JPH0524430A - Combustion heater for automobile - Google Patents

Abstract

PURPOSE:To reduce power consumption at igniting and, at the same time, increase the probability of ignition, in a combustion heater for automobile. CONSTITUTION:A heat storage plate 32 which stores heat generated from a heat generating part 33 of a glow plug 12 is provided near a fuel vaporization plate through-part of the glow plug 12. Thus power consumption needed to preheat fuel for vaporization can be saved, and the probability of ignition at extremely low temperature can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion type heater for an automobile, which has improved ignitability and saves power until ignition.

[0002]

2. Description of the Related Art A large vehicle such as a bus is provided with a heater for heating the interior of a vehicle by using engine cooling water. However, when the heating capacity of this heater alone is insufficient,
Combustion heaters that use kerosene, light oil, gasoline, etc. as fuel are used to increase the heating capacity of the heaters. As shown in FIG. 3, the combustion heater 1 heats engine cooling water that cools the vehicle running engine 2 into hot water, and heats the hot water for air heating through which air blown into the vehicle interior passes. The interior of the vehicle compartment is heated by introducing it into the exchanger 4 and blowing out the air, which has become hot air by exchanging heat with hot water in the heat exchanger 4, into the vehicle interior. The combustion heater 1 is provided with a combustion cylinder 5 in a casing 3, and a fuel vaporization which is a porous plate communicated with a fuel pump 7 at an end of a cylindrical combustion chamber 6 formed in the combustion cylinder 5. A plate 8 is provided.
The fuel from the fuel pump 7 is fed to the fuel vaporization plate 8 through the fuel supply line 22.

An air introducing passage 9 is formed on the outer periphery of the combustion cylinder 5, and the air passing through the air introducing passage 9 is introduced into the combustion chamber 6 through a large number of air holes 10. The air fan 11 sends the air into the combustion chamber 6. A glow plug 12 for igniting fuel is attached to the casing 3 so as to face the combustion chamber 6. The glow plug 12 is guided to a fuel vaporization plate 8 as shown in detail in FIG. It is provided adjacent to the fuel vaporization plate 8 in order to preheat the fuel and facilitate the vaporization. The combustion heater 1 has a heat exchange section 13 for heating a part of engine cooling water, and the heat exchange section 13 is
It is composed of a primary chamber 14 which communicates with the combustion chamber 6 and through which combustion gas flows, and a secondary chamber 15 through which cooling water flows. Primary room 1
4 is connected to an exhaust duct 16 that discharges the combustion gas after heat exchange, and the secondary chamber 15 is connected to a water pump 17 that supplies cooling water. In the figure, reference numeral "18" is a flame sensor for determining whether or not the fuel is normally ignited, "19" is a filter for removing dust in the fuel, and "20" is a water temperature for detecting a heated water temperature. The sensor, "21", is an overheat fuse.

[0004]

However, in such a combustion type heater 1 for an automobile, it is necessary to preheat the fuel vaporization plate 8 in order to generate vaporized fuel from the fuel vaporization plate 8. Therefore, the power consumption required for this preheating increases. Further, when the vaporized fuel preheated in this manner from the fuel vaporization plate 8 is mixed with air and ignited by the glow plug 12, the glow plug 12 is cooled by the mixture itself at an extremely low temperature. , The ignition probability is reduced. There are two such problems. In the conventional combustion heater 1, the glow plug 12 is projected so as to extend along the surface of the fuel vaporization plate 8 attached to the end of the combustion chamber 6 and at right angles to the axis of the combustion chamber 6. 12 is configured so that the fuel is easily preheated. However, since the preheating of the fuel vaporization plate 8 must be mainly based on the radiant heat of the glow plug 12, the preheating requires a large amount of electric power. Further, since the glow plug 12 is attached at the position as described above, it can be said that the ignitability is excellent in consideration of the rise of vaporized fuel, but it is orthogonal to the axis of the combustion chamber 6. When the glow plug 12 is projected in the direction, the air flowing from the periphery of the combustion chamber 6 flows along the glow plug 12, so that the glow plug 12 is cooled by this air and the initial flame is misfired. It is easy to do. Also, the airflow flowing along the glow plug 12 may blow off the flame during the growth period, which makes it difficult to grow.
This may also cause the initial flame to misfire. The present invention has been made to solve the problems associated with the above-described conventional techniques, and an object of the present invention is to provide a combustion-type heater for an automobile, which consumes less electric power during ignition and at the same time can improve the ignition probability. And

