JP2543063Y2 - Canister - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canister for capturing fuel vapor generated from a fuel system of an engine and preventing the vapor from being released into the atmosphere.

[0002]

2. Description of the Related Art A canister captures fuel vapor generated from a fuel tank or a carburetor when the engine is stopped by an adsorbent in the canister, takes in the atmosphere during operation of the engine, and desorbs fuel components from the adsorbent. To be sent to
Conventionally, there is a canister as disclosed in Japanese Patent Application Laid-Open No. 62-265460.

[0003] This canister has a cylindrical case 1 as shown in FIG. The case 1 is filled with activated carbon 2, and the bottom of the case 1 has a fuel reservoir 3.
Is provided. A fuel inlet pipe 4 and a fuel outlet pipe 5 are provided on the center axis of the case 1 in a double cylindrical shape. A hole 6 is provided in a portion of the fuel introduction pipe 4 that enters the fuel reservoir 3. A fuel vapor discharge hole 7 communicating with the fuel introduction pipe 4 is formed in an upper portion of the portion of the fuel outlet pipe 5 that has entered the fuel reservoir chamber 3, and a liquid fuel discharge hole 8 is formed below the fuel discharge pipe 7. Has been established. At the top of the case 1, an air inlet 9 is provided.

Thus, when the engine is stopped, the fuel from the fuel tank or the like becomes vapor and enters the fuel reservoir 3 through the hole 6 through the fuel introduction pipe 4. Then, this steam is adsorbed by the activated carbon 2 and only air is released into the atmosphere from the air inlet 9. During operation of the engine, the atmosphere enters the case 1 through the air inlet 9 by the action of the negative pressure from the engine, which desorbs steam from the activated carbon 2 and enters the fuel outlet pipe 5 through the hole 7 with the steam. Head for the engine cylinder. Also,
Liquid fuel is also drawn into the fuel reservoir 3 from the fuel tank. When the negative pressure is applied, the liquid collected in the fuel storage chamber 3 is also drawn into the fuel outlet pipe 5 from the lower hole 8 and travels to the engine cylinder and the like together with the steam.
Burn.

[0005]

In the above-mentioned conventional canister, the liquid content of the fuel stored in the fuel storage chamber 3 at the bottom of the case jumps toward the activated carbon due to the vibration of the engine, the vibration accompanying the running of the automobile, and the like. May come into direct contact with activated carbon. If the liquid adheres to the activated carbon, the performance of the activated carbon for adsorbing and desorbing fuel components is reduced.

In order to solve such a drawback, it is conceivable to increase the height of the ceiling of the fuel reservoir, but this causes a problem that the entire volume of the canister becomes large.

[0007]

According to the present invention, an adsorbent 21 for adsorbing fuel vapor generated in a fuel system of an engine is filled in a case 10, and the amount of fuel vapor and the amount of fuel vapor are reduced. A fuel reservoir 17 for closing the bottom for taking in the liquid component is formed at the bottom below the adsorbent 21 in the case 10, and the introduction and discharge of fuel and the introduction of air are performed at the top of the case 10. In the prepared canister, the fuel introduction passage 23 for introducing fuel extends downward in the case and opens into the fuel reservoir 17, and the fuel flowing from the fuel introduction passage 23 flows into the fuel reservoir 17. A trap plate 14 having a vertically penetrating hole for separating the liquid component from the adsorbent 21 is attached, and a space is provided between the upper surface of the trap plate and the adsorbent 21.
The trap plate 14 is formed and has a configuration having a column portion 14c that contacts the bottom of the fuel reservoir 17.

[0008]

The trap plate is prevented from moving toward the adsorbent when the liquid component of the fuel accumulated in the fuel reservoir chamber jumps up due to vibration of the engine or the like. Therefore, only the vapor of the fuel that has entered the fuel storage chamber rises in the case and is adsorbed by the adsorbent. In addition, a pillar is provided on the trap plate with holes that penetrate vertically.
Part is provided, so hit it against the lower lid
To position the trap plate in the vertical direction.
And the pillars can strengthen the trap plate itself.
Minimize the rocking movement of fuel in the fuel chamber
Can be.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the canister according to the present invention will be described below. As shown in FIGS. 1 and 2, the canister case 10 has a cylindrical portion 10 a that is placed vertically, an upper lid 10 b that closes the top of the cylindrical portion 10 a, and a cylindrical portion 10.
a and a lower lid 10c that closes the bottom of a.

