JPH0245033B2 - KIKAKI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a carburetor, and particularly to a sealed structure around a lead wire of a carburetor in which a fuel control electromagnetic valve is installed in a fuel chamber.

[Prior Art] Recently, attempts have been made to install a solenoid valve in the fuel chamber to correct and control the air in the low-speed system of the carburetor and the fuel in the main fuel system in a closed-loop manner based on the detection signal of an O ₂ sensor. It is being

An example of this is shown in FIGS. 1 and 2. FIG. 1 is a longitudinal sectional side view of the vaporizer of the above type, and FIG. 2 is an enlarged view of the main part of portion P in FIG. 1. In these figures, 1 is the intake pipe upper unit wall, 2 is the intake pipe intermediate unit wall, 3 is the choke valve, 4 is the bench lily, 5 is the fuel chamber, 6 is the solenoid valve, and 7 is the upper unit that supports the solenoid valve 6. An insulating plate attached to the inner surface of the wall 1, 8 a screw for fixing the insulating plate 7, 9 an excitation coil, 10 a coil lead wire, 11 an external terminal, and 12 a closely covered external lead wire 13. A cylindrical insulator made of rubber material, 14 the core wire of the lead wire 13, 15 the coil 9
It is a bobbin. Here, the cylindrical insulator 12 is
According to its common name, it is called a grommet.

As shown in detail in FIG. 2, the lead wire 13 whose upper end is connected to the external terminal 11 penetrates the vaporizer upper chamber wall 1 via the grommet 12 that tightly covers the outer surface of the insulation coating. There is. Further, the core wire 14 of the lead wire 13 is connected to the inner diameter portion 1 of the cylindrical metal fitting 18.
9 is also penetrated. The cylindrical metal fitting 18 has a collar 17 at one end, and a collar 23 at the other end which is formed by being pushed into the through hole 16 of the insulating plate 7 and then caulked. A collar 23 protruding into this fuel chamber 5
A solenoid valve outlet wire 10 is wound around the solenoid valve outlet wire 10 and fixed by soldering 20.

A diameter-enlarging step portion 21 is formed at the lower end of the through hole in the intake pipe upper wall 1. On the other hand, at the lower end of the grommet 12, a collar 22 is formed which is slightly thicker and slightly smaller in diameter than the depth of the enlarged diameter stepped portion 21. When the intake pipe upper wall 1 and the insulating plate 7 are tightened with the mounting screws 8 while the collar 22 is sandwiched between the cut surface of the enlarged diameter stepped portion 21 and the upper surface of the insulating plate 7, the solenoid valve 6 is supported. The installation of the insulating plate 7 to the upper wall 1 of the intake pipe is completed.

An example of this type of prior art is
−18543 etc.

[Problems to be Solved by the Invention] According to such a conventional structure, the cylindrical metal fitting 18
The portion where the core wire 14 protrudes beyond the brim 23 is completely closed by the continuous surface of the solder 20. Moreover, between the grommet 12 and the vessel wall 1 and the insulating plate 7,
In either case, the upper and lower surfaces of the collar portion 22 are pressed against each other, so that airtightness can be maintained reliably.

However, the outer periphery of the cylindrical metal fitting 18 to be press-fitted and the opposing surface of the through hole 16 of the insulating plate 7 are a combination of metal and insulating materials such as resin, and have different expansion coefficients, so they are heated to high temperatures during soldering. It was inevitable that small gaps would occur due to the influence of ambient temperature during use.

Therefore, there was a drawback that the fuel oozed into the atmosphere through the path of the arrow in FIG. 2 due to capillary action. Since the presence of flammable fuel at electrical connections is extremely dangerous, the above-mentioned conventional example involves a major practical problem.

An object of the present invention is to provide a carburetor having a structure in which leakage of fuel from around a lead wire for a solenoid valve is completely safe.

[Means for Solving the Problems] In order to achieve the above object, the present invention attaches an insulating plate to the inner surface of the upper intake pipe wall that covers the upper part of the fuel chamber, and uses this insulating plate to operate the fuel control solenoid valve. a lead wire for the excitation coil of the solenoid valve is drawn out from a hole penetrating the insulating plate and the upper intake pipe wall;
A collar is formed at the lower end of the cylindrical insulator that closely covers the lead wire inserted into the through hole of the device wall, and
In a vaporizer in which an enlarged diameter stepped portion is formed at the lower end of the through hole in the vessel wall, and the collar of the cylindrical insulator is sandwiched and tightened between the enlarged diameter stepped portion and the upper surface of the insulating plate, the stepped through hole of the insulating plate is Insert the stepped cylindrical fitting, and use an elastic member such as an O-ring to seal between the outer periphery of the stepped cylindrical fitting and the inner periphery of the stepped through hole of the insulating plate. The present invention proposes a vaporizer in which the exposed lower end portion of the core wire of the lead wire is soldered to the lower end surface of the stepped cylindrical fitting together with the internal output wire of the excitation coil without any gap.

