JP3139599B2 - Canister arrangement structure - 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 arrangement for preventing fuel vapor generated in a fuel tank of an internal combustion engine from diffusing into the outside air.

[0002]

2. Description of the Related Art A canister provided to prevent vaporized fuel from diffusing into the atmosphere, adsorbs fuel vapor on the surface when activated carbon packed inside comes into contact with fuel vapor,
Utilizing the property of detaching when air flows, the pipe extending from the fuel tank is connected to the canister, and the fuel vapor generated in the fuel tank is absorbed and temporarily stored, and the purge pipe extending from the canister is connected. When purge air is introduced from the air inlet of the canister by suction negative pressure and connected to the intake system of the engine, the adsorbed fuel vapor is released and purged to the intake system via the purge pipe.

As the temperature of activated carbon increases, self-heating is promoted to facilitate the release of fuel vapor and the purging ability can be improved, and the purging ability can be improved. If the purging proceeds, the adsorbing ability of fuel vapor can be restored. An example of using exhaust heat to heat a canister has been proposed. For example, Japanese Unexamined Utility Model Publication No. 58-144051 discloses a method in which a heat exchanger is provided adjacent to a canister, a cooling water passage returning to a radiator for cooling an engine is branched, and the heat is passed through a water pump on the way. A circulation path is configured to be guided to the exchanger and return the cooling water in the heat exchanger to a cooling water passage from the radiator to the engine.

[0004] During operation of the engine, a portion of the cooling water heated by the engine is led to the heat exchanger and circulated, so that the canister is warmed together with the activated carbon therein, thereby facilitating purging and increasing the adsorption capacity. By improving the function of the canister as described above, it is possible to reduce the size of the canister without increasing the capacity of the canister.

The publication also discloses an example of circulating exhaust gas of an engine to a heat exchanger provided in a canister and an example of circulating lubricating oil. In addition, there is an example in which a heater is mounted on the inner or outer periphery of the canister and is operated as required. In a device without a device for raising the temperature of a special canister, it is common practice to arrange the canister in an engine room to heat the canister by radiating heat from the engine body during engine operation.

[0006]

However, in the example described in the above publication, a heat exchanger is provided in a canister to form a circulation path of cooling water, and a pump and a circulation control means are required. There is a problem in cost, and reduction in weight is also hindered. When a heater is used, there is a similar problem since wiring, a control circuit and the like are required.

Further, if the canister is still at a high temperature even after the engine is stopped, the activated carbon tends to separate fuel vapor and cannot be adsorbed. Therefore, especially when the fuel evaporates immediately after the engine is stopped, the fuel vapor cannot be adsorbed. It is desirable that the temperature drop as soon as possible after the engine is stopped. However, if the cooling water circulates through the heat exchanger provided in the canister, the temperature does not drop immediately due to the residual heat of the cooling water after the engine is stopped, so that the fuel that actively evaporates cannot be adsorbed.

[0008] The same can be said of the arrangement of the canister in the engine room. In other words, the canister in the engine room is warmed by heat radiation from the engine during engine operation, and the purge efficiency is improved.However, even after the engine is stopped, the canister temperature does not decrease due to the residual heat in the engine room, so the fuel vapor adsorption process is sufficient. Can not.

[0009] The present invention has been made in view of such a point,
An object of the present invention is to provide a canister disposing structure having a simple structure in which the temperature of the canister is raised during the operation of the engine to promote purging, and the temperature is lowered immediately after the engine is stopped to sufficiently absorb the fuel vapor.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention temporarily absorbs fuel vapor generated in a fuel tank and purges the vapor into an intake system of an engine to prevent diffusion of fuel to the atmosphere. A duct in which the canister is arranged in a front fender separated from the engine room, and which has an intake near the canister behind the radiator fan arranged in the front of the vehicle body and guides the radiator exhaust air to the canister A member, and the duct member
Horizontal base of battery base and front wheel house
, The bottom plate of the duct member is inclined and the canister is disposed at a position higher on the downstream side than on the upstream side.

Therefore, during operation of the engine, the radiator exhaust air heated by the radiator is guided to the canister by the duct member, so that the canister can be heated to facilitate purging, and the ability to adsorb fuel vapor is restored. And, since the canister is located in the front fender that is isolated from the engine room, after the engine stops, the canister is not affected by the residual heat in the engine room and the temperature decreases due to the outside air to reduce the fuel vapor efficiency. Good adsorption can be achieved.

