JPS5933887Y2 - Air purifier for internal combustion engines - Google Patents

Description

[Detailed description of the invention] The present invention relates to an air purifier for internal combustion engines.
The present invention relates to an air cleaner configured to prevent fuel vapor generated when an engine is stopped after warming up from being released into the atmosphere.

Conventionally, in order to prevent fuel vapor from being released into the atmosphere, a filter element containing activated carbon was used to adsorb fuel vapor to the activated carbon, or a shutoff valve was installed in the air inlet pipe or air outlet pipe of the air purifier to close when the engine stopped. Alternatively, a fuel storage chamber is provided inside or outside the air purifier.

However, in the case of a method in which fuel vapor is adsorbed on activated carbon, installing the activated carbon and filter element separately poses problems in terms of space and high cost. There are problems of decreased performance as an element and increased cost.

Further, in the case of a method in which a shutoff valve is provided, there are problems of installation space and an increase in suction resistance due to the addition of the shutoff valve.

Furthermore, in the case of a system in which a fuel reservoir is provided, there are problems in the installation space of the fuel reservoir, the complexity of the shape of the air cleaner, and high costs.

Therefore, the present invention allows fuel vapor to be transferred to the atmosphere when the engine is stopped by making some changes to the conventional type of air cleaner for internal combustion engines, which has an air intake pipe that is branched into a cold air intake pipe and a hot air intake pipe. The purpose is to prevent the release of

In order to achieve this objective, the present invention provides a method for switching and driving the switching valve that switches the communication between the inside of the air purifier and the cold air intake pipe and the communication between the inside of the air purifier and the hot air intake pipe. Uses a negative pressure motor that operates on negative pipe pressure.

In addition, a temperature-sensing modulator is installed in the middle of the negative pressure line that connects this negative pressure motor and the engine's intake pipe, so that the temperature of the intake air that is drawn into the engine is adjusted accordingly. Controls the negative pressure in the intake pipe.

That is, the modulator and negative pressure motor communicate with the inside of the air purifier and the cold air intake pipe when the intake air to the engine is above a predetermined temperature, and when the intake air is below a predetermined temperature or when the engine is stopped, the air purifier is connected to the cold air intake pipe. The interior of the container and the hot air intake pipe are configured to communicate with each other.

Furthermore, a return valve is provided in the warm air intake pipe to allow only the flow of warm air from the warm air intake pipe toward the interior of the air purifier, but not to allow flow in the opposite direction.

Therefore, these check valves and switching valves reliably prevent the fuel vapor generated in the engine's intake system from being released into the atmosphere from the air introduction pipe of the air purifier while the engine is stopped. Contribute to prevention of pollution.

It should be noted that this effect can be achieved by making only a few simple modifications to the configuration of the conventionally known automatic cold/warm air switching type air purifier.

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

In FIG. 1, an internal combustion engine 1 has an intake pipe 2 and an exhaust pipe 3. As shown in FIG.

An air purifier main body 10 is attached to the upstream end of the intake pipe 2 via a carburetor 4.

This main body 10 consists of a case 12 housing a filter element 11 therein and a cap 13.
An air introduction pipe 14 is provided in a protruding manner at the 0-point.

The tip of the air introduction pipe 14 constitutes a cold air intake pipe 15.

An opening 16 is formed in the lower wall of the central part of the air introduction pipe 14. A warm air intake pipe 17 is connected to this opening 16, and the lower end of the warm air intake pipe 17 receives air warmed by the exhaust pipe 3 of the engine. It is connected to a collecting hot air intake 17'.

A switching valve 18 is provided in the air introduction pipe 14 to switch communication between the inside of the air purifier main body 10 and the cold air intake pipe 15 and the communication between the inside of the main body 10 and the hot air intake pipe 17.
Negative pressure motor 19 attached to the upper wall of the air introduction pipe 14
It is switched and driven by.

Referring to FIG. 5, the switching valve 18 has a rubber gasket 20 attached to its periphery and is connected to the air inlet pipe 1 by a shaft 22.
A bearing part 2 constitutes a pivoting part of the flap valve 21.
A flange portion 24 is fixed to the flap valve 3 at a certain angle with respect to the flap valve 21, and angularly moves together with the flap valve 21.

The negative pressure motor 19 has a negative pressure chamber 28 formed by metal or plastic upper and lower housings 25, 26 and a diaphragm 27, and an atmospheric pressure chamber 29, the negative pressure chamber 2
A compression spring 30 is disposed within the chamber 8 and acts to press the diaphragm toward the atmospheric pressure chamber 29.

The upper end of a rod 31 that extends slidably through the upper wall of the air introduction pipe 14 is fixed to the diaphragm 27, and the lower end of the rod 31 is attached to the flange portion 24 of the flap valve 21, as shown in FIG. It is pivoted.

That is, the lower end portion 31a of the rod 31 is bent and extends horizontally, and this horizontal lower end portion 31a rotates under self-pressure through the sleeve 33 with respect to the bearing 32 attached to the flange portion 24.

