JP3951358B2 - Sliding throttle valve type vaporizer - Google Patents

Description

[0001]
[Industrial application fields]
TECHNICAL FIELD The present invention relates to a carburetor for adjusting the amount and concentration of an air-fuel mixture supplied to an engine, of which a sliding throttle valve type whose opening and closing is controlled by a sliding throttle valve that is movably disposed in a throttle valve guide cylinder. It relates to a vaporizer.
[0002]
[Prior art]
A conventional sliding throttle valve type carburetor is shown in FIG.
The sliding throttle valve type carburetor is provided with a stop screw S for adjusting the minimum idling opening degree of the sliding throttle valve 20 and a throttle guide G for suppressing the rotation of the sliding throttle valve 20 in the throttle valve guide cylinder. .
Referring to FIG. 5, reference numeral 1 denotes a carburetor body in which an intake passage 2 penetrates the inside and a throttle valve guide tube 3 is continuously provided upward from the intake passage 2. A floating chamber 5 is formed along with the floating chamber main body 4, and a constant fuel level is formed in the floating chamber by the cooperative action of a valve seat, a float valve, and a float (not shown).
The stop screw S is on one side A of the longitudinal axis XX of the intake passage 2 and is screwed to the carburetor body 1 and orthogonal to the longitudinal axis XX of the intake passage 2. Be placed.
The tip of the stop screw S protrudes into the throttle valve guide tube 3 and is disposed in contact with the inclined surface 20A of the sliding throttle valve 20.
Therefore, by screwing the stop screw S, the minimum idling opening degree of the sliding throttle valve 20 is adjusted by moving the tip of the stop screw S forward and backward.
According to the stop screw S entering the throttle valve guide cylinder 3, the sliding throttle valve 20 is moved upward through the inclined surface 20A to increase the idling opening degree, while the stop screw S is retracted. The sliding throttle valve 20 moves downward through the inclined surface 20A to reduce the idling opening.
[0003]
The throttle guide G is located on the other side B of the longitudinal axis XX of the intake passage 2 and is fixed to the carburetor body 1 and is disposed orthogonal to the longitudinal axis XX of the intake passage 2. The
The front end of the throttle guide G protrudes into the throttle valve guide tube 3 and is inserted into a throttle guide groove 20B that is continuously drilled along the opening / closing movement direction of the sliding throttle valve 20.
Therefore, the sliding throttle valve 20 is prevented from rotating in the throttle valve guide cylinder 3.
[0004]
As described above, the throttle stop screw S and the throttle guide G sandwich the longitudinal axis XX of the intake passage 2 and are disposed opposite to each other on the line YY orthogonal to the longitudinal axis XX. The
The longitudinal axis XX and the orthogonal line YY are well shown in FIG.
[0005]
[Problems to be solved by the invention]
FIG. 6 shows a state in which the center of the sliding throttle valve 20 is completely aligned with the center of the sliding throttle valve guide tube 3.
In such a state, a gap E is formed over the entire circumference between the outer periphery of the sliding throttle valve 20 and the inner periphery of the throttle valve guide tube 3.
This gap E is necessary for the sliding throttle valve 20 to move in the throttle valve guide tube 3.
On the other hand, the throttle guide G is disposed in the center of the throttle guide groove 20B, and a gap F is formed between the outer periphery of the throttle guide G and the inner periphery of the throttle guide groove 20B. This gap F is necessary because, when the sliding throttle valve 20 moves in the closing direction in which a large negative pressure is generated in the intake passage 2A on the engine side, the sliding throttle valve 20 is on the engine side (left side in FIG. 6). 6 and moves to the left in FIG. 6 corresponding to the gap E.
This is because the right side surface G1 of the throttle guide G and the right side surface 20C of the throttle guide groove 20B are not brought into contact with each other during the suction movement of the sliding throttle valve 20 toward the engine.
FIG. 7 shows a state where the sliding throttle valve 20 is sucked and moved to the engine side.
[0006]
According to the above, a relatively large gap is formed between the outer periphery of the throttle guide G and the throttle guide groove 20B. On the other hand, the stop screw S is provided on the inclined surface 20A of the sliding throttle valve 20. When the tip abuts, the sliding throttle valve 20 receives a rotational pressing force in the clockwise direction J in FIG. 4, and the sliding throttle valve 20 may tilt.
This is because there is no element that regulates the rotation of the sliding throttle valve 20 in the clockwise direction.
[0007]
When the sliding throttle valve 20 is inclined as described above, the relative position with respect to the bypass hole (shown in FIG. 1 described later) opened facing the lower end surface of the sliding throttle valve 20 and the sliding The annular gap formed by the jet needle 21 attached to the throttle valve 20 and the needle jet changes, and according to this, the flow rate of fuel sucked into the intake passage 2 from these bypass holes and annular gap varies. This is not preferable for accurate fuel control and fuel control with excellent reproducibility.
[0008]
The sliding throttle valve type carburetor according to the present invention is made in view of the above problems, and suppresses the inclination of the sliding throttle valve when the sliding throttle valve comes into contact with the stop screw, thereby bypassing the bypass hole. And a sliding throttle type carburetor capable of accurately controlling the fuel sucked into the intake passage from the annular gap formed by the jet needle and the needle jet and controlling the fuel with excellent reproducibility. With the goal.
[0009]
[Means for solving the problems]
In order to achieve the above object, the sliding throttle valve type carburetor according to the present invention has a sliding throttle valve for opening and closing the intake passage in a throttle valve guide cylinder connected to the intake passage penetrating the carburetor body. Arranged,
The inclined surface formed at the lower end of the sliding throttle valve is in contact with a stop screw screwed to the carburetor body to adjust the minimum idling opening degree of the sliding throttle valve ,
Further, the sliding throttle valve has a throttle guide fixed to the carburetor body inserted in a throttle guide groove continuously drilled along the opening / closing movement direction of the sliding throttle valve. In the sliding throttle valve type carburetor where rotation is suppressed,
The stop screw is disposed in contact with the inclined surface of the sliding throttle valve perpendicular to the longitudinal axis of the intake passage,
Place the throttle guide on the longitudinal axis of the intake passage,
The stop screw and the throttle guide are arranged orthogonally on the transverse projection plane of the sliding throttle valve.
[0010]
