JPH0942659A - Liquid fuel burning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce discharge of hazardous exhaust gas constituents at the time of ignition and discharge of evaporated fuel constituents after stopping of combustion in a liquid fuel burning apparatus. SOLUTION: A fuel shut-off valve 63 is installed at a connection between a fuel passage 66 through which liquid fuel flows from a fuel pump 65 and a fuel absorbing body 12 in a glow plug box section 62, and the fuel shut-of valve 63 is opened due to a rise of fuel supply pressure from the fuel pump 65 and is closed by fall of the fuel supply pressure. A valve mechanism section of the fuel shut-off valve 63 is disposed adjacent to the fuel absorbing body 12 within the glow plug box section 62. After combustion operation is stopped, the fuel within the fuel passage 66 is prevented from being evaporated and supplied into a combustion chamber 4 by closing the fuel shut-off valve 63 so that increase of hazardous exhaust gas constituents due to excess fuel is prevented at the time of ignition. Right after extinguishing fire, increase of volatile fuel constituents evaporated by residual combustion heat is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device for burning liquid fuel (light oil, kerosene, etc.)
It is particularly suitable for heating electric vehicles.

[0002]

2. Description of the Related Art In a heating system for an electric vehicle, particularly in cold regions, it is required to reduce power consumption to a very small amount due to the limitation of the capacity of a vehicle battery. Therefore, as the heating device, a combustion type heating device that does not rely on electric power as a heat source and uses the combustion heat of fuel to perform heating is effective in an electric vehicle.

[0003]

However, the combustion type heating device discharges harmful components from the exhaust gas during its operation, and the fuel remaining in the combustion device main body remains after the operation is stopped. There is a problem that the residual heat evaporates and the harmful components are discharged to the outside. In particular, since electric vehicles are introduced to prevent pollution due to exhaust emission, installing a combustion-type heating device that has the problem of exhaust emission as described above is incompatible with the purpose of introducing electric vehicles. is there.

Therefore, in order to install the combustion type heating device in an electric vehicle, it is strongly required to reduce the emission of exhaust gas harmful components during the operation of the combustion type heating device and the fuel evaporation components after the operation is stopped. ing. The present invention has been made in view of the above points, and an object of the present invention is to provide a liquid fuel combustion apparatus that can effectively reduce the emission of exhaust gas harmful components and fuel vaporized components with a relatively simple configuration.

[0005]

SUMMARY OF THE INVENTION The inventor of the present invention has studied the causes of exhaust gas harmful components and fuel vaporized components discharged from a liquid fuel combustion apparatus through various experiments and studied them. As a result, a fuel passage for supplying liquid fuel to a combustion chamber (4). The liquid fuel remaining in (66, 63a) evaporates at the time of preheating of the combustion device and at a high temperature immediately after extinguishing, which causes an increase in exhaust gas harmful components due to excess fuel at fuel ignition, and immediately after extinguishing the fire. It was found that the combustion evaporation heat causes the emission of the fuel evaporation component.

Therefore, in the present invention, paying attention to the above considerations, the valve is opened at the connection between the fuel passage (66, 63a) and the combustion chamber (4) during the combustion operation of the combustion device to perform combustion. A fuel cutoff valve (63) that closes when the operation is stopped is installed. By this fuel cutoff valve (63), the fuel in the fuel passage (66, 63a) evaporates after the combustion operation is stopped and the combustion chamber (4 )
It is intended to prevent it from being supplied to the inside.

Further, in the invention according to claim 2, the fuel absorber (1) for absorbing and retaining the liquid fuel in the combustion chamber (4)
2) is provided, and the fuel passages (66, 63a) are
The fuel cutoff valve (63) is arranged so as to introduce the liquid fuel into the fuel absorber (12), and is adjacent to the fuel absorber (12) in the fuel passage (66, 63a). It is characterized in that it has a valve mechanism portion (63e, 63f) in its part.