[Function] In the present invention, an elastic member such as an O-ring is interposed between the outer periphery of the stepped cylindrical fitting and the inner periphery of the stepped through hole of the insulating plate, so that the outer periphery and the inner periphery are interposed. After that, as in the conventional case, the exposed lower end portion of the core wire of the lead wire is soldered to the lower end surface of the stepped cylindrical fitting together with the internal output wire of the excitation coil without any gap. Therefore, even if the dimension between the outer periphery of the stepped cylindrical fitting and the inner periphery of the stepped through hole of the insulating plate changes due to temperature changes, the intervening elastic member such as the O-ring will not move away from this part. Prevents fuel from seeping out.

[Embodiment] Next, an embodiment of the present invention will be described with reference to FIGS. 3 and 4.

The present embodiment shown in FIG. 3 is the same as the conventional example shown in FIG. 1 except for the portion P, so a description of that portion will be omitted. Furthermore, in FIG. 4, the structure and function above the insulating plate 7 are the same as in the conventional example.
The explanation will also be omitted.

A stepped cylindrical metal fitting 25 having a collar 17 at one end and having an elastic insulator such as an O-ring 26 attached to the outer periphery is inserted into the stepped through hole 24 of the insulating plate 7 .
Since the ball diameter of the O-ring 26 is made larger than the dimension including the change due to the coefficient of expansion of the gap formed between the outer circumference of the stepped cylindrical fitting 25 and the stepped through-hole 24, the O-ring 26 They are crushed in this gap and are pressed into contact. Therefore, the inner peripheral part of the stepped through hole 24 and the outer peripheral part of the stepped cylindrical fitting 25 are always maintained in an airtight state.

Furthermore, the stepped cylindrical metal fitting 25 is caulked below the insulating plate 7 to form a collar 23.

The core wire 14 of the lead wire 13 is inserted into the inner diameter part of the stepped cylindrical metal fitting 25, and the lead wire 10 of the coil 9 is wound around the end protruding from the collar 23, and soldered 20 is applied.

In this embodiment, the grommet 12 and the vessel wall 1 are
and the insulating plate 7, airtightness is maintained by pressure contact between the upper and lower surfaces of the collar 22. Further, the collar 23 of the stepped cylindrical fitting 25 and the protruding portion of the core wire 14 are closed by a continuous surface of the solder 20 that completely covers them. Finally, the stepped through hole 2 of the insulating plate 7
4 and the outer circumference of the stepped cylindrical fitting 25 are in pressure contact with the O-ring 26 as an elastic member of the present invention, so that the insulating plate 7 and the stepped cylindrical fitting 25 are not affected by heat. Even if a difference in expansion occurs, airtightness can be maintained reliably.

Therefore, all capillary passages for the fuel through the lead-out portion of the lead wire 13 are closed, and there is no fear of fuel seeping out as in the conventional example.

[Effects of the Invention] According to the present invention, the risk of fuel oozing out at the lead wire necessary for the excitation coil of the built-in solenoid valve is completely eliminated, and a highly safe carburetor can be obtained. .

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view showing an example of a conventional carburetor, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 4
The figure is a further enlarged view of the main part of FIG. 3. 1...Intake pipe upper unit wall, 2...Intake intermediate unit wall, 3
...Chiyoke valve, 4...Bench lily, 5...Fuel chamber, 6
... Solenoid valve, 7... Insulating plate, 8... Mounting screw, 9... Coil, 10... Lead wire, 11... External terminal, 12... Grommet, 13... Lead wire, 14... Core wire, 15...
Bobbin, 16...Through hole, 17...Brim, 18...Cylindrical metal fitting, 19...Inner diameter part, 20...Solder, 21...Diameter enlarged step part, 22...Brim, 23...Brim, 24...Stepped through hole, 25... Stepped cylindrical fitting, 26...O ring.

Claims (1)

[Scope of Claims] 1. An insulating plate is attached to the inner surface of the upper intake pipe wall that covers the upper part of the fuel chamber, a fuel control solenoid valve is supported by the insulating plate, and the insulating plate and the upper intake pipe wall are A lead wire for the excitation coil of the electromagnetic valve is drawn out from the penetrating hole, and a flange is formed at the lower end of the cylindrical insulator that closely covers the lead wire inserted through the container wall through hole. In a vaporizer in which an enlarged-diameter step is formed at the lower end of the hole, and the collar of the cylindrical insulator is clamped between the enlarged-diameter step and the upper surface of the insulating plate, the stepped through-hole of the insulating plate is A stepped cylindrical fitting is inserted between the outer periphery of the stepped cylindrical fitting and the inner periphery of the stepped through hole of the insulating plate, and elasticity is provided to seal between the outer periphery and the inner periphery. A vaporizer characterized in that the lower end exposed portion of the core wire of the lead wire is soldered to the lower end surface of the stepped cylindrical fitting together with the internal output wire of the excitation coil without any gap, with a member interposed therebetween.