JP2536531Y2 - Sliding throttle valve carburetor - 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 controlling the supply of air-fuel mixture to an internal combustion engine, and more particularly to a carburetor having a sliding throttle valve.

[0002]

2. Description of the Related Art In a sliding throttle valve type carburetor, a sliding throttle valve is provided so as to be slidable in a direction perpendicular to an intake passage and opens and closes the intake passage. Conventionally, the following configuration has been proposed in, for example, Japanese Patent Application Laid-Open No. 62-199953 in order to prevent the sliding throttle valve from becoming difficult to slide due to dust clogging or the like.

That is, in this sliding throttle valve type carburetor, a rotating mechanism such as a bearing or a roller is mounted on the sliding throttle valve, so that the sliding of the sliding throttle valve is smoothened. In order to ensure airtightness with the carburetor body, the sliding throttle valve is composed of two pieces, a main throttle valve and a sub throttle valve. The sub-throttle valve is brought closer to the carburetor body by the negative pressure of the intake pipe, thereby maintaining the airtightness inside and outside the intake passage. Further, it has been attempted to apply a suction negative pressure to the back surface of the sub-throttle valve to reduce the force of sucking the sub-throttle valve toward the carburetor body when the engine is decelerated or the like, thereby suppressing the sliding resistance. .

[0004]

However, according to the above structure, the main throttle valve shows smooth sliding due to the rotation mechanism, but the sub throttle valve is strongly brought to the carburetor body by the negative pressure of the intake pipe, and the speed is reduced. When the intake pipe negative pressure is large, as in the case of time, airtightness is good but a certain amount of throttle valve return force is required. Further, the configuration becomes complicated because the sliding throttle valve is composed of two members. The present invention provides a sliding throttle valve type carburetor in which the sliding throttle valve slides smoothly with respect to the carburetor body and maintains a sufficient airtightness between the sliding throttle valve and the carburetor body. It is intended to be.

[0005]

SUMMARY OF THE INVENTION A sliding throttle valve carburetor according to the present invention is provided with a carburetor main body having an intake passage formed therein, and slidably provided in the carburetor main body to open and close the intake passage. A sliding throttle valve which is capable of being fixed to a surface of the sliding throttle valve which receives an intake pipe negative pressure, and an outer edge of the sliding throttle valve overlaps an outer peripheral edge of the intake passage when the sliding throttle valve is closed. Close to the vaporizer main body, and the parts other than the outer edge
A ring-shaped seal member exposed in the intake passage .

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 is a diagram showing a first embodiment of the present invention. In this figure, the carburetor bodies 11, 12 which are integrally connected,
The intake passages 13 and 14 are formed in the same axial direction. The intake passage 13 located on the left side of the figure is an upstream passage communicating with the atmosphere, and the intake passage 14 located on the right side is a downstream passage communicating with the engine. That is, the intake pipe negative pressure generated by the engine acts on the intake passage 14 side. Intake passage 13,
A plate-shaped sliding throttle valve 17 is provided in a space 16 extending in a direction perpendicular to the direction 14 (a direction perpendicular to the paper surface). The sliding throttle valve 17 slides in the space 16 in conjunction with an accelerator mechanism (not shown) to open and close the intake passages 13 and 14.

Two parallel straight grooves 18 extending in a direction perpendicular to the plane of FIG. 1 are formed on the intake passage 14 side of the sliding throttle valve 17, that is, on the surface that receives the negative pressure of the intake pipe. A band-shaped shim 19 is provided in each of the straight grooves 18. Opposite to these linear grooves 18, two linear grooves 21 are formed on the end surface of the vaporizer main body 12, and each linear groove 21 is formed.
Are provided with a plurality of bearings 22, respectively.

A ring-shaped groove 23 is formed on the surface of the sliding throttle valve 17 on the side of the intake passage 14 and inside the two linear grooves 18, and a ring-shaped seal is formed in the ring-shaped groove 23. The member 24 is fitted. That is, the ring-shaped seal member 24 moves integrally with the sliding throttle valve 17 in the sliding direction of the sliding throttle valve 17 (direction perpendicular to the paper surface).
In the axial direction of the intake passages 13 and 14, the sliding throttle valve 1
7 can be displaced. Therefore, when the sliding throttle valve 17 closes the intake passages 13 and 14, the ring-shaped seal member 24 overlaps with the outer peripheral edges of the intake passages 13 and 14 and reduces the intake pipe negative pressure generated in the intake passage 14. It is brought into close contact with the end face of the vaporizer main body 12.

The ring-shaped seal member 24 is formed from a material having excellent operability and durability. As a material satisfying these conditions, a resin (for example, fluorine-based), or a fluorine-coated ceramic or metal is suitable.

FIG. 2 is an exploded view of the sliding throttle valve 17 and the ring-shaped seal member 24. A disk-shaped portion 25 is formed on the inner peripheral side of the ring-shaped groove 23 formed on the surface of the sliding throttle valve 17. The outer shape of the ring-shaped groove 23 is not a perfect circle,
A linear portion 23a is formed on the bottom surface 17a of the sliding throttle valve 17. The ring-shaped seal member 24 has substantially the same shape as the ring-shaped groove 23, and the bottom surface 17 a of the sliding throttle valve 17 is formed.
And a straight line portion 24a corresponding to.

