JPS5914622B2 - piston type vaporizer - Google Patents

Abstract

PURPOSE:To prevent a throttle valve from being frozen, by introducing oil onto the inside surface of the bore of the throttle valve. CONSTITUTION:An oil supply port 15 is provided in the wall 3 of the bore of the throttle valve and connected to an oil pump through a joint 16 and a pipe 17. An oil introducing groove 18 connected to the oil supply port 15 is provided on the inside surface 5 of the bore. When the engine is running, an appropriate quantity of oil regulated by an oil regulator is supplied from an oil pump to the oil introducing groove 18 through the pipe 17 and the oil supply port 15. The oil is filled in the gap between the throttle valve 4 and the inside surface 5 of the bore by the sliding motion of the valve 4. Thereby, the sliding motion of the throttle valve 4 is smoothed and moisture having invaded into the gap is removed or moisture is prevented from invading thereinto. Therefore, the freezing of such moisture is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a carburetor for a two-stroke engine installed in a snowmobile or the like, and more particularly to a piston type carburetor having an antifreeze structure.

The piston type vaporizer (Amal type vaporizer) as mentioned above is
The suction passage is opened and closed by a roughly cylindrical throttle valve that slides along the inner wall of the throttle valve bore as a guide, and the needle jet is generated by utilizing the negative pressure of the venturi section formed between the lower part of the valve and the suction passage. The fuel is sucked out from the venturi and mixed and atomized into the air flowing through the venturi section.

In this way, the sliding operation of the throttle valve is configured to open and close the air passage, form the venturi section, and adjust the amount of fuel sucked out, so the smoothness of the throttle valve's sliding is a major factor in performance. It is a requirement.

In contrast, in engines equipped with conventional piston-type carburetors, in cold weather, the latent heat of vaporization due to fuel vaporization works together with the low temperature of the outside air, and the carburetor body is heated immediately after engine startup or while the engine is running. When cooled properly, dew enters from the outside through the intake passage or condenses from the intake air and enters the gap between the sliding surface formed between the throttle valve and the inner wall of the throttle valve bore. The water freezes, causing the valve to freeze, making it impossible to slide, and causing the inconvenience that engine operation cannot be controlled.

However, as prior art for solving such inconveniences, Japanese Utility Model Application Publication No. 52-27527 and Japanese Utility Model Application Publication No. 52-275
According to these publications, oil is not supplied to the current contact surface where the throttle valve bore and the throttle valve are in contact.
Oil is supplied only when the sliding part of the throttle valve that is currently in contact with the oil slides into contact with the contact surface of the bore, and therefore there is a risk that the above-mentioned freezing may occur. There are drawbacks.

The present invention seeks to provide a piston-type carburetor with a throttle valve in which the above-mentioned disadvantages and drawbacks are eliminated.

In order to achieve this object, the carburetor according to the present invention includes a sleeve in which the throttle valve slides and a plurality of oil guide holes are bored over the entire circumferential wall, and a sleeve in which the throttle valve slides and which is provided with a plurality of oil guide holes over the entire circumferential wall. At the same time, an oil supply port leading to the oil pump is opened in the throttle valve bore wall, and the oil supply function of the oil pump is adjusted. Introducing oil from the supply port to almost the entire inner wall of the sleeve through the sponge-like member and the oil guide hole to eliminate moisture in the gap between the throttle valve and the sleeve,
Alternatively, the valve is configured to prevent the intrusion of moisture to prevent the valve from freezing, and also to facilitate the operability of the valve.

Embodiments of the present invention will be specifically described below with reference to the drawings.

In FIG. 1, numeral 1 is a carburetor main body, and 2 is an air-fuel mixture passage.

Approximately in the center of this passage 2 in the longitudinal direction, there is a throttle valve
A bore wall 3 is integrally formed, and a sleeve 4 is fitted into the bore inside the bore wall 3.

The sleeve 4 is made of a cylindrical body, and has a plurality of oil guide holes 5 formed throughout its circumferential wall, and is positioned within the bore by a ring 6 placed over its upper end.

