JP4116875B2 - Vehicle fuel tank system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improved technique for a vehicle fuel tank apparatus.
[0002]
[Prior art]
2. Description of the Related Art In a vehicle, a fuel tank device is known in which a breather passage provided in an upper portion of a tank is closed with a cut valve when liquid fuel injected into the fuel tank rises to a certain level (for example, Patent Documents). 1).
[0003]
[Patent Document 1]
Japanese Patent No. 2884475 (page 3, FIG. 1)
[0004]
According to Patent Document 1, a conventional fuel tank device for a vehicle is configured such that when a liquid fuel injected into a fuel tank rises to a certain level, a breather passage provided in the upper part of the tank is closed by a cut valve. The fuel evaporative gas emission prevention device is provided. The fuel evaporative emission prevention device is a device that temporarily stores the fuel evaporative gas in the fuel tank in the canister and causes the canister to inhale into the intake system of the engine when the engine is started.
[0005]
By the way, some vehicles, such as a front engine and a rear wheel drive vehicle (FR vehicle), have a drive system that transmits engine power to a rear wheel via a propeller shaft. In such a vehicle, it is necessary to have an arrangement relationship in which the fuel tank does not interfere with the propeller shaft that passes forward and backward.
[0006]
The minimum ground clearance of the propeller shaft is determined by the structure of the power system. On the other hand, the fuel tank is often arranged under the seat and is subject to a restriction on the seat height, so there is a limit to raising the ground height. In order to prevent the fuel tank from interfering with the propeller shaft, it can be considered that the center of the bottom of the tank is recessed upward to form a bowl shape. A conventional fuel tank apparatus using a saddle-shaped fuel tank will be described below.
[0007]
FIG. 4 is a configuration diagram of a conventional vehicle fuel tank apparatus, which is a modified version of the configuration shown in FIG. 1 of the above-mentioned Japanese Patent No. 2884475.
The conventional vehicular fuel tank apparatus 100 is formed by recessing the center of the bottom 101 of the tank upward so that the first fuel chamber 102, the second fuel chamber 103, and the first and second fuel chambers are formed in the tank. The vertical fuel tank 105 is divided into a central raised bottom communication chamber 104 that communicates between 102 and 103, a breather passage 106 is extended outward from the communication chamber 104, and a first fuel chamber is formed from the fuel inlet 107. A cut valve (float valve) that closes the breather passage 106 when the injected liquid fuel 108 rises to a certain level so that the liquid fuel 108 injected into the second fuel chamber 103 is accumulated in the second fuel chamber 103 via the communication chamber 104. 109) at the entrance of the breather passage 106.
[0008]
The reason why the breather passage 106 is extended outward from the communication chamber 104 and the cut valve 109 is provided at the inlet is as follows. The refueling floor of the gas station is slightly inclined. The vehicle stopped on the refueling work floor is slightly inclined to the left or right. Even in such a case, it is preferable to arrange the cut valve 109 not in the first and second fuel chambers 102 and 103 but in the communication chamber 104 in order to ensure an appropriate amount of fuel supply.
[0009]
The center of the bottom 101 of the fuel tank 105 can be recessed upward, and the propeller shaft 111 can be passed through that portion. The breather passage 106 is connected to a canister 113 via an on-off valve 112 that is opened by a tank internal pressure during refueling. In the figure, 114 is a breather passage, 115 is a float valve, 116 is a two-way valve, and 117 is a filler pipe.
[0010]
[Problems to be solved by the invention]
However, in the conventional fuel tank 108 shown in FIG. 4, the height H2 from the center of the bottom of the tank to the cut valve 109 must be relatively small. For this reason, the liquid fuel 108 flowing from the first fuel chamber 102 into the second fuel chamber 103 may hit the cut valve 109. As a result, the cut valve 109 is temporarily closed to close the breather passage 106. When the fuel injection is continued, the liquid level in the filler pipe 115 rises as the internal pressure rises, and when the tip of the fuel gun 118 is reached, the fuel gun 118 detects this and stops the injection. End up. At this time, the liquid fuel 108 in the second fuel chamber 103 has not reached a certain level. In order to perform a smoother refueling operation, it is preferable to eliminate the occurrence of such a phenomenon as much as possible.