FIG. 3 shows a portion of the ring-shaped sealing member 24 facing the intake passage 14 and a disk-shaped portion 25 of the sliding throttle valve 17. In this figure, a donut-shaped portion A indicated by hatching is a portion facing the intake passage 14.
That is, the outer diameter of the donut-shaped portion A is
Therefore, the donut-shaped portion A is a pressure receiving surface on which the negative pressure of the intake pipe acts on the ring-shaped seal member 24. The disc-shaped portion 25 is a pressure receiving surface on which the suction pipe negative pressure acts on the sliding throttle valve 17.

The vaporizer main body 12 of the ring-shaped seal member 24
Of the ring-shaped sealing member 2
The suction force acting on the intake passage 14 toward the intake passage 14 is adjusted by setting the pressure receiving area of the ring-shaped seal member 24 (the area of the donut-shaped portion A) to an appropriate size. As a result, a desired sealing property can be obtained with a minimum necessary suction force.

The sliding throttle valve 17 receives the negative pressure of the intake pipe via the disk-shaped portion 25 and is sucked toward the intake passage 14, but is received by the end face of the carburetor body 12 because it is supported by the bearing 22. Sliding resistance is small. Therefore, the opening and closing operation of the sliding throttle valve 17 is very smooth.

As described above, in this embodiment, the opening / closing operation of the sliding throttle valve 17 is not substantially affected by the negative pressure of the intake pipe received by the sliding throttle valve 17, and the sliding throttle by the negative pressure of the suction pipe is used. The sealing performance of the valve 17 is determined by the ring-shaped sealing member 24.
Obtained by And this ring-shaped sealing member 2
Since the pressure receiving area 4 is smaller than the cross-sectional area of the bore of the intake pipe 14, excessive suction force does not act on the ring-shaped seal member 24 even when the intake pipe negative pressure is large such as during deceleration. In addition, the sliding throttle valve 17 can be opened with a small force while maintaining appropriate airtightness.

In this embodiment, the sliding throttle valve 17
Is formed by one member, not by two members (main throttle valve and sub-throttle valve) as in the prior art, and the hermeticity is a ring-shaped seal fixed to the sliding throttle valve 17. It is obtained by the member 24. Therefore, the configuration of the sliding throttle valve 17 is simplified, and the cost of the carburetor can be reduced.

Further, in this embodiment, since the ring-shaped seal member 24 is fixed to the sliding throttle valve 17, the ring-shaped sealing member 24 is exposed in the intake passages 13 and 14 when the sliding throttle valve 17 is opened. Therefore, there is no possibility that fuel enters the ring-shaped groove 18.

FIG. 4 shows a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and only different parts will be described. A spring hole 31 is formed in the bottom of the ring-shaped groove 23 formed in the sliding throttle valve 17, and a spring 32 is disposed in the spring hole 31. The spring 32 urges the ring-shaped seal member 24 toward the carburetor body 12. Other configurations are the same as those of the first embodiment.

According to the configuration of the second embodiment, the same effects as those of the first embodiment can be obtained, but the following effects can also be obtained. That is, the sealing performance of the ring-shaped seal member 24 is obtained not only by the suction pipe negative pressure but also by the elastic force of the spring 32. Therefore, the pressure-receiving area of the ring-shaped seal member 24 can be made smaller than that of the first embodiment. For example, the pressure-receiving area can be reduced in the valve-closed state by making the inner diameter of the ring-shaped seal member 24 equal to the bore diameter of the intake passage 14. It is also possible to set it to 0.

The spring 32 may be a coil spring,
An appropriate elastic member can be applied.

[0020]

As described above, according to the present invention, the sliding throttle valve slides smoothly with respect to the carburetor body, and a sufficient airtightness between the sliding throttle valve and the carburetor body is maintained. You.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a sliding throttle valve type carburetor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a sliding throttle valve and a ring-shaped seal member.

FIG. 3 is a view showing a portion of the ring-shaped seal member facing the intake passage and a disk-shaped portion of the sliding throttle valve.

FIG. 4 is a sectional view showing a sliding throttle valve type carburetor according to a second embodiment of the present invention.

[Explanation of symbols]

 11, 12 Vaporizer body 13, 14 Intake passage 17 Sliding throttle valve 23 Ring-shaped groove 24 Ring-shaped seal member

Claims (2)

(57) [Scope of request for utility model registration] 1. A carburetor body having an intake passage formed therein, a sliding throttle valve slidably provided in the carburetor body and capable of opening and closing the intake passage, and an intake pipe of the sliding throttle valve. is fixed to the surface on the side which receives the negative pressure, the outer edge portion in the closed state of the sliding throttle valve is polymerized to the outer peripheral edge portion of the intake passage adheres to the carburetor body, a portion other than the outer edge the
A sliding throttle valve type carburetor comprising: a ring-shaped seal member exposed in an intake passage . 2. The sliding throttle valve carburetor according to claim 1, wherein said ring-shaped sealing member is fitted in a ring-shaped groove formed on a surface of said sliding throttle valve.