JPS62299614A - Air/fuel ratio control device for gun type burner - Google Patents

Abstract

PURPOSE:To permit fuel to completely burn and control the air/fuel ratio to the stoichiometric air/fuel ratio by injecting fuel from a nozzle at a constant pressure and moving the injection part of the nozzle relative to a baffle plate so as to change the amount of fuel supply with the nozzle position. CONSTITUTION:When a gun type burner is ignited, and the hot air temperature T detected by a hot air temperature sensor is greater than a set temperature To, the heater temperature HT is reduced and the nozzle position is moved backward, which causes the amount of fuel baffled by a baffle plate to become larger, resulting in less amount of fuel supply. If the hot air temperature T is lower than the set temperature To, the nozzle position is moved forward to increase the amount of fuel injected from the nozzle. On the basis of the heater temperature HT, the amount of fuel supply F is computed and the amount of air supply Q is computed to obtain the stoichiometric air/fuel ratio, and the fan speed is controlled accordingly to achieve the stoichiometric air/fuel ratio.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an air-fuel ratio control device for a gun-type burner, and particularly relates to an air-fuel ratio control device for a gun-type burner that controls the air-fuel ratio to the stoichiometric air-fuel ratio. This invention relates to a fuel ratio control device.

[Conventional technology]

In conventional gun-type burners, fuel is supplied from a fuel pump, etc. to a fixed nozzle via a feed pipe, and the fuel is injected from the nozzle, and the injected fuel is mixed with air blown by the rotation of a fan. The igniter is ignited by an ignition rod and combusted to generate hot air. The temperature of the hot air from the gun-type burner that is burned as described above is determined by detecting the temperature of the hot air generated by the gun-type burner using a temperature sensor, etc., and comparing the detected hot air temperature with a preset temperature. hand,
Controlled by controlling the amount of fuel supplied to the gun type burner. Further, at this time, the air fuel ratio of the gun type burner is controlled to the stoichiometric air fuel ratio by controlling the air amount supplied by a fan or the like based on the fuel amount.

(Problem to be Solved by the Invention) However, when the amount of fuel supplied to the gun-type burner is controlled, the particle size of the spray particles injected from the nozzle of the gun-type burner changes depending on the ejection pressure, and the amount of fuel injection increases. During large combustion, the injection pressure is high and the particles are fine and completely combusted, but during small combustion, the amount of fuel injected is reduced, so even if the air-fuel ratio is controlled to the stoichiometric air-fuel ratio, the atomization state remains unchanged. There was a problem that incomplete combustion was likely to occur and soot was generated.

The present invention was made to solve the above problem, and by changing the amount of fuel supplied depending on the position of the nozzle,
The object of the present invention is to provide an air-fuel ratio control device for a gun-type burner that completely burns the fuel injected from a nozzle without changing the jetting pressure and controls the air-fuel ratio to the stoichiometric air-fuel ratio.

[Means for solving problems]

In order to achieve the above object, the present invention has a nozzle that is provided with a nozzle that injects fuel at a predetermined injection angle and is movably arranged, and a hole that allows the fuel to pass and that is fixedly arranged on the fuel injection side of the nozzle. a moving device that moves the nozzle so that the nozzle hole of the nozzle and the hole of the shielding plate come into contact with and separate from each other; a detection means that directly or indirectly detects the position of the nozzle; The control means controls the air-fuel ratio to the stoichiometric air-fuel ratio by controlling the amount of air according to the position of the nozzle.

[Effect]

According to the present invention, by injecting fuel from a nozzle at a constant pressure and moving the injection hole of the nozzle in a direction approaching the shielding plate, the M of the fuel injected from the nozzle is shielded by the shielding plate. The amount of fuel is decreased and the amount of fuel supplied is increased. Conversely, by moving the nozzle in a direction away from the shielding plate, the amount of fuel shielded by the shielding plate increases and the amount of fuel supplied decreases. Furthermore, by controlling the amount of air depending on the position of the nozzle, the air-fuel ratio is controlled to the stoichiometric air-fuel ratio.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

A first embodiment of the present invention is shown in FIGS. 1 to 7, and FIG. 1 shows the configuration of a gun type burner. In the gun type burner, fuel is sent from a fuel pump (not shown) to a nozzle adapter 14 via a fuel vibrator 12 at a constant pressure that provides good atomization. The nozzle adapter 14 is linearly movable along the axis of a nozzle adapter guide 18 fixed by a fixing plate 16, and the nozzle adapter 14 is linearly movable via a rod 22 by a moving device 20. As a result, the nozzle hole 26 for injecting fuel on the nozzle tip 24 provided at the tip of the nozzle adapter 14 can be moved linearly. Also,
The nozzle adapter 14 is pressed toward the rod 22 by a spring 28 provided on the rod side of the nozzle adapter guide 18, and the position of the nozzle is determined by the moving device 20. A shielding plate 32 having a hole 34 in the center is fixedly arranged on the fuel injection side of the nozzle tip 24, and when the fuel sent to the nozzle adapter 14 is injected from the nozzle hole 26, the nozzle adapter guide 1B Only the fuel that has passed through the hole 34 of the shielding plate 32 fixedly arranged on the outer cylinder 30 provided at the other end is supplied.

