JP4867733B2 - Fuel pump - Google Patents

Description

  The present invention relates to a fuel pump that supplies fuel to a fuel consuming device.

  2. Description of the Related Art There is known a fuel supply device that can stably supply fuel even when the remaining amount of fuel in the fuel tank decreases (see, for example, Patent Document 1). As shown in FIG. 6, the fuel supply apparatus includes a sub tank 300 that is installed in the fuel tank and accumulates a part of the fuel in the fuel tank, and a fuel pump 400 that is accommodated in the sub tank 300. The fuel pump 400 is driven by the motor unit 900 and the rotational driving force of the motor unit 900 to suck the fuel in the sub tank 300 and supply it to a fuel consuming device (for example, an internal combustion engine) outside the fuel tank. And a pump unit 500.

  This pump part 500 has a blade part on the outer periphery, and includes one disk-shaped impeller that is rotationally driven by the motor part 900, and one pump flow path formed in an arc shape along the blade part. A pump case 530 is provided.

  In addition, the fuel supply apparatus is provided with a jet pump 550 for pumping fuel outside the sub tank 300 into the sub tank 300. The jet pump 550 is driven by using a part of the fuel flow discharged from the pump unit 500 as an energy source.

  On the other hand, as shown in FIG. 7, there is known a fuel pump 401 in which the jet pump 550 pumped into the sub tank 300 is abolished (see, for example, Patent Document 2). The fuel pump 401 is driven by the motor unit 901 and the rotational driving force of the motor unit 901 to suck the fuel in the sub tank 301 and supply it to a fuel consuming device (for example, an internal combustion engine) outside the fuel tank. In addition, a pump unit 501 that pumps fuel outside the sub tank 301 into the sub tank 301 is provided.

  The pump portion 501 has an outer peripheral blade portion 610 on the outer peripheral side and an inner peripheral blade portion 620 on the inner peripheral side, and a single disk-shaped impeller 600 that is rotationally driven by the motor portion 901, and an outer peripheral blade portion A pump case 531 having an outer peripheral pump flow path 700 formed in an arc shape along 610 and an inner peripheral pump flow path 800 formed in an arc shape along an inner peripheral blade portion 620 is provided.

The outer peripheral pump passage 700 is formed with an outer peripheral inlet 720 for sucking fuel in the sub-tank 301 and an outer peripheral outlet 730 for supplying fuel boosted in the outer peripheral pump passage 700 to the outside of the fuel tank. On the other hand, the inner peripheral pump flow path 800 has an inner peripheral suction port 820 for sucking fuel outside the sub tank 301, and an inner peripheral discharge port 830 for supplying fuel boosted in the inner peripheral pump flow path 800 into the sub tank 301. Is formed. An outer peripheral suction passage 740 that communicates with the outer peripheral suction port 720 and an inner peripheral suction passage 840 that communicates with the inner peripheral suction port 820 are formed on one side of the pump case 531 (see FIGS. 7 and 7). 8).
JP 2004-28054 A Special table 2003-532009 gazette

  The outer diameter of the pump case 531 of the fuel pump 401 is determined by the size of the fuel tank and the sub tank 301 and the like. Since the inner diameters of the outer peripheral and inner peripheral suction passages 740 and 840 formed on the side portion of the pump case 531 are determined by the demands of the fuel consuming device for supplying fuel, the outer peripheral and inner peripheral suction ports 720 and 820, respectively. It is larger than the diameter.

  In such a situation, the suction passages 740 and 840 cannot be arranged on the side of the pump case 531 in the radial direction. As a countermeasure, it is conceivable to dispose both suction passages 740 and 840 in the circumferential direction. If both suction passages 740 and 840 are shifted in the circumferential direction, the outer and inner suction ports 720 and 820 must also be shifted in the circumferential direction. When both the suction ports 720 and 820 are shifted in the circumferential direction, as shown in FIG. 8, a part of the outer peripheral pump flow path 700 including the outer peripheral discharge port 730 and an inner peripheral pump flow path 800 including the inner peripheral suction port 820 are obtained. Some overlap in the radial direction. This is called wrapping.

  Here, the fuel pressure in the outer peripheral pump flow path 700 becomes higher toward the outer peripheral discharge port 730. In the fuel pump 401 of the type in which the two pump flow paths 700 and 800 are formed in the pump case 531, the inner peripheral pump flow path 800 is not formed around the end of the outer peripheral pump flow path 700 on the outer peripheral discharge port 730 side. The two pump flow paths 700 and 800 are arranged so as to secure a distance from the end on the outer peripheral discharge port 730 side to the inner peripheral pump flow path 800 and suppress fuel leakage from the end on the outer peripheral discharge port 730 side. It is desirable to do.