The negative and positive chamber 28 of the negative pressure motor 19 is connected to the intake pipe 2 of the engine via a negative pressure line 34.

A temperature sensing modulator 35 and a backflow valve 36 are provided in the middle of the negative pressure line 34.

Negative pressure conduit 34 includes conduit 34a in order from the side closest to negative pressure←19.

34b and 34c.

The modulator 35 is installed in the air purifier main body 10 inside the filter element 11, as shown in FIG.

To explain in more detail with reference to FIG. 2, the modulator 35 has a plate-shaped base 38 attached to the bottom wall of the case 12 of the air purifier body via a gasket 37 with bolts or the like (not shown).

Two openings 39 and 40 are formed in the base 38, and short pipes 4L and 42 are respectively connected to these openings by welding. It is connected to a check valve 36 by a conduit 34b.

An inverted cup-shaped housing 43 is airtightly attached to the upper surface of the base 38 by brazing or the like, and is attached to the opening 39.4.
0, a space or chamber 44 is formed.

A screw hole 45 is formed in the center of the upper wall of the housing 43, and the screw hole 45 is internally threaded. A screw plug 47 having a through hole 46 in the center is screwed into the screw hole 45.

The peripheral edge of the lower end of the through hole 46 is chamfered to form a conical valve seat 48.

The through hole 46 has a head 4 shaped so as to be in close contact with the valve seat 48.
A valve body 50 having a numeral 9 at its lower end is inserted from the lower side, that is, from the chamber 44 side, and is attached to a U-shaped bimetal 51 at its upper end.

The bimetal 51 is attached to the base 3 by a screw 52 at its curved part.
A slit 53 is cut into the free end of the flange 38 a K at the rising end of the 8. The valve body 50 is fitted into the letter of appreciation portion 54.

The check valve 36 includes a cap 56 having a pipe 55 connected to the conduit 34b, and a pipe 57 connected to the conduit 34c.
and is fitted to the cap 56 at the peripheral edge thereof.
8, and a partition wall 59 sandwiched between a cap 56 and a case 58 is provided inside the main body.

In addition to the central hole 60, at least one ventilation hole 61 is formed in the partition wall 59.

In a chamber 62 formed between the partition wall 59 and the case 58, an umbrella-shaped valve body 63 made of an elastic material such as rubber is placed with its umbrella portion facing down. The handle portion of the umbrella is fitted into the central hole 60 of the partition wall 59.

The umbrella portion of the valve body 63 has a size that closes the ventilation hole 61.

Referring again to FIG. 5, the opening 16 formed in the lower wall of the air introduction pipe 14 is the entrance of a recess 14a formed by deep drawing the lower wall downward into a concave shape using a press or the like. A central hole 14b and a relatively large opening 14c are formed in the bottom wall of the recess 14a, and the warm air intake pipe 17 is fitted or welded to the outer peripheral surface of the recess 14a.

Inside the recess 14a, a valve body 64 having a shape and material similar to the umbrella-shaped valve body 63 is arranged with its umbrella facing upward, and its shaft (shaft portion of the umbrella) is placed against the bottom wall of the recess 14a. center hole 1
4b.

The umbrella portion of the valve body 64 closes the opening 14c due to its elasticity, thereby forming a check valve.

Next, the operation of the above-described embodiment will be explained in the order of engine stop, warm air intake operation, and cold air intake operation.

When the engine 1 is not operated, the pressure within the intake pipe 2 is equal to atmospheric pressure and no negative pressure is generated, so the pressure within the negative pressure chamber 28 of the negative pressure motor 19 is also equal to atmospheric pressure.

Therefore, the diaphragm 27 and the rod 31 inside the negative pressure motor 19 are pushed down by the compression spring 30, so that the switching valve 1 pivotally connected to the lower end 31a of the rod 31
The flange portion 24 of No. 8 is pressed against the lower wall of the air introduction pipe 140, and therefore, the flap pulp 21, which is integral with the flange portion 24 at a certain angle, rotates clockwise as seen in FIG. The state shown in the figure is reached, and communication between the inside of the air purifier main body and the cold air intake pipe 15 is cut off.

On the other hand, communication between the inside of the air purifier main body and the warm air intake pipe 17 is provided by an umbrella-shaped valve body 64.

Since it is cut off by the check valve, the interior space 14a' of the recess 14a serves as a fuel reservoir.

That is, fuel vapor generated from the fuel system when the engine is stopped is transferred to the air introduction pipe 14 by the action of the switching valve 18 and the check valve 640.
The fuel vapor is stored in the fuel storage chamber 14a' and prevented from being released to the outside, and when the engine is restarted, the stored fuel vapor flows from the warm air intake pipe 17 into the recess 1 against the elasticity of the check valve 640.
The warm air flowing into the air purifier body through the internal space of fuel tank 4a, that is, the fuel reservoir chamber 14a', carries the fuel into the engine 1 and burns it.

If the air taken into the engine 1 is lower than the predetermined temperature set by the bimetal 51, the engine automatically enters warm air intake operation.

