JPS6278458A - Slidable throttle valve type carburetter - Google Patents

Abstract

PURPOSE:To improve closing properties of a slide valve during rapid reduction, by a method wherein a slidable throttle valve is situated in a throttle valve guide cylinder connected to a suction passage extended through a carburetter body, and formation of a guide groove in the end surface of the slidable throttle valve causes slide guide of a flat laminar auxiliary slide valve. CONSTITUTION:A slidable throttle valve guide cylinder 3 is open to a position above the intermediate part of a suction passage 2 extended through a carburetter body 1, and a slidable throttle valve 9 is movably disposed in the guide cylinder 3. In the throttle valve 9, a flat laminar auxiliary slide valve 10, vertically movable within a specified range, is placed in an auxiliary slide valve guide groove 9B formed in a side 9A on the engine side of the throttle valve. The auxiliary slide valve 10 is pressed downward for energization to a position, allowing the upper end of an oblong hole 10A of the valve 10 to make contact with a regulating part 9C, through the force of a return valve 11 placed in a contracted state between the upper part of the auxiliary slide valve and a flange part 9D of the slidable throttle valve 9. The slidable throttle valve 9 is so formed that a control part 13 of a throttle valve lever 12 is engaged with a motion groove 9E formed in the side wall of the slidable throttle valve and it can be opened and closed through the medium of the lever 12.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a carburetor that supplies and controls a mixture to an engine.
In particular, the present invention relates to a sliding throttle valve type carburetor in which a sliding valve is disposed within a throttle valve guide cylinder connected to an intake passage passing through the carburetor body.

[Conventional technology]

Conventionally, a commonly used sliding throttle valve type carburetor is provided with a throttle valve guide tube that opens upward and is connected to an intake passage that passes through the carburetor body. The sliding throttle valve is arranged so that it can be moved freely, and the driver pulls the accelerator wire to open this sliding throttle valve.
When the throttle valve is closed, the sliding throttle valve is generally closed by the spring force of the throttle valve return spring when the driver loosens the accelerator wire. Further, the structure of this sliding throttle valve is generally cylindrical or rectangular (rectangular).

[Problem that the invention seeks to solve]

In such a sliding throttle valve type carburetor, during rapid deceleration operation in which the engine is suddenly decelerated from a high-speed operating state, the sliding throttle valve attempts to move in the closing direction by loosening the accelerator wire, On the other hand, in this state, the engine still maintains high rotational speed due to inertia. Therefore, during the intake process of the engine, and at the low opening of the throttle valve, a sudden negative pressure in the intake duct acts on the bottom of the sliding throttle valve on the engine side, causing the sliding throttle valve to return. It may lack smoothness. For this reason, it is considered to increase the return force by strengthening the throttle valve return spring used to return the sliding throttle valve, but this increases the opening operation force of the accelerator wire, which is not preferable in terms of operability. This phenomenon occurs in multiple sliding throttle valve type carburetors that use multiple single carburetors, and the sliding throttle valve is rectangular in shape and does not come into contact with the inner cylinder of the sliding valve. If the airway is flat and the diameter of the intake tract is large, it will be noticeable.

[Means for solving problems]

The sliding throttle valve type carburetor of the present invention was developed in view of the above-mentioned problems, and its purpose is to improve the blocking performance of the sliding valve during sudden engine deceleration. To achieve this purpose, an auxiliary sliding valve guide groove was bored on the sliding end surface of the sliding throttle valve on the engine side.

A flat plate-shaped auxiliary sliding valve is placed in the auxiliary sliding valve chamber groove, one side of which slides on the throttle valve guide cylinder on the engine side, and the other side of which slides within the auxiliary sliding valve chamber groove. The sliding valve is allowed to slide only within a certain range in the sliding valve guide groove, and is pressed in the closing direction by an auxiliary sliding return spring that is weaker than the throttle valve return spring.