Further, when the fuel is shielded by the shielding plate 32 according to the position of the nozzle hole 26, a return hole 36 provided at the bottom of the shielding plate 32 passes through the shielding plate 32 and the outer cylinder 30. The fuel that has been blocked by the fuel return pipe is returned to the fuel tank, and the amount of fuel injected from the nozzle hole 26 is kept constant to control the amount of fuel that is combusted. Further, a nozzle position sensor 40 that indirectly detects the position of the nozzle is attached to the moving device 20.

On the other hand, the amount of air supplied necessary for combustion is controlled by controlling the fan motor 44 of the sirocco fan 42, and the air sent into the burner is
The ignition rod is mixed with the fuel injected from 6 and passed through the hole 34 of the shielding plate 32 by the flame holder (diffuser) 48, is connected to the ignition transformer 50, and is protruded between the frame holder 48 and the outer cylinder 30. 52, it is ignited and burned. The fan motor 44 has a rotation speed sensor 5 that detects the rotation speed of the fan.
8 is provided.

Further, a hot air temperature sensor 54 for detecting the temperature of the hot air generated by the gun type burner and a setting device 56 for setting the temperature of the hot air generated by the burner are provided.

The moving device 20, nozzle position sensor 40, fan motor 44, hot air temperature sensor 54, setting device 56, and rotation speed sensor 58 are each connected to an electronic control circuit 60 composed of a microcomputer or the like.

Regarding the moving device zO and the nozzle position sensor 40,
This will be explained in more detail using FIGS. 2 and 3. This moving device 20 uses a thermal expansion body to move the nozzle position, and the nozzle position sensor 40 indirectly detects the nozzle position.

As shown in FIGS. 2 and 3, the moving device 20 has a film heater 84 on which a nichrome wire 82 is printed on an insulator 80 (silicon rubber, Nomex, Kapton, etc.). It is composed of bimetal 86. According to this moving device 20, the heater 8
4 changes the shape of the bimetal 86, the rod 22 is pushed and moved, the position of the nozzle hole 26 on the nozzle tip 24 is moved, and the nozzle tip 24 is moved.
The amount of combustion reaches its maximum when it comes into contact with the shielding plate 30.

Further, when the temperature of the heater is lowered and the shape of the bimetal 86 does not change, the combustion amount becomes minimum.

The nozzle position sensor includes a temperature sensor 88 that detects the temperature of the heater 84, and indirectly detects the nozzle position.

As shown in FIG. 4, the electronic control circuit 60 is a central processing bag! (CPU) 62, read-only memory (ROM)
64, random access memory (RAM) 66,
It is configured to include an input port door 8, an output port door 0, and a bus 72 such as a data bus or a control bus that connects these.

The input port 8 includes a setting device 56 and a rotation sensor 58.
is connected, and an analog-to-digital converter (A
DC) 74, a hot air temperature sensor 54, and a nozzle position sensor 40 are connected via a multiplexer 76.

The CPU 62 controls the multiplexer 76 and the ADC filter 4, and sequentially converts the outputs of the hot air temperature sensor 54 and the nozzle position sensor 40 into digital signals and stores them in the RAM 66. The output port doors G are connected to the moving devices 20. through drive circuits 77.78, respectively. connected to the fan motor 44;
The CPU 62 controls the moving device 20 and the fan motor 44 by controlling the drive circuit. Above ROM64
The control routine program described below is stored in advance.

FIG. 5 shows the control routine of the first embodiment. When the gun type burner is ignited, the hot air temperature T detected by the hot air temperature sensor is stored in the RAM in step 150.
is read from step 15 in step 152.
It is determined whether or not the hot air temperature T read in step 0 is equal to or higher than the preset temperature TO.
In the above case, the heater temperature HT is lowered by controlling the current supplied to the heater in step 154. As a result of the heater temperature being lowered, the position of the nozzle is retracted as shown in FIG.