Further, since the canister is arranged by utilizing the space in the front fender, it is advantageous in terms of space, has a high degree of freedom in layout, and has a simple structure in which only a duct member is arranged, thereby reducing costs. be able to. Duct member is battery base and front wheel
Since it is arranged between the horizontal plate of the house,
It is sufficient to be short without bending it more than
Key in the intake of the radiator exhaust air behind the radiator fan.
Because it is located near Janistar, it can be shorter and shorter
Data exhaust air to the canister efficiently with a slight temperature drop
Can guide you. Duct member and battery base
Fixed between the horizontal plate of the front wheel house
The number of mounting points and work required to secure the duct members
The number can be reduced. Further, since the bottom plate of the duct member is inclined and located at a higher position on the downstream side than on the upstream side, it is possible to prevent water from entering from the upstream intake.

By providing a canister cover for covering the canister and connecting the downstream end of the duct member to the canister cover, intrusion of mud and water can be prevented by the canister cover, and the radiator can be connected to the duct member by connecting the duct member to the canister cover. The exhaust air can be efficiently guided to the canister, and the purge efficiency can be further improved.

[0014]

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention shown in FIGS. 1 to 12 will be described below. FIG. 1 is a schematic view in which a left front side of a vehicle body from a radiator of a four-wheeled vehicle to a fender of a left front wheel is partially omitted, FIG. 2 is a plan view, FIG. 3 is a front view, and FIG. It is a side view.

A radiator fan 2 is provided behind a radiator 1 located at the front center of the vehicle body, and an engine 3 is mounted further behind the radiator fan 2. A front wheel house 4 is formed on the left side of these. The front wheel house 4 has an arcuate plate portion 4a at the front and rear positions where the engine 3 is mounted, and swells, and the top portion bulges inward to form a damper housing 4b.

The arc plate 4a of the front wheel house 4
Extends forward to form a horizontal plate portion 4c and an arc plate portion 4a
The inner edge of the horizontal plate portion 4c is bent downward to form a vertical plate portion 4d, and the lower end of the vertical plate portion 4d is bent inward to form a channel portion 4e opened upward. The channel portion 4e is covered with a frame member 5 bent in an L-shape to form a side frame 6 having a rectangular cross section oriented in the front-rear direction.
Is defined.

An arc plate portion 8a and a horizontal plate portion 8 are provided below the arc plate portion 4a and the horizontal plate portion 4c of the front wheel house 4.
An inner fender 8 made of c is provided, and a fender space 9 is formed between the upper and lower sides, and the fender space 9 is isolated from the engine room 7 by the vertical plate portion 4 d of the front wheel house 4 and the side frame 6. A battery 10 having a substantially rectangular parallelepiped shape is mounted on a battery base 11 from the horizontal plate portion 4 c of the front wheel house 4 to the side frame 6.

A canister 20 is mounted in the fender space 9 separated from the engine room 7, and a canister cover 21 is put on the canister 20.
The canister 20 incorporates activated carbon in a main body casing 20a having a rectangular cylindrical shape, and is attached to a vertical plate portion 4d of the front wheel house 4 via a bracket 19.

As shown in FIGS. 5 and 6, the canister
A connecting pipe 20c connected to an intake system from a rear surface of the cylindrical head 20b and swelling to a fuel tank and a connecting pipe 20d connected to a fuel tank are formed on the upper part of the main body casing 20a. Are located up and down and project rearward.

A connecting pipe 20f communicating with the atmosphere protrudes rearward from a bulging portion 20e on the right side of the cylindrical head 20b. An engaging bulging portion 20g is provided on the right side surface of the main body casing 20a. The engaging bulging portion 20g has a trapezoidal shape in a side view as shown in FIG. And make
Grooves 20h, 20h are formed on the inclined front and rear side edges.

A pair of left and right hose clamps 20i are provided on the rear surface of the rectangular cylinder of the main casing 20a so as to be able to clamp two hoses. Therefore, a purge hose 22 is connected to the upper connection pipe 20c protruding from the cylindrical head 20b, and the purge hose 22 bent downward is connected to one of the hose clamps 20c.
A fuel vapor introduction hose 23 is connected to a lower connecting pipe 20d projecting from the cylindrical head 20b, and the fuel vapor introduction hose 23 bent downward is connected to the other hose clamp.
The purge hose 22 and the fuel vapor introduction hose 23 pass between the vertical plate 4 d of the front wheel house 4 and the inner fender 8, and the purge hose 22 is connected to the intake system of the engine 3. Introductory hose 23
Is connected to the fuel tank.

An air introduction hose 24 is connected to a connection pipe 20f protruding from the bulging portion 20e on the right side of the cylindrical head 20b, and the air introduction hose 24 bent downward has an open lower end opening to the atmosphere.