Thus, even if the stop screw comes into contact with the sliding throttle valve and a rotational pressing force acts on the sliding throttle valve, the rotational pressing force is suppressed by the throttle guide and the throttle guide groove. Thus, accurate fuel control and fuel control with excellent reproducibility can be achieved.
[0011]
【Example】
Hereinafter, an embodiment of the sliding throttle valve type carburetor according to the present invention will be described.
FIG. 1 is a longitudinal sectional view taken along the longitudinal axis XX of the intake passage 2.
FIG. 2 is a longitudinal sectional view taken along the line PP in FIG.
In addition, about the same structure part as FIG. 5, the description is abbreviate | omitted using the same code | symbol.
S is a stop screw, which is disposed on one side A of the longitudinal axis XX of the intake passage 2. (Well shown in Figure 2)
The stop screw S is screwed to the carburetor body 1 and is disposed perpendicular to the longitudinal axis XX of the intake passage 2, and its tip protrudes into the throttle valve guide tube 3. Is disposed in contact with the inclined surface 7A of the sliding throttle valve 7.
[0012]
G is a throttle guide that is fixed to the carburetor main body 1 and whose tip protrudes into the throttle valve guide cylinder 3, and is disposed on the longitudinal axis XX of the intake passage 2.
The tip of the throttle guide G is inserted and disposed in a throttle guide groove 7B that is continuously drilled along the opening / closing movement direction of the sliding throttle valve 7.
[0013]
In summary, the stop screw S is disposed perpendicular to the longitudinal axis XX of the intake passage 2, and the throttle guide G is disposed on the longitudinal axis XX of the intake passage 2. The stop screw S and the throttle guide G are arranged orthogonally on the transverse projection plane of the sliding throttle valve 7.
This is best shown in FIG.
[0014]
The gap Fa (corresponding to the gap F of the conventional example) between the throttle guide groove 7B and the throttle guide G in the present invention is extremely small.
The reason is described below.
FIG. 3 shows a state in which the center of the sliding throttle valve 7 is completely aligned with the center of the sliding throttle valve guide tube 3.
In such a state, a gap E is formed over the entire circumference between the outer periphery of the sliding throttle valve 7 and the inner periphery of the throttle valve guide tube 3.
This gap E is necessary for the sliding throttle valve 7 to move in the throttle valve guide tube 3.
On the other hand, the throttle guide G is disposed at the center of the throttle guide groove 7B, and an extremely small gap Fa is formed between the outer periphery of the throttle guide G and the inner periphery of the throttle guide groove 7B.
When the sliding throttle valve 7 is moved in the closing direction in which a large negative pressure is generated in the engine side intake passage 2A, the sliding throttle valve 7 is sucked to the engine side (left side in FIG. 3). It moves to the left corresponding to the gap E.
[0015]
What should be noted here is that the throttle guide groove 7B is formed along the longitudinal axis XX of the intake passage 2.
According to the above, when the sliding throttle valve 7 is moved in the closing direction as described above, when the sliding throttle valve 7 is sucked to the engine side and moves leftward in FIG. The gap Fa formed between the inner periphery of the groove 7B does not impose any restrictions on the leftward movement stroke of the sliding throttle valve 7.
That is, it is only necessary that there is a very small gap Fa and the sliding throttle valve 7 can move to the engine side.
[0016]
Here, according to the present invention, when the sliding throttle valve 7 moves in the closing direction and the tip of the stop screw S comes into contact with the inclined surface 7A of the sliding throttle valve 7, the sliding throttle valve 7 is shown in FIG. A rotational pressing force in the clockwise direction J is received.
According to the above, the sliding throttle valve 7 is intended to rotate in the clockwise direction J, but this rotation is suppressed by the inner peripheral surface 7B of the throttle guide groove 7B coming into contact with the outer peripheral surface of the throttle guide G. Thus, the sliding throttle valve 7 is not tilted and is arranged in the throttle valve guide cylinder 3 in the upright state.
This is because the stop screw S and the throttle guide G are arranged orthogonally on the transverse projection plane of the sliding throttle valve 7.
Further, as described above, when the gap Fa between the throttle guide groove 7B and the throttle guide G is set to a very small gap, the inclination of the sliding throttle valve 7 can be suppressed to an extremely small range.
[0017]
Thus, the inclination of the sliding throttle valve 7 when the sliding throttle valve 7 comes into contact with the stop screw S is suppressed, and the sliding throttle valve 7 can be arranged in the upright state in the throttle valve guide cylinder 3. According to this, the relative positional relationship with the bypass hole 8 formed corresponding to the sliding throttle valve 7 and the jet needle 21 and needle jet 22 attached to the sliding throttle valve 7 are formed. It is possible to accurately control the annular gap, and thus to perform accurate fuel control.
Further, when the sliding throttle valve 7 repeatedly opens and closes, the sliding throttle valve 7 is always restrained from tilting and can always be returned to the upright state, whereby the bypass hole 8 and the annular gap Variation of the fuel sucked out into the intake passage 2 is suppressed.
[0018]
【The invention's effect】
As described above, according to the sliding throttle valve type carburetor according to the present invention, the stop screw is disposed in contact with the sliding throttle valve perpendicular to the longitudinal axis of the intake passage,
Place the throttle guide on the longitudinal axis of the intake passage,
Since the stop screw and the throttle guide are arranged orthogonally on the transverse projection plane of the sliding throttle valve, the sliding throttle valve can always be kept upright in the throttle valve guide cylinder. And the annular gap formed by the jet needle and the needle jet can be accurately maintained, and accurate fuel control and fuel control with excellent reproducibility can be performed.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a sliding throttle valve type vaporizer according to the present invention.
FIG. 2 is a longitudinal sectional view taken along the line PP in FIG.
3 is an enlarged cross-sectional view of the sliding throttle valve in FIG. 1, showing a state in which the sliding throttle valve is disposed at the center of the throttle valve guide tube.
4 is an enlarged cross-sectional view showing a state in which the sliding throttle valve in FIG. 3 is sucked to the engine side.
FIG. 5 is a longitudinal sectional view showing a conventional sliding throttle valve type vaporizer.
6 is an enlarged cross-sectional view of the sliding throttle valve in FIG. 5, showing a state in which the sliding throttle valve is disposed at the center of the throttle valve guide tube.
7 is an enlarged cross-sectional view showing a state in which the sliding throttle valve in FIG. 6 is sucked to the engine side.
[Explanation of symbols]
2 Intake passage 3 Throttle valve guide cylinder 7 Sliding throttle valve S Stop screw G Throttle guide XX Longitudinal axis of intake passage

