JPH0433406Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a device for protecting a choke valve of a carburetor from shocking high pressure caused by an abnormal explosion (hereinafter referred to as backfire) in an intake pipe.

2. Description of the Related Art FIG. 3 shows a plan view and a vertical cross-sectional view of a carburetor 1 whose upper portion is connected to an air cleaner (not shown) when the choke valve 2 of the carburetor 1 is fully closed. The chiyoke valve 2 is connected to the rotating shaft 3
It opens and closes to the fully open position shown by the two-dot chain line.

Problems to be solved by the invention In the above device, if the air-fuel mixture becomes too lean due to the operation or malfunction of the air-fuel mixture when starting at low temperature or while driving, the air-fuel mixture becomes too lean due to the air-fuel mixture being too lean due to the air-fuel mixture being too lean. Even if opened, fire may remain. In such a state, a so-called backfire, which ignites and causes combustion in the intake pipe, occurs, generating a shockingly high pressure. Here, the gap between the choke valve 2 and the inner wall of the carburetor 1 is small, so if a backfire occurs in this state, the choke valve 2 will stick to the inner wall of the carburetor 1 due to the impulsive high pressure, causing so-called galling. It may become inoperable. The present invention attempts to eliminate the above-mentioned obstacles by providing a pressure relief valve in the vaporizer 1.

Means for Solving the Problems In order to solve the above problems, a cylindrical member having a tapered hole expanded toward the air cleaner side, and a cylindrical member inserted into the hole having a tapered surface at the same angle as the hole. and a tapered movable valve whose tapered surface moves into and separates from the tapered hole according to the flow of gas in the vaporizer, and a locking member that prevents the movable valve from jumping out from the hole. The pressure relief valve is attached to the inner wall of the carburetor in parallel with the chyoke valve with respect to the flow path of the vaporizer and aligned with the outer periphery of the chyoke valve in the closed state.

Function Normally, the tapered hole of the cylindrical member and the tapered movable valve come into contact with each other due to the intake airflow from the air cleaner and close the same hole. Since sealability can be obtained, there is no gas leakage even when the check valve is closed, and the operation of the check valve is not inhibited. When reverse pressure is generated by the backfire, the tapered movable valve separates from the tapered hole in response to the gas flow and quickly rises until it comes into contact with the locking member. At this time, since the tapered hole expands toward the air cleaner side, the pressure relief valve opens wide, smoothly and quickly releasing the impulsive high pressure along the tapered surface, and protecting the choke valve.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. However, members that are the same as those in the prior art are given the same reference numerals and explanations will be omitted. In FIG. 1, 2a is a notch provided in the choke valve 2, and 4 is a pressure relief valve attached to the inner wall of the carburetor 1. The pressure relief valve 4 includes a cylindrical member 5 having a tapered hole 5a that widens toward an upper air cleaner (not shown), and a cylindrical member 5 that is inserted into the hole 5a and has a tapered surface at the same angle as the hole 5a. A movable tapered movable valve 6 and a locking member 7 that prevents the movable valve 6 from popping out from the first hole 5a.
, and is configured such that its outer edge aligns with the notch 2a when the first half-choke valve 2 is closed.

The locking member 7 is attached to the upper part of the tubular member 5, has a hole 7b having a diameter equal to the long diameter of the hole 5a, and has a structure in which a rod-shaped locking part 7a is installed in the center of the outer hole 7b. It's summery.

With the above structure, the pressure relief valve of the present invention normally closes the tapered hole 5a of the cylindrical member and the tapered surface of the movable valve 6 by coming into contact with the tapered surface of the movable valve 6 under pressure from the intake airflow from the air cleaner. I'm here. When the movable valve 6 opens and closes in the vertical direction as shown in the figure, the movable valve 6 is also closed by its own weight. In this state, since the tapered surfaces close together as a sealing surface, the sealing performance is good and the intake air from the air cleaner does not leak from the pressure relief valve. Therefore, since the flow rate is determined only by the choke valve 2, more than necessary is not sucked in, and malfunction of the choke valve does not occur, making it possible to improve starting performance.

Here, when an impulsive high pressure is generated by the backfire, the movable valve 6 comes off the tapered hole 5a and is pushed up until it comes into contact with the locking portion 7a of the locking member 7. At this time, since the movable valve 6 is not receiving any force other than the above pressure, it quickly opens in response to the gas flow and releases the back pressure, so the choke valve 2 is not affected by the back pressure due to the backfire. Further, since the tapered hole 5a widens toward the air cleaner side, the pressure relief valve can be widened greatly when the movable valve 6 is in contact with the locking portion 7a, and the opening passage is also tapered. Because it is tapered, reverse pressure is released smoothly and quickly along the same tapered surface. Then, when the back pressure subsides, the movable valve 6 descends, and the pressure relief valve 4 becomes closed again.

Further, as shown in FIGS. 2a and 2b, if a space 8 is provided on the inner wall of the carburetor 1 and a pressure relief valve 4 is installed,
Air resistance does not increase.

Effects of the invention As mentioned above, the present invention has been developed by attaching a pressure relief valve to the inner wall of the carburetor that opens and closes when the tapered surface contacts and separates according to the gas flow. Since good sealing performance can be obtained, there is no leakage of intake air and good starting performance can be achieved. Furthermore, since there is no need for a means to energize the movable valve, and there is no need to adjust it with a simple configuration, when a backfire occurs, the valve can be opened reliably and quickly, and the tapered hole expands toward the air cleaner side. Because of this, it opens wide when opening, allowing the back pressure caused by the backfire to escape smoothly and quickly along the tapered surface, and preventing the adverse effect of back pressure on the choke valve, thereby improving the durability of the carburetor valve. It has an excellent effect of increasing the amount of water.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention.
Fig. 1a is a plan view of the main part of the vaporizer, Fig. 1b is a vertical cross-sectional view of the main part of the vaporizer, Fig. 2 shows another embodiment of the present invention, and Fig. 2a is the main part of the vaporizer. 2b is a longitudinal sectional view of the main part of the vaporizer, FIG. 3 shows the prior art, FIG. 3a is a plan view of the main part of the vaporizer, and Fig. 3b is a plan view of the main part of the vaporizer. FIG. 2 is a vertical cross-sectional view of the main parts of the carburetor. DESCRIPTION OF SYMBOLS 1... Carburizer, 2... Chiyoke valve, 4... Pressure relief valve, 5... Cylindrical member, 5a... Tapered hole, 6... Movable valve, 7... Locking member.

Claims (1)

[Scope of utility model registration request] In a carburetor connected to an air cleaner, there is provided a cylindrical member having a tapered hole that opens toward the air cleaner, and a cylindrical member that is inserted into the hole and has a tapered surface at the same angle as the hole so that the gas inside the carburetor can be removed. A pressure relief valve consisting of a tapered movable valve whose tapered surface comes into close contact with and separates from the tapered hole according to the flow of water, and a locking member that prevents the movable valve from jumping out from the hole, 1. A valve protection device for a vaporizer, characterized in that the device is attached to an inner wall of the carburetor in parallel with the Cheyoke valve with respect to the flow path of the vaporizer and aligned with the outer periphery of the Cheyoke valve in the closed state.