage amplification amplifier 118. The PWM integrated value 143 is amplified by the amplifier 118 and then passed through a constant current circuit 119 to a proportional valve 120 that continuously changes the gas pressure of the gas combustor (the valve drive current 14
5) and the proportional valve 120 follows the A / D conversion value 140, and thus P, according to the program in the microcomputer section 100.
It produces the desired maximum gas pressure which produces the desired heat of combustion corresponding to the WM pulse 142. If at this time the proportional valve
If 120 does not produce this desired maximum gas pressure, the volume 114 is fine-tuned to cause proportional valve 120 to produce this desired maximum gas pressure. However, during the above,
First, the amplifier 118 can supply a sufficient driving current 145 to the proportional valve 120 via the constant current circuit 119 when the input 143, that is, the maximum value 5V of the PWM pulse integration value is input. However, it shall have a sufficient amplification degree.
Further, during the above, secondly, the CPU 111 causes the input value to the CPU 111, that is, the A / D conversion value 14 when the maximum gas pressure by the proportional valve 120 is achieved and confirmed as described above.
The fixed value of 0 is stored in the storage device 110 of the microcomputer unit 100.

When the minimum gas pressure adjustment is performed once and the maximum gas pressure adjustment is performed once according to the above, as a result, the determined values of the A / D converted values 130 and 140 are stored in the microcomputer unit 100. In the microcomputer unit 100, points A and B that satisfy the functional relationship of the combustion calorific value corresponding to the PWM-Duty shown in FIG. 3 based on the newly stored data and the established program shown in FIG. , And an operating curve 300 having the lower limit at point A and the upper limit at point B is determined as a new program. Therefore, once the above adjustments have been made, a gas combustor equipped with the proportional control calculation unit 101 including the microcomputer unit 100 can be used under the characteristics of the operation curve 300 above and below the upper and lower limits of the accurate gas pressure. Therefore, it can be used while ensuring an accurate combustion heat quantity.

[0013]

According to the gas pressure regulator of the gas combustor according to the present invention, the present invention has the above-mentioned constitution and operation.
The gas pressure adjustment of the gas combustor can be performed by using a single gas pressure adjustment volume, and therefore two gas pressure adjustment volumes required in the conventional gas combustor similar to the present invention can be provided. One can be omitted, and the adder that adds the output of the minimum gas pressure setting unit and the output of the maximum gas pressure setting unit required by the conventional gas combustor can also be omitted. As a result, the cost due to the reduction of the number of parts Down and parts space can be saved. Further, in the conventional gas combustor similar to the present invention, the gas pressure adjustment at the time of shipment and maintenance of the equipment is controlled by the minimum gas pressure setting means.
In contrast to the case where the N adjustment and the MAX adjustment by the maximum gas pressure setting means have to be alternately repeated many times, in the case of the present invention, one MIN adjustment and one MAX adjustment are sufficient.
Therefore, by using the present invention, it is possible to avoid the inconvenience that the adjustment work becomes very troublesome at the time of mass-production shipment and maintenance of the device as in the related art.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 A / D conversion value and PWM in a proportional control calculation unit
It is explanatory drawing which shows the correspondence of -Duty.

FIG. 3 is a graph in which PWM-Duty is the vertical axis and the gas combustion heat quantity number is the horizontal axis.

FIG. 4 is a block circuit diagram of a first example of a conventional technique.

FIG. 5 is a block circuit diagram of a second example of the related art.

[Explanation of symbols]

 100 Microcomputer section 101 Proportional control calculation section 107 Minimum output command section 108 Maximum output command section 112 A / D conversion section 113 PWM section 114 Gas pressure adjusting volume 120 Proportional valve 129 Minimum gas pressure setting voltage 139 Maximum gas pressure setting voltage

Continuation of the front page (56) References JP-A-2-13709 (JP, A) JP-A-5-33936 (JP, A) JP-A-4-302912 (JP, A) Actual development Sho-61-88071 (JP , U) Actually open 63-122801 (JP, U) Actually open 61-125685 (JP, U) Japanese Patent Publication 3-60015 (JP, B2) Actual Public 2-47653 (JP, Y2)

Claims (1)

(57) [Claims] 1. A gas pressure adjusting device for a gas combustor comprising a proportional valve for continuously changing the gas pressure of the gas combustor and a proportional control calculation unit for outputting a drive signal to the proportional valve, wherein the proportional valve A minimum output command means for outputting the minimum output of the control calculation part, a maximum output command means for outputting the maximum output, and a minimum gas pressure setting voltage under the minimum output command A single gas pressure adjusting volume for generating a maximum gas pressure setting voltage is provided below, and the proportional control calculation unit includes an A / D conversion unit, a microcomputer unit, and a PWM.
And an A / D converter that inputs the gas pressure setting voltage from the gas pressure adjusting volume and outputs the A / D converter.
The converted value is transferred to the PWM section via the microcomputer section, and the PWM section converts the A / D converted value into a PWM pulse having a predetermined duty factor according to a control signal of the microcomputer and outputs it to the proportional valve as a drive signal. A gas pressure adjusting device for a gas combustor, characterized in that