According to the third aspect of the invention, the fuel cutoff valve (63) is normally closed, and the fuel passage (6)
6, 63a) is configured to open when the fuel pressure rises. Further, in the invention of claim 4, the fuel cutoff valve (63) is always closed by the biasing force of the spring means (63j), and the fuel pressure in the fuel passage (66, 63a) is the spring means ( 63j) is configured to open when it rises until it overcomes the urging force.

According to the fifth aspect of the invention, the combustion chamber (4) is provided with a fuel absorber (12), and the fuel passages (66, 63a) are liquid in the fuel absorber (12). A valve housing (63b, 63c) arranged to introduce fuel, the fuel cutoff valve (63) forming a part (63a) of the fuel passage (66, 63a).
And a fuel discharge port (63d) formed in the valve housing (63b, 63c) so as to be adjacent to the fuel absorber (12), and a seat surface (formed on the end face of the fuel discharge port (63d) ( 63e) and a valve portion (63g) that is movably arranged with respect to the valve housings (63b, 63c) and that opens and closes the seat surface (63e), and that valve portion (63g) has a predetermined spring force. The seat surface (63
e) The spring means (63j) for pressing is provided.

Further, in the invention according to claim 6, there is provided a heating device using the liquid fuel combustion device according to any one of claims 1 to 5, in which combustion gas burned in the combustion chamber (4) is used. A heat exchanger (5) for exchanging heat with the heating medium to heat the heating medium, and a heater unit (2) for heating the room using the heating medium as a heat source.

According to the first to sixth aspects of the present invention, by adopting the above-mentioned technical means, the fuel component evaporated by the heat of the high temperature combustion chamber side during combustion stoppage (immediately after extinguishing and during preheating) is combustor body. It is possible to prevent the inflow into the inside by the fuel cutoff valve, and as a result, at the time of fuel ignition, it is possible to effectively suppress an increase in exhaust gas harmful components due to excess fuel, and
Emission of the evaporated fuel component after the combustion operation is stopped can also be effectively reduced.

According to the second and fifth aspects of the present invention, since the valve mechanism portion of the fuel cutoff valve is arranged at a portion adjacent to the fuel absorber, the fuel remaining space on the downstream side of the valve mechanism portion is made small. Therefore, the above effect can be further improved.
Further, in the inventions according to claims 3 to 5, the opening / closing of the fuel cutoff valve is performed by a mechanically simple structure utilizing the change of the fuel pressure, so that the device of the present invention can be implemented at low cost.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 4 show an embodiment of the present invention. FIG. 1 shows an overall system of a heating device for an electric vehicle, and 1 is a liquid fuel combustion device according to the present invention. There is heat exchange between the combustion gas and water to produce hot water (heating medium). Reference numeral 2 denotes a heater unit for heating the passenger compartment, which heat-exchanges the hot water heated by the liquid fuel combustion apparatus 1 with the blast air of the blower 2a (air inside or outside the passenger compartment) to heat the blast air. The heated air (warm air) is blown into the passenger compartment. 3 is a liquid fuel combustion device 1 for hot water
A water pump that circulates between the heater unit 2 and the heater unit 2.

Liquid fuel combustion apparatus 1 and water pump 3
Is installed in a motor room in which a traveling motor of the electric vehicle is installed, and the heater unit 2 is installed in a vehicle room of the electric vehicle. FIG. 2 shows a specific structure of the liquid fuel combustion apparatus 1. This apparatus is roughly divided into a combustion chamber 4, a heat exchanger 5, an ignition device 6, and a blower 7 for combustion air.