[0011]
Accordingly, an object of the present invention is to provide a technique capable of performing a smoother refueling operation by allowing liquid fuel to be smoothly injected into both fuel chambers of a saddle-shaped fuel tank.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, the center of the bottom of the tank is recessed upward so that the first fuel chamber, the second fuel chamber, and the first and second fuel chambers are formed in the tank. The fuel tank is divided into a communication chamber with a central raised bottom that communicates with the fuel tank. The breather passage extends from the communication chamber to the outside, and the liquid fuel injected into the first fuel chamber from the fuel inlet is connected to the communication chamber. In the fuel tank device for a vehicle provided with a cut valve at the inlet of the breather passage when the injected liquid fuel rises to a certain level so as to close the breather passage.
The saddle-shaped fuel tank is provided with a baffle plate that prevents liquid fuel flowing from the first fuel chamber to the second fuel chamber from directly hitting the cut valve.
[0013]
The liquid fuel flowing from the first fuel chamber to the second fuel chamber can be blocked by the baffle plate from being temporarily blocked by hitting the cut valve. For this reason, the operation of the cut valve when liquid fuel is injected can be stabilized. Therefore, a smoother refueling operation can be performed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that “front”, “rear”, “left”, “right”, “upper”, and “lower” follow the direction seen from the driver. The drawings are to be viewed in the direction of the reference numerals.
[0015]
FIG. 1 is a configuration diagram of a vehicular fuel tank apparatus according to the present invention, and shows a cross section of a fuel tank 20 of the vehicular fuel tank apparatus 10 as viewed from the front.
The fuel tank 20 is provided with a bulging portion 22 in the tank by recessing the center of the bottom 21 of the tank upward. By doing so, the first fuel chamber 23 and the second fuel chamber are formed in the tank. 24 is a saddle-shaped fuel tank divided into a central raised bottom communication chamber 25 that communicates between the first and second fuel chambers 23, 24, and a raised portion 26 that protrudes upward in the center of the upper portion is integrated. Formed. The interior of the raised portion 26 also serves as the communication chamber 25. In addition, the presence or absence of the protruding part 26 is arbitrary.
[0016]
A vehicle (not shown) equipped with a saddle-shaped fuel tank 20 at the rear is a front-mounted engine / rear wheel drive vehicle (FR vehicle), and the power of the engine 31 shown in the upper left of the figure is applied to the rear wheel via a propeller shaft 32. an automatic vehicle driving system for transmitting. The propeller shaft 32 is a transmission shaft that extends in the front-rear direction of the vehicle (front and back direction in this figure). The fuel tank 20 is characterized in that it is formed in a bowl shape by denting the center of the bottom 21 of the tank upward so as not to interfere with the propeller shaft 32.
[0017]
The vehicular fuel tank apparatus 10 extends a filler pipe 41 (fuel supply pipe 41) upward from the first fuel chamber 23, and includes a fuel injection port 42 at the tip thereof. 1, a breather passage 43 is extended, the tip thereof is connected to the vicinity of the fuel inlet 42 in the filler pipe 41, and a fuel evaporative emission prevention device 50 (abbreviation: evaporation system) is further provided.
[0018]
The liquid fuel injected from the fuel injection port 42 into the first fuel chamber 23 can be stored in the second fuel chamber 24 via the communication chamber 25.
The filler pipe 41 includes a first check valve 44 that opens when liquid fuel is injected from the fuel injection port 42 at an end in the first fuel chamber 23.
The first breather passage 43 is a passage through which fuel evaporative gas flows in an amount corresponding to the amount of air that is caught in the liquid fuel and flows through the filler pipe 41 during normal fuel injection, and a check valve 45 ( A second check valve 45) is provided. The check valve 45 is opened in the event of an abnormality such as a second breather passage 52 to be described later being closed, and allows fuel evaporative gas to escape from the fuel tank 20 to the outside through the fuel inlet 42, and has a small hole 45a.
[0019]
The fuel evaporative emission prevention device 50 temporarily stores the fuel evaporative gas generated in the fuel tank 20 in the canister 51, and when the engine 31 is started, the intake system 33 (air cleaner 34) of the engine 31 together with the outside air from the canister 51 is started. , A vaporizer 35, an intake manifold 36, etc.).