A cylindrical space formed between the sleeve 4 and the bore inner wall T is filled with a sponge-like member 8 for absorbing and diffusing oil.

The throttle valve 9, which is fitted into the sleeve 4 and slides up and down, is biased downward by a throttle spring 10, and when the accelerator grip (not shown) is not operated, the throttle valve 9 shields the suction passage 2 and A jet needle 11 provided to protrude from the lower part of the valve 9 closes an opening of a needle jet (not shown) to restrict the outflow of fuel.

Further, an oil supply hole 12 is bored in the inner wall 7 of the throttle valve bore, and is connected to the discharge side of the oil pump via a joint 13 and an oil pipe 14, and is arranged to supply oil. .

Note that 15 is a cap that covers the upper part of the inner wall 7 of the throttle valve bore, and 16 is a main air jet.

With this structure, when the engine is operated, the oil supplied to the inner wall T of the throttle valve bore through the oil supply pipe 14, joint 13, and oil supply port 12 due to the oil supply action of the oil pump is transferred to the sponge-like member. It penetrates into the entire area due to the absorption and diffusion effect of 8.

Oil is guided and supplied to the entire inner wall of the sleeve 4 from a plurality of oil guide holes 5 formed over the entire peripheral wall of the sleeve 4 provided in contact with the sponge-like member 8. Since the water is introduced into the gap formed between the water and the inner wall of the throttle valve 9 and fills the gap, the sliding movement of the throttle valve 9 becomes smooth and almost all moisture that enters the gap is eliminated. It also prevents moisture from entering.

Furthermore, the oil introduced into the gap is dripped downward and is sucked into the combustion chamber (not shown) of the engine together with the air-fuel mixture flowing in the air-fuel mixture suction passage 2, where it performs a lubricating action, resulting in oil separation. Since refueling is achieved, there is no need to worry about contaminating the spark plug or creating a so-called bridge in the spark plug, unlike the mixed refueling method, which generates a mixture containing lubricating oil in the fuel to lubricate the inside of the combustion chamber. The performance of the engine can also be improved.

As explained above, according to the vaporizer of the present invention, the oil sent by the oil pump is first permeated and absorbed over the entire area by the absorption and diffusion action of the sponge-like member, and then passes through the oil guide hole of the sleeve. Since it is supplied to the entire sliding surface of the sleeve, including the current contact surface between the throttle valve and the sleeve, the throttle valve is reliably frozen even under conditions where the throttle valve is likely to freeze, such as during cold weather. Therefore, the operation of the throttle valve and its operability are smoothed, and the operation of the engine can be controlled reliably at all times, and the amount of oil to be supplied can be reduced.

[Brief explanation of drawings]

FIG. 1 is a partially omitted vertical sectional view showing an embodiment of the present invention, and FIG. 2 is a perspective view showing the sleeve in FIG. 1. 1... Carburetor body, 2... Mixture intake passage, 3... Throttle valve bore wall, 4...
...Sleeve, 5...Oil guide hole, 6
... Ring, 7 ... Boa inner wall, 8 ...
... Sponge-like member, 9... Throttle valve, 10... Throttle spring, 11.
... Jet needle, 12 ... Oil supply hole, 13 ... Joint, 14 ...
・・Oil No No Eve, 15・・・・Cap, 16
...Main air agent.

Claims (1)

[Claims] 1. In a piston type carburetor of the type in which an intake passage is opened and closed by a throttle valve sliding in a throttle valve bore, a throttle valve slides in the bore,
In addition, a sleeve having a plurality of oil guide holes drilled over the entire circumferential wall and a human pump-like member to be filled into the space formed between the sleeve and the inner wall of the bore are fitted, and , an oil supply port leading to the oil pump is opened, and oil is supplied from the supply port to almost the entire inner wall of the sleeve via the sponge-like member and the oil guide hole by the oil feeding action of the oil pump. A piston type vaporizer featuring: