JP2584400B2 - Vaporizer heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for a carburetor for producing an air-fuel mixture required for an engine by vaporizing fuel.

[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 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.

[0003] The disadvantages associated with cooling the vaporizer are:
When the outside air temperature is low and the humidity is high (for example, in winter), the cooling causes the moisture in the air to freeze in the intake passage, thereby hindering the flow of intake air. This phenomenon occurs when the outside temperature is 5
Under conditions such as below ℃ and high humidity, it easily occurs after a while after starting the engine.

Means for preventing such a phenomenon have already been applied to many carburetors in various general-purpose engines and the like, such as motorcycle engines. JP-A-62-2
No. 26352 discloses, as one of such means,
It has been proposed 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, there is an example of heating (heating) the vaporizer by guiding a part of the engine exhaust to the vaporizer, or circulating warm water, that is, cooling water whose temperature has increased, in the vaporizer. The present applicant has already filed a patent application for an invention for heating a vaporizer using a heat pipe.

[0005]

The heating means for the vaporizer is a) simple in structure and low in cost, and b) does not require a change in the structure of the vaporizer body and can be easily applied to various types of vaporizers. It is desirable to be able to do this, and c) appropriately heat the necessary parts so as not to be excessive. However, conventional vaporizers are not always ideal in this respect.

That is, in the case of an electric heater, the heater itself is expensive and always consumes electric power.
There is a disadvantage in cost. In the example of the above-mentioned publication, there is a further inconvenience that a part of the vaporizer must be modified in order to bury the heater. As for the means for circulating hot water in the vaporizer, it is necessary to form a circulation path in the vaporizer, which increases the cost in terms of structure and cannot be used for general-purpose vaporizers, etc., whose type is difficult to change. is there. When using exhaust heat or the like, local heating is difficult and heating tends to be excessive, and in some cases, problems such as vapor lock and percolation may be caused. Further, under the current situation where mass production has not yet been achieved, heat pipes are not necessarily inexpensive depending on the type and dimensions.

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

[0008]

A heating device for a vaporizer according to the present invention comprises: a heat transfer block (a block made of a material having a high thermal conductivity such as aluminum or copper) which is attached in contact with a vaporizer body; The block is combined with a pipe through which engine cooling water flows. In the carburetor, the location where icing in the intake passage is most likely to occur is the slow system intake passage in which the mixture of the mixture flows at a high speed when the engine is running at low speed because the opening of the passage is narrow. The heat transfer block is brought into contact with the near outer surface. In order to fix the heat transfer block, bolts and nuts used for assembling the carburetor body and various rigid objects near the carburetor (such as support frames for engines and carburetors) can be used. If necessary, a new mounting portion (such as a screw hole) is provided in a portion of the vaporizer that is easily formed. Also, the above-mentioned pipe is provided with a suitable pipe joint or the like at a part of the passage of the engine cooling water (one point at each of the upstream and downstream) to serve as an inlet / outlet of the cooling water and is connected thereto. Since the cooling water in the pipe circulates according to the pressure difference between the two inlets and outlets, no dedicated circulation means (such as a pump) is provided in the pipe.

[0009] In this heating device, the upstream end of the pipe is connected to a cooling water bypass passage branched from a passage of the engine cooling water to the radiator via a thermostat .

[0010]

When the heat transfer block is brought into contact with the carburetor main body and the engine cooling water is passed through the pipe, the carburetor heating device of the present invention heats the carburetor as follows. Heating). That is, when the temperature of the engine cooling water rises with the operation of the engine (warm-up operation), the temperature of the heat transfer block into which the cooling water enters through the pipe also rises, but the block is brought into contact with the carburetor body. Therefore, heat is transmitted to the vaporizer main body through the contact portion, and the vaporizer can be heated.

In connection with the above operation, this heating device has the following features. First, it functions by a simple configuration of a combination of a heat transfer block and a tube. As a heat transfer block, a hole or recess for water flow is provided in a part of a lump of aluminum, copper, etc., and a contact area that contacts the vaporizer with a small area and mounting (fixing) to maintain the contact state It suffices if the pipe is provided with an inlet / outlet for the engine cooling water and a connection with the heat transfer block. In any case, no special costing materials, parts, processing, etc. are required, so that this heating device is easily configured at low cost. Further, the temperature of the engine cooling water rises without consuming power or the like, and circulates without using a special pump or the like, so that the operating cost does not increase.

