JP2563868B2 - Vaporizer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carburetor for vaporizing fuel to produce an air-fuel mixture to be supplied to an engine, and more particularly to a carburetor equipped with a means for preventing icing. The carburetor of the present invention is used for various general-purpose engines, including automobile engines.

[0002]

2. Description of the Related Art A spark ignition engine such as a gasoline engine is equipped with a vaporizer for the purpose of vaporizing fuel and mixing it with air to form a gas. Since the vaporizer loses heat of vaporization as the fuel is vaporized, the temperature of the vaporizer is usually slightly lower than the outside temperature during operation of the engine.

The disadvantages associated with cooling the vaporizer are:
Icing occurs when the outside temperature is low and the humidity is high (such as in winter). As the air cools, the water in the air freezes in the intake passage, blocking the flow of intake air. This phenomenon is likely to occur after a while after the engine is started under the condition that the outside temperature is below 5 ° C. and the humidity is high. The portion of the carburetor where icing is most likely to occur is the slow intake passage where the air-fuel mixture flows at high speed when the engine is rotating at a low speed due to the narrow passage opening.

The means for preventing icing has already been applied to many carburetors in various general-purpose engines, including engines for motorcycles. JP 62-2635
As one of such icing preventing means, Japanese Unexamined Patent Publication No. 2 (1994) proposes to attach an electric heater to a part of the vaporizer. The heat conduction from the heater warms the intake passage of the carburetor. In addition, a carburetor designed to be heated by the exhaust heat of the engine and a carburetor designed to be heated by hot water, that is, cooling water whose temperature has risen can be seen.

[0005]

Regarding the means for preventing icing in the carburetor, a) the structure is simple and inexpensive, and b) the necessary portions are appropriately heated (heated) so as not to become excessive. It is desirable that the heat loss is small. However, the conventional vaporizer is not necessarily ideal in this respect.

That is, first, in the case of an electric heater, it is indispensable to attach the heater body and to connect wiring from the heater to the power source, which is troublesome in structure. Moreover, it always consumes electricity. Even in the case of heating with warm water, the structure is complicated and the cost is not cheap in that each pipe for returning and returning must be provided in order to circulate the cooling water. Further, when exhaust heat or the like is used, it is difficult to heat locally and the heating tends to be excessive, which may cause problems such as percolation in some cases.

An object of the present invention is to provide a vaporizer which is extremely preferable in terms of the above a) to c).

[0008]

In the vaporizer of the present invention, a heat pipe is used as a means for preventing icing, and the heat dissipation portion (low temperature portion) at one end of the pipe is the vaporizer itself (vaporizer body).
Attached to the heat input part (high temperature part) which is the other end of the pipe
Is connected to the engine heating portion which is lower than the mounting portion of the heat radiating portion. And that engine heat
As a part, the passage of engine cooling water to the radiator
From the cooling water branched via a thermostat from
Select a heat passage, and connect the heat section above the heat pipe to this.
It will continue. A heat pipe is a pipe whose inside is almost evacuated and contains a liquid (working liquid). The liquid is evaporated in a high temperature part and condensed in a low temperature part to utilize the latent heat of evaporation / condensation. It is a well-known pipe-shaped heat transfer body that performs heat transfer between the two.

With respect to this heat pipe, as described in claim 2, it is preferable that the heat radiating portion is mounted near the passage of the slow system. Further, as in claim 3, it is preferable to use a heat pipe in which water is sealed.

[0010]

[0011]

In the carburetor of the present invention, the heat of the warm part of the engine is transferred to the carburetor itself via the heat pipe, thereby preventing icing. The details of this heat transfer are as follows. That is, since the heat input part (the "other end" mentioned above) of the heat pipe is connected to the warm part of the engine, the liquid in the pipe evaporates at that part (because the inside of the pipe is close to vacuum, It boils and evaporates even at temperature), thereby depriving the latent heat of vaporization. The vaporized liquid vapor moves in the pipe to the heat radiating portion (the above-mentioned "one end"), that is, the attachment portion to the carburetor having a lower temperature than the engine heating portion,
There, it condenses and returns to liquid, at which time latent heat of condensation is released toward the vaporizer. The condensed liquid smoothly returns to the inside of the pipe to the heat input part provided at a position lower than the heat dissipation part by the action of gravity (or the capillary action of the charge called a wick), etc. Evaporate again.

