JP2020190207A - Fuel supply device - Google Patents

Abstract

To provide a fuel supply device capable of inhibiting suction of fuel from being interrupted, for example, when fuel in a fuel tank becomes inclined from a horizontal direction.SOLUTION: Fuel supply devices 10, 10a, 10b each include a pump 130 for pressurizing and feeding fuel sucked out of a fuel tank, the pump having a vapor release hole 135, a filter device 110 having a filter for filtering fuel sucked into the pump, a fuel storage part 140 provided at a gravity-direction upper side further than the filter device and connected to the vapor release hole, and a fuel discharge part 145 for discharging the fuel stored in the fuel storage part toward a gravity-direction lower side. When a flow amount of the fuel flowing from the vapor release hole into the fuel storage part is larger than a specified amount, the flow amount is larger than the discharge amount of fuel to be discharged from a fuel discharge part, and when the flow amount is smaller than the specified amount, the flow amount is smaller than the discharge amount.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a fuel supply device.

The fuel supply device is a device arranged at the bottom inside the fuel tank to pressurize and send the fuel sucked from the inside of the fuel tank. Among such fuel supply devices, a filter device having a filter for filtering fuel is arranged at the bottom of the fuel tank. The fuel supply device sucks the fuel in the fuel tank through the filter device (for example, Patent Document 1).

International Publication No. WO2017 / 141628

In such a fuel supply device, for example, when the fuel tank continues to be tilted from the horizontal direction, or when the vehicle turns and lateral acceleration is applied to the fuel tank, the fuel in the fuel tank is discharged. It may remain biased to one side. If such a state continues, the fuel at the position in contact with the filter device is sucked, and then the liquid level and the filter device are separated, and the fuel that is biased to one side in the fuel tank remains. Regardless, fuel suction may be delayed. In order to solve such a problem, a technique capable of suppressing the stagnation of fuel suction even when the fuel in the fuel tank is biased to one side is desired.

According to one form of the present disclosure, a fuel supply device is provided. This fuel supply device is a fuel supply device (10, 10a, 10b) that is arranged at the bottom inside the fuel tank and supplies fuel from the fuel tank, and pressurizes the fuel sucked from the fuel tank. From a pump (130) which is a pump to send and has a vapor discharge hole (135) for discharging vaporized fuel, a filter device (110) having a filter for filtering the fuel sucked into the pump, and the filter device. A fuel storage unit (140) provided on the upper side in the direction of gravity and connected to the vapor discharge hole to store fuel released from the vapor discharge hole, and a fuel stored in the fuel storage unit on the lower side in the direction of gravity. When the inflow amount of fuel flowing into the fuel storage section from the vapor discharge hole is larger than the specified amount, the inflow amount is discharged from the fuel discharge section. When the inflow amount is larger than the emission amount of the fuel and the inflow amount is smaller than the specified amount, the inflow amount is smaller than the emission amount. In such a form, for example, when the fuel in the fuel tank is tilted from the horizontal direction, the amount of fuel sucked by the pump is reduced, so that the amount of fuel flowing into the fuel storage section from the vapor discharge hole is reduced. When is reduced, the inflow amount becomes smaller than the amount of fuel discharged from the fuel discharge part. That is, the fuel stored in the fuel storage unit is discharged toward the filter device side. Therefore, for example, when the fuel in the fuel tank is tilted from the horizontal direction, in addition to the fuel at the position in contact with the filter device, the fuel is supplied from the fuel storage section to the filter device side via the fuel discharge section. Since the fuel to be sucked can be sucked, it is possible to prevent the suction of the fuel from being delayed.

The form of the present disclosure is not limited to the fuel supply device, and can be applied to various forms such as a vehicle equipped with the fuel supply device and a fuel supply method. Further, the present disclosure is not limited to the above-mentioned forms, and it is needless to say that the present disclosure can be carried out in various forms without departing from the gist of the present disclosure.