[Effect]

During sudden engine deceleration and slow rotation, when the sliding throttle valve drops to near the fitting opening, a large negative pressure in the intake passage acts on the side of the sliding throttle - Jf on the engine side, causing the sliding throttle rib to slide. At this time, most of the suction force is received by the auxiliary sliding valve.On the other hand, the sliding throttle valve is closed by the force of the throttle valve return spring. However, by making the spring force of the throttle valve return spring greater than the spring force of the auxiliary spring, the intake passage is blocked with the auxiliary throttle valve left in place, and the engine speed decreases due to this blockage. When the negative pressure in the intake passage decreases, the auxiliary throttle valve follows the sliding throttle valve due to the spring force of the auxiliary spring, and a desired throttle valve opening can be obtained.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sliding throttle valve type carburetor according to the present invention will be described below with reference to the drawings. 1 is a carburetor in which an intake passage 2 passes through the carburetor, and a sliding throttle valve guide cylinder 3 opens above the middle part of the intake passage 2. A float base body 4 is disposed at the lower part of the carburetor body l, and a float chamber 5 is formed by the lower concave portion of the carburetor body l and the float base body 4. A float 9 is disposed within the float chamber 5, and a constant liquid level is always formed within the float chamber 5 by operating a float valve that opens and closes a valve seat disposed within the fuel passageway. A needle jet 6 opens in the intake passage 2, and a mixing nozzle 7 and a main jet 8 are connected to this needle jet 216, and the mixing nozzle 7 and the main jet 8 are immersed below the constant liquid level in the float chamber 5. . A sliding throttle valve 9 is movably disposed within the sliding throttle valve guide cylinder 3. This sliding throttle valve 9 will be explained in detail with reference to Figure ff12. An auxiliary sliding valve guide groove 9B is bored in the side surface 9A on the engine side of the sliding throttle valve 9, and an auxiliary sliding valve that can move within a certain range along the opening/closing direction of the sliding throttle valve 9 is provided within the groove in the auxiliary sliding valve chamber. A sliding valve lO is arranged.

The reason why this auxiliary sliding valve lO can move within a certain range is that the auxiliary sliding valve lO
This can be carried out by inserting a long hole 10A drilled into the auxiliary throttle valve 10, and is usually compressed between the upper part of the auxiliary throttle valve 10 and the flange 9D of the sliding throttle valve 9, and the auxiliary sliding valve return It is in a pressed state by the spring 11, and is held in a state in which the second part of the long hole 10A is in contact with the regulating part 9B. 9E is an operating groove provided on the side wall of the sliding throttle valve 9;
The throttle valve E is fitted with the control element 13 provided at 8-12. This throttle valve lever 12 is operated by the driver.

Reference numeral 14 designates a throttle rib C return spring whose spring force is set to be sufficiently stronger than that of the auxiliary sliding valve return spring 11.

The auxiliary sliding valve lO is fitted into the auxiliary sliding valve guide groove 9B of the sliding throttle valve 9, and is then placed in the throttle valve guide cylinder 3.

Next, its effect will be explained.

At the low opening of the sliding throttle valve 9, the sliding throttle valve 9 is pressed downward by the throttle rib lever 12, so the sliding throttle jf 9 is in the downward position, and at this time the auxiliary sliding valve lO is located in the auxiliary sliding valve guide groove 9B and is located in the elongated hole 10A.
The upper part of the auxiliary sliding valve return spring 1 is attached to the regulating part 9C.
1, the opening of the sliding throttle valve 9 is regulated.

Next, when the throttle valve lever 12 is rotated clockwise in the figure in order to increase the rotation of the engine, this rotational force is applied to the operating groove 9E via the controller 13, and the sliding throttle valve 9 moves upward. Moving. At this time, the auxiliary sliding valve 10 moves upward synchronously with the sliding throttle valve 9 at the regulating portion 9C, thereby increasing the amount of air to the engine and increasing the rotation of the engine.

