JPH0315811Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to a carbon canister that is installed in automobile engines and the like to prevent evaporated fuel from dissipating into the atmosphere.

(Prior Art) A carbon canister is used that temporarily adsorbs fuel gas that evaporates from a gasoline tank or the like of an internal combustion engine onto an adsorbent such as activated carbon, and releases it to the intake pipe side during engine operation. An example is shown in FIG. Fuel gas that evaporates from the gasoline tank 50 is guided into the container 32 through the introduction pipe 31 of the carbon canister 30 and is once adsorbed by the adsorbent 33. During engine operation, the purge valve 34 is opened and the fuel gas is discharged from the discharge pipe 35 into the intake air of the engine. The fuel gas is discharged to the downstream side of the throttle valve 52 of the pipe 51. Purge valve 34
is the pipe end opening 35 of the discharge pipe 35 as shown in FIG.
a is a plate-shaped valve body 4 fixed to a diaphragm 39;
It is covered by 0. The purge valve 34 is divided into an upper negative pressure chamber 41 and a lower purge chamber 45 by the diaphragm 39, and a spring 42 is disposed inside the negative pressure chamber 41 and presses the diaphragm 39 through a retainer 43 to push the diaphragm 39 through the valve body 40. The opening 35a in the purge chamber 45 is closed. Negative pressure chamber 41 communicates with the upstream side of throttle valve 52.

(Problems to be Solved by the Invention) In the conventional carbon canister 30 as described above, the throttle valve 52 is closed during engine idling, so negative pressure does not act on the negative pressure chamber 41 and the purge valve closes. 34 is closed. discharge pipe 3
5, an intake pipe negative pressure of about 500 to 600 mmHg is acting. When the throttle valve 52 is opened and the negative pressure in the intake pipe reaches the negative pressure chamber 41, the purge valve 34 suddenly opens, and the negative pressure in the discharge pipe is impulsively propagated to the purge chamber 45 and further into the container. . At this time, the valve body 40 separates from the opening 35a all at once, so air impact noise (air bong) is generated and accompanied by vibration.
Further, in the fully open position, the valve body 40 collides with the stopper 44, generating a collision sound (solid boom) and vibration.

(Means for Solving the Problem) In the carbon canister of this invention, the upper surface of the valve body of the purge valve is inclined with respect to the axial direction of the purge valve.

(Function) In the carbon canister of this invention, the upper surface of the valve body of the purge valve is pressed against the end opening of the discharge pipe in a state of inclination with respect to the axial direction of the valve, and the pressing force from the spring is an unbalanced load. When opening a valve, first open the valve from the side with the weaker spring pressure, correcting the inclination.

(Embodiment) FIG. 2 shows a carbon canister 1 according to an embodiment of this invention, and FIG. 1 shows its purge valve 2. Second
In the figure, a carbon canister 1 includes an introduction pipe 3 and a discharge pipe 4, and stores activated carbon 7 as an adsorbent in a container 6 having an atmospheric communication hole 5 in the bottom. A purge valve 2 is provided at the top of the container 6. As shown in FIG. 1, the inside of the purge valve 2 is divided into an upper negative pressure chamber 11 and a lower purge chamber 12 by a diaphragm 10 to which a plate-shaped valve body 9 is fixedly attached. A pipe end opening 4a of the discharge pipe 4 is provided which communicates with the container 6. Negative pressure chamber 11 communicates with the upstream side of throttle valve 52 (see FIG. 3) of the engine intake pipe, and a spring 13 is disposed inside to press valve body 9 via retainer 14 to close opening 4a. ing. The valve body 9 has different thicknesses on the left and right sides as shown at t ₁ and t ₂ in the figure, and has an inclined upper surface. A suitable slope is 2° to 6°. As in FIG. 3, the other end of the introduction pipe 3 communicates with the fuel tank 50, and the other end of the discharge pipe 4 communicates with the downstream side of the throttle valve 52.

When the engine is operated, intake pipe negative pressure is transmitted to the discharge pipe 4. When the throttle valve opens, negative pressure is generated in the negative pressure chamber 11, and the valve body 9 separates from the opening 4a, but the upper surface of the valve body is inclined and the spring 13
Since the pressing force is not uniform, the thickness of the valve body 9 is thin (t ₂ ), and the valve opens from the side with the weaker pressing force. Also, for this reason, the valve body rises at a slower speed when the valve is opened, and the stopper 15
Collisions with the vehicle are also alleviated.

In the purge valve 20 shown in FIG. 5, the pipe end opening 21a of the discharge pipe 21 is inclined with respect to the axial direction of the purge valve 20. The valve body 23 is tilted and pressed against the opening 21a by the spring 24. When opening the valve, the first step is to leave the opening from one side to correct the inclination.
This is similar to that of the embodiment.

(Effect of the invention) The carbon canister of this invention tilts the top surface of the valve body so that the pressing force of the spring becomes an uneven load, so when opening the valve, it opens from the side with weaker pressing force to correct the inclination. , the valve does not open all at once, and no air impact noise is generated due to negative pressure in the discharge pipe. In addition, the initial velocity of the valve body's rise becomes slower, and collisions with the stopper are alleviated, resulting in less collision noise and vibrations.

[Brief explanation of the drawing]

Figure 1 is a diagram of the purge valve according to this invention.
FIG. 2 shows an embodiment of this invention, FIG. 3 shows a state in which a carbon canister is installed, FIG. 4 shows a conventional purge valve, and FIG. 5 shows another purge valve. 2, 20...purge valve, 9...valve body, 1
0, 22...Diaphragm, 13, 24...Spring, 4a, 21a...Opening.

Claims (1)

[Scope of utility model registration request] The adsorbent is stored in a container equipped with an inlet pipe and a discharge pipe and an atmosphere communication hole in the bottom, and is further divided by a diaphragm into a negative pressure chamber and a purge chamber communicating with the inside of the container. In a carbon canister comprising a purge valve that opens the pipe end of a discharge pipe and closes the opening by pressing a valve body fixed to a diaphragm with a spring disposed in a negative pressure chamber, the upper surface of the valve body A carbon canister characterized by being provided at an angle with respect to the axial direction of the purge valve.