It is explanatory drawing which shows the schematic structure of the fuel supply device. It is explanatory drawing explaining the flow FL of fuel. It is a figure which showed the fuel tank which arranged the fuel supply device inside. It is a figure which showed the fuel tank which arranged the fuel supply device inside. It is explanatory drawing which shows the schematic structure of the fuel supply device of the comparative example. It is explanatory drawing which shows the schematic structure of the fuel supply apparatus of 2nd Embodiment. It is explanatory drawing which shows the schematic structure of the fuel supply device of 3rd Embodiment. It is explanatory drawing which shows the schematic structure of the fuel pump which uses an impeller. It is an enlarged view which a part of a fuel pump is enlarged.

A. First Embodiment:
The fuel supply device 10 of the first embodiment shown in FIG. 1 is arranged at the bottom inside a fuel tank installed in a moving body such as a vehicle, and supplies fuel from the fuel tank. The XYZ axes of FIG. 1 have an X-axis, a Y-axis, and a Z-axis as three spatial axes orthogonal to each other. The XYZ axes in FIG. 1 correspond to the XYZ axes in the other figures.

The fuel supply device 10 includes a filter device 110, a suction pipe 120, a pump 130, and a fuel storage unit 140. FIG. 1 shows a part of the configuration of the fuel supply device 10, and the configuration (not shown) includes a valve device, a fuel flow path for supplying fuel to the engine, and the like.

The filter device 110 is located at the bottom inside the fuel tank. The filter device 110 filters the fuel sucked into the pump 130. The filter device 110 has a structure in which two cloth-like members having a substantially rectangular shape are welded to each other at a peripheral portion, and a space capable of accommodating a holding member (not shown) is formed inside. The holding member is a member forming a skeleton that holds the cloth-like member in an inflated state.

The suction pipe 120 connects the filter device 110 and the pump 130. In the present embodiment, the suction pipe 120 is connected to the + side of the filter device 110 in the Z-axis direction and is connected to the-side of the pump 130 in the Y-axis direction. The suction pipe 120 forms a fuel flow path for guiding fuel from the filter device 110 to the pump 130.

The pump 130 pressurizes and sends the fuel sucked from the fuel tank via the filter device 110. The pump 130 feeds fuel to a fuel flow path for supplying fuel to the engine via a valve device (not shown) that regulates the pressure of the fuel sent from the pump 130.

FIG. 2 shows the fuel flow FL sucked by the pump 130. The flow FL indicates a flow in which the fuel contained in the filter device 110 is taken into the pump 130 via the suction pipe 120 and then sent to the valve device.

Returning to the description of FIG. 1, the pump 130 has a vapor discharge hole 135. The vapor discharge hole 135 discharges vaporized fuel, vapor, together with a small amount of liquid fuel that is part of the fuel sucked by the pump 130. In the present embodiment, the vapor discharge hole 135 discharges vapor toward the − side in the Y-axis direction. In FIG. 2, the vapor discharge hole 135 is shown with a thickness in the Y-axis direction in order to clarify the position where the vapor discharge hole 135 is arranged. However, FIG. 2 does not accurately represent the dimensions of the fuel supply device 10.

The fuel storage unit 140 is provided on the + side in the Z-axis direction with respect to the filter device 110. The fuel storage unit 140 is connected to the vapor discharge hole 135 and can store the fuel released as vapor from the vapor discharge hole 135. In the present embodiment, the fuel storage unit 140 has a rectangular parallelepiped shape. Since the portion of the fuel storage unit 140 that is connected to the vapor storage unit 135 is open, the fuel is discharged from the vapor storage unit 135 toward the inside of the fuel storage unit 140.

The fuel storage unit 140 has a fuel discharge unit 145 and an opening 147. The fuel discharge unit 145 discharges the fuel stored in the fuel storage unit 140 toward the − side in the Z-axis direction. In the present embodiment, the fuel discharge unit 145 is a tubular member extending from the portion of the fuel storage unit 140 on the − side in the Z-axis direction toward the − side in the Z-axis direction. The opening 147 is formed in the fuel storage portion 140 on the + side in the Z-axis direction, which is the upper end side in the gravity direction.