[0020]
Such a fuel evaporative gas emission preventing device 50 includes a second breather passage 52 that extends outward from the upper portion of the communication chamber 25 (that is, the upper portion of the raised portion 26) and is connected to the inlet of the canister 51, and the second breather passage 52. The first cut valve 53 provided at the inlet of the breather passage 52, the on-off valve 54 interposed in the middle of the second breather passage 52, and the upper part of the communication chamber 25 (that is, the upper part of the raised portion 26) outward. A third breather passage 55 extending to the secondary side of the on-off valve 54 in the second breather passage 52; a second cut valve 56 provided at the inlet of the third breather passage 55; The two-way valve 57 interposed in the middle of the breather passage 55 and the solenoid valve 59 interposed in the bypass passage 58 of the third breather passage 55 are included.
[0021]
The canister 51 is filled with an adsorbent such as activated carbon that adsorbs fuel evaporative gas.
The second and third breather passages 52 and 55 and the bypass passage 58 serve as a fuel evaporative gas conduit for guiding the fuel evaporative gas generated in the fuel tank 20 to the canister 51.
[0022]
The first cut valve 53 is a float valve that closes the second breather passage 52 when the liquid fuel injected into the fuel tank 20 rises to a certain level. The first cut valve 53 is housed in the valve case 61, a fuel passage hole 62 opened in the lower end surface of the valve case 61, a gas passage hole 63 opened in the side wall of the valve case 61, and the valve case 61. The float-type valve body 64 is lifted by the rise of the liquid fuel, the valve seat 65 is lifted and closed, and the spring (not shown) springs in the direction of opening the valve body 64.
[0023]
The on-off valve 54 is a diaphragm valve that is opened by the pressure in the fuel tank 20 during refueling. The second breather passage 52 is connected to the valve chamber 71 and the filler pipe 41 is connected to the spring chamber 72 via the communication pipe 73. The vicinity of the fuel inlet 42 is connected.
[0024]
The second cut valve 56 is a float valve in which the third breather passage 55 is kept open as much as possible by disposing it higher than the first cut valve 53, and the liquid fuel injected into the fuel tank 20 By closing the third breather passage 55 when the pressure rises to a certain level higher than the level detected by the first cut valve 53, it is possible to prevent the liquid fuel from flowing out into the canister 51.
The two-way valve 57 is a pressure regulating valve that keeps the pressure in the fuel tank 20 within a certain range.
The solenoid valve 59 is a valve used when checking for a leak in the breather passage from the fuel tank 20 to the canister 51.
[0025]
Incidentally, in the fuel tank 20, the height H1 from the center of the tank bottom 21 to the first cut valve 53 must be relatively small.
In contrast, according to the present invention, the fuel tank 20 includes the baffle plate 81 that prevents the liquid fuel flowing from the first fuel chamber 23 to the second fuel chamber 24 from directly hitting the first cut valve 53. It is characterized by that. The baffle plate 81 is a partition wall that surrounds the fuel passage hole 62 by extending from the bulging portion 22 toward the communication chamber 25 in the bottom 21 of the tank and surrounding at least the lower half of the first cut valve 53. is there.
[0026]
FIG. 2 is a plan cross-sectional view of the upper portion of the fuel tank according to the present invention. When liquid fuel 83 is injected from the filler pipe 41 into the first fuel chamber 23, the second fuel from the first fuel chamber 23 is shown. It shows that the liquid fuel 83 flowing into the chamber 24 is surrounded by a baffle plate 81 having a substantially U shape in plan view so as to prevent the liquid fuel 83 from directly hitting the first cut valve 53. The baffle plate 81 having a substantially U shape in plan view opens toward the second fuel chamber 24.
[0027]
Next, the operation of the vehicle fuel tank apparatus 10 having the above configuration will be described.
FIG. 3 is an operational view of the vehicle fuel tank apparatus according to the present invention.
When the liquid fuel 83 is injected from the fuel inlet 42 with the fuel gun 82, the liquid fuel 83 is filled into the first fuel chamber 23 of the fuel tank 20 through the filler pipe 41. At this time, since the float type valve body 64 is lowered, the first cut valve 53 is open. The air in the fuel tank 20 and the fuel evaporative gas generated in the fuel tank 20 are equivalent to the liquid fuel 83 that is filled, and the on-off valve 54 from the first cut valve 53 through the second breather passage 52. The valve chamber 71 is entered. As a result, since the pressure in the valve chamber 71 exceeds the atmospheric pressure in the spring chamber 72, the on-off valve 54 is opened.