The upper lid 10b holds the upper lattice member 11 between the upper lid 10b and the cylindrical portion 10a. Above and below the upper lattice member 11, filters 13 for preventing leakage of the adsorbent described later are provided.
Are fixed respectively. The lower lid 10c has a container shape with a relatively deep bottom, into which the trap plate 14, the first lower grid member 15 and the second lower grid member 16 are inserted in order from bottom to top. I have.

The trap plate 14 is provided integrally with the lattice plate portion 14a and above and below the lattice plate portion 14a, and pillar portions 14b, 14b, which contact the first lower lattice member 15 and the face plate of the lower lid 10c, respectively. 14c. The lattice plate portion 14a has a large number of holes penetrating in the vertical direction, so that the liquid component of the fuel contained in the case can be dropped from above to below and the vapor component can be passed from below to above. ing.

The space between the first lower lattice member 15 and the face plate of the lower lid 10c, in which the trap plate 14 is stored, is a fuel reservoir chamber 17, in which a fuel tank or the like is provided as described later. The fuel component coming from the fuel system enters. The fuel reservoir chamber 17 by the grid plate portion 14a of the trap plate 14 is divided into upper and lower, the lower is the liquid component storing chamber 17 b
Next, the upper is in the inlet chamber 17 a steam min. Liquid fraction, it is bouncing in storage chamber 17 b, the jumping over the more the grid plate portion 14a is prevented. In addition, the liquid level may be higher than the lattice plate portion 14a, and even in such a case, excessive vibration of the liquid level is prevented.

The second lattice member 16 has a cylindrical portion 16a inserted into the lower lid 10c, and a lattice portion 16b inserted into the cylindrical portion 10a provided on the upper side thereof.
The first lower lattice member 15 is fitted under the cylindrical portion 16a, and a filter 18 for preventing leakage of an adsorbent, which will be described later, is sandwiched between the two. Lattice part 16b
Has a large number of lattices in a cylinder having a diameter smaller than that of the cylindrical portion 10a, and an annular filter 19 is attached to an outer peripheral surface thereof in order to prevent leakage of an adsorbent described later.

The upper edge of the lattice portion 16b is fitted with an annular projection 20 provided on the inner periphery of the cylindrical portion 10a to prevent the adsorbent described later from leaking. Cylindrical part 10a of case 10
A substantially cylindrical room is formed between the filter 13 on the upper lid side and the filter 18 on the lower lid side, and, for example, activated carbon for adsorbing fuel such as gasoline is formed in the room. Is filled.

The lattice portion 16 of the second lower lattice member 16
An annular empty space 22 is formed between b and the inner wall surface of the cylindrical portion 10a. The empty chamber 22 and the fuel storage chamber 17 are separated by an adsorbent layer 21a having a predetermined thickness. In the case 10, a fuel introduction passage 23 is provided vertically along the inner wall surface.

The inlet 23a of the fuel introduction passage 23 is
b. A pipe coming from a fuel tank or the like is connected to the inlet 23a. The fuel introduction passage 23 extends downward from the inlet 23a through the thickness of the upper lattice member 11 and further extends downward as a pipe 24 connecting the upper lattice member 11 and the lower part of the cylindrical portion 10a. , The lower part of the cylindrical part 10a and the second lower lattice member 1
6 penetrates downward. And the exit 2
3b is open in the fuel reservoir 17.

As a result, the vapor or liquid fuel flowing from the fuel tank or the like flows through the fuel introduction passage 23 into the fuel reservoir 17, and the vapor passes through the trap plate 14 and the first lower grid member 15. To reach the adsorbent layer 21 and is adsorbed by the adsorbent layer 21 while rising. The liquid component accumulates below the trap plate 14 in the fuel reservoir 17. The case 1
Inside 0, a fuel outlet channel 25 is provided vertically along the inner wall surface at a location separated from the fuel inlet channel 23.