Hereinafter, each of the above components will be specifically described. The combustion chamber 4 has a cylindrical shape extending in the horizontal direction, and is a mixing cylinder 41 for mixing combustion air and fuel vapor.
And a combustion cylinder 42 connected to the downstream side of the mixing cylinder 41. An air supply pipe 43 for supplying combustion air is concentrically arranged in the center of the mixing cylinder 41.
A plurality of slits 44 extending in the axial direction are provided on the circumferential surface of the air supply pipe 43. In addition, the mixing cylinder 41
A plurality of air supply holes 41a are opened in the circumferential direction of the. Further, between the mixing cylinder 41 and the combustion cylinder 42,
A flame holding diaphragm plate 45 for holding the flame in the mixing cylinder 41 is provided.

The ignition device 6 and the fuel supply unit connected thereto are the main part of the present invention, and as shown in the enlarged view of FIG. 3, have a glow plug 61 for fuel ignition, and this glow plug 61 is It is screwed and fixed to a mounting plate 62c that is integral with the cylindrical glow plug boss portion 62. The glow plug 61 is provided with a heating portion 61b made of an electric resistor wound around the outer circumference of a cylindrical center support rod 61a.

The surface of the heating portion 61b is covered with a heat-resistant member made of ceramics, and the heating portion 61b is arranged concentrically and vertically in the glow plug boss portion 62. A fuel absorber (wick) 12 is arranged on the inner peripheral surface of the glow plug boss portion 62. The fuel absorber 12 is made of heat-resistant metal such as stainless steel in the shape of a wire mesh, and absorbs and retains liquid fuel (light oil, kerosene, etc.) to promote evaporation of the liquid fuel.

In the glow plug boss portion 62, a fuel cutoff valve 63 for connecting and disconnecting the liquid fuel introduced into the fuel absorber 12 is provided at the base of the glow plug 61. Liquid fuel is introduced into the fuel cutoff valve 63 from a fuel tank 64 by a fuel pump 65 via a fuel pipe (fuel passage) 66. Here, the fuel pump 65 is configured by a pump that electrically operates like a solenoid pump, and in this example, the fuel tank 64 and the fuel pump 65 constitute a fuel supply unit.

The fuel cutoff valve 63 is provided with valve housings 63b and 63c forming a fuel passage 63a connected to a fuel passage 66 from the fuel pump 65. The valve housings 63b and 63c are formed in a cylindrical shape and are integrally joined by welding or screwing. All the components of the fuel cutoff valve 63 are made of metal having excellent corrosion resistance,
For example, it is formed of stainless steel (SUS).

In the valve housings 63b and 63c, a fuel discharge port 63d is provided at a portion of the inner peripheral surface of the glow plug boss portion 62 adjacent to the fuel absorber 12 (right end portion in FIG. 3). A seat surface 63e is formed on the end surface of the fuel discharge port 63d. On the other hand, a valve body 63f is movably disposed inside the valve housings 63b and 63c, and a seat surface 63e is located at the tip of the valve body 63f and is located further on the fuel discharge side than the seat surface 63e.
A valve portion 63g opposed to is integrally formed, and the seat surface 63e is opened and closed by the valve portion 63g. Therefore, in this example, the valve portion 63g and the seat surface 63e are
The above constitutes a valve mechanism portion of the fuel cutoff valve 63.

A valve housing 63c having a seat surface 63e
And the valve body 63f, in particular, the seat surface 63e and the valve portion 6
In order to prevent abrasion and damage of 3 g, in this example, quenched SUS440C is used, and other parts are SUS304. Further, as the specific shapes of the seat surface 63e and the valve portion 63g, in this example, the seat surface 63e
Since e is a linear conical inclined surface and the valve portion 63g is a curved inclined surface, the seat surface 63e and the valve portion 6 are
3g is securely brought into contact with the entire circumference in the circumferential direction so that the flow of fuel can be surely cut off.

In order to stably move the valve body 63f inside the valve housings 63b and 63c, the valve body 63f
A sliding portion 63i with a slit having a predetermined axial dimension is integrally formed on the shaft portion 63h of f, and the outer peripheral portion of the sliding portion 63i with the slit slides on the inner peripheral surfaces of the valve housings 63b and 63c. On the other hand, the valve element 63f is adapted to move stably in the axial direction.