As shown in FIGS. 7 to 9, the canister cover 21 put on the canister 20 is
A main body cover portion 21a composed of two walls, a front wall and a side wall, which cover the front and left sides of the rectangular cylindrical main body casing 20a of the canister 20.
And an upper cover 21b that covers the cylindrical head 20b and the bulging portion 20e of the canister 20 with front, rear, left and right side walls and an upper wall, and has an elliptical cross section protruding upward from the upper wall opening of the upper cover 21b. And a connecting cylinder 21c.

The canister cover 21 includes an upper cover 21
A front and rear engaging projection 21d is provided at a lower end edge of the right side wall of b.
An engagement protrusion 21e is provided on the right edge of the front wall of the main body cover portion 21a, and the engagement protrusions 21d and 21e are engaged with the bracket 19 to be supported.

As shown in FIGS. 10 and 11, the upper and lower corner portions of the upper portion of the substantially rectangular bracket body plate portion 19a extend in the radial direction while bending inward to form the mounting portions 19b and 19c. The lower rear corner also extends rearward to form a mounting portion 19d. On the bracket body plate portion 19a, ridges 19 cut and raised outwardly symmetrically in the front-rear direction.
e, 19e are formed.
h, 20h, the front-back distance becomes smaller as going downward.

The upper side of the bracket body plate portion 19a is bent inward to form a horizontal flange 19f.
An engagement hole 19 for engaging the canister cover 21 before and after 19f.
g and 19g are formed, and an engagement hole 19h is also formed in a lower front corner of the bracket body plate portion 19a.

The engaging bulging portion 20g on the right side of the canister 20 is fitted between the protruding strips 19e, 19e of the bracket 19 from above, and the protruding strips 19e, 19e and the grooves 20h, 20h are fitted. When the canister 20 is supported by the bracket 19 (see FIG. 12), and the canister 20 is covered with the canister cover 21, the upper portion of the canister 20 becomes an upper cover portion 21b.
The main body casing 20a covers the front and left sides with the main body cover portion 21a of the canister cover 21. At this time, the engaging projections 21d of the canister cover 21 and the engaging holes 19g of the horizontal flange 19f of the bracket 19 cover the engaging projections 21d. , 19g, and another engaging projection 21e is engaged with an engaging hole 19h at the lower front of the bracket 19, so that the canister cover 21 is also supported.

The bracket 19 itself has three extended mounting portions.
19b, 19c, and 19d are fixed to the vertical plate portion 4d of the front wheel house 4 by bolts and supported. Therefore, the canister 20 is mounted in the fender space 9 by the bracket 19
, And a canister cover 21 that covers the canister 20 is also fixed to the bracket 19.

The main body cover 21a of the canister cover 21 covers the front and left sides of the canister body, the vertical plate 4d of the front wheel house 4 covers the right side, and the arc plate 8a of the inner fender 8 covers the rear. I have.

The cylindrical head portion 20a and the bulging portion 20d of the canister 20 are covered by an upper cover portion 21b of the canister cover 21. Above the upper wall of the upper cover portion 21b, a horizontal plate portion 4c of the front wheel house 4 is covered. An oval opening 4f is formed in the horizontal plate portion 4c so as to face the connecting tube portion 21c.

A duct tube 30 having an upstream end inlet 30a behind the radiator fan 2 is bent leftward from the inlet 30a so that the tube main body 30b is connected to the battery base 11 and the horizontal plate 4c of the front wheel house 4. And is bent downward toward the elliptical opening 4f of the horizontal plate portion 4c through the elliptical opening 4f so that the downstream end opening 30c is formed in the connecting cylindrical portion 21c of the canister cover 21. It is inserted.
As described above, since the duct main body 30b is disposed substantially horizontally between the battery base 11 and the horizontal plate portion 4c of the front wheel house 4, the duct pipe 30 is short enough to be bent without being bent more than necessary. The discharged air can be efficiently guided to the canister 20 with a slight temperature drop.

The upstream end inlet 30a of the duct tube 30 has a rectangular opening facing forward located behind the radiator fan 2 and near the canister 20 near the outer periphery, and the duct tube 30 is located upstream of the tube body 30b. Brackets protruding from the front and rear sides
31 is fixedly supported on the lower surface of the upper battery base 11 by screws 32 and is sandwiched between the battery base 11 and the horizontal plate portion 4c of the front wheel house 4, and the downstream end opening 30c of the duct pipe 30 is connected to the canister cover 21. Is fitted and connected to the connecting cylindrical portion 21c.

