JPH0311406Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a canister for preventing air pollution caused by evaporated fuel from fuel supply systems such as fuel tanks and vaporizers of automobiles.

[Prior Art] For example, in a canister disclosed in Japanese Patent Application Laid-open No. 55-60650, a container containing an evaporated fuel adsorbent has a check valve that allows evaporated fuel to flow from the fuel tank to the container, and a It is connected to the fuel tank by a pipe equipped in parallel with a check valve that allows backflow (inflow) of evaporated fuel into the fuel tank. Each of the check valves described above is composed of a spherical valve body made of synthetic resin and a valve seat with a hole provided in a metal plate, and the metal plate is embedded in a container made of synthetic resin.

However, with the above-mentioned canister, not only is the insert molding process time-consuming, such as positioning the metal plate within the mold, but also the assembling of the valve body and the spring is also time-consuming, making it difficult to reduce costs.
In addition, the check valve is placed adjacent to the evaporated fuel adsorbent, and the atmosphere side is communicated with the fuel tank through the evaporated fuel adsorbent and the check valve, so a large amount of evaporated fuel is adsorbed by the evaporated fuel adsorbent. When this occurs, the ventilation resistance of the evaporated fuel adsorbent increases, preventing the flow between the atmosphere side and the fuel tank, and as the fuel in the sealed fuel tank decreases, the inside of the fuel tank becomes lower than atmospheric pressure. If the fuel tank is too low, even a slight impact may cause the fuel tank to deform.

In the canister disclosed in Japanese Utility Model Application Publication No. 56-90923, evaporated fuel in the fuel tank is adsorbed into the suction part of the container through a check valve in the pipe, and fuel in the suction part passes through the check valve in the pipe to the intake pipe. be sucked into. On the other hand, when the pressure in the fuel tank becomes negative, outside air is sucked into the fuel tank through a check valve in a pipe that penetrates the atmosphere opening in the bottom wall of the container, the lower cavity, and the adsorption section.

In the above-mentioned canister, each check valve is installed inside each pipe, and the pipe is inserted into the suction part of the container or passed through the suction part and extended to the atmosphere port. Piping takes time. Further, since the pipe passing through the suction part directly communicates with the atmosphere port, it is necessary to separately provide means such as a filter to prevent the dust sucked in together with the outside air from clogging the check valve.

[Problems to be solved by the invention] The purpose of the invention is to have a simple structure, easy processing and assembly, and to prevent the exhalation action of the fuel tank from being obstructed even if a large amount of evaporated fuel is adsorbed to the evaporated fuel adsorbent. Our goal is to provide canisters that are not available.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the present invention is such that a bypass passage is defined by a partition wall extending from the upper end wall to the lower end along the peripheral wall of the container whose lower end is open. A valve box is defined inside the container adjacent to the upper end wall and the partition wall, and an adsorption section for accommodating the evaporated fuel adsorbent is provided in the empty space excluding the valve box and the bypass passage of the container, and the valve box is connected to the fuel tank on the upper end wall. A purge control valve is installed at the lower end of the valve box to allow vaporized fuel to flow from the fuel tank to the adsorption section via the valve box. A valve is installed, an exhalation valve is installed in the partition wall to allow outside air to flow from the bypass passage through the valve box to the fuel tank, and a bottom plate with an air vent is connected to the bottom end of the container with a filter in between. .

[Operation] The evaporated fuel in the fuel tank pushes open the check valve from the valve box of the container, flows out to the adsorption part, and is adsorbed by the evaporated fuel adsorbent. The evaporated fuel adsorbed by the evaporated fuel adsorbent in the container is sucked into the intake pipe when the purge control valve opens during high-speed operation of the engine.

When the internal pressure of the fuel tank becomes negative, outside air is sucked into the fuel tank through the atmosphere port in the bottom plate of the container, the bypass passage, and the exhalation valve.

[Embodiment of the invention] As shown in FIG. 1, a canister A according to the invention includes a valve box 15 having a check valve and an exhalation valve inside a container 6, and an intake pipe of an engine on the upper end wall of the container 6. Each container is integrally equipped with a purge control valve 14 operated by a pressure of 10 degrees, the inside of the container 6 is filled with an evaporated fuel adsorbent 7 such as granular activated carbon, and an atmosphere port 18 is provided at the bottom. The valve body 15 communicates with the interior of the fuel tank 16 via a pipe 24 and a known rollover valve 17 .

The purge control valve 14 has an upper high pressure chamber communicating with the upstream side of the throttle valve 27 of the intake pipe 10 via a pipe 20, and a lower low pressure chamber communicating with the downstream side of the throttle valve 27 of the intake pipe 10 via a pipe 19. communicated.