Here, if the clearance between the outer peripheral portion of the slitted sliding portion 63i and the inner peripheral surfaces of the valve housings 63b and 63c is too small, the opening / closing operation of the valve body 63f is hindered, and the clearance is about 10 μm. It is preferable to set a predetermined clearance. Further, the liquid fuel flows toward the fuel discharge port 63d side through a plurality of (four in the illustrated example of FIG. 3B) slits provided in the slitted sliding portion 63i.

Further, the valve body 6 is provided in the valve housing 63b.
A coil spring (spring means) 63j is provided to press 3f toward the seat surface 63e by a predetermined spring force. In order to support the coil spring 63j in a stable manner, as shown in FIG.
3k and a ring-shaped groove 63 into which the ends of the coil springs 63j are fitted in the ends of the valve housing 63c, respectively.
m and 63n are provided.

The spring constant of the coil spring 63j is the valve portion 63g when the valve body 63f moves in the fuel discharge direction (to the right in FIG. 3A) in response to the fuel discharge pressure of the fuel pump 65.
It is necessary to set in accordance with the fuel discharge pressure so that the valve surface 63e is separated from the seat surface 63e.
In order to ensure the seating (valve closing effect) on 3e, the coil spring 63j is provided within a range in which necessary fuel consumption can be secured.
It is preferable that the spring constant of is as large as possible.

Further, the fuel discharge port 6 of the valve housing 63c
The 3d side end portion is fitted into a circular mounting hole 62a provided at the base of the glow plug boss portion 62 and joined to the glow plug boss portion 62 by welding. Here, between the end of the valve housing 63c on the fuel discharge port 63d side and the fuel absorber 12 lined on the inner peripheral surface of the glow plug boss 62, the opening / closing operation of the valve body 63f should not be hindered. A space 63p for performing the operation is provided. This space 63p
Is designed to minimize the amount of fuel remaining inside the valve body 63f when the valve body 63f is closed.

The combustion air blower (air supply means) 7 is
It is arranged below the mixing cylinder 41 portion of the combustion chamber 4, and has a centrifugal blower fan 71 and a driving motor 72 thereof. The blower 7 blows the air sucked from the air intake port 73 to the inlet side of the air supply pipe 43 by the blower fan 71. Further, a part of the combustion air supplied by the blower 7 is branched, passes through the air passage 75, and the air hole 4 opened in the mixing cylinder 41.
It directly flows into the mixing cylinder 41 from 1a.

Further, a part of the combustion air supplied by the blower 7 is branched, passes through the air passage 76, and enters into the glow plug boss portion 62 through a plurality of air holes 62b formed in the glow plug boss portion 62. It is supposed to flow in. The combustion air blown by the blower 7 is distributed so that about 80% of the combustion air is supplied to the air supply pipe 43 and about 10% is supplied to each of the air passage 75 and the air passage 76.

The combustion gas passing through the combustion tube 42 of the combustion chamber 4 makes a U-turn at the downstream end (the right end portion in FIG. 2) of the combustion tube 42 and is formed into a cylindrical shape on the outer peripheral surface side of the combustion tube 42. The gas is discharged from the exhaust port 47 to the outside through the exhaust passage 46. Heat exchanger 5 for exchanging heat between combustion gas and water
Is formed in a cylindrical shape further on the outer peripheral side of the cylindrical exhaust passage 46, and sucks warm water from the warm water inlet 33 located at the right end of FIG. 2 by the operation of the water pump 3 shown in FIG. Hot water is supplied to the hot water inlet portion 51 of the heat exchanger 5.

The hot water passage 52 in the heat exchanger 5 is designed so that hot water flows in from the hot water inlet 51 at the right end in FIG. 2 and the hot water flows spirally from the right side to the left side in FIG. Further, the heat exchanger 5 exchanges heat with the combustion gas through the plate-shaped fins 53 arranged so as to project into the exhaust passage 46 to heat the hot water. In the heat exchanger 5, a hot water outlet 54 is arranged above the left end of FIG. 1, and the hot water flows out from the hot water outlet 54 toward the heater unit 2 for heating the passenger compartment in FIG. It has become.