Therefore, the number of attachment points and man-hours for fixing the duct tube 30 are reduced. As shown in FIG. 3, the pipe main body 30b of the duct pipe 30 is arranged such that the bottom plate is particularly inclined and gradually becomes higher toward the downstream.

Since the duct tube 30 is disposed as described above, the radiator exhaust air warmed by the radiator 1 by the rotation of the radiator fan 2 is taken into the inlet 30a of the duct tube 30 and guided to the tube main body 30b. Then, the canister 20 is discharged from the downstream end opening 30c into the canister cover 21, so that the canister 20 can be efficiently warmed.

The upstream end inlet 30a of the duct pipe 30 has a rectangular opening located in the vicinity of the outer peripheral portion behind the radiator fan 2, so that the radiator exhaust air can be efficiently taken in. Since it is located closer, the pipe body 30b is short and can be sent to the canister 20 while substantially maintaining the temperature of the radiator exhaust air.

Therefore, during operation of the engine, the radiator exhaust air heated by the radiator can be efficiently guided to the canister 20 by the duct pipe 30 and efficiently heated by the canister cover 21, so that the canister 20 promotes self-heating of the activated carbon inside. As a result, the purge of the fuel vapor adsorbed on the activated carbon to be sent to the engine intake system can be increased, and at the same time, the purging is promoted, so that the fuel vapor adsorption capacity can be restored.

Further, since the canister 20 is disposed in the fender space 9 separated from the engine room 7 by the vertical wall 4d of the front wheel house 4 and the side frame 6, the residual heat in the engine room 7 after the engine is stopped. The canister 20 can quickly lower the temperature by the outside air without being affected by the canister 20, and can efficiently adsorb the fuel vapor generated in the fuel tank.

Canister using fender space 9
Since 20 are arranged, the space such as the engine room 7 can be effectively used, which is advantageous in terms of space. Further, the canister cover 21 is connected to the downstream end opening 30c of the duct pipe 30 to efficiently exhaust the radiator exhaust air.
Therefore, the canister 20 can be efficiently warmed to improve the purging ability.

The canister cover 21 can also serve to prevent mud and water from entering the canister 20. Since the bottom plate of the pipe main body 30b of the duct pipe 30 is inclined and located at a higher position on the downstream side than on the upstream side, it is possible to prevent water from entering through the inlet 30a. Furthermore, since the radiator exhaust air is used to heat the canister 20, the maximum temperature of the heat source is limited, the parts are not damaged by heat, and no special measures are required to protect the parts.Simple configuration Thus, cost can be reduced.

Next, an example in which the rotation of the radiator fan 2 is controlled by a signal from the engine control unit ECU in a vehicle equipped with an air conditioner will be described. To explain this control procedure according to the flowchart of FIG. 13, the engine water temperature T _W is determined whether or not the predetermined temperature T _W1 (e.g. 30 ° C.) or higher (Step 1), jumps to Step 5 if less than T _W1, In step 5, it is determined whether or not the engine water temperature T _W is equal to or higher than a predetermined water temperature T _W2 (for example, 80 ° C.). In this case, since it is equal to or lower than T _W2 , the process proceeds to step 7 and the radiator fan 2 is stopped.

If the engine coolant temperature T _W exceeds the predetermined coolant temperature T _W1 in Step 1, it is determined in Step 2 whether or not the engine is idling. If not, it is determined in Step 3 whether the air conditioner is running. If the air conditioner is operating, it is determined in step 4 whether the vehicle is decelerating. If the vehicle is not decelerating, the process proceeds to step 6 to determine whether the engine is operating. 2
Is driven forward, and when the engine is stopped, the routine proceeds to step 9, where the radiator fan 2 is driven reversely.

That is, when the air conditioner is driven and running at a constant speed or acceleration, the radiator fan 2 is driven to rotate forward to send high-temperature radiator exhaust air to the canister 20 to promote purging. The radiator fan 2 is driven in reverse to absorb the hot air around the canister 20 through the duct tube 30 and take in the outside air to the canister.
20 can be cooled quickly and the fuel vapor adsorption efficiency is improved.

When the air conditioner is idle (step 2), the air conditioner is not operating (step 3),
When the vehicle is decelerating (Step 4), the process jumps to Step 5 to determine whether the engine coolant temperature T _W is equal to or higher than the predetermined coolant temperature T _{W2. If the} engine coolant temperature T _W does not reach the predetermined coolant temperature T _W2 , the process proceeds to Step 7 to stop the radiator fan 2. As a result, unnecessary noise caused by unnecessary driving of the radiator fan 2 can be avoided, and high quality can be improved.

