JPS60213732A - Liquid fuel burning device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of unevenness in a delay time as low as possible, by a method wherein, when combustion is switched to high and low, a timing, at which a flow rate of a pump is varied, is delayed by a specified time than a timing at which an amount of a combustion air is varied. CONSTITUTION:When combustion of a burner is switched from low combustion to high combustion or from high combustion to low combustion, a delay circuit 13, which causes an electromagnetic pump 7 to be operated after a specified time has elapsed since a burner motor 4 is functioned to vary an amount of the air for combustion supplied thereby, is provided. Namely, a microcomputer 17 decides a delay time depending upon the intensity of the output of an A/D converter 14 which converts the given voltages in an analogue formation, into which a given D.C. voltage Vcc outputted by a rectifying circuit 11 is divided by resistors 15 and 16, into a digital signal. After the delay time has elapsed, a signal, by means of which a high/low changing-over switch 8 of the electromagnetic pump 7 is changed over to the contract for low combustion side, is outputted from an output terminal 17b to a combustion control circuit 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a liquid fuel combustion device for heating, etc. by burning liquid fuel such as kerosene.

(B) Prior art In conventional liquid fuel combustion devices of this type, the timing at which the amount of combustion air is increased is the timing at which the flow rate of the pump that supplies fuel increases when the burner switches from weak combustion to strong twist firing. By delaying the fuel consumption for a certain period of time, it is possible to compensate for the delay time until the actual combustion amount changes due to the pump's own response delay and piping resistance, etc., and prevent lift combustion or misfire due to excessive air flow. Japanese Patent Publication No. 57-292
As disclosed in Publication No. 7, pumps have improved in performance over the past few years to the point where they can respond instantaneously and vary the flow rate even when the combustion amount is switched from weak combustion to strong twist firing or from strong twist firing to weak combustion. This has significantly improved, and the current system is such that the amount of combustion air is varied and the flow rate of the pump is varied after a predetermined period of time has elapsed.

In addition, conventionally, the delay time is determined by a C-R time constant circuit, but due to variations in the capacitance of the capacitors that make up the C-R time constant circuit, there is an error of about ±30% of the set delay time. It had a range.

G/U Purpose of the Invention As described above, the present invention uses a C@R hourly circuit that delays the timing of varying the pump flow rate by a certain period of time in contrast to the timing of varying the amount of combustion air when switching between strong and weak combustion. The aim is to prevent errors (variations) in delay times as much as possible.

B) Structure of the Invention The present invention includes an A/D converter that converts an analog voltage obtained by a fist that sets a resistance value to a desired value into a digital signal, and a and a microcomputer that determines the delay time, and when changing the combustion amount of the burner from weak combustion to strong twist firing, it changes the supply amount of the air blower and controls the flow rate of the micro combinator. The oil supply device is configured to operate after the output delay time has elapsed.

(E) Example Below, a liquid fuel combustion apparatus which is an example of the present invention will be described.
To explain based on the figure and Fig. 2, (l) is 1oov
(2) is a heater that vaporizes kerosene as a liquid fuel, and the heater (2) is controlled by a bimetal thermometer (3) as a temperature control means connected in series. (4) is a burner motor as a blower device that supplies combustion air to a burner (not shown). Burner motor (4
) are connected in parallel to the heater (2) via a switch (5) and a strong/weak changeover switch (6). (7) is an electromagnetic pump serving as an oil supply means for supplying kerosene to a burner (not shown), and the electromagnetic pump (7) is connected to the burner saver (4) to switch between strong and weak (through a changeover switch (8)). They are connected in parallel. Also, the strong/weak selector switch (6) (
8) is always connected to the strong twist firing contacts (A) and (B). (9) is an electric ignition device, and the electromagnetic pump (7
), and when the power source (1) is energized by closing the switch (5), the ignition operation is performed for a predetermined period of time and then stopped.

(101 is a step-down transformer connected to the power supply (1) and the negative side, aυ is a rectifier circuit connected to the secondary side of the step-down transformer a, and e output terminal (lla) of the rectifier circuit aυ and e It outputs a DC voltage ■cc between the output terminals (llb). (1z is the switch (5), the changeover switch (6) for the burner motor (4), and the changeover switch (8) for the electromagnetic pump (7). A3 is a combustion control circuit that controls pressure so as to vary the amount of combustion air supplied to the burner motor (4) when switching the combustion of the burner (not shown) from weak combustion to strong twist firing or from strong twist firing to weak combustion. This is a delay circuit that causes the electromagnetic pump (7) to operate a predetermined time after activation.