Reference numeral 9 is a frame sensor for detecting the presence or absence of flame in the mixing cylinder 41, which is composed of a photodiode. 10
Is a hot water temperature sensor arranged at the hot water inlet portion 51 of the heat exchanger 5, detects the temperature of the hot water flowing into the heat exchanger 5 and controls the combustion amount (combustion load), and is composed of a thermistor. . Reference numeral 11 denotes a thermostat for preventing heating by air (for preventing overheating), which is disposed on the outer surface side of the heat exchanger 8 and
It detects the outside surface temperature of the and opens and closes the switch.

The fuel absorber 12 for absorbing and retaining the liquid fuel is arranged not only on the inner peripheral wall surface of the glow plug boss portion 62 described above but also on the inner peripheral wall surface of the mixing cylinder 41. FIG. 5 is a block diagram showing a schematic configuration of electric control. 13 is an electric control device, 14 is an operation switch of a vehicle heating device, 15 is an on / off operation of the blower 2a of the heater unit 2 for heating the vehicle interior, and a blower. 2a is a heater fan switch for speed switching. Reference numeral 16 is an operation indicator light.

Next, the operation of the above configuration will be described.
The operation switch 14 is opened, the combustion device 1 is stopped,
When the fuel pump 65 is stopped, the fuel pump 65
3 does not act on the valve body 63f of the fuel cutoff valve 63, the valve body 63f moves leftward in FIG. 3 by the spring force of the coil spring 63j, and the valve portion 63g is seated on the seat surface 63e. are doing. Therefore, the fuel cutoff valve 63
The fuel discharge port 63d is closed.

Next, when the operation switch 14 is turned on,
The operation indicator lamp 16 blinks by the electric control device 13, and at the same time, the glow plug 61 and the water pump 3 are energized. For the glow plug 61, a predetermined time (for example, about 20 seconds)
Power is supplied, and the glow plug 61 is preheated during this period. At this time, the fuel discharge port 63d of the fuel cutoff valve 63 is
Since the inner portion of the glow plug boss portion 62 adjacent to the fuel absorber 12 is closed, even if the temperature of the glow plug 61 becomes high due to preheating, a small amount of fuel in the space 63p evaporates. Only.

After the preheating of the glow plug 61 is completed, the combustion air blower 7 is energized, and the blower 7 is started. At almost the same time, the fuel pump 65 is energized to start supplying fuel. As a result, the fuel pump 6
Since the fuel discharge pressure of 5 acts on the valve body 63f of the fuel cutoff valve 63, the valve body 63f moves to the right in FIG. 3 against the spring force of the coil spring 63j, and the valve portion 63g moves toward the seat surface. Separate from 63e. Therefore, the fuel discharge port 63d of the fuel cutoff valve 63 is opened, the fuel is supplied into the glow plug boss portion 62, the mixture of fuel and air is ignited by the glow plug 61, and combustion is started.

Simultaneously with ignition, the flame sensor 9 detects the flame of combustion, and after a predetermined time (for example, about 35 seconds) has passed, the glow plug 61 is deenergized, and thereafter, the steady combustion state is entered. At this time, the heating fan 2a is started and the operation indicator lamp 16 is continuously turned on. In the steady combustion state, the hot water inlet portion 51 of the heat exchanger 5
HI- of the combustion amount (combustion load) of the combustion device according to the hot water temperature detected by the hot water temperature sensor 10 arranged in
The LO is automatically switched.