When the inflow amount of fuel flowing from the vapor discharge hole 135 into the fuel storage unit 140 is larger than a predetermined predetermined amount, the inflow amount is larger than the fuel discharge amount discharged from the fuel discharge unit 145. When the inflow amount of the fuel flowing from the vapor discharge hole 135 into the fuel storage unit 140 is smaller than the above-mentioned specified amount, the inflow amount is smaller than the fuel discharge amount discharged from the fuel discharge unit 145. In the present embodiment, the technical content will be described assuming that the inflow amount is proportional to the flow rate of the fuel in the flow FL described with reference to FIG. The specified amount will be described later.

FIG. 3 shows a fuel tank TK in which the fuel supply device 10 is arranged inside. For example, in the state of FIG. 3, since the fuel tank TK is in a horizontal state, the liquid level of the fuel FU in the fuel tank TK is also horizontal. Hatching is applied to the position where the fuel FU exists. As the fuel soaks into the cloth-like member constituting the filter device 110, the fuel contained in the filter device 110 is sucked into the pump 130 via the suction pipe 120. The vapor is discharged from the vapor discharge hole 135 toward the fuel storage unit 140 together with a small amount of liquid fuel that is a part of the fuel sucked by the pump 130.

FIG. 3 shows the flow IN of the fuel flowing from the vapor discharge hole 135 into the fuel storage unit 140. In the state of FIG. 3, since the filter device 110 is immersed in a sufficient amount of fuel, the flow rate of the fuel by the flow FL is sufficiently large. In such a situation, since the inflow amount due to the flow IN is larger than the specified amount, the inflow amount becomes larger than the fuel discharge amount discharged from the fuel discharge unit 145. Further, FIG. 3 shows the flow EX of the fuel discharged from the fuel discharge unit 145. In the first embodiment, the amount when the inflow amount due to the flow IN becomes equal to the discharge amount due to the flow EX is the specified amount. In the state of FIG. 3, since the inflow amount due to the flow IN is larger than the specified amount, the amount of fuel stored in the fuel storage unit 140 increases.

FIG. 4 shows a fuel tank TK in which the fuel supply device 10 is arranged inside. In the state of FIG. 4, for example, since the fuel tank TK is tilted from the horizontal direction, among the fuel FUs in the fuel tank TK, the fuel FUs not included in the filter device 110 are in the fuel tank TK. It is in a state of being biased to one side.

In the state of FIG. 4, the liquid fuel outside the filter device 110 is biased to the − side in the Y-axis direction, and the filter device 110 does not touch the liquid fuel outside the filter device 110. As a result, the filter device 110 sucks in gas, and the flow rate of fuel due to the flow FL is small. In such a situation, since the inflow amount due to the flow IN is smaller than the specified amount, the inflow amount is smaller than the fuel discharge amount discharged from the fuel discharge unit 145. In the state of FIG. 4, since the inflow amount due to the flow IN is smaller than the discharge amount due to the flow EX, the amount of fuel stored in the fuel storage unit 140 is reduced. When the state as shown in FIG. 4 continues, after the filter device 110 and the fuel FU inside are sucked, the fuel FU biased to the-side in the Y-axis direction remains in the fuel tank TK. However, the fuel supply device 10 cannot suck the fuel.

In the fuel supply device 10, as described with reference to FIG. 4, when the filter device 110 is not in contact with the liquid fuel outside the filter device 110, the amount of fuel stored in the fuel storage unit 140 is reduced. .. As a result, a fuel amount equal to or greater than the inflow amount from the vapor discharge hole 135, including the fuel stored in the fuel storage unit 140, is supplied to the filter device 110. Therefore, even when the fuel in the fuel tank TK is biased to one side, it is possible to prevent the fuel suction from being delayed.

FIG. 5 shows a fuel supply device 10p of a comparative example. The fuel supply device 10p has the same configuration as the fuel supply device 10 of the first embodiment except that the fuel storage unit 140 is not provided. In the state of FIG. 5, for example, as in the state of FIG. 4, since the fuel tank TK is in a state of being tilted from the horizontal direction, among the fuel FUs in the fuel tank TK, the fuels not included in the filter device 110 The FU is in a state of being biased to one side in the fuel tank TK.