  However, as described above, a part of the outer peripheral pump flow path 700 and a part of the inner peripheral pump flow path 800 are overlapped due to restrictions on the arrangement of the suction passages 740 and 840. The fuel leaks into the inner peripheral pump flow path 800, and the overall efficiency of the fuel pump 401 is reduced.

  The overall efficiency of the fuel pump means that the voltage applied to the motor unit 901 is V, the current is A, the pressure of the fuel discharged from the outer discharge port 730 is P, and the flow rate of the fuel discharged from the outer discharge port 730 is L. Then, (total efficiency) = (P × L) / (V × A).

  In such a type of fuel pump 401, there is a problem peculiar to Patent Document 2 that does not occur in the fuel pump 400 of the type as in Patent Document 1, such as fuel leakage from the outer peripheral pump flow path 700 to the inner peripheral pump flow path 800. For this reason, the overall efficiency of the fuel pump 400 of Patent Document 1 may be lowered.

  The present invention has been made in order to solve the above-mentioned problem. In a fuel pump of a type having two pump flow paths of an outer periphery and an inner periphery in a pump portion and driven by a single impeller, the pump An object of the present invention is to provide a fuel pump capable of forming an outer periphery and an inner periphery suction passage communicating with both pump flow paths in a side portion of the case, and suppressing a decrease in the overall efficiency of the fuel pump.

  As a result of repeating trial and error to achieve the above object, the inventor is in a state where the outer peripheral pump flow path and the inner peripheral pump flow path are wrapped due to the arrangement of the outer peripheral and inner peripheral suction passages. In addition, the present inventors have found a relationship that can achieve an overall efficiency superior to that of a pump-type fuel pump as described in Patent Document 1 above.

According to the first aspect of the present invention, in a fuel pump including a motor unit and a pump unit that boosts the sucked fuel driven by the rotational driving force of the motor unit and discharges the boosted fuel.
The pump part has an outer peripheral blade part and an inner peripheral blade part, and is an impeller that is rotationally driven by the motor part, and an outer peripheral pump channel formed in an arc shape along the outer peripheral blade part. An outer peripheral pump passage that pressurizes the fuel sucked from the outer peripheral suction port formed at the end and discharges from the outer peripheral discharge port formed at the other end, and is formed in an arc shape along the inner peripheral blade portion An inner peripheral pump flow path for boosting fuel sucked from an inner peripheral suction port formed at one end and discharging from an inner peripheral discharge port formed at the other end; An outer peripheral suction passage formed on one side and communicating with the outer peripheral suction port, and an inner peripheral suction passage formed on one side and communicating with the inner peripheral suction port,
Connecting the outer circumferential discharge opening side outer peripheral pump flow paths, in a configuration in which the inner circumferential suction opening side inner peripheral pump flow paths overlap in the radial direction, the outer circumferential discharge opening side end portion of the rotation center and the outer pump channel of the impeller The angle formed by the straight line and the straight line connecting the rotation center of the impeller and the inner peripheral suction port side end of the inner peripheral pump flow path is 11 ° to 58 °.

According to this arrangement, connecting the straight line connecting the outer peripheral discharge port-side end portion of the rotation center and the outer pump channel of the impeller, the inner peripheral inlet side end portion of the rotation center and the inner pump channel of the impeller Since the angle formed with the straight line is 11 ° or more, the outer peripheral and inner peripheral suction passages can be formed on one side of the pump case. Further, since the angle formed by the straight line is set to 58 ° or less, it is possible to reduce the amount of fuel leakage from the outer peripheral pump flow path to the inner peripheral pump flow path. The overall efficiency can be ensured.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a fuel supply device using the fuel pump of the present invention, and shows a state in which the fuel supply device is installed in a fuel tank. The vertical direction indicated by the arrow in FIG. 1 indicates the direction of gravity of the fuel tank mounted on the vehicle. FIG. 2 is a cross-sectional view of a main part of the fuel pump of FIG. The fuel pump in FIGS. 1 and 2 is schematically shown so that the structure and function of the pump can be easily understood.

  The fuel supply device 1 is a device that supplies the fuel in the fuel tank 2 to a fuel consuming device such as an internal combustion engine outside the fuel tank 2. The fuel supply device 1 includes a sub tank 3 and a fuel pump 4. The sub tank 3 is installed on the bottom surface 21 of the fuel tank 2 and temporarily stores the fuel in the fuel tank 2. The fuel pump 4 is accommodated in the sub tank 3, sucks the fuel temporarily stored in the sub tank 3, and supplies it to the internal combustion engine outside the fuel tank 2.

