JP2602659Y2 - Cap for restricting opening of needle valve for vaporizer fuel adjustment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap for regulating the opening of a needle valve for manually adjusting the fuel flow rate of a carburetor for supplying fuel to a gasoline engine.

[0002]

2. Description of the Related Art Generally, a carburetor for supplying fuel to a gasoline engine has a low-speed fuel passage for supplying fuel in a low-speed operation region with no load or a low load and a main fuel passage for supplying fuel in other operation regions. Many of them are equipped with a manual needle valve that adjusts the effective area of the low-speed fuel passage to reduce the CO concentration of the exhaust during no-load operation and adjusts the low-speed fuel flow rate to meet the emission regulations. ing.

On the other hand, in a carburetor for supplying fuel to a general-purpose gasoline engine, the flow rate of the main fuel flowing through the main fuel passage is very small, and the deviation rate of the fuel flow rate due to the dimensional error and quality difference of each part is large. Due to the individual performance differences, the CO concentration of the exhaust gas easily comes into contact with the emission regulations, and it has been proposed to install a manual needle valve in the main fuel passage to adjust the effective area of the exhaust gas. 4
7-21848).

[0004] These needle valves are operated by a maker of a carburetor or an engine or a maker of a vehicle or a machine equipped with the carburetor or an engine to adjust the fuel flow rate, and are operated by a user of the vehicle or the machine. A cap is attached to the head of the needle valve so that the exhaust condition cannot be deteriorated, and the needle valve cannot be operated by engaging with the needle valve unless a special tool is used. It is widely practiced that a locking piece that is engaged and protrudes outwardly can be operated only within a range of one rotation against a stopper on the carburetor body side. It is considered that such a cap is not limited to the needle valve in the low-speed fuel passage, but is also attached to a needle valve provided in the main fuel passage in a carburetor of a general gasoline engine (Japanese Utility Model Application Laid-Open No. 61-134555). Reference).

However, when the exhaust condition is deteriorated due to the aging of the performance of the carburetor or the engine or the environmental change in the place of use, the user of the vehicle or the machine may have to make adjustments. On the other hand, the cap is fixed to the head of the needle valve so that it cannot be removed by ordinary means, and can be operated only within one rotation with a normal tool as described above.

Therefore, in order for the user to readjust the improper fuel flow rate to within the range of conforming to the exhaust regulation, the cap must be forcibly removed using a tool. There is a concern that the head of the needle valve may be damaged or deformed, or the needle valve may be damaged.

[0007]

The problem to be solved by the present invention is that a manual needle valve for adjusting the effective area of the fuel passage is provided only for the manufacturer, and the cap is attached to operate the user. Is prohibited or restricted, it is difficult or impossible for a well-meaning user to remove the cap and re-adjust the fuel flow to within the emission regulation compliance range without affecting the carburetor body and the needle valve. That is the point.

[0008]

In order to solve the above-mentioned problems, the present invention leaves an easily breakable thin portion at the bottom on the peripheral side surface of a cap body which is fitted to a rotary operation head of a needle valve. The purpose of the present invention is to provide a widening groove and adopt such a means so that it can be removed without affecting the carburetor body and the needle valve.

[0009]

In the same manner as in the prior art, the needle valve is mounted on at least one of the low-speed fuel passage and the main fuel passage and fixed to the head of the needle valve for adjusting the effective area of the passage so as to limit the operable range of the needle valve. is there. When re-adjusting the fuel flow rate by operating the needle valve beyond the limit range by the cap, insert a thin plate-like hard member such as a screwdriver into the expansion groove and rotate it to break the thin part. The cap body is taken out from the head by changing the expansion.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. A needle-like valve formed at the tip of a needle valve 3 for adjusting the effective area of a fuel passage 2 provided inside a carburetor body 1 is described. The valve element 4 is inserted.

The needle valve 3 comprises the valve body 4, a screw portion 5 screwed into the carburetor body 1, and a rotating operation head 6 protruding outside the carburetor body 1. Is formed by a base portion 7 having substantially the same diameter as the screw portion 5 and a head portion 8 having a diameter larger than that of the screw portion 5. The base portion 7 has a tool groove 9 for engaging with a screwdriver on the base end face thereof. 8 has an annular retaining groove 10 on the outer peripheral surface.