When the state as shown in FIG. 5 continues, after the fuel FU in the filter device 110 is sucked, the fuel is sucked even though the fuel biased to one side in the fuel tank TK remains. Can't. Further, since the fuel supply device 10p of the comparative example does not include the fuel storage unit 140, the suction of fuel tends to be delayed in the state as shown in FIG.

According to the embodiment described above, for example, when the fuel in the fuel tank TK is tilted from the horizontal direction, the amount of fuel sucked by the pump 130 decreases, so that the fuel flows into the fuel storage unit 140 from the vapor discharge hole 135. When the inflow of fuel is reduced, the inflow becomes smaller than the amount of fuel discharged from the fuel discharge unit 145. That is, the amount of fuel stored in the fuel storage unit 140 is reduced. Therefore, for example, when the fuel in the fuel tank TK is tilted from the horizontal direction, in addition to the fuel in the filter device 110, the fuel storage section 140 moves to the filter device 110 side via the fuel discharge section 145. Since the supplied fuel can be sucked, it is possible to prevent the fuel suction from being delayed.

Further, the fuel storage unit 140 has an opening 147 on the upper end side in the direction of gravity. Therefore, when the fuel stored in the fuel storage unit 140 is full and then the fuel flows into the fuel storage unit 140 through the vapor discharge hole 135, the fuel can be discharged from the opening 147. Therefore, even after the fuel storage unit 140 is full, the vapor can be continuously discharged from the vapor discharge hole 135.

B. Second embodiment:
FIG. 6 shows the fuel supply device 10a of the second embodiment. The fuel supply device 10a has the same configuration as the fuel supply device 10 of the first embodiment except that it includes a tubular member 137 and a fuel discharge unit 145a different from the fuel discharge unit 145.

The tubular member 137 is a member extending along the Y-axis direction and connects the vapor discharge hole 135 and the fuel storage portion 140. The fuel discharge portion 145a is a tubular member that branches off from the tubular member 137 and extends toward the − side in the Z-axis direction.

Similar to the state described with reference to FIG. 3, in the state of FIG. 6, since the filter device 110 is immersed in a sufficient amount of fuel, the flow rate of fuel by the flow FL is sufficiently large. In such a situation, since the inflow amount due to the flow IN increases, the flow velocity of the flow IN also increases. In the structure of the fuel supply device 10a described above, when the flow velocity of the flow IN is sufficiently large, the flow rate to the flow EX is unlikely to increase, so that the inflow amount due to the flow IN is larger than the discharge amount due to the flow EX. In the second embodiment, the minimum value of the inflow amount at which the flow velocity of the flow IN increases to the extent that the inflow amount due to the flow IN becomes larger than the discharge amount due to the flow EX is the specified amount in the present embodiment.

Since the specified amount is determined in this way, even in the fuel supply device 10a, when the inflow amount due to the flow IN is larger than the specified amount, the inflow amount is larger than the discharge amount due to the flow EX. Further, when the inflow amount due to the flow IN is smaller than the specified amount, the inflow amount is smaller than the discharge amount due to the flow EX.

In the state of FIG. 6, since the flow velocity of the flow IN is sufficiently large, the inflow amount by the flow IN is larger than the discharge amount by the flow EX, so that the amount of fuel stored in the fuel storage unit 140 increases. Further, in the fuel tank TK in which the fuel supply device 10a is arranged inside, as shown in FIG. 4, for example, when the fuel tank TK is tilted from the horizontal direction, the flow velocity and the inflow amount of the flow IN are increased. As it decreases, the amount discharged by the flow EX increases. Then, when the inflow amount due to the flow IN becomes smaller than the discharge amount due to the flow EX, the amount of fuel stored in the fuel storage unit 140 begins to decrease, so that the fuel stored in the fuel storage unit 140 is filtered. Supplied to 110. Therefore, even when the fuel in the fuel tank TK is biased to one side, it is possible to prevent the fuel suction from being delayed. Therefore, the same effect as that of the first embodiment can be obtained in the second embodiment.