The fuel outlet passage 25 includes a first fuel outlet passage 25a located below and a second fuel outlet passage 2 located above.
5b, and the lower ends thereof are the entrances 25c and 25d.
It has become. The first inlet 25 c is provided integrally with the trap plate 14, opens below the trap plate 14 in the fuel storage chamber 17, and is immersed in the liquid stored in the fuel storage chamber 17. ing. First fuel outlet 25a
From the first inlet 25c to the second lower grid member 1
6 penetrates upward through the thickness of the cylindrical portion 16a, and communicates with the annular space 22. A mist blowing nozzle 26 is attached to a location communicating with the empty room 22.

The second inlet 25d faces the annular space 22, and is adapted to take in the vapor of the fuel passing through the annular space 22. The second fuel outlet pipe 25b penetrates upward through the thickness of the cylindrical portion 10a from the second inlet 25d, and passes through the pipe 27 attached in the same manner as the pipe 24 so as to be within the thickness of the upper lattice member 11. To the outlet 25e provided in the upper lid 10b.

The second inlet 25d faces the atomizing nozzle 26 at a predetermined distance from the atomizing nozzle 26, and causes the atomizing nozzle 26 to eject fuel mist from the atomizing nozzle 26 by an airflow of fuel vapor or the like toward the second inlet 25d. ing. Spray nozzle 26
Is set such that spraying starts only when the flow rate of the airflow passing therethrough reaches a predetermined value. This flow rate is, for example, 16 l / min.

At the outlet 25e of the second fuel outlet passage 25b, a diaphragm valve 28 for opening and closing the outlet 25e is attached. A hole 29 communicating with the engine is provided in the upper chamber of the diaphragm valve 28, and a valve seat surrounding the discharge port 30 is provided in the lower chamber. When a negative pressure is applied from the engine side, the valve element attached to the diaphragm 31 separates from the valve seat and opens a flow path toward the discharge port 30, and when the negative pressure is eliminated, the valve element contacts the valve seat and closes the flow path. .

At the center of the upper lid 10b of the case 10,
At the time of fuel derivation from the fuel derivation passage 23, the atmosphere is
An atmosphere introduction port 32 for introducing the gas into the chamber 0 is provided. Next, the operation of the canister will be described in accordance with the flow of fuel. When the engine is stopped, the vapor of the fuel coming from the fuel tank or the carburetor enters the fuel introduction passage 23 through the inlet 23 a, descends, and enters the fuel reservoir 17. Then, it passes upward through the first lower lattice member 15 and the filter 18,
It rises in the adsorbent layer 21. While rising, it is adsorbed by the adsorbent 21.

As a result, the fuel vapor generated in the fuel tank and the like is not radiated to the atmosphere as it is. During operation of the engine, outside air is drawn into the case 10 from the air inlet 32 by the action of a negative pressure periodically generated on the engine side. The outside air desorbs the fuel vapor from the adsorbent 21 while descending in the adsorbent layer 21, and enters the empty room 22 with the fuel vapor.
Then, the fuel enters the second fuel outlet passage 25b from the second inlet 25d looking into the vacant space 22, rises in the second fuel outlet passage 25b, and heads toward the engine cylinder from the diaphragm valve 28 during the opening operation.

Further, the fuel enters the fuel reservoir 17 through the fuel introduction passage 23 in a vapor or liquid state from the fuel tank or the vaporizer due to the negative pressure. Of these, the vapor component passes upward through the first lower lattice member 15 and the filter 18, enters the adsorbent layer 21, and reaches the vacant space 22 through the adsorbent layer 21a having a predetermined thickness. A certain amount of this vapor is adsorbed and removed by the adsorbent layer 21 a, and only the surplus enters the empty room 22. Then, the surplus portion joins the fuel vapor desorbed from the upper adsorbent layer 21 at the second inlet 25d, and rises in the second fuel outlet passage 25b.

Therefore, an increase in the concentration of fuel toward the engine can be prevented. On the other hand, the liquid portion of the fuel is collected below the lattice plate portion 14a of the trap plate 14 in the fuel storage chamber 17. When a predetermined amount is accumulated, the first inlet 25c sinks therein.
The liquid component may splash in the storage chamber 17a, but is prevented from jumping upward by the grid plate portion 14a. The liquid level may accumulate above the lattice plate portion 14a, and even in such a case, excessive vibration of the liquid level is prevented.