Second, since the heat transfer block only makes contact with the vaporizer (heats the vaporizer by heat conduction through the contact portion), it is not necessary to modify the vaporizer itself. In order to mount the heat transfer block in such a state, generally, bolts and nuts used for assembling the carburetor body and frames near the carburetor can be used. Also, there is no need to modify the vaporizer body. If it is not possible to mount them using them, a new mounting part (such as a screw hole) will be provided in the vaporizer. Since it can be selected relatively freely, it can be easily provided for general-purpose vaporizers by partial simple additional processing.

[0013] The second point is that the total cost required for heating including the vaporizer body is lower than that of the first point, and that the existing vaporizer that is in use is less expensive. Also means that the heating device may have its own economic value as a so-called kit part (i.e. it can be sold separately).

A third feature is that necessary portions of the vaporizer can be appropriately heated without excessively. The reason is that a) the temperature of the engine cooling water, which is the heat source, is suppressed by the action of the radiator so that the temperature does not become extremely high, and b) the space between the cooling water and the heat transfer block or between the block and the carburetor. The amount of heat transfer between the blocks depends on the size (inside area) of the cooling water introduction section in the block, the area of the contact section between the block and the vaporizer (or the heat resistance of the sheet etc. sandwiched between the two if necessary). ), Etc., and c) the ability to locally heat the vaporizer at the contact point with the block. For this reason, of course, the above-described problems such as the vapor lock hardly occur.

In this heating device, the upstream end of the pipe is
Since the cooling water is connected to the bypass passage, the third feature described above is exhibited in a more preferable state. That is: 1) When the engine is cold, the passage to the radiator is closed by the thermostat and the engine cooling water flows to the bypass passage, so that the water temperature in the passage rises rapidly with the start of the engine. Therefore, this device using the cooling water in the bypass passage as a heat source can quickly heat the vaporizer, and effectively heats the vaporizer during the warm-up operation.

2) After the warm-up, the passage to the radiator is opened by the thermostat and the bypass passage is closed, so that high-temperature cooling water from the engine does not flow in the passage (cooling slightly lowered through the radiator). Only water enters). That is, since the water temperature in the passage is slightly lower than before the warm-up, the temperature brought to the carburetor by this device is appropriately reduced during the load operation, which is preferable.

[0017]

An embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view of a carburetor 1 to which a heating device 10 is attached, FIG. 2 is a front view of the carburetor 1, and FIG. 3 is a system showing a relationship between the carburetor 1 and the device 10 with an engine 6 and the like. FIG. As shown in FIG. 3, the carburetor 1 is connected to a general-purpose engine 6 via an intake pipe 6a, and supplies gas mixture to the engine 6 by vaporizing gasoline. The heating device 10 mainly includes an aluminum block (aluminum heat transfer block) 11 that comes into contact with the vaporizer 1 and a pipe 12 through which engine cooling water passes. Hereinafter, the configuration of the device 10 will be mainly described.

As shown in FIGS. 1 and 2, the aluminum block 11 has a concave portion 11a into which engine cooling water enters from a pipe 12, which will be described later, and a contact portion 11b having a shape conforming to the side shape of the carburetor 1 to be contacted. And form. The block 11 is attached to the mounting frame 13 by screws 14 (FIG. 2).
The block 11 is mounted so as to be in contact with the side surface of the vaporizer 1 by utilizing this. That is,
The vaporizer 1 is provided with a cover 2 as shown in the figure,
The mounting frame 13 is provided with mounting bolts 2a
b, the block 11 is mounted inside the mounting frame 13 such that the contact portion 11b contacts a predetermined side surface of the vaporizer 1. The side portion with which the block 11 is in contact is defined as an intake passage 1 a in the carburetor 1.
This is a portion close to a slow passage (not shown) leading to (FIG. 2).