Based on the above operation, this vaporizer has the following features. First, icing is prevented by a simple structure in which a single heat pipe is connected to the warm part of the engine. Secondly, if the heat radiating part of the heat pipe is attached to the necessary part, that part and its vicinity will be locally heated (heated), and the carburetor will exceed the temperature of the engine heating part to which the heat input part is connected. Since it is not heated, excessive heating is prevented as long as the selection of the heating portion is appropriate. Third, since the heat pipe's (apparent) thermal conductivity is extremely high, the heat of the engine heating part is efficiently transmitted (that is, there is little loss) to the carburetor, and the carburetor is necessary to prevent icing. The temperature rises quickly and accurately. Claim 1 Saw
The carburetor of the engine that connects the heat input part of the heat pipe
Select the above bypass passage for cooling water as the heating part.
Then, the heating is ideally performed as follows. Sanawa
A ) In the first place, the passage of cooling water and its vicinity are
The water temperature rise is suppressed by the action and it does not become an extremely high temperature
Therefore, connect the heat input part of the heat pipe to such a part.
Then, the extreme temperature rise cannot occur in the vaporizer. b) When the engine is cold, use the thermostat.
The passage to the radiator is closed and engine cooling water is
It flows into the Y-pass passage, and the temperature of the same passage
It quickly rises. Therefore, the carburetor should be added quickly.
Effectively prevents icing from being heated and warming up.
It is. c) After warming up, the radiator is thermostatted.
To the inside of the passage because the passage to
The high temperature cooling water from the engine does not flow into the
Only the cooling water whose temperature has dropped a little through will enter). Shi
Therefore, the temperature of the passage will drop slightly before warming
The temperature brought to the oxidizer also drops appropriately during load operation.
Is preferable.

In the vaporizer according to the second aspect of the invention, heat from the heat pipe is easily transferred to the passage of the slow system.
As described above, the passage that is most likely to cause icing is heated first, and icing is effectively prevented.

The liquid sealed in the heat pipe is selected from many types such as CFCs.
Since the carburetor temperature that easily causes icing is around 0 ° C. and the most common surface temperature of an engine is about several tens to 100 ° C., the liquid is water as described in claim 3. Is the best. This is because water is suitable for carrying heat transfer between the warm part of the engine and the carburetor in view of the above temperature conditions, and is advantageous in cost compared with other liquids.

[0015]

[0016]

[0017]

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be introduced below with reference to the drawings. First, FIG. 1 and FIG. 2 are examples of a carburetor 10 configured by diverting a conventional carburetor main body, and FIG. 1 is a view of an upper portion of an engine 1 including the carburetor 10 seen from a side (side), FIG. 2 is a sectional view of the vaporizer 10. In addition, the following
Vaporizer 10 (Figs. 1 and 2) and vaporizer 20 (Fig.
3) does not correspond to what is described in the claims.

In FIG. 1, a carburetor 10 vaporizes gasoline to supply an air-fuel mixture to the engine 1, and its main body 11 is attached to the engine 1 via an intake pipe.

A heat pipe 18 is attached to the vaporizer 10 for the purpose of preventing so-called icing.
That is, as shown in FIG. 2, an aluminum block 17 as an attachment is fixed to a portion of the block 1 close to the slow passage fuel passage 13 reaching the intake passage 12.
One end of the heat pipe 18, that is, the heat radiating portion 18a is attached by inserting the heat pipe 18 into the inside and tightening with the screw 17a. The heat pipe 18 used is made of copper with water sealed therein and has an outer diameter of about 6 mm.
Then, the heat input portion 18 that is the other end portion of the heat pipe 18
b is the water pump 3 of the engine 1 as shown in FIG.
The cylinder block 2 close to the above was provided with a hole 2a and was inserted to be connected.

The heat of the cylinder block 2 into which the heat input portion 18b is inserted is quickly and efficiently transmitted to the heat radiating portion 18a in the heat pipe 18, and further, through the aluminum block 17 having good heat conduction. It is transmitted to the vaporizer main body 11. Slow passage 13 where icing is most likely to occur
Since the block 17 is fixed in the vicinity of, icing is effectively prevented.

Inside the heat pipe 18, the heat input section 18
The vapor evaporated in b reaches the heat radiating part 18a, and the water condensed there returns to the heat input part 18b again. In this example,
Measures are also taken to smooth the movement of such vapor (gas) and water (liquid). That is, the position of the heat input part 18b, that is, the position of the hole 2a provided in the cylinder block 2 is made lower (lower) than the position of the heat dissipation part 18a connected to the vaporizer main body 11. Thereby, the circulation of water and steam is promoted by the action of gravity. further,
With the heat radiating portion 18a side up, the heat pipe 18
Having an inclination of more than ° is also effective in the same meaning as above.

Continuing with the vaporizer 20 shown in FIG. 3, the vaporizer 10 shown in FIGS.
Is different. That is, without using attachments such as blocks (reference numeral 17 in the examples of FIGS. 1 and 2), the mounting holes 21a of the heat radiating portion 28a of the heat pipe 28 are attached.
Is provided on the vaporizer main body 21 itself. The conventional vaporizer needs to be modified in connection with the mounting hole 21a, but the structure is simple and the heat pipe 28 can be easily connected.