FIG. 2 shows a detailed diagram of the above-mentioned delay circuit (131).
14) is the Φ output terminal (11a) of the rectifier circuit αB and θ
Resistor α9αe connected in series between output terminals (llb)
This is an A/D converter that converts the cc analog divided voltage into a digital signal. (Ln is the combustion control circuit a
When a signal for changing the combustion amount from strong twist firing to weak combustion or from weak combustion to strong twist firing is input from 21 to the input terminal (17g), the electromagnetic pump is activated in accordance with the digital signal output from the A/D converter a. (7) is a micro combinator (hereinafter referred to as a microcomputer) which outputs a delayed activation signal from an output terminal (17b).

The present invention has the above-mentioned configuration, and its operation will be described in detail below. First, assuming that the burner (not shown) has risen to a predetermined temperature (the vaporization temperature of kerosene) due to the heat generated by the heater (21), when the switch (5) is closed, kerosene is pumped to the burner (not shown) by the electromagnetic pump (7). At the same time, combustion air is supplied from the burner motor (4) to form a vaporized mixed gas, which is supplied to the ignition device (not shown) and vaporized.
9), it is ignited and combustion begins.

Now, if we switch from strong twist firing to weak combustion, the combustion control circuit α2 is connected to the burner motor (4)'s strong/weak selection switch (
6) to the weak combustion contact (c) side, and input a combustion switching signal to the input terminal (17a) of the microcomputer αη. Therefore, the microcomputer (17) converts the analog predetermined voltage obtained by dividing the predetermined DC voltage vco output from the rectifier circuit aυ by the resistor α51 (le) into a digital signal.
Determine the delay time according to the magnitude of the output of the /D converter a4, and after the delay time (digital signal value) has elapsed, set the strong/weak switch (8) of the pressure electromagnetic pump (7) to the weak combustion contact. 2) A signal for switching the side busy state is output from the output terminal (17b) to the combustion control circuit (121).

Furthermore, by setting the resistance value of the resistance <ts<to mentioned above to an arbitrary value, the delay time can be freely set. For example, in the embodiment shown in FIG.
D converter (141 output 8 bits (AO~A?)
The 8-bit digital signal is output as a digital signal.
If you set the digital signal output from (Ao to A4) as Can be set.

The present invention is as described above, and the delay time for activating the electromagnetic pump (7) can be freely set by selecting the resistance value of the resistor (151). Even when changing the value, it can be used on the same board by simply changing the resistance value of the resistor (151 (16)).Also, the delay time can be controlled in units of 0.1 seconds, making it extremely accurate. It is possible to perform high combustion rate switching operations, and it is possible to prevent lift combustion and red flame combustion due to variations in delay time.

(F) Effects As described above, the present invention allows the delay time until the oil supply device is activated to be freely set by setting the resistance value to a desired value, and the switching operation of the combustion amount is extremely high. Since this can be carried out based on accurate drilling time, there are advantages such as no abnormal combustion occurring due to variations in delay time.

[Brief explanation of the drawing]

81 and 2 are diagrams showing an embodiment of the liquid fuel combustion apparatus of the present invention, in which FIG. 1 is a schematic electrical circuit diagram, and FIG.
The figure is a detailed diagram of the delay circuit. (4)...burner motor (air blower), (7)...
・Electromagnetic pump (oil feeding means), α...A/D converter,
αn...Microcomputer. Applicant: Sanyo Electric Co., Ltd. and 1 other representative: Patent attorney: Shizuo Sano

Claims (1)

[Claims] (1) Burner busyness can be obtained by setting the resistance value to a desired value in a liquid fuel combustion device equipped with an oil supply means for supplying liquid fuel and a blower device for supplying combustion air to the burner. A / converts analog voltage into digital signal
It consists of a D converter and a microcomputer that determines the delay time according to the digital signal output from the A/D converter, and the burner is configured to vary the combustion amount of the burner from weak combustion to strong twist firing and from strong twist firing to weak combustion. 1. A liquid fuel combustion device characterized in that, when shifting, the supply amount of the blower device is varied, and the oil feeder is operated after a delay time outputted by the microcomputer has elapsed.