[0005]

According to the present invention for achieving the above object, a fuel vaporizing plate for vaporizing combustion fuel is provided at one end of a combustion chamber, and a glow plug is provided adjacent to the fuel vaporizing plate. In the combustion heater for an automobile, an air introduction path is provided on the outer periphery of the one end of the combustion chamber and air is introduced into the combustion chamber through an air hole formed on the outer periphery of the combustion chamber. Is provided so as to penetrate the fuel vaporization plate from a direction along the axis of the combustion chamber, and a heat storage portion is provided in the vicinity of the portion where the glow plug penetrates the fuel vaporization plate.

[0006]

In the present invention thus constructed, the heat generated from the glow plug at the time of ignition is first stored in the heat storage section, and the fuel permeated through the fuel vaporization plate is stored in the heat storage section together with the glow. It evaporates with the heat generated by the plug. The heat storage unit stores the heat generated by the glow plug until the fuel permeates into the fuel vaporization plate penetrating portion. Therefore, the fuel that has penetrated to the penetration portion of the fuel vaporization plate is efficiently evaporated. Further, since the air-fuel mixture of the evaporated fuel and the supplied air exists around the glow plug, the ignitability is improved. Further, since the air flow does not directly contact the glow plug, a long-term flame is surely grown without being blown by the air, and there is no risk of misfire. Also, since the air flows in from a position away from the glow plug, the initial flame that grows at the tip of the glow plug is less affected by the air flow, and since the glow plug itself is not cooled, the initial flame grows reliably. Will be done. Further, since the glow plug is placed laterally along the axis of the combustion chamber for a while, and a complicated control device is not required, the shape of the entire device is reduced. In particular, when the glow plug is provided along the center axis of the combustion chamber, the side wall of the combustion chamber does not interfere with the growth of the flame, and the combustion is smoothly performed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A combustion type heater for an automobile according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an essential part showing an embodiment of a combustion heater for an automobile according to the present invention. Members common to those shown in FIG. 3 and FIG. The description is omitted. The combustion heater 30 has a combustion cylinder 5 provided in a casing 3, and an air introduction path 9 for guiding air from an air fan 11 is formed between the casing 3 and the combustion cylinder 5. A combustion chamber 6 is formed in the combustion cylinder 5, and a fuel vaporization plate 8 composed of a porous plate is provided at the end of the combustion chamber 6. A glow plug 12 is provided so as to penetrate through the casing 3 and the fuel vaporization plate 8 along the central axis of the combustion chamber 6.
A heat storage plate 32 that is in contact with the fuel vaporization plate 8 is provided around the portion that protrudes into the combustion chamber 6. The heat storage plate 32 stores the heat generated from the heat generating portion 33 of the plug 12. The shape of the heat storage plate 32 is preferably as shown in the figure in order to mutually satisfy the two functions of heat storage and the function of promoting fuel vaporization from the fuel vaporization plate 8. That is, in order to more efficiently absorb the heat from the heat generating portion 33, the outer periphery of the heat generating portion 33 is in contact with the periphery of the hole opened in the fuel vaporization plate 8 so that the plug 12 faces the combustion chamber. Is formed so as to surround the fuel vaporization plate 8 as well as the side surface of the fuel vaporization plate 8 so as to promote vaporization from the fuel vaporization plate 8. In addition, this heat storage plate 32 is provided so that the heat storage property is not hindered.
Are in line contact or point contact with the casing 3, and most of them form an air gap therebetween. The air passing through the air introduction passage 9 passes through the air holes 10 provided around the combustion cylinder 5 and flows into the combustion chamber 6. In the figure, reference numeral "37" is a slit for introducing air.

Next, the operation of the embodiment will be described. First, as is clear from the timing chart shown in FIG. 2, when the start switch is turned on, the switch of the air fan 11 (neither is shown) is turned on, and the inside of the combustion heater 30 is scavenged. When this scavenging is completed, the air fan 11
The switch for the glow plug 12 is turned on at the same time as the switch for No. The motor of the fuel pump 7 is started when the glow plug 12 is heated after a predetermined time has elapsed. The heat generated from the glow plug 12 at this time is
The portion that is stored by the heat storage plate 32 and is in contact with the heat storage plate 32 of the fuel vaporization plate 8 is heated.

