JPS6126755Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oil burner used in hot air blowers and the like, and particularly to one in which the combustion state in the combustion section is controlled in multiple stages.

Conventionally, in this type of oil burner, for example, an oil pump that discharges and supplies oil fuel to the combustion section and a combustion air fan that supplies air are drivingly connected to the same axis of the motor, and the motor is rotated at low speed. A motor control device is installed to control the rotation speed in two stages: "L" for high rotation and "H" for strong rotation, and the amount of oil fuel from the oil pump and the amount of air from the combustion air fan are changed in two stages. It is known that the combustion state in the combustion section is controlled in two stages by controlling the combustion state.

However, in such an oil burner, since the oil pump and the combustion air fan are driven on the same axis of the motor, the gradient characteristic of the amount of oil discharged from the oil pump changes as the motor rotation speed changes. Since the gradient characteristic of the amount of air supplied from the combustion air fan changes more greatly than the gradient characteristic of the amount of air supplied from the combustion air fan, the ratio of the amount of supplied air to the amount of oil and fuel, that is, the air-fuel ratio, must be adjusted to an appropriate value during both "L" and "H" rotations of the motor. The problem is that it cannot be converted into a value and burned. In other words, if the air-fuel ratio is set to an appropriate value when the motor is rotating at "L", then when the motor is rotating at "H"
There was a problem that there was an excess of oil and fuel when the motor rotated, and on the other hand, if the setting was made so that the appropriate value would be obtained when the motor was rotating at the "H" position, there would be too much air when the motor was rotating at the "L" position.

Therefore, the present applicant has previously proposed the following in order to solve such problems. That is, in an oil burner in which the ratio between the amount of air supplied from the combustion air fan and the amount of oil fuel discharged and supplied from the oil pump when the motor rotates at "L", that is, the air-fuel ratio, is set to an appropriate value. The pump chamber of the oil pump and the oil supply system are connected through a relief passage, and a relief valve is interposed in the relief passage. By keeping the oil pump at a constant pump height, the air-fuel ratio when the motor is rotating at "H" is set to an appropriate value, and the oil fuel is maintained at both "L" and "H" rotations of the motor. It is designed to allow proper combustion (see the specification and drawings of Japanese Utility Model Application No. 169790/1983).

However, the above proposal requires a relief valve to be interposed in the relief passage, which makes the structure complicated and expensive, and the relief pressure of the relief valve is set by spring force. The disadvantage is that it is difficult and unreliable.

This invention was made in consideration of these points,
To maintain a constant head of a pump by relieving oil fuel in a pump chamber to an oil supply system through a bypass passage having a predetermined head height when the rotation speed of a motor exceeds a predetermined number without requiring a relief valve. The purpose of this is to ensure good combustion by setting the air-fuel ratio to an appropriate value when controlling the motor's rotation speed in multiple stages, as well as to simplify the structure, improve reliability, and reduce costs. It is.

Therefore, the configuration of the present invention is such that an oil pump and a combustion air fan are drivingly connected on the same shaft of a motor whose rotation speed is controlled to be weak and strong, and air is supplied from the combustion air fan when the motor is rotating weakly. In an oil burner in which the ratio between the amount of oil and the amount of oil fuel discharged and supplied from the oil pump is set to an appropriate value, the pump chamber of the oil pump is set at a predetermined head height with respect to the oil level of the pump chamber. It communicates with the atmospheric part of the oil supply system through a bypass pipe having a vertical part, and the head height of the vertical part is set so that the ratio of the air amount to the oil fuel amount becomes an appropriate value when the motor is strongly rotated. By setting the lift of the pump at a constant height when the rotation speed is above a predetermined number, the ratio of the amount of air to the amount of oil and fuel at each stage of rotation of the motor can be set to an appropriate value.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows an oil burner A for a hot air blower according to the present invention, in which 1 is a housing, and 2 is a double-shaft motor disposed in the center of the housing 1 with a drive shaft 3 in the vertical direction. Then, the double shaft motor 2
The rotation speed is controlled by a known motor control device (not shown) in two stages: "L" for weak rotation and "H" for strong rotation. Further, 4 is an oil pump for oil feeding disposed below the double-shaft motor 2 and driven by the motor,
The oil pump 4 has a pump chamber 7 in a pump receiver 5 to which oil fuel is supplied from an oil tank (not shown) of an oil supply system through an oil supply port 6.
is a center hole 8 through which the drive shaft 3 passes through.
partitioned into upper and lower parts by a partition plate 8 having a
An oil reservoir chamber 7a communicating with the oil supply port 6, and the oil reservoir chamber 7
A is formed with a rotor chamber 7b communicating with it through the K center hole 8a of the partition plate 8, and the lower end of the drive shaft 3 of the double-shaft motor 2 extends into the rotor chamber 7b. An oil rotor 9 is fixed to the lower end of the shaft 3, and the oil rotor 9, which rotates with the rotation of the drive shaft 3 of the motor 2, moves oil from the oil reservoir chamber 7a to the rotor chamber 7.
The rotor chamber 7b is configured so that it is sucked into the upper part of the rotor chamber 7b and discharged from the lower part of the rotor chamber 7b.