C. Third Embodiment:
FIG. 7 shows the fuel supply device 10b of the third embodiment. The fuel supply device 10b has the same configuration as the fuel supply device 10a of the second embodiment except that it includes a tubular member 137b different from the tubular member 137 and a fuel discharge unit 145b different from the fuel discharge unit 145a. ..

The tubular member 137b is a member extending along the Y-axis direction, like the tubular member 137 of the second embodiment, and connects the vapor discharge hole 135 and the fuel storage portion 140. The fuel discharge portion 145b is a tubular member that branches from a position near the center of the outer peripheral surface of the tubular member 137b and extends toward the − side in the Z-axis direction. In the tubular member 137b, the cross-sectional area of the portion near the center in the Y-axis direction is smaller than the cross-sectional area of both end portions in the Y-axis direction. The cross-sectional area referred to here is the cross-sectional area when the tubular member 137b is cut in the XZ plane. In other words, the cross-sectional area of the tubular member 137b at the position where the fuel discharge portion 145b is formed is the cross-sectional area of the tubular member 137b at the position where the tubular member 137b and the vapor discharge hole 135 are connected and the cross-sectional area of the tubular member 137b and the fuel storage. It is smaller than the cross-sectional area of the tubular member 137b at the position where the portion 140 is connected. The structure of the cross-sectional area of the tubular member 137b is for causing a Venturi effect when fuel flows into the tubular member 137b due to the flow IN.

Similar to the state described with reference to FIG. 3, in the state of FIG. 7, since the filter device 110 is immersed in a sufficient amount of fuel, the flow rate of the fuel due to the flow FL is sufficiently large. In such a situation, since the inflow amount due to the flow IN increases, the flow velocity of the flow IN also increases. In the structure of the fuel supply device 10b described above, when the flow velocity of the flow IN is sufficiently large, the fuel FU in the fuel tank TK is sucked from the fuel discharge portion 145b by the Venturi effect generated inside the tubular member 137b. At this time, since the discharge amount by the flow EX is 0 and the fuel is flowing in from the fuel discharge unit 145b, it can be said that the inflow amount by the flow IN is larger than the discharge amount by the flow EX. In the third embodiment, the minimum value of the inflow amount at which the flow velocity of the flow IN increases to the extent that the inflow amount due to the flow IN becomes larger than the discharge amount due to the flow EX is the specified amount.

Since the specified amount is determined in this way, even in the fuel supply device 10b, when the inflow amount due to the flow IN is larger than the specified amount, the inflow amount is larger than the discharge amount due to the flow EX. Further, when the inflow amount due to the flow IN is smaller than the specified amount, the inflow amount is smaller than the discharge amount due to the flow EX.

In the state of FIG. 7, since the flow velocity of the flow IN is sufficiently large, the amount of fuel stored in the fuel storage unit 140 increases due to the inflow by the flow IN and the inflow from the fuel discharge unit 145b. Further, in the fuel tank TK in which the fuel supply device 10b is arranged inside, as shown in FIG. 4, for example, when the fuel tank TK is tilted from the horizontal direction, the flow velocity and the inflow amount of the flow IN are increased. As the amount decreases, the Venturi effect weakens, so that the amount of inflow from the fuel discharge unit 145b also decreases. If the amount of inflow from the fuel discharge part 145b continues to decrease, the amount of inflow from the fuel discharge part 145b becomes 0, and then the amount of discharge from the fuel discharge part 145b due to the flow EX starts to increase. Then, when the inflow amount due to the flow IN becomes smaller than the discharge amount due to the flow EX, the amount of fuel stored in the fuel storage unit 140 begins to decrease, so that the fuel stored in the fuel storage unit 140 is filtered. Supplied to 110. Therefore, even when the fuel in the fuel tank TK is biased to one side, it is possible to prevent the fuel suction from being delayed. Therefore, the same effect as that of the first embodiment and the second embodiment can be obtained in the third embodiment.