[0028]
In this way, the fuel evaporative gas flows from the fuel tank 20 to the first cut valve 53 → second breather passage 52 → open / close valve 54, or the second cut valve 56 → third breather passage 55 → second. The breather passage 52 enters the canister 51 and adsorbs components such as hydrocarbon (HC) by the adsorbent, and the remaining air is released to the outside air. Since the internal pressure of the fuel tank 20 hardly increases, the liquid fuel 83 is injected smoothly.
[0029]
As the injection of the liquid fuel 83 proceeds, the level of the liquid fuel 83 in the first fuel chamber 23 rises and exceeds the top of the bulging portion 22. As a result, the liquid fuel 83 overflows the bulging portion 22 and flows into the second fuel chamber 24. At this time, the level (liquid level) of the liquid fuel 83 flowing into the second fuel chamber 24 is a level at which the first cut valve 53 closes the second breather passage 52.
[0030]
However, the baffle plate 81 is arranged around the first cut valve 53 so as to prevent the liquid fuel 83 flowing from the first fuel chamber 23 into the second fuel chamber 24 from directly hitting the first cut valve 53. Surrounding. For this reason, the first cut valve 53 is not closed by the liquid fuel 83 flowing into the second fuel chamber 24. The operation of the first cut valve 53 when the liquid fuel 83 is injected can be stabilized. Therefore, a smoother refueling operation can be performed.
[0031]
Thereafter, when the liquid fuel 83 injected into the fuel tank 20 rises to a certain level, the tank is full (a state where the maximum amount of oil is stored). This is detected by the first cut valve 53 and the second breather passage 52 is closed. Since the interior of the fuel tank 20 is generally cut off from the atmosphere, the internal pressure increases as the liquid level inside the fuel tank 20 increases thereafter. When the injection is continued, the liquid level in the filler pipe 41 rises as the internal pressure increases, and when the tip of the fuel gun 82 is reached, the fuel gun 82 detects this and stops the injection (auto stop). This completes the refueling operation.
[0032]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
In the claims 1, saddle-shaped fuel tank, by recessing the center of the bottom of the tank upwards, a bulging portion which is bulged in the tank up to the vicinity of the cut valve, provided in the bulging portion of the communication chamber Te, the liquid fuel flowing from the first fuel chamber to the second fuel chamber, temporary breather passage by cut valve by blocking as per should not be directly cut valve when exceeding the top of the bulging portion a baffle plate to prevent Do occlusion, since with a can liquid fuel flowing from the first fuel chamber to the second fuel chamber, that temporarily closed when cut valve, is prevented by the baffle plate . For this reason, the operation of the cut valve when liquid fuel is injected can be stabilized. Therefore, a smoother refueling operation can be performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a fuel tank device for a vehicle according to the present invention. FIG. 2 is a plan sectional view of an upper portion of the fuel tank according to the present invention. 4] Configuration diagram of a conventional fuel tank system for vehicles [Explanation of symbols]
DESCRIPTION OF SYMBOLS 20 ... Saddle-shaped fuel tank, 21 ... Bottom of tank, 23 ... First fuel chamber, 24 ... Second fuel chamber, 25 ... Communication chamber, 42 ... Fuel inlet, 52 ... Breather passage (second breather passage) ), 53 ... Cut valve (first cut valve), 81 ... Baffle plate, 83 ... Liquid fuel.

Claims (1)

By denting the center of the bottom of the tank upward, the tank is divided into a first fuel chamber, a second fuel chamber, and a central raised bottom communication chamber that communicates between the first and second fuel chambers. And a breather passage extending outward from the communication chamber, and liquid fuel injected from a fuel injection port into the first fuel chamber is passed through the communication chamber to the second fuel chamber. A fuel tank device for a vehicle having a cut valve that closes the breather passage when the injected liquid fuel rises to a certain level, at the inlet of the breather passage;
The saddle-shaped fuel tank, by recessing the center of the bottom of the tank upwards, a bulging portion which is bulged in the tank to the vicinity of the cut valve, provided in the bulging portion of the communication chamber the by the cut valve by the liquid fuel flowing into the second fuel chamber from said first fuel chamber, to prevent as per should not be directly to the cut valve upon exceeding the top of the bulging portion a fuel tank for a vehicle, characterized in that it comprises a baffle plate to prevent temporary occlusion of the breather passage, a.

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