Further, the upper end of the drive shaft 3 of the double-shaft motor 2 extends to the center of the carburetor 18, which will be described later, and an oil supply passage 10 is formed in the center of the drive shaft 3. The lower end of the oil supply passage 10 communicates with the rotor chamber 7b of the pump chamber 7 via an orifice 11 with a filter. On the other hand, a boss member 1 is provided at the upper end of the drive shaft 3 and has a vertical communication passage 12 that communicates with the upper end of the oil supply passage 10.
3 is connected to the boss member 13 and the upper end of the drive shaft 3 with a diffusion plate 14 sandwiched therebetween. ) with multiple openings (for example, 4
) horizontal discharge ports 15, 15... are bored, and on the outer periphery of the upper end of the boss member 13, collision plate portions 16a, 16a facing each horizontal discharge port 15 with a certain angle deviation are provided. A diffusion vane 16 having... is attached. Therefore, oil pump 4
The oil is supplied to each horizontal discharge port 1 through the oil supply passage 10 of the drive shaft 3 and the communication passage 12 of the boss member 13.
The oil is discharged horizontally from 5, 15, .
It is configured to atomize the particles by collision with ... and supply them into the vaporizer 18.

On the other hand, 17 is a combustion air plate fan fixed to the upper part of the drive shaft 3 of the double-shaft motor 2 and driven, and 18 is a combustion air plate fan disposed at a predetermined distance above (downstream) of the plate fan 17 to vaporize oil fuel. A preheating electric heater 19 is disposed on the outer periphery of the vaporizer 18 to heat the vaporizer 18 to promote vaporization, and a buffer plate 20 is provided above the vaporizer 18. cylindrical vaporizing tube 2
1 is provided, and a flame port 22 made of wire mesh is formed on the outer peripheral surface of the vaporization tube 21, while an electrode plug 23 for ignition is arranged near the flame port 22 and facing across a gap. The vaporizer 18
The oil fuel is mixed with the air taken in by the plate fan 17 from the intake port 24 provided in the housing 1, and this gaseous fuel is passed through the electrode plug 23 at the flame port 22. The structure is such that it is ignited and combusted by a discharge arc. Here, the amount of air supplied from the plate fan 17 and the oil pump 4
The ratio of the amount of oil fuel discharged and supplied into the carburetor 18 is set to be an appropriate value when the double-shaft motor 2 is rotating at "L".

As a feature of the present invention, reference numeral 25 is a bypass pipe for bypassing the oil fuel in the rotor chamber 7b of the pump chamber 7, and the bypass pipe 25 has a predetermined head height with respect to the oil level of the pump chamber 7. The lower end of the vertical portion 25a is communicated with the rotor chamber 7b, while the vertical portion 25a
The upper end of the oil reservoir chamber 7a in the pump chamber 7 is communicated with an atmospheric section 26 above the inside of the oil reservoir chamber 7a through an overflow section 25b. Here, the head height of the vertical portion 25a is such that the oil/fuel in the rotor chamber 7b is bypassed to the atmospheric portion 26 of the oil reservoir chamber 7a via the bypass pipe 25 when the rotation speed of the double-shaft motor 2 is above a predetermined number of rotations. The pressure in the rotor chamber 7b, that is, the lift height of the oil pump 4, is set at a height that is constant.
It is configured such that the ratio between the amount of air supplied from the oil pump 7 and the amount of oil fuel discharged and supplied from the oil pump 4 is set to an appropriate value.

In addition, 27 is a leak hole that opens the oil supply passage 10 upward through the communication passage 12 of the boss member 13 so as to leak the air mixed in the oil supply passage 10, and 28 is a leak hole that opens the oil supply passage 10 upwardly through the communication passage 12 of the boss member 13. 1, a mounting plate 29 is used for fixedly supporting the mounting plate 28;
The vortex prevention plate provided above is used to suppress the generation of vortices so as to prevent air from being drawn into the rotor chamber 7b of the pump chamber 7.