Further, as shown in FIG. 7, as a result of the nozzle being moved back, more fuel is shielded by the shielding plate, and the amount of fuel supplied is reduced. Also, the hot air temperature T is the set temperature To
If so, the heater temperature HT is increased in step 156. As a result of the heater temperature being increased, the position of the nozzle is advanced as shown in FIGS. 6 and 7, and the amount of fuel injected from the nozzle is increased. Then, in step 158, the heater temperature HT detected by the temperature sensor 88 is read. Since the heater temperature is proportional to the amount of nozzle movement, the nozzle position is indirectly read.

In step 160, fuel supply 31F is calculated from heater temperature 1 (T), and in step 162, step 1
The air supply amount Q is calculated from the fuel supply IF calculated in step 60 to achieve the stoichiometric air-fuel ratio, and in step 164 the air supply IQ calculated in step 162 is converted to the fan rotation speed NEo. The fan rotation speed NE is read, and in step 168 it is determined whether the current fan rotation speed NB is less than or equal to the fan rotation speed NEo calculated in step 164.
If the answer is yes, the fan rotation speed is increased in step 170; if the answer is no, the fan rotation speed is increased in step 172.
The fan rotation speed is reduced and the air-fuel ratio is controlled to the stoichiometric air-fuel ratio.

Note that the moving device 20 for moving the nozzle is the eighth one.
As shown in the figure, oil 92 is inside the cylinder 90.
It is possible to use a moving device that linearly moves the position of the nozzle tip 24 by injecting oil and heating the same heater 94 as described above to expand the oil 92 and move the rod 22 via the piston 91. In this case, a temperature sensor 96 that detects the temperature of the heater 94 can be used as a means for indirectly detecting the position of the nozzle.
Shape memory alloys can also be used as moving devices.

Further, as a means for controlling the air supply amount, as shown in FIG. 9, the number of rotations of the fan 42 is kept constant, and a damper 98 is provided at the air inlet of the fan 42 to control the damper motor 100. By this, the opening degree of the damper 98 can be controlled, and the damper 98 can be used to control the amount of air.

Next, a second embodiment of the present invention will be described with reference to FIGS. 10 to 12. In FIGS. 10 to 12, parts that are the same as those in the first embodiment are given the same reference numerals, and explanations thereof will be omitted. FIG. 10 shows the configuration of a gun type burner, in which a sensor capable of directly detecting the amount of movement of the rod 22 is used as the nozzle position sensor 40.

As shown in FIG. 11, the moving device 20 includes a motor (step motor) 104 and a cam 102 fixed to the output shaft of the motor 104. When the cam 102 is rotated by the motor 104, the rod 22 is cam 102
The position of the nozzle tip 24 is moved by the movement of the nozzle tip 24. Further, the nozzle position detection means includes limit switches SWI, SW2 . SW3. It is composed of SW4 and a movable piece 106 whose one end is rotatably supported by the upper end of the nozzle position sensor 40 and whose other end is supported between dogs 108. This nozzle position 1 sensor 40 has limit switches SWl, SW2, . SW3.
SW4 is turned on in this order.

FIG. 12 shows the control routine of the second embodiment. When the gun type burner is ignited, Step! In step 74, the hot air temperature T is read, and in step 176, it is determined whether the hot air temperature T read in step 174 is equal to or higher than the preset temperature To. If the hot air temperature T is equal to or higher than the preset temperature To, At step 178, the motor 104 is reversed, thereby retracting the nozzle position and reducing the amount of fuel delivered. If the hot air temperature T is lower than the set temperature TO, the motor 104 is rotated forward in step 180 to advance the nozzle and increase the amount of fuel supplied.

In step 182, the position of the nozzle is determined based on the on/off state of the limit switch, in step 184, the fuel supply IP is calculated based on the nozzle position, and in step 186, the stoichiometric air-fuel ratio is calculated from the fuel supply amount F calculated in step 184. Air Supply II
Q is calculated and in step 188
The air IQ calculated in is calculated as the fan rotation speed NEo.

In step 200, the current fan rotation speed NE is read, and in step 202, the current fan rotation speed N
It is determined whether or not B is equal to or less than the fan rotation speed NEo calculated in step 188. If the result is affirmative, the fan rotation speed is increased in step 204, and if the result is negative, the fan rotation speed is increased in step 206. The fan rotation speed is reduced and the air-fuel ratio is controlled to the stoichiometric air-fuel ratio.