That is, when the temperature detected by the temperature sensor 10 reaches the upper limit set temperature (for example, 80 ° C.), both the fuel pump 65 and the combustion air blower 7 are at low speed (L
O) operation is performed, and the combustion device performs combustion operation according to the LO combustion amount. Then, when the combustion operation by the LO combustion amount is continued and the temperature detected by the temperature sensor 10 decreases to the lower limit set temperature (for example, 70 ° C.), the fuel pump 6 is restarted.
5 and the blower 7 for combustion air are both in high speed (HI) operation, and the combustion device performs combustion operation according to the HI combustion amount.

In this way, by automatically switching the combustion amount (combustion load) of the combustion device in two steps of HI-LO,
The hot water temperature is automatically controlled within a predetermined range. Then, in the heater unit 2, the air blown by the blower 2a is heated by exchanging heat with the hot water circulated by the water pump 3, and the heated air is blown into the vehicle interior to heat the vehicle interior.

When the operation switch 14 is turned off to stop the operation of the heating device, the fuel pump 65 is stopped. As a result, the fuel discharge pressure of the fuel pump 65 does not act on the valve body 63f of the fuel cutoff valve 63, so the valve body 63f moves to the left in FIG. 3 by the spring force of the coil spring 63j, and the valve portion 63g becomes Sit on the seat surface 63e. Therefore, the fuel discharge port 63d of the fuel cutoff valve 63 returns to the closed state again.

After turning off the operation switch 14,
The combustion air blower 7 and the water pump 3 are continuously operated for a predetermined time (for example, 20 seconds) to perform a scavenging operation (post-purge), and then the combustion air blower 7 and the water pump 3 are stopped. To do. Even when the combustion device performs the combustion operation with the LO combustion amount, the amount of heat radiation on the heater unit 2 side is small, so when the temperature detected by the temperature sensor 10 reaches the upper limit set temperature, the operation switch 14 is turned off. After performing the same scavenging operation (post-purge) as before,
The combustion operation based on the LO combustion amount is restarted.

The outline of the operation of the heating device as a whole is as described above. Next, the fuel cutoff valve 63 which characterizes the present invention is described.
The effect of the above will be described in detail. As described above, during the combustion operation of the combustion device 1, the fuel cutoff valve 63 is opened by the valve mechanism portion including the valve portion 63g and the seat surface 63e to open the fuel discharge port 63d to ignite the liquid fuel in the ignition device 6 part. Through the combustion chamber 4 side.

On the other hand, while the combustion of the combustion apparatus 1 is stopped, the valve mechanism section is closed and the fuel discharge port 63d is closed as the liquid fuel supply pressure decreases. Here, it is important to note that the valve mechanism portion has the fuel absorber 1 inside the glow plug boss portion 62.
It is located in a region adjacent to 2. That is,
After the fuel discharge port 63d is once closed by closing the valve mechanism portion, even if the fuel passage portions 66 and 63a become high in temperature due to preheating of the glow plug 61 and residual heat after combustion is stopped, Since the mechanism portion is adjacent to the fuel absorber 12, only a small amount of fuel in the space 63p evaporates, and the fuel remaining in the fuel passage portions 66, 63a evaporates, and the glow plug The fuel absorber 12 on the inner circumference of the boss portion 62 is not excessively absorbed.

Therefore, when the fuel is ignited, it is possible to effectively prevent the harmful components (mainly hydrocarbon: HC) in the exhaust gas from increasing due to excess fuel. Similarly, after the combustion is stopped, the fuel remaining in the fuel passage portions 66 and 63a is evaporated, and the fuel evaporation component discharged into the atmosphere can be greatly reduced. By the way, when a valve structure (a general-purpose structure used as a check valve) as shown in FIG. 6 is used as the fuel cutoff valve 63, the fuel downstream of the ball-shaped valve portion 63g ′ that opens and closes the seat surface 63e ′. A relatively large space 63p 'for accommodating the coil spring 63j' is formed on the side, and a relatively large amount of fuel remains in this space 63p ', which is not preferable.