When the fuel pump motor is started, the fuel is fed by the fuel pump 7, impregnated in the fuel vaporization plate 8 and guided to the mounting portion of the heat storage plate 32 in the preheated state. The fuel that has reached this point evaporates due to the heat stored in the heat storage plate 32 and the heat supplied from the heat generating portion 33 of the flow plug 12. Since the heat storage plate 32 has the above-mentioned functions, the ignition probability at an extremely low temperature is improved.

When the switch of the air fan 11 is turned on again after a certain amount of fuel has been fed, air is introduced from the air fan 11 into the air introduction passage 9 and passes through the air hole 10 from the air introduction passage 9. And flows toward the combustion chamber 6. At this time, the fuel vaporized from the fuel vaporization plate 8 is also introduced into the combustion chamber 6. At this point, the glow plug 12 ignites. In the initial stage of this combustion, the fuel evaporated from the vicinity of the heat storage plate 32 exists around the glow plug 12 and therefore ignites very easily, so that the ignitability is improved. Moreover, since the air flow from the air holes 10 does not directly hit the glow plaque 12, the flame in the growing period is surely grown without being blown away by the air, and there is no risk of misfire. Also, the air holes 10
Since the glow plug 12 is present at a position away from, the initial flame that grows at the tip of the glow plug 12 is less affected by the air flow, and the glow plug 12 itself is not cooled. The flame will definitely grow. In particular, since the glow plug 12 is provided along the central axis of the combustion chamber 6, the side wall of the combustion chamber 6 does not interfere with the growth of the flame, and the combustion is smoothly performed. When combustion is started in this way, power supply to the glow plug 12 is stopped and normal combustion is performed.

As is apparent from the above-mentioned points, in this embodiment, the glow plug 12 is of a horizontal type, so to speak, along the axis of the combustion chamber 6, so that the casing 30 has a small vertical dimension. Moreover, since the control device for controlling the rotation speed of the fan or the pump described above is unnecessary, the overall size of the device can be reduced. Further, since a relatively large amount of air-fuel mixture exists near the heat generating portion 33 of the plug 12 due to the effect of the heat storage plate 32, it is possible to improve the ignition probability at an extremely low temperature. Further, since the vaporization of the fuel is mainly performed on the basis of the heat stored in the heat storage plate 32, the heat generation capacity of the plug 12 can be reduced, and the power consumption thereof can be reduced. The present invention is not limited to the embodiment described above, and the glow plug 12 does not necessarily have to be provided along the central axis of the combustion chamber 6,
It may be slightly displaced. Further, although the above embodiment shows the case where the engine cooling water is heated, it goes without saying that the present invention can be applied to a combustion heater that directly heats the air blown into the vehicle compartment.

[0012]

As described above, according to the present invention, since the glow plug has the heat storage portion in the vicinity of the fuel vaporizing plate penetrating portion, the ignitability is improved especially at extremely low temperatures, and the growth of flame is also inhibited. And there is no risk of misfire without the use of complex control devices. Further, since the glow plug is horizontally placed along the axis of the combustion chamber, the overall shape of the device can be reduced. Further, since the fuel is vaporized efficiently, the power consumption of the glow plug can be saved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of a combustion heater for an automobile according to the present invention.

FIG. 2 is a timing chart.

FIG. 3 is a schematic diagram including a combustion device of a conventional combustion-type heater for an automobile.

FIG. 4 is a schematic cross-sectional view showing a heater portion of the combustion device.

[Explanation of symbols]

 6 ... Combustion chamber 8 ... Fuel vaporization plate 9 ... Air introduction path 10 ... Air hole, 12 ... Glow plug 32 ... Heat storage plate (heat storage part) 33 ... Heat generation part

Claims (1)

Claim: What is claimed is: 1. A fuel vaporization plate for vaporizing combustion fuel is provided at one end of a combustion chamber, a glow plug is provided adjacent to the fuel vaporization plate, and the one end of the combustion chamber is provided. A combustion type heater for an automobile, wherein an air introduction path is provided on the outer periphery and air is introduced into the combustion chamber from an air hole formed on the outer periphery of the combustion chamber, wherein the glow plug is arranged in a direction along an axis of the combustion chamber. A combustion heater for an automobile, characterized in that the fuel vaporization plate is provided so as to penetrate therethrough, and a heat storage portion is provided in the glow plug in the vicinity of the portion where the fuel vaporization plate penetrates.