JPS5847153A - Intake heater for internal combustion engine - Google Patents

Abstract

PURPOSE:To efficiently heat and atomize fuel, by piling up a plurality of ceramic heating plates having numerous through holes, so that a distance is set between the plates and the through holes are not coaxial with one another in the direction of mixture flow. CONSTITUTION:Quadrangular flanges 2a, 1b are provided on the top of an intake pipe 2 and the bottom of a carburetor 1 at which a throttle valve 3 is installed. The flanges 1b, 2b are clamped to each other by bolts 6 so that an upper and a lower gaskets 4a, 4b and an insulator 5 are interposed. Two ceramic heating plates 7a, 7b are piled up with an interposed annular spacer 9 in the passage hole 5a of the central part of the insulator 5, thereby constructing an intake heater. The heating plates 7a, 7b have numerous through holes 71a, 71b which are regularly located in the plates but have an eccentricity of about 1mm. to each other in the direction of mixture flow.

Description

DETAILED DESCRIPTION OF THE INVENTION A ceramic heater is provided in the mixing passage of the internal combustion engine according to the present invention.
The present invention relates to a heating device which is provided with a heater to heat and atomize the atomized fuel in the air-fuel mixture.

As a means of promoting atomization of fuel supplied to an internal combustion engine, it has been proposed to fill the air-fuel mixture passageway with ceramic ivy, which has a positive resistance-temperature characteristic. - The temperature rises well and is advantageous for heating the fuel during cold starting of the internal combustion engine.

Ceramic heaters generally have a two-cam structure with a large number of through holes. In the case of a heater with an L-shaped structure, some of the fuel will not be atomized as it will rapidly flow through the through hole along with the un-atomized fuel mixture.
It passes through the through hole. Therefore, if the area of each through-hole is made smaller, the length of the through-hole, that is, the thickness of the outlet, may be increased, but this would increase the ventilation resistance of the air-fuel mixture, which would be inconvenient. arise. It is also possible to make the shape of the through hole curved in the thickness direction of the cam structure, but such a shape is not easy to process and the ventilation resistance increases. It's inconvenient.

Therefore, there is a need for an intake air heating device that can easily increase the flow resistance of the air-fuel mixture, has a large effective heating area for Tanabata, and is easy to manufacture. The purpose is to stack plate-shaped ceramic heaters with a large number of through holes in the thickness direction with gaps between them, and to face each other so that the through holes of the upper and lower heaters are mixed. The above objective can be achieved by arranging the awning so that it is slightly offset with respect to the direction of air flow.

In the present invention, the heaters are laminated with gaps between each other in a thin F-shaped manner, and these through-holes prevent the air-fuel mixture from passing through the current, and the un-atomized fuel droplets adhere to the top surface of each heater. Since the attached fuel flows along the periphery of the through-hole in the shape of a droplet and flows to the back surface of the heater, both the upper and lower surfaces of each heater are used as heating surfaces, so the heating efficiency of the fuel is extremely good. However, in the present invention, since the positions of the through holes in the stacked upper and lower heaters are slightly eccentric, the adhesion of fuel droplets to each heater can be improved.

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

In the first embodiment shown in FIG. 1 and FIG.
Wow, a converter! ! It is a whirring intake pipe. The carburetor 1 has a mixture passage 1 m having a circular cross section, and a throttle valve 3 is installed in the passage 1a. 7 square langes 1b are formed at the lower end of the carburetor 1, and 7 langes 2a of the same shape are formed at the upper end of the intake pipe 2; Gasket 4m, made of conductive material such as 4b carbon, and insulator 5 made of thermal and electrical insulation such as phenolic or epoxy resin. It's a sexual material. These numbers are the same as number a141 and insulator S's outer shape 7 lunge 1b and Rh.

There is a circular through hole 5 in the center of the insulator 5, which is concentric with the air-fuel mixture passage 1a and has a diameter larger than that of the passage 1a.
is formed. Parallel planar portions '5b and 5o are formed at two locations facing each other in the diametrical direction of the through hole 5&.

Inside the insulator 50 through hole S&, eight plate-shaped ceramic plates having the same external shape as the insulator 50 are installed in a laminated manner. , the inner diameter matches the mixture passage 1&, and the outer diameter matches the ink! A ring-shaped spacer 9 that matches the through hole 8 & of L and #6 is interposed, and both ceramic heaters face each other across the vbFi underarm.

The ceramic is also in contact with the upper surface and 7b of the tank 1 and the lower gasket 4b.

Both ceramic heaters? &, 7kFi is the same shape, has a large number of circular through holes arranged in an orderly manner in a geometric pattern, and is slightly, for example, about α6-, relative to the center of the center of this pattern. Eccentric. Both ceramic heaters 7& and hood b of the same shape are stacked on top of each other with the front and back sides turned upside down. A through hole? 1 m and the through hole 71b of the heater tube b are positioned about 1 m apart from each other in the surface direction.

Ceramic heater 7aS? b is PTO ceramic whose main component is barium titanium.

PTO ceramic hemostasis has resistance-temperature characteristics and a cue point at a specific temperature, and when electricity is applied, it generates heat and reaches the cue point temperature at once, and after that, the electrical resistance increases rapidly, causing the current to become almost constant. It has the property of self-adjusting its temperature around the -21 point.