4 and 5 show an example in which the heat input portion 38b of the heat pipe 38 provided in the vaporizer 30 is connected to the cooling water bypass passage 9 of the engine 6. Heat pipe 3
The heat radiating portion 38a of No. 8 is connected to the carburetor main body 31 via the block 37 as in the example of FIGS. 1 and 2, but the one heat input portion 38b is an end portion in the conduit of the bypass passage 9. The parts were inserted and sealed and fixed using a silicone compound. As a result, the heat of the cooling water flowing through the bypass passage 9 is transferred to the carburetor main body 31 through the heat pipe 38.

As well known, the bypass passage 9 is a part (branch passage) of the engine cooling water passage 8 connecting the engine 6 and the radiator 7 as shown in FIG.
Bypassing between the forward and backward flow paths. Passages 8a and 8c from the engine 6 to the radiator 7
Is the outgoing flow path, and the passage 8d from the radiator 7 to the engine 6 and the water pump 8e are the return flow paths. A thermostat 8b is provided between the passages 8a and 8c, and the thermostat 8b is connected to the upstream of the pump 8e. The bypass passage 9 is provided therebetween. When the water temperature is low, the cooling water flows only from the passage 8a to the passage 9 by the action of the thermostat 8b, and returns to the engine 6 via the pump 8e.
When the temperature reaches 80 ° C. or higher, the thermostat 8b closes the flow path to the passage 9 and transfers the cooling water discharged from the engine 6 to the passage 8c.
It flows into the radiator 7 and the passage 8d.

Based on the above-described action of the thermostat 8b and the cooling action of the radiator 7, the cooling water in the bypass passage 9 rapidly rises to 70-80 ° C,
After that, the downstream water temperature of the radiator 7 is 50-60 ° C.
Maintained to a degree. Since the heat input part 38b of the heat pipe 38 is connected to the bypass passage 9 having such a temperature, the carburetor 30 of this embodiment effectively prevents icing immediately after the engine 6 is started, and operates the carburetor 30. Will not be overheated by the continuation of.

[0027]

The vaporizer of the present invention has the following effects.

1) The icing is accurately prevented by the structure which is simple and less likely to cause a failure and consumes no electric power or the like.

2) A necessary portion is locally heated to prevent icing, and excessive heating can be avoided only by appropriately selecting an engine heating portion connecting the heat input portion of the heat pipe.

3) The body of the carburetor efficiently receives the heat of the engine heating portion, so that the temperature rises to the required temperature quickly and accurately, and icing is appropriately prevented. Furthermore, 4) The temperature rises quickly and icing is effectively prevented.
And causes inconvenience such as percolation
There is no excessive temperature rise.

Further, in the vaporizer according to the second aspect of the invention, 5) the portion most susceptible to icing is effectively heated, so that the icing prevention effect is excellent.

The vaporizer of claim 3 is particularly advantageous in terms of 6) temperature conditions, that is, efficient heat transfer and cost.

[0033]

[Brief description of drawings]

FIG. 1 is a drawing showing a first embodiment of the present invention, showing an upper part (shown in cross section) of an engine 1 and a carburetor 10 as seen from a side.

FIG. 2 is a drawing showing the above vaporizer 10 and is shown in FIG.
It is a II-II sectional view.

FIG. 3 is a sectional view of a vaporizer 20 as a second embodiment of the present invention.

FIG. 4 is a top view of a carburetor 30 and an engine 6 as a third embodiment of the present invention.

FIG. 5 is a system diagram showing a carburetor 30 and a bypass passage 9 of engine cooling water in the third embodiment.

[Explanation of symbols]

 1.6 engine 2 cylinder block (engine heating portion) 9 bypass passage (engine heating portion) 10.20.30 vaporizer 13.23 slow passage 18.28.38 heat pipe 18a.28a.38a heat dissipation portion 18b .. 38b Heat input part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-9644 (JP, A) SAIKAI 59-96350 (JP, U)

Claims (3)

(57) [Claims] 1. A heat radiating portion at one end of a heat pipe is attached to the carburetor itself, and a heat input portion at the other end of the heat pipe is connected to an engine heating portion lower than a mounting portion of the heat radiating portion . It is a carburetor, and the thermostat from the passage of engine cooling water to the radiator.
The bypass passage for the cooling water branched through the above
It is considered to be the engine heating part, and fill in the heat pipe on this
A vaporizer characterized in that a heat section is connected . 2. The carburetor according to claim 1, wherein the heat radiating portion of the heat vapor is mounted near a passage of a slow system. 3. The vaporizer according to claim 1, wherein the liquid inside the heat pipe is water.