Therefore, in the embodiment, the rotor chamber 7b of the pump chamber 7 of the oil pump 4 is
It communicates with the atmosphere part 26 of the oil reservoir chamber 7a of the pump chamber 7 through a bypass pipe 25 having a vertical part 25a with a predetermined head height relative to the oil level of the oil surface, and the head height of the vertical part 25a is By setting the lift height of the oil pump 4 to a constant height when the motor 2 has a predetermined rotation speed or more, the ratio between the amount of air supplied from the plate fan 17 and the amount of oil fuel discharged and supplied from the oil pump 4 can be improved. In other words, the air-fuel ratio can be set to an appropriate value not only when the double-shaft motor 2 rotates in the "L" direction but also when it rotates in the "H" direction. That is, as shown in FIG. 2, when the air-fuel ratio is set to an appropriate value and the rotational speed is increased when the double-shaft motor 2 is rotating at "L", the amount of oil increases more than the amount of air. However, the vertical portion 25a of the bypass pipe 25 is designed so that the lift of the oil pump 4 is constant when the rotation speed is higher than a predetermined number in accordance with the amount of air when the double-shaft motor 2 rotates at "H".
Since the head height is set, the oil amount is constant above the predetermined rotation speed, and the air-fuel ratio is set to a positive value when the double-shaft motor 2 rotates at "H". As a result, the double-shaft motor 2
The oil fuel can be properly combusted during each rotation, and good combustibility can be ensured.

Moreover, the structure of the oil burner A is such that a bypass pipe 25 having a vertical portion 25a with a predetermined head height is
By simply providing this, the appropriate air-fuel ratio can be set for each rotation of the double-shaft motor 2, which simplifies the structure and reduces costs. The settings can be easily and reliably performed.

Furthermore, in general, when the air-fuel ratio is set at room temperature, the fluidity of the oil fuel decreases at low temperatures (for example, -10°C) and a predetermined amount of oil fuel is not discharged into the carburetor 18. There is a problem that it becomes impossible to ignite. However, in the case of the present invention, as can be seen from FIG.
Below the "H" number of times, more oil fuel is supplied than air compared to the state of proper air-fuel ratio at room temperature, so if the rotation speed of the double-shaft motor 2 at the time of ignition is slightly lowered, it is possible to reduce the number of revolutions, especially at low temperatures. At the time of ignition, it is possible to use an excess amount of oil fuel regardless of the decrease in fluidity of the oil fuel, thereby improving ignitability.

In addition, even if the lift height of each oil pump 4 produced in large quantities with respect to the rotation speed differs due to processing variations, etc., the vertical portion 2 of the bypass pipe 25
By adjusting the head height of 5a, the maximum lift of each oil pump 4 can be easily matched, and the performance of the oil burner A as a product can be easily standardized.

In the above embodiment, the pump chamber 7 of the oil pump 4
A bypass pipe 25 is connected to the atmospheric part 26 of the pump chamber 7.
However, it is of course possible to communicate with an atmospheric part of an oil supply system such as an oil tank in addition to the atmospheric part 26 of the pump chamber 7.

In addition, in the above embodiment, an oil burner in which the motor 2 is controlled in rotation speed in two stages, "L" and "H" has been described. It can also be applied to a burner, in which case bypass pipes each having a vertical portion with a predetermined head height relative to the oil level in the pump chamber depending on the motor rotational speed control stage may be provided.
In this case as well, the head height of each vertical portion may be set with reference to the "L" rotation of the motor, so that the appropriate air-fuel ratio is achieved during each of the other rotations.

As explained above, according to the present invention, the pump chamber of an oil pump is communicated with the atmosphere of the oil supply system through a bypass pipe having a vertical portion at a predetermined head height with respect to the oil surface of the pump chamber. Even with this simple structure, the ratio between the amount of air supplied from the combustion air fan and the amount of oil and fuel discharged and supplied from the oil pump is always kept at an appropriate value at each rotation of the motor whose rotation speed is controlled in multiple stages. Since the fuel can be set, the oil fuel can be burnt well and the combustibility can be improved. Further, since the bypass pipe is simply a bypass pipe having a vertical portion having a predetermined head height, the structure can be simplified, costs can be reduced, and reliability can be improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view showing the overall configuration, and FIG. 2 is a diagram showing the gradient characteristics of the oil amount and air amount with respect to the rotational speed of the motor. 2...Double shaft motor, 4...Oil pump, 7...Pump chamber, 17...Plate fan, 25...Bypass pipe, 25a...Vertical section, 26...Atmospheric section.

Claims (1)

[Scope of utility model registration request] An oil pump 4 and a combustion air fan 17 are drivingly connected on the same shaft of a motor 2 whose rotation is controlled to be weak and strong, and the amount of air and oil supplied from the combustion air fan 17 when the motor 2 is rotating weakly is controlled. In an oil burner in which the ratio of the amount of oil and fuel discharged and supplied from the pump 4 is set to an appropriate value, the pump chamber 7 of the oil pump 4 is set at a predetermined head height with respect to the oil level of the pump chamber 7. It communicates with the atmosphere part 26 of the oil supply system through a bypass pipe 25 having a vertical part 25a of An oil burner characterized in that the height of the oil pump 4 is set to a constant value when the rotation speed is equal to or higher than a predetermined number of revolutions.