A port 21a (FIG. 2) provided in the upper end wall 28 of the container 6 communicates with the float chamber 13 of the vaporizer via a tube 21. One end of the intake pipe 10 is connected to an air cleaner 12, and the other end is connected to an intake port 9 that is opened and closed by an intake valve 26 of the engine. 5 is a cylinder of the engine, and 25 is a piston.

As shown in FIG. 2, according to the present invention, the canister A is a substantially cup-shaped container 6 with an open bottom end.
A partition wall 8 extending from the upper end wall 28 to the lower end is provided on the inner peripheral wall of the
The bypass passage 8 is integrally formed by a. A cylindrical valve box 15 is configured inside the container 6 adjacent to the partition wall 8a and the upper end wall 28, and a cup-shaped valve seat 36 is fitted to the lower end of the valve box 15. The wire mesh filter 35 is supported so that it does not come off.

A plurality of passages 42 are provided in the upper end wall 28 of the valve seat 36, and the through holes 42 can be opened and closed by a mushroom-shaped check valve 34 made of rubber. Partition wall 8 that partitions valve box 15
A through hole 43 provided in a can be opened and closed by an exhalation valve 33 similar to the check valve 34. An opening for mounting an exhalation valve 33 is provided in the peripheral wall of the container 6,
And it is closed by a lid 32.

A port 24 protrudes upward from the upper end wall 28 of the container 6 that partitions the valve box 15 and connects the aforementioned pipe 24.
a is integrally provided. Similarly, a port 21a for connecting the aforementioned tube 21 is integrally provided in the center of the upper end wall 28 of the container 6.

The purge control valve 14 is configured as follows. A valve box 22 is integrally formed on the upper end wall 28 of the container 6,
A diaphragm 30 that opens and closes the end of the passage 39 is
It is held between the valve box 22 by the lid 29. A spring 31 is interposed between the diaphragm 30 and the upper end wall 28. The upper chamber of the diaphragm 30 is connected to the upstream side of the throttle valve 27 of the intake pipe by a pipe 20, and the lower chamber of the diaphragm 30 is connected to the intake pipe 10 by a pipe 19.
The throttle valve 27 is connected to the downstream side of the throttle valve 27 .

Inside the container 6, adjacent to the upper end wall 28, a wire mesh filter 38 and a felt filter 37 are supported in an overlapping manner. A conical bottom plate 11 having an air vent 18 is fitted and fixed to the lower end of the container 6 with a felt filter 40 and a wire mesh filter 41 sandwiched therebetween. An empty space other than the valve box 15 and the bypass passage 8 of the container 6, specifically, between the filter 37 and the filter 40, is filled with an evaporated fuel adsorbent 7 such as activated carbon.

Since the exhalation valve 33 and the check valve 34 are constructed in the same way, the case of the check valve 34 shown in FIG. 3 will be explained. The check valve 34 is formed as a mushroom-shaped body made of relatively soft rubber or synthetic resin, and the umbrella portion 34c can be easily bent by the pressure difference acting on the upper and lower surfaces. A shaft portion 34a is integrally formed at the center of the umbrella portion 34c, and a ball portion 34b is provided at an intermediate portion of the shaft portion 34a. The ball portion 34b is connected to the valve seat 36 or the partition wall 8a.
To attach it to the valve, insert the shaft 34a into the hole in the valve seat 36 or the partition wall 8a, pull the shaft 34a strongly,
By simply pulling out the bulb portion 34b to the opposite side of the valve seat 36 or the partition wall 8a, the peripheral edge of the umbrella portion 34c is held in close contact with the valve seat 36 or the partition wall 8a.

Next, the operation of the device of the present invention will be explained. As shown in FIG. 1, fuel in the fuel tank 16 is sent to the float chamber 13 of the carburetor by a fuel pump (not shown), and is sucked from the float chamber 13 into the intake pipe 10. When the fuel tank 16 is filled with evaporated fuel and the internal pressure of the fuel tank 16 becomes high, the evaporated fuel flows out into the valve box 15 via the rollover valve 17 and the pipe 24, and closes the check valve 34 through the through hole 42. Push open,
After passing through the filter 35, the vaporized fuel adsorbent 7 in the container 6
is adsorbed to. In this way, the harmful components (mainly hydrocarbons) in the evaporated fuel are adsorbed by the evaporated fuel adsorbent 7, and the purified air is passed through the filters 40, 41,
It is discharged into the atmosphere through the atmosphere port 18.

When the engine is operating at low speed, that is, when the throttle valve 27 is throttled, the purge control valve 14 is connected to the diaphragm 3 connected to the upstream side of the throttle valve 27 in the intake pipe 10.
0, the pressure in the lower chamber of the diaphragm 30 downstream of the throttle valve 27 of the intake pipe 10 is lower than the pressure in the upper chamber of the diaphragm 3.
0 is drawn downward against the force of spring 31, and passage 39 is closed. Therefore, at this time, the purge control valve 14 prevents the evaporated fuel in the evaporated fuel adsorbent 7 of the canister A from being sucked into the intake pipe 10, disturbing the idling operation, and increasing the concentration of exhaust gas due to incomplete combustion. It acts to suppress it.