D. Other embodiments:
In the first embodiment described above, the technical content will be described assuming that the inflow amount of fuel flowing from the vapor discharge hole 135 into the fuel storage unit 140 is proportional to the fuel flow rate in the fuel flow FL sucked by the pump 130. did. However, the amount of fuel flowing into the fuel storage section from the vapor discharge hole is inversely proportional to the flow rate of the fuel flowing out from the fuel storage section, and other factors such as the flow rate of fuel in the flow of fuel sucked by the pump are used. You may have a relationship. The fuel supply device can be configured according to the relationship between the inflow amount of fuel flowing into the fuel storage unit from the vapor discharge hole and the flow rate of the fuel flowing out from the fuel storage unit.
The fuel supply device 10a of the second embodiment described above includes a fuel discharge unit 145a, but the present disclosure is not limited to this. For example, the fuel supply device 10a of the second embodiment may include the fuel discharge unit 145 of the first embodiment in addition to the fuel discharge unit 145a. In such a form, when the filter device 110 is immersed in a sufficient amount of fuel, the amount of inflow due to the flow IN becomes larger than the amount of fuel discharged from the fuel discharge unit 145 and the fuel discharge unit 145a. Therefore, the diameters of the vapor discharge hole 135, the fuel discharge unit 145, and the fuel discharge unit 145a are designed. Further, the fuel supply device 10b of the third embodiment may also include the fuel discharge unit 145 of the first embodiment in addition to the fuel discharge unit 145b.

The present disclosure is not limited to the above-described embodiment, and can be realized by various configurations within a range not deviating from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the column of the outline of the invention may be used to solve some or all of the above-mentioned problems, or one of the above-mentioned effects. It is possible to replace or combine as appropriate to achieve a part or all. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

FIG. 8 shows a fuel pump 20 using an impeller. The fuel pump 20 includes a motor unit 30 and a pump unit 40. The motor unit 30 and the pump unit 40 are integrally configured.

The motor unit 30 has a stator 32 around which a coil 31 is wound, a rotor 33 rotatably provided inside the stator 32, and a shaft 34 that rotates together with the rotor 33. FIG. 8 shows the axis CA, which is the axis of the shaft 34.

The pump unit 40 includes a first pump housing 41, a second pump housing 42, and an impeller 43. The impeller 43 is housed in the space SP formed between the first pump housing 41 and the second pump housing 42. The impeller 43 is formed of resin in a substantially disk shape. The impeller 43 is coupled to the shaft 34 and rotates with the shaft 34.

The first pump housing 41 has a suction port 44. Further, the first pump housing 41 has a first groove 45 extending in a C shape in the circumferential direction on the side where the impeller 43 is arranged. The first groove 45 communicates with the suction port 44.

The second pump housing 42 has a communication port 46 that communicates with the motor unit 30 side. Further, the second pump housing 42 has a second groove 47 extending in a C shape in the circumferential direction on the side where the impeller 43 is arranged. The second groove 47 communicates with the communication port 46.

When the impeller 43 rotates together with the shaft 34, the fuel in the fuel tank in which the fuel pump 20 is installed is sucked into the space SP from the suction port 44, flows through the first groove 45, and is pressurized by the rotation of the impeller 43. .. The pressurized fuel flows through the second groove 47 and is discharged from the communication port 46 to the motor unit 30. The fuel discharged from the pump unit 40 to the motor unit 30 flows through the gap between the stator 32 and the outer shell of the fuel pump 20 and the gap between the stator 32 and the rotor 33, and is discharged from the discharge port 50 to the internal combustion engine. ..

In the fuel pump shown in FIG. 1 of JP-A-2017-821116, the impeller that has been deformed such as warpage or swelling due to the impeller being immersed in the fuel sucked into the space SP is the first pump housing or It may come into contact with the second pump housing and be locked. Further, when the fuel is sucked, the pressure applied to the first pump housing side and the pressure applied to the second pump housing side are different, so that the impeller is pressed against the first pump housing side and the sliding resistance is large. There is a risk of becoming. An increase in sliding resistance may lead to a decrease in flow rate due to wear and vibration due to interference between the impeller and the first pump housing.