As can be understood from the above description,
The range (definition) of the combustion chamber 4 in the claims means the whole including a space defined by the combustion cylinder 42 and the mixing cylinder 41, and a space defined by the inner circumference of the glow plug boss portion 62. There is. Next, FIG. 7 is experimental data showing the effect of the present invention, the vertical axis is the total amount of hydrocarbons (THC) contained in the combustion exhaust gas, and the horizontal axis is the one after the start of operation (ON) of the combustion device. It is the elapsed time. The measurement conditions of the experimental data in FIG. 7 are: outside air temperature: 0 ° C., used fuel: kerosene, heating capacity of the combustion device: 5 KW, and as a result of the experiment, compared to the conventional device (without the fuel cutoff valve 63) shown by the broken line Then, in the device of the present invention (with the fuel cutoff valve 63), the total hydrocarbon amount (THC) at the time of ignition could be greatly reduced to 1/2 or less.

Further, the discharge amount of the fuel evaporation component immediately after the combustion was stopped could be greatly reduced by the device of the present invention as follows. As the measurement conditions of the experiment, the combustion device was stored within 5 minutes after the combustion was stopped, and the combustion device was left for 1 hour in the sealed box body and then discharged into the sealed box body. The amount of fuel evaporation component was measured. At this time, the ambient temperature of the closed box is 41 ° C.

As a result of the experiment, the conventional device (without the fuel cutoff valve 63) emitted 0.0040 g per experiment, while the device of the present invention (with the fuel cutoff valve 63) per experiment. The discharge amount was reduced to 0.0016 g. (Second Embodiment) FIG. 8 shows a second embodiment. In the first embodiment, as shown in FIG.
Although the groove 63m is formed in the spring pedestal 63k of f and the end portion of the coil spring 63j is fitted into this groove 63m, the coil spring 63j is supported, but in the second embodiment, the spring pedestal 63k is supported. A small diameter portion 6 slightly smaller than the inner diameter of the coil spring 63j
3q is formed, and the coil spring 6 is formed by the small diameter portion 63q.
By guiding the inner diameter of 3j, the coil spring 6
3j is stably supported by a flat spring pedestal 63k. (Third Embodiment) FIG. 9 shows a third embodiment. In the first embodiment, as shown in FIG. 3 (a), a portion of the valve body 63f on the front side of the fuel flow B is located. The slitted sliding portion 63i and the coil spring 63j are arranged at the rear side portion of the fuel flow B, respectively. In the third embodiment, on the contrary, the rear side portion of the fuel flow B is arranged. And a coil spring 63j at the front side portion of the fuel flow B, respectively. Even in such an arrangement form, the same effect as that of the first embodiment can be exhibited.

The present invention is not limited to the above-described first to third embodiments, but can be variously modified. For example, in the first embodiment, the seat portion of the fuel cutoff valve 63 is configured. The seat surface 63e is a conical inclined surface, and the valve portion 6
Although 3g is a curved surface, both 63e and 63g may be conical inclined surfaces. Also, the seat surface 63
It is also possible that e is formed by two inclined surfaces having different inclination angles, and the connection corner portions of the two inclined surfaces contact the inclined surface of the valve portion 63g.

Further, in the above embodiment, the heat exchanger 8 has a hot water type configuration in which the combustion gas and water (heat medium) are heat-exchanged to heat the water. Air for heating the passenger compartment instead of water in 8 (heat medium)
It is also possible to adopt a warm-air type configuration in which is directly heated by combustion gas. Further, in the above-mentioned embodiment, the heating device for an electric vehicle has been described, but the present invention may be applied to a heating device for an automobile equipped with an air-cooled engine, a bus vehicle, or the like.

Further, the present invention is not limited to the heating system for automobiles, but can be widely applied to liquid fuel combustion systems for various purposes.

[Brief description of drawings]

FIG. 1 is an overall system diagram of a heating device for an electric vehicle to which the device of the present invention is applied.