FIG. 13 shows a routine for controlling the air-fuel ratio to the stoichiometric air-fuel ratio without using a temperature sensor.
The set temperature TO is read in step 210, and the number of pulses NP of the step motor of the nozzle moving device corresponding to the set temperature TO is selected based on a table previously stored in the ROM as shown in FIG.

While supplying drive pulses to the step motor, the number of drive pulses is counted, and in step 212, when the count value matches the number of pulses NP selected in step 210, the drive of the motor is stopped. That is, the position of the nozzle is moved to provide a predetermined fuel supply amount corresponding to the hot air temperature TO.

At step 214, the air amount Q corresponding to the set temperature TO is selected from the table shown in FIG. This air amount Q corresponds to the stoichiometric air-fuel ratio. Step 216
In step 214, the air supply amount Q selected in step 214 is converted into the fan rotation speed N. In step 218, the current fan rotation speed NE is read, and in step 220
In step 216, it is determined whether the current fan rotation speed NE is less than or equal to the fan rotation speed NEo converted. If the result is affirmative, the fan rotation speed is increased in step 222; if the result is negative, the fan rotation speed is increased. In step 224, the fan rotation speed is reduced and the air-fuel ratio is controlled to the stoichiometric air-fuel ratio.

Note that the means for controlling the air amount may be configured to control the air amount by controlling the opening degree of the damper 98 as described in FIG.

In addition to the above-mentioned moving device 20 for moving the nozzle, the moving devices shown in FIG. 2, FIG. 8, FIG. 11, and FIGS. 15 to 19, etc. can be used.

In the moving device shown in FIG. 15, a continuous groove 112 is provided on the upper surface of a cylinder 110, and the cylinder 110 is connected to a motor (step motor).
114 causes a pin 116 on the rod 22 to move along the groove 112, so that the rod 22 is moved.

In the moving device shown in FIG. 16, a pinion 118 is rotated by a motor (step motor) 120, a rack 122 moves linearly, and the rod 22 is moved.

In the moving device shown in FIG. 17, a diaphragm 126 is moved against a piston 12 by air pressure sent from a pneumatic device 124.
8 so that the rod 22 is moved linearly.

The moving device shown in FIG.

The moving device shown in FIG. 19 uses a step motor, and by changing the current supply to the stator coil 134 according to a signal from an electronic control circuit, the rotor 136 rotates forward or reverse, and the rod 22 is moved. .

〔Effect of the invention〕

As explained above, according to the present invention, since the injection pressure of the fuel injected from the nozzle of the gun type burner is kept constant, stable particles are always obtained, complete combustion is achieved, and the air-fuel ratio is adjusted to the stoichiometric air-fuel ratio. The effect is that it can be controlled to

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a gun type burner showing a first embodiment of the present invention, FIG. 2 is a schematic diagram showing a moving device of the first embodiment,
3 is a schematic cross-sectional view taken along line m-m in FIG. 2, FIG. 4 is a block diagram showing details of the control circuit in FIGS. 1 and 1O, and FIG. 5 is a 7I of the first embodiment. Flowchart showing the control routine, Figure 6 is a diagram showing the relationship between heater temperature and nozzle movement amount, Figure 7 is a diagram showing the relationship between nozzle movement amount and fuel supply amount, and Figure 8 is a diagram showing other movements. a schematic diagram showing the device;
Figure 9 is a schematic diagram showing the damper of the gun type burner,
FIG. 0 is a schematic diagram of a gun type burner showing a second embodiment of the present invention, FIG. 11 is a schematic diagram showing a moving device of the second embodiment,
FIG. 12 is a flowchart showing the control routine of the second embodiment, FIG. 13 is a flowchart showing another control routine, FIG. 14 is an explanatory diagram showing details of the routine in FIG. 13, and FIG.
6, FIG. 17, FIG. 18, and FIG. 19 are schematic diagrams showing the moving device of the second embodiment. 20... Moving device, 24... Nozzle chip, 26... Nozzle hole, 32... Shielding plate, 34... Hole, 40... Nozzle position sensor, 42... Sirocco fan.

Claims (1)

[Claims] (1) A movably arranged nozzle that is provided with a nozzle hole that injects fuel at a predetermined injection angle, a shielding plate that is provided with a hole that allows fuel to pass through and that is fixedly arranged on the fuel injection side of the nozzle, and the nozzle a moving device that moves the nozzle so that the nozzle of the nozzle and the hole of the shielding plate come into contact with and separate from each other; a detection means that directly or indirectly detects the position of the nozzle; An air-fuel ratio control device for a gun-type burner, comprising: control means for controlling the air-fuel ratio to a stoichiometric air-fuel ratio by controlling the air-fuel ratio.