That is, in this case, the bimetal 51 bends downward as seen in FIG.
a and the space inside the filter element 11 in the air purifier body through the chamber 44, and therefore atmospheric pressure is introduced into the negative pressure chamber 28 of the negative pressure motor 19, whereby the switching valve 18 The state shown in Figure 1 will be the same as when the engine is stopped.

Therefore, the intake air of the engine enters through the hot air intake 17' and the hot air intake pipe 17, and this air flow resists the elasticity of the umbrella-shaped check valve 640 (i.e.,
(by deforming the umbrella part upward), the air enters the inside of the air purifier main body through the air introduction pipe 14 through the opening 14c, and is sucked into the engine 1 from there.

When the intake air of the engine 1 is at or above the predetermined temperature, the bimetal 51 bends upward as seen in FIG. Conduit 34a to negative pressure chamber 28, modulator 35
Negative pressure within the intake pipe 2 is transmitted through the chamber 44, the conduit 34b, the check valve 36, and the conduit 34c.

Therefore, in the negative pressure motor 19, the diaphragm 27 deforms upward in FIG. 1 against the spring 30 due to the pressure difference between the negative pressure chamber 28 and the atmospheric pressure chamber 29, and pulls up the rod 31. 18 is rotated counterclockwise as viewed in FIG. 1 to be in the state shown in FIG. 5.

Therefore, communication between the hot air intake pipe 17 and the inside of the air purifier main body is cut off by the flap pulp 21 that constitutes the switching valve 18, and cold air is passed from the cold air intake pipe 15 to the air introduction pipe 1.
4 into the interior of the air purifier body, and from there, it is sucked into the engine 1 through the intake pipe 2.

This is the cold air intake operation of the engine.

The check valve 36 is configured so that the increase in pressure (reduction in negative pressure) in the intake pipe 2 caused by the accelerated operation of the engine during cold air intake operation is transmitted to the negative pressure motor 19, and the switching valve 18 is activated as shown in FIG. This prevents inhalation.

That is, when the pressure inside the intake pipe 2 is lower than a predetermined value (when the negative pressure is greater than or equal to the predetermined negative pressure value), the umbrella portion of the check valve 63 deforms downward to reduce the intake pipe negative pressure. The pressure is transmitted to the negative pressure chamber 28 of the motor 19. However, when the pressure inside the intake pipe 2 rises when the engine accelerates (when the intake pipe negative pressure becomes low), the head portion of the check valve 63 closes the vent hole 61 due to the differential pressure. Closed, the negative pressure in the negative pressure chamber 28 of the negative pressure motor 19 is maintained, and the switching valve 18 is kept in the cold air suction state shown in FIG.

However, this state does not last for a long time; for example, when the engine is stopped, the pressure in the negative pressure chamber of the negative pressure motor 19 increases many times after the engine is stopped, and eventually becomes equal to atmospheric pressure.

The path through which atmospheric pressure enters is the conduit 34a. 34b and pipe 41
．． 42, the gap between the valve body 49 and the valve seat 48, etc., and although each gap is minute, atmospheric pressure gradually enters.

As explained above, the air purifier of the present invention has a conventional configuration with a changeover valve that switches between a hot air intake state and a cold air intake state depending on the temperature of the air sucked into the engine, but with some structural changes. By simply adding this, in addition to the cooling/heating switching effect described above, there is the effect of trapping fuel vapor generated when the engine is stopped in the air cleaner.

In the above embodiment, the bimetal 51 is used to bring the valve body 49 of the modulator 35 into contact with and away from the valve seat 48 depending on the temperature of the intake air, but thermowax may be used instead of the bimetal. It is obvious to the business operator.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the air purifier for internal combustion engines of the present invention, Fig. 2 is a longitudinal sectional view of a temperature sensing modulator, Fig. 3 is a plan view of the bimetal, and Fig. 4 is a negative FIG. 5 is a longitudinal sectional view of the check valve installed in the pressure pipe, and is a partially enlarged sectional view showing the cold air/warm air switching valve, the check valve provided in the hot air intake pipe, and the fuel storage chamber. 1... Internal combustion engine, 10... Air purifier body, 14... Air introduction pipe, 15...
Cold air intake pipe, 17...Hot air intake pipe, 18.
...Switching valve, 19...Negative pressure motor, 35
...Temperature sensing modulator, 64...
・Check valve in the warm air intake pipe.

Claims (1)

[Scope of utility model registration request] An air cleaner for an internal combustion engine has an air introduction pipe branched into a cold air intake pipe and a warm air intake pipe, and the air cleaner is installed in the air introduction pipe to communicate between the inside of the air cleaner and the cold air intake pipe. A switching valve that switches communication between the inside of the air purifier and the warm air intake pipe, a negative pressure motor that switches and drives the switching valve, and a negative pressure pipe that connects the negative pressure motor and the engine intake pipe. a temperature-sensing modulator that controls the intake pipe negative pressure supplied to the negative pressure motor according to the temperature of the intake air that is drawn into the engine; An air cleaner for an internal combustion engine, comprising a check valve that allows only the flow of warm air toward the inside of the air cleaner and prevents the flow of warm air from flowing in the opposite direction.