On the other hand, when the engine is operating at high speed, that is, when the throttle valve 27 is fully open, the throttle valve 27 of the intake pipe 10
Since the pressure difference between the upstream and downstream sides of will be small,
The diaphragm 30 of the purge control valve 14 is connected to the spring 31
The passage 39 is opened by being pushed up by the force of . Therefore, the evaporated fuel adsorbed on the evaporated fuel adsorbent 7 passes through the passage 39, the valve box 22, and the pipe 19 to the intake pipe 1.
0 and is used for combustion in the engine. As a result, the evaporated fuel adsorbent 7 is regenerated.

After the engine is stopped, the evaporated fuel in the float chamber 13 of the carburetor is adsorbed by the evaporated fuel adsorbent 7 through the pipe 21 and the port 21a.

As the temperature drops after the engine stops, fuel tank 1
When the internal pressure of 6 becomes negative pressure, the outside air enters the atmosphere port 1.
8. After passing through the filters 41 and 40 and the bypass passage 8, the exhalation valve 33 is opened through the through hole 43 of the partition wall 8a to enter the valve box 15, and further through the port 24a and the pipe 24, it is sucked into the inside of the fuel tank 16.

[Effects of the invention] As described above, in the present invention, a bypass passage is defined by a partition wall extending from an upper end wall to a lower end along the peripheral wall of a container whose lower end is open, and a bypass passage is defined inside the container adjacent to the upper end wall and the partition wall. The valve box is partitioned, and the empty space of the container excluding the valve box and the bypass passage is equipped with an adsorption section that accommodates the evaporated fuel adsorbent, and the upper end wall has a port that communicates the valve box with the fuel tank and a port that connects the adsorption section to the intake pipe. A purge control valve that allows the flow of evaporated fuel is installed, a check valve that allows the evaporated fuel to flow from the fuel tank to the adsorption section via the valve box is installed at the lower end of the valve box, and a bypass passage is installed in the bulkhead. An exhalation valve that allows outside air to flow from the tank to the fuel tank via the valve box is installed, and a bottom plate with an air vent is connected to the bottom end of the container with a filter sandwiched in between.The structure of each valve is simple and durable. The valve box that supports each valve is integrated with the container, and the container is molded with resin, making it easy to mass-produce, and it is easy to install on vehicles and connect pipes, reducing costs. In particular, compared to installing an exhalation valve directly in the fuel tank, there is no need for a separate filter, and the filter in the adsorption section is integrated with the filter in the bypass passage.
The number of parts and assembly man-hours are reduced.

When the internal pressure of the fuel tank decreases, outside air is sucked into the fuel tank from the atmosphere vent through the filter, bypass passage, exhalation valve, and valve box, without passing through the adsorption unit, resulting in deformation due to the abnormal decrease in the internal pressure of the fuel tank. This prevents evaporated fuel from being sucked into the adsorption section.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a canister that removes evaporated fuel from the fuel supply system of an engine according to the present invention, Figure 2 is a side sectional view of the canister, and Figure 3 is a valve that constitutes a check valve and an exhalation valve. FIG. 2 is a side cross-sectional view of the body. 6... Container, 7... Evaporated fuel adsorbent, 8... Bypass passage, 8a... Partition wall, 10... Intake pipe, 1
1...Bottom plate, 14...Purge control valve, 15...Valve box, 16...Fuel tank, 18...Atmospheric port, 24
a... Port, 28... Upper end wall, 33... Exhalation valve, 34... Check valve, 40, 41... Filter.

Claims (1)

[Scope of utility model registration request] A bypass passage is defined by a partition wall extending from the upper end wall to the lower end along the peripheral wall of the container whose lower end is open, and a valve box is defined inside the container adjacent to the upper end wall and the partition wall, and the valve box of the container and the bypass passage are separated. An adsorption section that accommodates the evaporative fuel adsorbent is provided in the empty space except for the evaporative fuel adsorbent, and a port that connects the valve box to the fuel tank and a purge control valve that allows the evaporative fuel to flow from the adsorption section to the intake pipe are installed on the upper end wall. A check valve is installed at the lower end of the valve box to allow the flow of evaporated fuel from the fuel tank to the adsorption section via the valve box, and a check valve is installed on the bulkhead to allow the flow of outside air from the bypass passage to the fuel tank via the valve box. A canister consisting of a bottom plate with an air vent and a filter sandwiched between the lower end of the container and an exhalation valve.