JPS5924858Y2 - Fuel vapor release suppression device for internal combustion engines - Google Patents

Description

[Detailed description of the invention] The invention provides an internal combustion engine that, after the engine has stopped operating,
The present invention relates to a fuel vapor release suppression device that prevents vaporized fuel generated from a carburetor or an intake pipe from being released into the atmosphere.

The purpose of this is to open and close the air inlet pipe of the intake air cleaner with a shut-off valve connected to a negative pressure motor, and when the engine is running, the negative pressure motor is operated by the negative pressure generated in the engine's intake pipe. When the engine stops, the negative pressure in the intake pipe becomes atmospheric pressure and the on-off valve closes, allowing vaporized fuel generated from the carburetor and intake pipe to flow through the air introduction pipe. In addition, when starting the engine, a check valve installed in the on-off valve is used to facilitate engine startup, and when the engine suddenly accelerates, the negative pressure in the intake pipe becomes close to atmospheric pressure. Another object of the present invention is to provide a fuel vapor release device that can keep a negative pressure motor in operation and keep an on-off valve open, thereby supplying a sufficient amount of intake air necessary for an engine and suppressing the release of evaporated fuel into the atmosphere. It is.

The present invention will be explained below with reference to embodiments shown in the drawings.

1 to 4, reference numeral 1 denotes a carburetor, one end of which is connected to an engine E via an intake pipe 2, and the other end connected to an intake air cleaner 4 having a filter 3.

5 is an air introduction pipe of the intake air cleaner 4.

6 is a negative pressure motor, which is connected to the air introduction pipe 5 of the intake air cleaner 4.
It is fixed with screws via a bracket (not shown).

The main appearance of this negative pressure motor 6 is formed by sandwiching and tightening a rubber diaphragm 6b between housings 6a and 6b. It has a chamber 6e and an atmospheric chamber 6f formed by a diaphragm 6b and a housing 6d.

Further, metal plates (not shown) are attached to both sides of the diaphragm 6b, and the rod 7 is attached to the metal plate.
g is fixed.

Note that a coil spring 6C is interposed in the negative pressure chamber 6e.

7 is a check valve, and this check valve 7 is connected to the negative pressure pipe 6 of the negative pressure motor 6.
It is installed in the middle of the rubber hoses 8 and 9 that connect the air intake pipe 2 and the intake pipe 2.

The structure of this check valve 7 is as shown in FIG. 2, and includes a disc-shaped resin cap 7C having conduits 7a and 7b
, 7d and a resin cylindrical body 7e having an H-shaped cross section constitute the main external appearance, and the caps 7C, 7d and the body 7e are fixed by adhesive or rotational friction bonding.

A rubber umbrella-shaped valve body 7h for opening and closing one valve lower g is attached to the support portion 7f of the body 7e of the check valve 7.

Note that the A chamber 7i is separated from the support portion 7f of the body portion 7e of the check valve 7.
, Room B 7j is a formal example.

The valve body 7h of the check valve 7 opens to open the valve lower g only when the negative pressure in the intake pipe 2 reaches a certain level.Therefore, the conduit 7b is connected to the rubber hose 9 side, and the conduit 7a is It is connected to the rubber hose 8 side.

10 is a metal rectangular plate-shaped on-off valve, and this on-off valve 10
is disposed within the inlet 5a of the air inlet pipe 5 of the suction air cleaner 4.

The bearing 10a of this on-off valve 10 is rotatably connected to a bearing (not shown) fixed by welding to the inner wall of the air introduction pipe 5, and the bearing 10b of the bracket 10d fixed by welding
is rotatably connected to a bearing (not shown) of the rod 6g of the negative pressure motor 6.

Reference numeral 11 denotes a rubber umbrella-shaped check valve, and this check valve 11 is attached to the on-off valve 10 so as to open and close four valve ports 10C provided at the tip of the on-off valve 10.

This check valve 11 connects the air intake pipe 5 to the intake air cleaner 4.
The valve is opened to allow air to flow only to the Noro Weekly Day 3 side, and closed to allow air to flow in the opposite direction.

In the above configuration, before the engine E is started, negative pressure is not introduced into the negative pressure chamber 6e of the negative pressure motor 6, so that the rod 6
g does not operate, and the on-off valve 10 closes the inside of the air introduction pipe 5.

When the engine E is started in such a state, a slight negative pressure in the intake pipe 2 acts on the check valve 11 of the on-off valve 10, which opens the valve port 10C.

As a result, the contaminated air flows through the valve port 10C of the on-off valve 10, where it is purified and supplied to the engine E.

Therefore, even if the on-off valve 10 is closed, it will not be difficult to start the engine E.

After the engine E is started, the large negative pressure generated in the intake pipe 2 causes the valve body 7h of the check valve 7 to open, opening the valve lower g, and introducing negative pressure into the negative pressure chamber 6e of the negative pressure motor 6. be done.

As a result, the diaphragm 6b is extended against the load of the spring 6C, and the on-off valve 10 is pulled up via the rod 6g, and the on-off valve 10 is opened and the air introduction pipe 5 is opened.

Therefore, the air necessary for engine E can be supplied.

On the other hand, when engine E performs sudden acceleration, etc., the intake pipe 2
The negative pressure inside the check valve 7 becomes as low as atmospheric pressure, but due to the negative pressure introduced into the negative pressure chamber 6e of the negative pressure motor 6, the negative pressure in the A chamber 71 of the check valve 7 is greater than that in the chamber B7j. , the valve body 7h closes the valve lower g.