Claims (2)

A sliding throttle valve that opens and closes the intake passage is arranged in a throttle valve guide cylinder that is connected to the intake passage that penetrates the carburetor body.
The sliding throttle valve is in contact with a stop screw screwed to the carburetor body, and the minimum idling opening degree is adjusted.
Further, the sliding throttle valve has a throttle guide fixed to the carburetor body inserted in a throttle guide groove continuously drilled along the opening / closing movement direction of the sliding throttle valve. In the sliding throttle valve type carburetor where rotation is suppressed,
The stop screw S is disposed in contact with the sliding throttle valve 7 perpendicularly to the longitudinal axis XX of the intake passage 2;
The throttle guide G is disposed on the longitudinal axis XX of the intake passage 2;
A sliding throttle valve type carburetor characterized in that a stop screw S and a throttle guide G are arranged orthogonally in a cross-sectional projection view of the sliding throttle valve 7. A sliding throttle valve that opens and closes the intake passage is arranged in a throttle valve guide cylinder that is connected to the intake passage that penetrates the carburetor body.
The inclined surface formed at the lower end of the sliding throttle valve is in contact with a stop screw screwed to the carburetor body to adjust the minimum idling opening degree of the sliding throttle valve ,
Further, the sliding throttle valve has a throttle guide fixed to the carburetor body inserted in a throttle guide groove continuously drilled along the opening / closing movement direction of the sliding throttle valve. In the sliding throttle valve type carburetor where rotation is suppressed,
The stop screw S is disposed in contact with the inclined surface 7A of the sliding throttle valve 7 perpendicular to the longitudinal axis XX of the intake passage 2;
The throttle guide G is disposed on the longitudinal axis XX of the intake passage 2;
A sliding throttle valve type vaporizer characterized in that a stop screw S and a throttle guide G are arranged orthogonally on the transverse projection plane of the sliding throttle valve 7.

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