FIG. 2 is a cross-sectional view of the liquid fuel combustion device showing the first embodiment of the present invention.

3A is an enlarged cross-sectional view of a main part of FIG. 2, and FIG. 3B is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a partially enlarged sectional view of FIG.

FIG. 5 is an electrical control block diagram according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of a valve structure as a comparative example for explaining the function and effect of the first embodiment of the present invention.

FIG. 7 is a graph for explaining the function and effect of the first embodiment of the present invention.

FIG. 8 is a cross-sectional view of essential parts showing a second embodiment of the present invention.

FIG. 9 is a cross-sectional view of essential parts showing a third embodiment of the present invention.

[Explanation of symbols]

4 ... Combustion chamber, 5 ... Heat exchanger, 6 ... Ignition device, 7 ... Combustion air blower, 63 ... Fuel cutoff valve, 63a ... Fuel passage, 6
3b, 63c ... Valve housing, 63d ... Fuel discharge port, 6
3e ... Seat surface, 63g ... Valve part, 63j ... Coil spring, 64 ... Fuel tank, 65 ... Fuel tank,

Claims (6)

[Claims] 1. A combustion chamber (4) for mixing and burning liquid fuel and combustion air, fuel supply means (64, 65) for supplying liquid fuel to the combustion chamber (4), and the combustion chamber (4). Liquid fuel combustion comprising air supply means (7) for supplying combustion air to the combustion chamber, and ignition means (6) for igniting and burning a mixture of liquid fuel and combustion air supplied to the combustion chamber (4) In the apparatus, a fuel cutoff valve (63) is installed at or near a connection between the fuel passage (66, 63a) through which the fuel from the fuel supply means (64, 65) flows and the combustion chamber (4), A liquid fuel combustion apparatus characterized in that the fuel cutoff valve (63) is opened during combustion operation and closed during combustion stop. 2. The combustion chamber (4) is provided with a fuel absorber (12) for absorbing and retaining liquid fuel, and the fuel passages (66, 63a) are provided with the fuel absorber (1).
The fuel cutoff valve (63) is arranged to introduce liquid fuel into the fuel passage (66, 63).
The liquid fuel combustion apparatus according to claim 1, wherein a valve mechanism portion (63e, 63f) is provided in a portion of a) adjacent to the fuel absorber (12). 3. The fuel cutoff valve (63) is normally closed and is configured to open when the fuel pressure in the fuel passage (66, 63a) rises. The liquid fuel combustion apparatus according to claim 1 or 2. 4. The fuel cutoff valve (63) is always closed by the biasing force of the spring means (63j), and the fuel pressure in the fuel passage (66, 63a) is the spring means (6).
The liquid fuel combustion apparatus according to claim 3, wherein the valve is opened when the pressure rises to overcome the urging force of 3j). 5. A fuel absorber (1) is provided in the combustion chamber (4).
2) is provided, and the fuel passages (66, 63a) are connected to the fuel absorber (1).
2) is arranged so as to introduce liquid fuel, and the fuel cutoff valve (63) includes a valve housing (63b, 63c) forming a part (63a) of the fuel passage (66, 63a). A fuel discharge port (63d) formed in the valve housing (63b, 63c) so as to be adjacent to the fuel absorber (12), and a seat surface (63e) formed on an end face of the fuel discharge port (63d). ), A valve portion (63g) that is movably disposed with respect to the valve housing (63b, 63c) and that opens and closes the seat surface (63e), and the valve portion (63g) with a predetermined spring force. The liquid fuel combustion apparatus according to claim 1, further comprising spring means (63j) that presses the seat surface (63e) side. 6. A heating apparatus using the liquid fuel combustion apparatus according to claim 1, wherein the combustion gas burned in the combustion chamber (4) and the heating medium are heat-exchanged. A combustion-type heating device comprising: a heat exchanger (5) for heating a heating medium by means of heating; and a heater unit (2) for heating the interior of the room by using the heating medium as a heat source.