JPH03286919A - Air quantity controller - Google Patents

Abstract

PURPOSE:To obtain an air quantity controller which can feed and control a proper air quantity even when the characteristic of a sensor changes by providing a fan driving means for adding a corrected value during the operation of a fan to the output of the air quantity sensor detected in accordance with the operating state of the fan and calculating and outputting the driving output of the fan. CONSTITUTION:The characteristic of an air quantity sensor 3 changes due to aged deterioration or the adhesion of dust for a long time. When an air quantity is controlled with characteristic g(w) at this time maintained, even if the driving voltage of a fan is outputted at w2 and the air quantity is actually proper, the air quantity sensor 3 outputs V4. Namely, only the air quantity corresponding to the output of w3 is detected, the output of the fan is increased until the sensor outputs V2 to thereby obtain w4. Then, air/fuel ratio changes to cause an abnormal combustion. Thus, a correcting means 63 compares an initial characteristic f(w) with the present characteristic g(w) and calculated the difference therebetween to obtain the corrected value. Then, the corrected value is added to the present characteristics g(w) to obtain a corrected characteristic h(w), so that the driving output of the fan is controlled based thereon.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an air volume control device.

<Prior Art> Conventionally, a rotation speed detector and an MLll sensor are used to control the amount of air blown by a fan, and based on these detected values, the fan Ii! There is one that corrects the dynamic force and divides it so that it reaches the target air volume. In particular, the air volume control of the combustor needs to be carried out with great precision, since if the combustion system and air volume are not supplied in a well-balanced manner, a dangerous mode of abnormal combustion will occur. This also applies to household combustion appliances such as water leakers, hot water heaters, and bathtubs. However, when it comes to household combustion appliances, it is difficult to find high-quality ones. Controls involving IH devices are expensive, so they cannot be adopted without discretion, and since these devices are mainly installed outdoors, they are not seen by many people, making it difficult for users to perform maintenance and inspections. It is something that cannot be expected. Therefore, there is a need for an inexpensive and maintenance-free airflow control device.

(Mill to be solved by the invention) By the way, among the control methods described above, in the one that detects the rotation speed, even if the suction port or discharge port (exhaust port) of the fan is blocked by dust or head wind, the fan will not continue to operate. Since it continues to rotate, a separate blockage detection device is required. On the other hand, in the case of using an airflow sensor, since the airflow amount can actually be detected, it is possible to detect a blockage state, but there is a problem that the characteristics of the sensor change over a long period of time.

(Means for solving !ill) In view of the above TAM, the present invention aims to provide an air volume control device that can supply and control an appropriate air volume even if the characteristics of a sensor change, and is characterized by the following configuration. It is said that That is, an initial state storage means stores the relationship between the fan drive output and the air volume sensor output during the first fan operation after the S source is turned on, and stores the relationship between the fan drive output and the air volume sensor output each time the fan operates from the second time onwards. Comparing the memory contents of the current state storage means for storing the information, the initial state storage means and the current state storage means,
A correction means for calculating a correction value of the air volume sensor output, and a fan drive means for calculating and outputting the fan 1 creation force by adding the correction value to the air volume sensor output detected according to the operating state of the fan. There is.

(Function) Since the characteristics of the airflow sensor when the power is turned on are compared with the characteristics of the airflow sensor after that, deviations from the initial values are constantly corrected. It is also possible to always obtain appropriate fan drive output.