On the other hand, in the fuel pump 20 shown in FIG. 8, since the space SP has a two-stage tapered shape, interference between the first pump housing 41 or the second pump housing 42 and the impeller 43 is suppressed. ing.

A two-step taper shape in the space SP will be described with reference to FIG. FIG. 9 shows a partially enlarged fuel pump 20. Further, FIG. 9 shows a portion P1 and a portion P2 of the portion of the second pump housing 42 that defines the space SP on the upper side of the paper surface at a certain distance from the axis CA. Further, FIG. 9 shows a portion P3 and a portion P4 located at a certain distance from the axis CA in the portion of the first pump housing 41 that defines the space SP on the lower side of the paper surface.

The shortest distance from the axis CA to the partial P2 and the partial P4 is the same. The shortest distance from the axis CA to the partial P1 and the partial P3 is the same. The shortest distance from the axis CA to the portion P1 is twice the shortest distance from the axis CA to the portion P2. The shortest distance from the axis CA to the portion P3 is twice the shortest distance from the axis CA to the portion P4.

From the left side of the paper surface to the right side of the paper surface, the portion P1 and the portion P3 correspond to the tapered shape of the first stage, and the portion P2 and the portion P4 correspond to the tapered shape of the second stage. The shortest distance L1 from the impeller 43 to the partial P1 is smaller than the shortest distance L2 from the impeller 43 to the partial P2. Further, the shortest distance L3 from the impeller 43 to the partial P3 is smaller than the shortest distance L4 from the impeller 43 to the partial P4. The shortest distance L1 is larger than the shortest distance L3, and the shortest distance L2 is larger than the shortest distance L4. By forming the first pump housing 41 and the second pump housing 42 in this way, among the interferences between the first pump housing 41 or the second pump housing 42 and the impeller 43, in particular, the second pump housing 42 And the interference between the impeller 43 and the impeller 43 can be suppressed.

The ratio of the shortest distance L1 to the shortest distance L2 and the ratio of the shortest distance L3 to the shortest distance L4 may be the same or different.

10 ... Fuel supply device, 110 ... Filter device, 120 ... Suction pipe, 130 ... Pump, 135 ... Vapor discharge hole, 140 ... Fuel storage unit, 145 ... Fuel discharge unit

Claims (5)

A fuel supply device (10, 10a, 10b) that is arranged at the bottom inside the fuel tank and supplies fuel from the fuel tank.
A pump (130) that pressurizes and sends the fuel sucked from the fuel tank and has a vapor discharge hole (135) that discharges the vaporized fuel.
A filter device (110) having a filter for filtering the fuel sucked into the pump, and
A fuel storage unit (140) provided on the upper side in the direction of gravity from the filter device and connected to the vapor discharge hole to store fuel released from the vapor discharge hole.
A fuel discharge unit (145) that discharges the fuel stored in the fuel storage unit downward in the direction of gravity is provided.
When the inflow amount of the fuel flowing from the vapor discharge hole into the fuel storage part is larger than the specified amount, the inflow amount is larger than the discharge amount of the fuel discharged from the fuel discharge part.
A fuel supply device in which the inflow amount is smaller than the emission amount when the inflow amount is smaller than the specified amount. The fuel supply device according to claim 1.
A fuel supply device having an opening (147) formed at the upper end side of the fuel storage portion in the direction of gravity. The fuel supply device according to claim 1 or 2.
The fuel discharge unit is a fuel supply device formed on the lower end side of the fuel storage unit in the direction of gravity. The fuel supply device according to claim 1 or 2.
The vapor discharge hole and the fuel storage portion are connected by a tubular member (137b).
The fuel discharge unit is a fuel supply device formed on the outer peripheral surface of the tubular member. The fuel supply device according to claim 4.
The cross-sectional area of the tubular member at the position where the fuel discharge portion is formed includes the cross-sectional area of the tubular member at the position where the tubular member and the vapor discharge hole are connected, and the tubular member and the fuel storage portion. A fuel supply device that is smaller than the cross-sectional area of the tubular member at the connected position.

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