As a result, the liquid does not reach the filter 18 or the adsorbent layer 21 and the adsorbent adsorption / desorption performance is prevented from lowering. As shown in FIG. 3, when the fuel reservoir chamber is a conventional structure than (b), when the structure of the present invention (a) is, for example, after when the adsorbent capacity is two liters's Is B. W. C (normal butane adsorption / desorption performance) is 150 g, whereas the former is 125 g, indicating that the adsorption / desorption performance of fuel vapor is greatly improved.

When the fuel vapor flows to the second inlet 25d together with the flow of air, a negative pressure is generated in the spray nozzle 26. For this reason, the liquid component in the fuel reservoir 17 rises in the first fuel outlet passage 25a from the first inlet 25c, and is ejected in the form of a mist from the atomizing nozzle 26. Then, the fuel vapor flows from the second inlet 25d into the second fuel outlet passage 25b together with the fuel vapor.

The spray nozzle 26 is activated at the same time when the flow rate of the steam flowing into the second inlet 25d reaches a predetermined amount, for example, 16 l / min. Here, the control of the gasoline discharge amount by the first fuel lead-out path is exemplified by a graph in FIG. In this figure, reference numeral A indicates an ideal gasoline discharge amount control diagram. That is, the discharge of the liquid in the fuel in the canister rises sharply when the flow rate of the steam discharged from the canister reaches a certain amount, and after that amount is kept for a while, sharply decreases. It is desirable.

Reference numeral B indicates a gasoline discharge amount control diagram in the above-described conventional example. This is a case in which the two holes 7 and 8 are both closed by the liquid. The discharge amount of the liquid gasoline rises rapidly from the beginning of the engine operation, and gradually decreases with an increase in the amount of steam discharged from the canister. And is far from the ideal line A. Symbol C indicates a gasoline discharge amount control diagram in the present invention. As is apparent from the above, the canister according to the present invention works almost like an ideal type.

[0030]

[Effects of the Invention] Since the present invention has the above-described structure, even if the liquid component of the fuel stored in the fuel storage chamber jumps up due to the vibration of the engine or the like, it is directed toward the adsorbent. Can be blocked. Therefore, it is possible to appropriately maintain the adsorption / desorption performance of the adsorbent for fuel vapor over a long period of time.

Further, since it is not necessary to increase the height of the ceiling of the fuel storage chamber, it is possible to reduce the size of the entire canister. In addition, a trap plate with holes that penetrate vertically
Is provided with a pillar so that it hits the lower lid
In this way, the vertical direction when attaching the trap plate is
At the same time positioning and trap plate can be strengthened
In addition, the swinging motion of the fuel in the fuel reservoir
Can be

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a canister according to the present invention.

FIG. 2 is an enlarged view showing a lower portion of FIG. 1 in an enlarged manner.

FIG. 3 shows adsorbent capacity and B.I. W. It is a diagram showing the relationship with C.

FIG. 4 is a gasoline discharge amount control diagram.

FIG. 5 is a partially cutaway perspective view of a conventional canister.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Case 14 Trap plate 14a Lattice plate part 15 1st lower lattice member 16 2nd lower lattice member 17 Fuel storage chamber 17a Liquid storage chamber 17b Vapor inflow chamber 21 Adsorbent

Continuing on the front page (72) Inventor Hideo Moriwaki 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside of Honda R & D Co., Ltd. (72) Hideo Watanabe 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside the research institute (72) Atsushi Suzuki 143 Miwa-cho, Hamamatsu-shi, Shizuoka (72) Inventor Tsutomu Mori 199, Ishigami, Tenryu-shi, Shizuoka (56) References Open-worked 61-140158 (JP, U) −2287 (JP, Y2)

Claims (1)

(57) [Scope of request for utility model registration] An adsorbent for adsorbing fuel vapor generated in a fuel system of an engine is filled in a case, and a fuel reservoir chamber for closing a bottom portion for taking in a fuel vapor and a liquid component is provided in the case. In a canister formed at a lower portion below and configured so that introduction and discharge of fuel and introduction of air are performed at an upper portion of the case, a fuel introduction path for introducing fuel extends downward in the case and the fuel is open to the reservoir chamber, wherein the fuel reservoir chamber trap plate having a hole penetrating vertically to isolate the attached liquid fraction of the fuel flowing from the fuel feed path from said adsorbent, said trap plate top surface The space is formed between
The canister is characterized in that the trap plate has a column contacting the bottom of the fuel reservoir.