The fuel passage 2 is either a low-speed fuel passage or a main fuel passage, and when a needle valve 3 is provided at the other end, it is exactly the same as that shown in the figure, and will not be described again.

A cap for regulating the effective area of the fuel passage 2, that is, the valve opening, is designated by the reference numeral 15, and has a cylindrical cap body 16 closely fitted to the head 6 and a stopper protrudingly formed on the carburetor body 1. 13, and is generally made of a hard synthetic resin. An annular retaining ridge 18 is formed on the inner peripheral surface of the cap body 16 to be fitted into the retaining groove 10 of the head 6, and an expanding groove 20 extending in the central axis direction is formed on the peripheral side surface. It is provided over the entire length except for the thin portion 19 at the bottom, and a cross-shaped engaging groove 21 for engaging a screwdriver is provided on the base end surface.

In this embodiment having such a structure, the maker of the carburetor, engine or vehicle or machine adjusts the effective area of the fuel passage 2 by screwing the needle valve 3 so as to pass the emission regulation. At this time, the cap main body 16 is put on the head 6 and the retaining ridge 18 is fitted into the retaining groove 10 to be fitted and fixed.

That is, the cap 15 is fitted to the head 6 without fear of being pulled out, and is fitted with the cap body 16 pressed against the outer peripheral surface of the head 6 or the head 6 has a flat knurl. When it is in place, it is fixed so that it can rotate together by being bitten. Therefore, when the screwdriver is engaged with the engagement groove 21 and rotated, the operation can be performed only within a range of one rotation in which the locking piece 17 protruding outward from the cap body 16 contacts the stopper 13. Therefore, the effective passage area cannot be changed until it exceeds the emission regulation compliance range.

Next, when the exhaust condition is deteriorated due to a change over time in the performance of a vehicle or a machine or an environmental change in a place of use, and it becomes necessary for the user to perform readjustment, a thin plate-shaped hard member such as a screwdriver is used. It is inserted into the groove for expansion 20 and rotated, and both side surfaces of the groove for expansion 20 are pushed so as to increase the interval between them. As a result, the thin portion 19 breaks over the entire length, and the cap body 16 is expanded and deformed, and separates from the outer peripheral surface of the head 6. That is, the cap 15 in the state of FIG. 2A is deformed as shown in FIG. 2B and can be removed in the base direction of the head 6 or outward.

After the cap 15 is removed in this manner, the screwdriver is engaged with the tool groove 9 to operate the needle valve 3 to readjust the effective area of the fuel passage 2. If another cap 15 is prepared, the cap 15 can be fitted to the head 6 after readjustment, so that a certain operation cannot be performed. Also, the used cap 15 that has been broken by expanding the expanding groove 20 cannot be reused.

[0018]

As is apparent from the above description, according to the present invention, a widening groove is provided on the outer surface of the cap body fitted and fixed to the head of the needle valve while leaving a thin portion at the bottom. In addition to having the same opening restriction function, when the user himself needs to adjust the effective area of the fuel passage, the excessive force is expanded by expanding the expansion groove and breaking the thin part. In addition to the main body and needle valve, they can be easily removed from the needle valve head without damaging or deforming the needle valve or damaging the needle valve, allowing the user to readjust without worrying about impairing the function of the vaporizer. It becomes.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a use state of an embodiment of the present invention.

FIG. 2 is a side view of the embodiment shown in FIG. 1 and a side view in an expanded state.

[Explanation of symbols]

15 cap, 16 cap body, 17 locking piece, 19 thin portion, 20 groove for expansion,

Claims (1)

(57) [Scope of request for utility model registration] The present invention has a needle-shaped valve body at a distal end and a head for rotation operation at a base end, and is screwed into a carburetor body to reduce the effective area of at least one of a low-speed fuel passage and a main fuel passage. An opening regulating cap fitted and fixed to the head of the carburetor fuel adjusting needle valve controlled by the needle-shaped valve body, wherein an easily destructible thin portion is formed on a peripheral side surface of the cap body fitted to the head. The opening restricting cap, characterized in that an opening groove is provided while leaving a bottom.