Therefore, since negative pressure is maintained in the negative pressure chamber 6e of the negative pressure motor 6, the on-off valve 10 maintains an open state and does not prevent the supply of air necessary for the engine E.

Furthermore, when the engine E is stopped, no negative pressure is introduced into the negative pressure chamber 6e of the negative pressure motor 6, so the diaphragm 6b is compressed by the load of the spring 6C, so the rod 6
An on-off valve 10 closes the air introduction pipe 5 of the intake air cleaner 4 via g.

As a result, fuel vapor generated from the carburetor 1 and the intake pipe 2 is not released into the atmosphere through the air introduction pipe 5 of the intake air cleaner 4.

FIG. 5 shows a modification of the embodiment shown in FIG. 1 in which the air introduction pipe 5 of the intake air cleaner 4 is shaped like a T-shape so that contaminated air is introduced from the lower introduction port 5a.

FIG. 6 shows another embodiment of the present invention in which the check valve 11 of the on-off valve 10 is made of rubber and has a flat plate shape and is attached with rivets 12.

Figure 7 shows a rivet 12 at the tip of the check valve 11.
At the same time, when the on-off valve 11 is closed, the check valve 11
This figure shows still another embodiment of the present invention in which the tip of the air inlet tube 5 contacts the inner wall of the air introduction pipe 5 of the intake air cleaner 4 shown in FIG.

According to this embodiment, when the check valve 11 is open, contaminated air flows through the rectangular gap between the inner wall of the air introduction pipe 5 and the tip of the on-off valve 11.

In the present invention, the negative pressure motor 6 is not limited to a diaphragm type, but may be a bellows type.

Further, the check valve may be constructed of a spring and a metal valve body.

Further, the on-off valve 10 is connected to the air introduction pipe 5 of the intake air cleaner 4.
Although it was installed inside, it may of course be installed outside.

As mentioned above, in the present invention, the air cleaner is operated via an intake air cleaner that cleans the intake air to the internal combustion engine, and a membrane member that expands and contracts by cutting off the introduction of negative pressure to the negative pressure chamber. A negative pressure motor having a rod, and a check valve that is installed in the negative pressure path connecting the negative pressure chamber of the negative pressure motor and the intake pipe of the internal combustion engine and opens only when the negative pressure in the intake pipe becomes large. , an on-off valve that is rotatably connected to the rod of the negative pressure motor and opens and closes the inlet of the air inlet pipe of the suction air cleaner; Since the engine is equipped with a check valve that shuts off the flow of air in the opposite direction, when the engine is stopped after operation, the negative pressure in the intake pipe no longer acts on the negative pressure motor, and the on-off valve closes the air intake pipe. Since the intake port is closed, the fuel vapor generated from the carburetor and the intake pipe to which the intake air cleaner is connected will not be released into the atmosphere through the air introduction pipe, thereby preventing air pollution.

In addition, when starting the internal combustion engine, even if the on-off valve closes the inlet of the air intake pipe of the intake air cleaner, the check valve installed in this on-off valve opens, so that the intake air necessary for the internal combustion engine is supplied to the internal combustion engine. Therefore, starting the engine will not be difficult.

In addition, when the internal combustion engine is operating, the large negative pressure in the intake pipe acts on the negative pressure motor and opens the on-off valve, so the necessary intake air is secured to the internal combustion engine, and under such conditions, there is no load on the internal combustion engine. In the past, even if the negative pressure in the intake pipe suddenly rose to near atmospheric pressure, the check valve between the negative pressure motor and the intake pipe would close and maintain the high negative pressure state of the negative pressure motor. The on-off valve remains open, and the supply of intake air to the internal combustion engine is not obstructed, making it possible to eliminate malfunctions in the internal combustion engine.

In this way, the present invention can ensure intake air for the internal combustion engine in all operating ranges of the internal combustion engine, and can also prevent fuel vapor from being released into the atmosphere.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of the device of the present invention, FIG. 2 is a sectional view showing the detailed structure of the check valve 7 shown in FIG. 1, and FIG.
The figure is a sectional view showing in detail the mounting relationship between the on-off valve 10 and the check valve 11 in Fig. 1, Fig. 4 is a plan view of Fig. 3, and Fig. 5 is a main part showing a modification of Fig. 1. The schematic cross-sectional views, FIGS. 6 and 7, are cross-sectional views showing other embodiments of the device of the present invention. 1... vaporizer, 2... suction pipe, 3...
...Ro week off, 4...Suction air cleaner, 5
...Air introduction pipe, 5a...Inlet port, 6
...Negative pressure motor, 6b...Diaphragm forming a membrane member, 6e...Negative pressure chamber, 6g...
...Rod, 7...Check valve, 10...
- Opening/closing valve, 11... Check valve, E... Internal combustion engine.

Claims (1)

[Scope of utility model registration request] An intake air cleaner having a filter that cleans intake air to an internal combustion engine; a negative pressure motor having a rod that is operated via a membrane member that expands and contracts by cutting off the introduction of negative pressure to a negative pressure chamber; A check valve is provided in a negative pressure path connecting the negative pressure chamber of the negative pressure motor and the intake pipe of the internal combustion engine and opens only when the negative pressure in the intake pipe becomes large, and a check valve is provided on the rod of the negative pressure motor. An on-off valve that is rotatably connected and opens and closes the inlet of the air introduction pipe of the intake air cleaner; and an on-off valve that is provided on the on-off valve to allow air to flow from the air introduction pipe of the intake air cleaner only to the filter side in the opposite direction. 1. A fuel vapor release suppression device for an internal combustion engine, comprising a check valve that blocks air flow to the internal combustion engine.