As a pipe 12 for passing the engine cooling water through the aluminum block 11, a T-joint (T-shaped joint having three ports) 12c is inserted and connected to the recess 11a of the block 11, and the other T-joint 12c is connected to the other. The upstream and downstream rubber tubes 12a and 12b were connected to the two ports respectively. If the other end of each of the tubes 12a and 12b is connected to two appropriate places in the passage of the engine cooling water (it is necessary to have a slight pressure difference, and the high pressure side is the upstream side), Cooling water is T joint 12c
Through the recess 11a of the block 11. If the temperature of the cooling water rises with the operation of the engine,
Using the heat as a heat medium, the temperature of the block 11 also rises, and the carburetor 1 is heated via the contact portion 11b, thereby preventing icing in the intake passage.

The vaporizer heating apparatus 10 constructed as described above
In this embodiment, the end of the upstream rubber tube 12a (that is, the upstream end of the tube 12) is connected to the cooling water bypass passage 9 of the engine 6, as shown in FIG. The end of the downstream rubber tube 12b was connected immediately before (upstream) the water pump 8e. By doing so, a part of the cooling water flowing through the bypass passage 9 flows toward the pump 8e through the tubes 12a and 12b, and the recess 11 in the aluminum block 11 through the T joint 12c.
a (FIGS. 1 and 2).

As is 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.
The path between the forward and return flow paths is bypassed. 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 operation of the thermostat 8 b and the cooling operation of the radiator 7, the cooling water in the bypass passage 9 is heated to 70 to 80 ° C.
And then maintained at about 50-60 ° C., which is the water temperature downstream of the radiator 7.

Since the upstream end of the pipe 12 is connected to the bypass passage 9 having such a water temperature, the heating device 10 allows the carburetor 1 to effectively freeze ice in the intake passage immediately after the start of the engine 6. , And is not excessively heated even when the operation is continued.

Note that the connection between the block 11 and the pipe 12 is not limited to the branching connection using the T joint 12c or the like. For example, by attaching ordinary pipe joints to the inlet side and the outlet side of the block 11, and connecting the tubes 12a and 12b through them,
The engine cooling water may flow in the block 11 at substantially the same flow rate as in the tubes 12a and 12b. The block 11 is made of aluminum, and the tubes 12a and 12
It goes without saying that b is not limited to rubber. In addition, it goes without saying that embodiments other than the above-described embodiment are conceivable with respect to detailed matters such as the shape of the block 11 and the method of attachment. The object of use of the apparatus of the present invention is also a carburetor in various general-purpose engines including an automobile engine.

[0024]

The heating device for a vaporizer according to the present invention has the following effects.

1) The structure is simple, the manufacturing cost is low, and there is no consumption of electric power or the like, so that no operation cost is required. In addition, failures are unlikely to occur because the structure is simple.

2) Since there is no need to change the structure of the vaporizer body,
It is more advantageous in terms of cost, and can be easily applied to various types of vaporizers.

3) Necessary portions of the vaporizer can be appropriately heated so as not to be excessive.

Further, in connection with the above 3), 4) the freezing in the intake passage is effectively prevented by the rapid temperature rise, and the excessive temperature rise causing inconveniences such as fuel vapor lock and percolation is prevented. Not bring.

[Brief description of the drawings]

FIG. 1 shows a vaporizer heating apparatus 1 according to one embodiment of the present invention.
FIG. 2 is a plan view of the vaporizer 1 to which the reference numeral 0 is attached.

FIG. 2 is a front view of the vaporizer 1 of FIG.

FIG. 3 is a system diagram showing a relationship between a carburetor 1 and a heating device 10 with an engine 6 and the like.

[Explanation of symbols]

 Reference Signs List 1 carburetor 6 engine 7 radiator 9 bypass passage 10 heating device 11 aluminum block (heat transfer block) 12 tubes

Claims (1)

(57) [Claims] And 1. A heat transfer block mounted in contact with the carburetor body, a tube leading the engine cooling water in the block are combined, thermostat from the passage of the engine coolant leading to the radiator
Into the bypass passage of the cooling water
A heating device for a vaporizer, wherein an upstream end of the pipe is connected .