Next, a state in which the engine is rapidly decelerated from a state in which it is rotating at high speed will be explained. When the operating force pulling the throttle valve lever 12 is released, the throttle valve return spring 1
When the throttle valve C lever 12 rotates counterclockwise due to the spring force of step 4, this rotational force is transmitted through the control element 13 to a dynamic force fl' jζ
The sliding throttle rib 1'9 attached to 9E moves to the lower blade.

1′? ? When the dynamic throttle valve 9 moves downward and descends to the vicinity of the minimum opening, the rotational speed of one engine is still maintained at a high rotational speed due to inertia, so the auxiliary sliding valve 10
High intake tract negative pressure acts on the side of the engine. At this time, the driver desires to return the sliding throttle jr to an idling state with a lower opening, so a downward pressing force of 4-j is applied to the sliding throttle J9 via the throttle valve lever 12. In this state, the auxiliary sliding valve lO receives high intake tract negative pressure from the engine, and a lateral suction force acts on it, providing resistance to downward movement. However, in the present invention, the auxiliary return spring II is defeated by the force of the sliding throttle valve return spring 14 while the auxiliary sliding valve 10 remains in that position. 9 is capable of immediately descending to the low idling opening position even in a sudden deceleration state while compressing the auxiliary return spring 11.
Ru.

When the rotation of the engine decreases, the lateral suction force on the auxiliary sliding valve 10 decreases, so the auxiliary sliding valve 10 moves within the elongated hole 10A by the spring force of the auxiliary sliding valve return spring 11. The sliding throttle valve 9 can completely control the minimum idling air amount and return to the original position.

〔Effect of the invention〕

According to the sliding throttle valve type carburetor that will be released in 2011, the driver can reliably return the sliding throttle valve to its minimum idling opening, and the throttle valve lever and sliding throttle valve (auxiliary sliding (excluding valves) is a device that can be moved completely in one piece, which eliminates the need for special operations during deceleration operation, such as increasing the returning force of a sliding throttle valve midway through, and can greatly improve operability. It is.

In particular, even in a multiple carburetor using a plurality of sliding throttle valve type carburetors, the sliding throttle valve can be reliably returned, so that the reversible safety-L is preferable.

In addition, the spring force of the sliding throttle valve return spring allows the sliding throttle valve to return reliably without applying excessive operating force between the throttle valve lever and the sliding throttle valve, thereby significantly improving the durability of these systems. It is something that can be done. Furthermore, by using an auxiliary sliding valve during deceleration operation to temporarily delay the blockage of the intake tract, it is possible to suppress the rise in negative pressure in the intake tract on the engine side than by the sliding throttle valve, thereby reducing the leanness of the air-fuel mixture. It is possible to prevent irregular combustion in the engine such as afterfire. In this embodiment, a rectangular sliding throttle valve has been described, but the present invention is not limited to this shape.

[Brief explanation of drawings]

The figure shows an embodiment of a sliding throttle valve type carburetor according to the present invention. Figure 1 is a longitudinal sectional view, Figure 2 is a sliding throttle valve,
It is a perspective view of an auxiliary throttle valve. 9...Sliding throttle valve. 9B・φ・Auxiliary sliding valve guide groove, 9C...Restriction part, 10...Auxiliary sliding valve, 10A・
・Fist guide hole, II...φ Auxiliary sliding valve return spring μ29 / 9

Claims (1)

[Claims] In a sliding throttle valve type carburetor, in which a throttle valve chamber cylinder is provided adjacent to the intake passage passing through the carburetor body, and a sliding throttle valve is disposed within the throttle valve guide cylinder, the sliding throttle valve is connected to the engine. An auxiliary sliding valve chamber groove is bored on the side sliding end surface, and one side slides the throttle valve chamber cylinder on the engine side into the auxiliary sliding valve chamber groove, and the other side slides into the auxiliary sliding valve chamber groove. A flat plate-shaped auxiliary sliding valve that can slide inside the
A sliding throttle valve type carburetor that is allowed to slide within a certain range in an auxiliary sliding valve guide groove and is pressed in the closing direction by an auxiliary sliding valve return spring that is weaker than the throttle valve return spring.