C Embodiment) The present invention will be described below with reference to an illustrated embodiment. 1 is a fan casing, and 2 is a fan motor. Reference numeral 3 denotes an air volume sensor placed at a suitable location in the fan casing 1. Reference numeral 4 denotes a combustor such as a burner, and the combustion device is increased or decreased by a proportional control valve 5. 6 is a control consisting of a micro combi coater, etc.! ! At the position, the proportional control valve 5 and the fan motor 2 are set to f.
It is controlled dynamically. The control device 6 is programmed with a combustion sequence, and has an initial state memory that stores the relationship between the fan drive output (IK pressure) and the air volume sensor output (voltage) during pre-purge when the fan is operated for the first time when power is supplied to IIk. The storage contents of the means 6I, the current state storage means 62 that stores the relationship between the fan drive output and the air volume sensor output every pre-purge during the second and subsequent fan operations, the initial state WJA storage means 61, and the current state storage means 62. and a fan drive means 64 that calculates and outputs a fan drive output by adding the correction value to the air volume sensor output detected according to the operating state of the fan. is made up of.

Next, the operation of the above configuration will be explained.

When combustion is performed for the first time, the fan motor 2 is turned on and pre-purge is performed. At this time, the dynamic voltage of the fan 1 is kept constant, and the output voltage of the air volume sensor 3 at that time is determined. The same operation is performed with multiple fan f subvoltages changed, and the relationship between the fan f dynamic voltage and the output voltage of the air volume sensor 3 is memorized. That is, the characteristic f(v) shown in the solid line shown in FIG. 2 is obtained. At this time, the correction value is O, which is 0, and the characteristic sound is controlled according to this characteristic, and combustion is performed.

From the second time after the power is turned on, the fan drive voltage and the output normal pressure of the airflow sensor 3 are read in the same way during pre-purge, but this 1SlI value is stored separately from the initial value and updated every time the fan is operated. To go. Over a long period of time, the characteristics of the air volume sensor 3 change due to aging, dust adhesion, and the like.

The characteristic g(1) at this time is shown by the broken line in Figure @2.

If controlled in this state, the dynamic voltage of fan 1g will be W,
The airflow sensor 3 outputs V even though the amount M is actually a layer pressure. In other words, it will be detected that only the rtkji equivalent to the output of Ws is being output, and the fan output will be increased until the output of V2 is output and then set to W4, which will change the air-fuel ratio and cause abnormal combustion. . Therefore, the correction means 63 compares the initial characteristic f(v) and the current characteristic g<v), calculates the difference, and obtains a correction value.

Then, a correction value is added to the current characteristic gFv) to obtain a correction characteristic b(v), and the fan drive output is controlled based on this. For example, when combustion with the maximum gas amount is requested, the fan drive voltage outputs W, but the corresponding air volume sensor output becomes vl, and the fan drive voltage is W.
You will no longer end up with a +.

In this embodiment, the initial value and the current value are detected during pre-purging, but they may be read during post-purging or when the combustion is in a stable state.

(Effects of the Invention) As described above, the present invention corrects the characteristics of the airflow sensor so that they are equal to the initial state, so even if the characteristics of the airflow sensor change due to aging or dust adhesion, the fan is always driven properly. Even if it is used in a combustion appliance that does not require long-term maintenance and inspection, stable combustion can be maintained. In addition, no separate equipment is required,
It can be made inexpensively. Furthermore, it is capable of responding to changes in the characteristics of the airflow sensor due to ambient temperature, and is extremely useful.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a characteristic diagram of fan output and air volume sensor output. 1... Fan casing 2... Fan motor 3... Air volume sensor 6... Meter control device 61... Initial state storage means 62... Current state storage means 63... Correction means 64... Fan drive means

Claims (1)

[Claims] In a device that detects the airflow rate of the fan using an airflow sensor, corrects the fan drive output based on this detection output, and controls the fan drive output to reach the target airflow, the fan drive output and airflow rate change when the fan is operated for the first time after the power is turned on. an initial state storage means for storing the relationship between the sensor output and the sensor output; a current state storage means for storing the relationship between the fan driving pressure and the air volume sensor output each time the fan is operated for the second time and thereafter; an initial state storage means and the current state storage means; and a fan drive that calculates and outputs a fan drive output by adding the correction value to the air volume sensor output detected according to the operating state of the fan. An air volume control device characterized by comprising: means.