The radiator fan 2 if the engine water temperature T _W is determined whether the engine operation proceeds to step 6 if the predetermined temperature T _W2 or during engine operation at Step 5
Is driven forward (step 8), and when the engine is stopped, the radiator fan 2 is driven reversely (step 9).

That is, if the engine water temperature T _W is equal to or higher than the predetermined water temperature T _W2 even during the idle state or deceleration, the radiator fan 2 is driven to rotate forward to promote purging, and the air conditioner and the engine are stopped but the engine water temperature T _W When the water temperature is equal to or higher than the predetermined water temperature T _W2 , the radiator fan 2 is reversely driven to rapidly cool the canister 20 to improve the fuel vapor adsorption efficiency.

By controlling the driving of the radiator fan 2 as described above, the radiator fan 2 can be controlled only when necessary.
, The rotation frequency is minimized, the durability of the radiator fan 2 is improved, and unnecessary noise is prevented from being generated, so that high quality can be improved.

When the outside air temperature is high and the fuel vapor in the fuel tank is generated intensively, such as in summer, the radiator fan 2 is driven forward during the engine operation to promote purging, and after the engine is stopped, the radiator fan 2 is rotated reversely. By driving the canister 20, the canister 20 can be quickly cooled to improve the fuel vapor adsorption efficiency.

[0049]

[0050]

[0051]

[0052]

[0053]

According to the present invention, since the radiator exhaust air is sent to the canister in the fender through the duct pipe, the radiator exhaust air heated by the radiator is guided to the canister by the duct member during operation of the engine, so that the canister is heated and purged. And the ability to adsorb fuel vapor can be restored. And, since the canister is located in the front fender that is isolated from the engine room, after the engine stops, the canister is not affected by the residual heat in the engine room and the temperature decreases due to the outside air to reduce the fuel vapor efficiency. Good adsorption can be achieved.

Further, since the canisters are arranged by utilizing the space in the front fender, it is advantageous in terms of space and has a high degree of freedom in layout, and has a simple configuration in which only duct members are arranged, thereby reducing costs. be able to.

By providing a canister cover for covering the canister and connecting the downstream end of the duct member to the canister cover, intrusion of mud and water can be prevented by the canister cover, and the radiator can be connected to the duct member by connecting the duct member to the canister cover. The exhaust air can be efficiently guided to the canister, and the purge efficiency can be further improved.

[0056]

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a vehicle body left front side from a radiator to a left front wheel fender of a four-wheeled motor vehicle according to an embodiment of the present invention, with a part of the vehicle front left side omitted;

FIG. 2 is a plan view of the same.

FIG. 3 is a front view of the same.

FIG. 4 is a side view of the same.

FIG. 5 is a top view of the canister.

FIG. 6 is a side view of the same.

FIG. 7 is a top view of the canister cover.

FIG. 8 is a side view of the same.

FIG. 9 is a front view of the same.

FIG. 10 is a top view of the bracket.

FIG. 11 is a side view of the bracket.

FIG. 12 is a partially omitted top view showing an attached state of the canister.

FIG. 13 is a flowchart showing a procedure of drive control of a radiator fan.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Radiator, 2 ... Radiator fan, 3 ... Engine, 4 ... Front wheel house, 5 ... Cover plate member,
6 ... side frame, 7 ... engine room, 8 ... inner fender, 9 ... fender space, 10 ... battery,
11… Battery base, 19… Bracket, 20… Canister, 21… Canister cover, 22… Purge hose, 23
... fuel vapor introduction hose, 24 ... atmosphere introduction hose, 30 ... duct pipe, 31 ... bracket.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasuo Okamoto 1-4-1, Chuo, Wako-shi, Saitama Pref. Honda Technical Research Institute Co., Ltd. (56) References Japanese Utility Model 4-24652 (JP, U) Japanese Utility Model 3-92549 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02M 25/08 311 F02M 25/08 B60K 15/077 F01P 5/06 505 F01P 5/06 511

Claims (2)

(57) [Claims] 1. A canister for temporarily adsorbing fuel vapor generated in a fuel tank and purging it into an intake system of an engine to prevent diffusion of fuel into the atmosphere is disposed in a front fender separated from an engine room. A duct member that has an intake near the canister behind the radiator fan disposed in the section and guides the radiator exhaust air to the canister, wherein the duct member is a battery.
Between the base and the horizontal plate of the front wheel house.
Rarely, the canister arrangement structure is characterized in that the bottom plate of the duct member is inclined and the downstream side is higher than the upstream side. 2. The canister arrangement structure according to claim 1, wherein a canister cover for covering said canister is provided, and a downstream end of said duct member is connected to said canister cover.