JPS6091421A - Pressure controller - Google Patents

Abstract

PURPOSE:To stabilize the accuracy of a pressure controller and to ensure the constant control of flow rate by using a semiconductor sensor as a pressure sensor. CONSTITUTION:For a pressure controller, a semiconductor sensor 1 consisting of a silicon pressure sensor is used to detect the pressure of an air path for combustion and convert the measured pressure into air pressure signals. Then the pressure controllers detects and measures the pressure produced a control valve 9 which is opened and closed by a control motor 8 by the sensor 1. This pressure is converted into electric signals with amplification 2 and supplied to a comparator 3. At the same time, the set voltage signal sent from a setting part 5 is also supplied to the comparator 3. These two signals are compared with each other to drive a relay 6 or 7. Thus the motor 8 is revolved forward and reversely and therefore the opening amount of the valve 9 is changed to obtain the coincidence between the set pressure value and the measured pressure value.

Description

[Detailed description of the invention] The present invention relates to pressure controllers.

For example, in burners, etc., pressure controllers are used to control the pressure of combustion air, etc. and adjust the air ratio to a constant level. There is.

However, with this mechanical type, the pressure setting is performed using a spring, so the setting accuracy is poor, and there are also problems in that remote setting is not possible or the detected pressure cannot be measured.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure controller that can eliminate the above-mentioned conventional problems by using a semiconductor sensor as a pressure sensor.

Next, the present invention will be explained with reference to the drawings which are one embodiment.

In the figure, 1 is a semiconductor sensor consisting of a silicon pressure sensor that detects the pressure in the combustion air flow path A and converts the measured pressure into an air pressure signal, 2 is an amplifier, 3 is a comparator, 4 is a correction circuit, and 5 is a A pressure setting part receives a setting signal from the outside and sets the pressure, 6 and 7 are relays, 8 is a control motor operated by the relay, and 9 is detected by the semiconductor sensor 1 which is opened and closed by the control motor 9. The measured pressure is converted into an electrical signal, amplified by an amplifier 2, and input to a comparator 3. On the other hand, a set pressure signal is input from the setting section 5 to the comparator 3, and both signals are compared by the comparator 3. Then, depending on the magnitude of the comparison signal, the relay 6
．． 7, the control motor 8 is rotated in either the forward or reverse direction to change the opening degree of the control valve 9, so that the pressure set value and the measured value become equal. Note that by extracting the signal from the amplifier 2, the measured value can be transmitted to the outside. In addition, when the mass flow rate of combustion air is made constant, etc., a correction signal from a correction circuit including a resistance temperature detector k is inputted to the setting section 5, and the setting value of the setting section 5 is corrected. Just do it like this.

FIG. 2 shows a case where the present invention is applied to make the pressure of combustion air and fuel pressure proportional. The humidity of the combustion air is measured by the temperature sensors T and C, and the pressure of the combustion air is corrected based on this temperature signal, and the control valve 9 is controlled by the control motor 8. and inputting the fuel pressure as a setting signal to the second pressure controller C, measuring the temperature of the fuel with the fuel temperature sensors T and C,
A case is shown in which the P size pressure is corrected based on this temperature signal and the fuel pressure is controlled to be constant as described above.

FIG. 3 shows a case where the signal from the oxygen concentration indicator is used as the setting signal, and the pressure controller is operated using this and the combustion air pressure to set the oxygen supply amount to a predetermined value.

FIG. 4 shows an example of a correction circuit, and this correction circuit consists of a resistor R
It consists of a series circuit of a resistance temperature detector, a resistor R2, and a resistor R2.
The change in resistance due to temperature of the resistance thermometer is output to the setting section as a change in the output voltage E to the setting section 5, and the correction amount is determined by the resistance R, which is connected in series.
An approximation value close to the theoretical formula required for correction is obtained by combining or arranging the values of R2.

As is clear from the above description, according to the present invention, a semiconductor sensor is used for pressure detection. Unlike mechanical sensors such as diaphragms, this semiconductor sensor has stable accuracy over a long period of time, so it is possible to perform high-level pressure control over a long period of time. In addition, since the pressure signal is captured as an electrical signal, it is possible not only to set it remotely but also to take out the measured value output, and it can be connected to other instruments and can be used in a wide range of applications.

Further, by providing the correction circuit in the setting section, not only is there no need for an expensive computing unit, but also constant flow control can be performed with a simple configuration even when humidity changes.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the pressure sensor according to the present invention, FIGS. 2 and 3 are flow sheets showing examples of use of the pressure controller according to the present invention, and FIG. 4 is an example of the correction circuit of FIG. FIG. C...Pressure controller, 1...Semiconductor sensor, 3
...Comparator, 4...Correction circuit, 5...Measuring section, 8
...Control motor, 9...Control valve. Patent applicant Chugai Roko Kogyo Co., Ltd.

Claims (2)

[Claims] (1) A semiconductor pressure sensor, a pressure setting section, a control section that compares the pressure signal detected by the pressure sensor with an output signal of the setting section and outputs a control signal, and a control valve according to the signal from the control section. A pressure controller comprising: a drive motor that drives the pressure controller; (2) The pressure setting section includes a correction circuit that changes the pressure setting value based on an external signal.