A restraining electrode terminal 12 is wrapped around the insulator 5, and one end bent into a claw shape is attached to the through hole 1 of the insulator 6.
1Tfif! 1ls5b, and is in contact with the side surfaces of heater 7a, Wb, and spacer 9. Note that the positive electrode terminal 12 and the spacer 9 are made of a copper plate. Also, ceramic heater aS? Both the front and back sides of b are nickel plated to form electrode surfaces. Above positive electrode terminal 1! ! It is connected to the battery via a key switch (not shown). On the other hand, + electric heater '7a
In the intake air heating device of the above configuration, which is electrically grounded through gaskets 4 and 4'b of Wb Co., Ltd., when the key switch is turned on when starting the internal combustion engine, the voltage of the battery becomes correct. A voltage is applied to the electrode terminal 11.

Current is positive electrode terminal 1! ! It flows from the spacer 9 to the ceramic and -ta? After flowing through each of a and Wb in the thickness direction, this current is grounded through gaskets 4 and 4b, and this current causes the ceramic heater a1 to rise to the temperature xso'c of the melting point temperature at KW14. K rises and its temperature & CJl is maintained.

The air-fuel mixture supplied from the air pump 1 to the air pipe and trachea 2 is heated through a ceramic heater, so each through hole in the air hole (b) is 1 m long.

Pass through 71b. At this time, an empty tIL and a sufficiently atomized fuel-like through-hole fl,? The flow resistance is small, and the amount of heat consumed to heat the air and atomized fuel is also small. If there is not enough fuel, the fuel flows as a tympanic membrane flow that collides with the upper surface of the heater 7a, passes through the periphery of each through-hole, and also flows to the back surface of the heater 7a and adheres thereto. In addition, the un-atomized fuel that has passed through the ceramic heater fIb is also scattered and attached to the ETI on the ceramic heater fIb, forming a one-liquid film flow and reaching the back surface. in this case,
Through hole of ceramic heater 7a? 1& and Ceramic Beetough 10 through hole 1b are misaligned, so Peter? The adhesion rate of un-atomized fuel to the upper surface of the fuel tank is improved. In this way, both the upper and lower surfaces of the ceramic heaters 7a and Wb act as heating surfaces for the non-atomized fuel adhering thereto, resulting in extremely high heating efficiency.

FIG. 3 and FIG. 1 show the second embodiment.
The shape of the through-hole of each ceramic heater and the positional relationship between the through-holes of both peaks are different from the embodiment shown in FIG. Each heater e1 has a large through hole (1o) and a hole (14) of the same diameter in the center, and each heater has a large number of small holes in its center. Through hole 7a a.

724 is the formation. And both heaters 'Ia.

At a predetermined angle around the center axis of F aa, approximately 18 degrees of twist in the example shown,
They are arranged at mutually shifted positions.

This embodiment takes into consideration the fact that most of the un-atomized fuel flows on the wall of the atomizer as a liquid film flow, and that a small amount of un-atomized fuel flows through the center of the mixture passage. Issei Fu0. The water is effectively heated and atomized at the shoulder side of the lid. Since we have made a lucky hole in the center, the ventilation resistance will be reduced, and the heat of heating the air and already atomized fuel will be even less wasted. It is advantageous.

In addition, as in the third embodiment shown in FIG.
A large number of through holes in the same position in the heaters 7 and 7f (not shown)? 1, 71f may be formed, and both the heaters and the heater f may be arranged at positions shifted by a predetermined angle with respect to the central axis.

As described above, in the F&air heating device of the present invention, the upper and lower surfaces of each heater act as heating surfaces, and an extremely large effective heating surface can be obtained with a compact heater device. Moreover, since the un-atomized fuel adhering to the heating surface is heated, the heat of the heater effectively works to atomize the fuel, and the air and
lification:? ::2:::ni::2:::2:a#:: By providing a positional shift in the through-hole of each pinita, the papering quality can be improved. In the above embodiment, two ceramic vine heaters are used, but three or more ceramic vine heaters may be stacked. In this case, as in the first embodiment, a plurality of sheets of the same type with a geometric pattern and the center of the pattern eccentric from the center of Tanabata are sequentially stacked with the front and back reversed, and the cost is high. The heater can be configured advantageously both physically and in terms of assembly. Further, as in the other embodiments, by adjusting the rotation angle of the ceramic heaters of the same shape to a predetermined angle, it is possible to easily construct a repeater device. Furthermore, the outer shape and the shape of the through hole of the ceramic heater are not limited to a round shape, but may be polygonal, for example.

[Brief explanation of drawings]

1 and 2 A first embodiment of the present invention is shown. FIG. 1 is a vertical cross-sectional view of the air heating device. FIG. 3 shows the second embodiment of the figure 1; FIG. 3 is a vertical sectional view taken along the line; FIG. 4 is an end view taken along W-1/I[K of FIG. , FIG. 5 is a plan view of a ceramic beater according to a third embodiment of the fifth figure. 1... Carburetor 2... Intake pipe)a
1 piece b1 01 d1 f...Plate-shaped ceramic and -ta S -=---- Spacer 12...Positive electrode terminal' Fig. 1 Fig. 2 Fig. 3 Figure 4

Claims (1)

[Claims] A heater made of a dragonfly with a positive resistance-temperature characteristic was installed in the air-fuel mixture passage of an internal combustion engine. 0rIk air heating for an internal combustion engine, characterized in that a plurality of ceramic heaters are stacked with a cnis between them, and the through holes of the upper and lower ceramic heaters facing each other are arranged so that the positions of the through holes are shifted with respect to the flow direction of the air-fuel mixture. Equipment O