JPH0444840Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a canister used in a fuel vapor processing device for a vehicle.

(Prior art) In recent vehicles, as shown in Fig. 6, the upper space in the fuel tank and the canister C are connected by a ventilation passage _L1 with a check valve V placed in the middle, and the canister C and the engine intake pipe. are connected by purge passage L ₂ , and the fuel tank T is connected when stopped or when driving.
The fuel vapor generated in the canister C is introduced into the canister C through the ventilation passage _L1 and adsorbed onto the activated carbon.
Air is sucked in from the bottom of the canister C using a predetermined negative pressure in the intake pipe based on engine operation, and the adsorbed fuel is separated from the activated carbon, sent into the intake pipe through the purge passage _l2 , and vapor is released from the fuel line to the outside. I try not to.

Canister C placed on the above line
As shown in Fig. 7, the interior of the case 11 is divided into three parts, and in the upper chamber, a ventilation passage _l1 opens in the annular partition in the center, and a purge passage _l2 opens around it. The lower chamber is provided with a barge air intake 11a, and the middle chamber is provided with perforated plates 12a, 12b and a nonwoven fabric 13 at the upper and lower ends.
The upper and lower perforated plates 12a, 13b are arranged one on top of the other with the perforated plates 12a on the outside, and a predetermined amount of activated carbon 14 in the form of granules, fragments, powder, etc. is stored between them.
12b in a compressed state.

When filling the activated carbon 14, case 1
After installing the upper perforated plate 12a and the nonwoven fabric 13b horizontally in the case 1, the case 11 is turned upside down and set in the activated carbon filling equipment, and the activated carbon 14 is packed as close as possible therein, and then the lower nonwoven fabric 13b and The perforated plate 12b is incorporated so that the internal pressure of the activated carbon 14 is slightly increased when the perforated plate 12b is assembled.

(Problem that the invention aims to solve) By the way, in conventional canisters, as mentioned above, activated carbon is packed in the case as closely as possible, and then the lower nonwoven fabric and perforated plate are pressed together and assembled. However, in many cases, bridges are formed inside the activated carbon layer as shown by the dotted line in Figure 7, and the pressing force from the perforated plate acts only in the vicinity, causing damage to the entire activated carbon layer. Because it is not widespread,
Activated carbon shakes due to vehicle vibrations, splits into spheres, and wears out at the same time, causing the fine particles to scatter outside, resulting in insufficient capacity, which prevents the canister from functioning properly and releases steam to the outside. .

Therefore, the purpose of this invention is to provide a canister that can uniformly hold activated carbon in the form of granules and fragments, prevent wear, and maintain a constant adsorption performance without deteriorating. do.

(Means for Solving the Problems) Based on the above-mentioned purpose, this invention has developed a case in which a ventilation passage, a purge passage, and an outside air intake are opened.
As a canister in a fuel vapor processing device filled with activated carbon in the form of fragments, the adsorption member is compressed and accommodated between porous support members, in which activated carbon is press-sealed inside an elastic bag membrane made of fibers that can be expanded and contracted. That is.

(Example) Figures 1 and 2 show an example of this invention, in which 1 is a cylindrical case made of synthetic resin or light metal, and the inside has an annular partition in the center and an integral upper part. The middle stage is partitioned into three stages with a predetermined volume by the perforated plate 2a and the lower perforated plate 2b, and a ventilation passage _l1 connected to the fuel tank is opened in the annular partition wall of the upper stage. A purge passage _l2 connected to the intake pipe of the engine is opened in the surrounding area, and a barge air intake port 1a is opened in the lower chamber.

As shown in Figure 2, activated carbon 4 in the form of granules, fragments, and powder is placed in the middle chamber of a predetermined volume using a fiber material with heat resistance and strength, such as carbon fiber or glass fiber, which can be expanded and contracted. The adsorption member A is housed in an elastic bladder membrane 3 which is braided into an elastic membrane 3, which is tightly packed in a state where the membrane 3 expands, and which holds activated carbon 4 by the contraction pressure of the membrane 3. The plate 2b is installed in the case 1 so as to press the suction member A.

Therefore, when the vehicle is stopped, running, or refueled, the fuel vapor generated in the tank as usual passes through the ventilation passage _l1 and enters the center of the case 1, causing the bag membrane of the adsorption member A to The fuel penetrates into the interior through the mesh 3 and is adsorbed and held by the activated carbon 4, and the outside air flows in from the lower end intake port 1a due to the intake pipe negative pressure corresponding to the engine load, and the fuel adsorbed by the activated carbon 4. It vaporizes and leaves the upper chamber, and flows out to the intake pipe side through the purge passage _L2 .

Even if the vibration of the vehicle is applied to the case 1 during this time, the entire activated carbon 4 is tightly held by the pressing force of the elastic membrane 3, so it does not shake and is prevented from being worn out, increasing the adsorption capacity. remains constant for a long time.
Note that the perforated plate may be replaced by a wire mesh or a member provided with slits.

FIG. 3 shows a modified example, in which an adsorption member in which activated carbon 4 is tightly packed inside the elastic membrane 3 as described above is used as an annular adsorption member A ₁ and a rod-shaped adsorption member as shown in FIG. The rod _- shaped adsorption member A ₂ is fitted into the center of the annular adsorption member A ₁ and housed in the case 1. In this case, the adsorption capacity and heat resistance are Activated carbons 4 having different properties such as elasticity can be used in combination, increasing adsorption performance and making it possible to finely adapt to vehicle types with different fuel vapor generation conditions.

In addition, A to C in FIG. 5 respectively show other modified examples, and in FIG.
Three suction members A ₁ , A ₂ , A ₃ are formed to hold the , and these are stacked and housed in the middle chamber of the case 1, and between the upper and center ones and the middle and lower ones. The fins 5 are arranged alternately and their edges are fixed to the case 1.
A ring-shaped adsorption member A is housed in a middle chamber, and a space cylinder 1b provided at the center of the lower wall of the case 1 having an intake port 1a is tightly fitted into the center hole of the adsorption member A. In these devices, the existence of the fins 5 and the space cylinder 1b dissipates the heat of adsorption generated when fuel vapor is adsorbed, thereby preventing abnormal temperature rise of the adsorption member and preventing extreme temperature rise of the adsorption member due to vaporization of fuel. Temperature drop can be prevented.

Furthermore, in Figure C, the two cases 1 each housing the suction member A in the middle chamber between the upper and lower perforated plates 2a and 2b are placed facing each other and placed in the upper chamber (in the center in the figure).
The ventilation passage _l1 is opened on one side of the chamber, and the purge passage _l2 is opened on the other side, so that there is no space between the suction members A. is provided to effectively dissipate the heat of adsorption of fuel vapor.

(Effects of the invention) As described above, this invention is used as a canister for fuel vapor processing in vehicles by press-sealing activated carbon in the form of granules, fragments, etc. inside an elastic bag membrane made of fibers that can be expanded and contracted to provide porous support. Since it is compressed and accommodated between the members, the adsorption member can be maintained in an immovable state, and the entire activated carbon can be held uniformly by the contraction pressure of the membrane, even when vibrations from the vehicle are applied. Activated carbon does not shake and break up into large and small spheres, and does not wear out, so it will not run out of capacity even after long-term use.
It does not reduce the adsorption performance of activated carbon. In addition, activated carbon can be contained in various ways that could not be done with conventional bulk packing, and the adsorption capacity and utility value of the canister can be increased.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of this invention. FIG. 2 is a partially cutaway perspective view of the suction member. FIG. 3 is a partially cutaway side view of a modified example. FIG. 4 is a perspective view of the suction member. FIGS. 5A, 5B, and 5C are partially cutaway side views of other modified examples, respectively. FIG. 6 is a side view of a portion of the fuel vapor processing system. FIG. 7 is a sectional view of a conventional canister. In the diagram, 1...Case, 1a...Intake port, 2
a, 2b...Perforated plate, 3...Elastic bag membrane, 4...Activated carbon, A, _A1 , _A2 , _A3 ...Adsorption member, _l1 ...Charge passage, _l2 ...Purge passage.

Claims (1)

[Scope of utility model registration request] In a canister of a fuel vapor processing device, activated carbon in the form of particles or fragments is filled between porous support members in a case with openings for ventilation passages, purge passages, and outside air intake. 1. A canister for a fuel vapor processing apparatus, characterized in that an adsorption member in which the activated carbon is pressed and sealed inside an elastic membrane is compressed and accommodated between porous support members.