  As shown in FIG. 1, the sub tank 3 is a cylindrical or box-shaped resin container having a bottom 31 and a side wall 34 extending upward from the outer peripheral edge of the bottom 31. The sub tank 3 can store the fuel in the fuel tank 2 at a liquid level independent of the liquid level of the fuel tank 2. Since the area of the bottom 31 of the sub tank 3 is smaller than the area of the bottom surface 21 of the fuel tank 2, even if the liquid level of the fuel tank 2 is reduced, the sub tank 3 has a height that allows the fuel pump 4 to suck the liquid level. can do.

  A through hole 32 is formed in the bottom 31 of the sub tank 3. A leg portion 33 extends toward the bottom surface 21 on the outer wall of the bottom portion 31. Therefore, a gap 35 is formed between the bottom 31 of the sub tank 3 and the bottom surface 21 of the fuel tank 2.

  The fuel pump 4 includes a pump unit 5 and a motor unit 9 that drives the pump unit 5. The pump unit 5 is disposed below the motor unit 9. The motor unit 9 is a DC motor with a brush, and a permanent magnet (not shown) is annularly arranged in a substantially cylindrical housing 41, and an armature 91 is coaxially arranged on the inner peripheral side of the permanent magnet. It has a configuration. The armature 91 has a coil (not shown) wound around the outer periphery of a core (not shown) and a shaft 92. A commutator (not shown) and a brush (not shown) are provided on the armature 91.

  The upper end portion of the shaft 92 is rotatably supported by a bearing (not shown) accommodated in an end cover 412 provided at the upper end of the housing 41. The end cover 412 is provided with a connector 413, and electric power is supplied from an external power source to the armature 91 via a terminal (not shown) embedded in the connector 413, a brush, and a commutator. When the armature 91 is rotated by the supplied electric power, the impeller 6 as an impeller rotates together with the shaft 92. The form of the motor unit 9 is not limited to a brushed DC motor as in this embodiment, but may be a brushless motor.

  The detail of the pump part 5 is demonstrated based on FIG. The pump unit 5 has a function of sucking the fuel in the sub tank 3 and supplying it to the outside of the fuel tank 2 and a function of sucking the fuel outside the sub tank 3 and supplying it to the sub tank 3. The pump unit 5 includes an impeller 6, a pump casing 51, and a pump cover 52. A pump case is formed by the pump casing 51 and the pump cover 52, and the impeller 6 is rotatably accommodated therein.

  As shown in FIG. 2, the impeller 6 is made of a resin excellent in fuel resistance, and is formed in a substantially disc shape. The outer peripheral edge of the impeller 6 is formed with a high-pressure pump blade portion 61 as an outer peripheral blade portion over the entire circumference. The inner peripheral side of the high-pressure pump blade portion 61 is formed as an inner peripheral blade portion over the entire circumference. The low-pressure pump blade part 62 is formed.

  The high-pressure pump blade portion 61 includes a plurality of blade pieces extending radially at predetermined intervals, a blade groove formed between adjacent blade pieces, and a radial direction from the axial center of the inner peripheral side wall of the blade groove. It has a projecting portion for discharging and an annular portion for connecting the outer peripheral side tip portion of the blade piece over the entire circumference. The side surface in the axial direction of the protrusion is a curved surface, and has a shape such that the thickness decreases as it goes toward the tip. The low pressure pump blade portion has the same configuration as the high pressure pump blade portion.

  As shown in FIG. 2, the pump casing 51 and the pump cover 52 are made of, for example, aluminum or a resin having excellent fuel resistance and high strength. The pump casing 51 is press-fitted and fixed to one end of the housing 41, and a bearing 94 is fitted in the center thereof. The pump cover 52 is fixed to one end of the housing 41 by caulking or the like while being covered with the pump casing 51. A thrust bearing 95 is press-fitted and fixed at the center of the pump cover 52. The bearing 94 rotatably supports the radial side surface of the lower end portion of the shaft 92, and the thrust bearing 95 supports the axial end surface of the lower end portion of the shaft 92.

  Since the pump casing 51 and the pump cover 52 are accommodated in the housing 41, the outer diameters of the pump casing 51 and the pump cover 52 depend on the outer diameter of the housing 41. The outer diameter of the housing 41 depends on the size of the sub tank 3 that accommodates the fuel pump 4. Further, the size of the sub tank 3 depends on the size of the fuel tank 2 that accommodates the sub tank 3, and the size of the fuel tank 2 depends on the size of the vehicle on which the fuel tank 2 is mounted. In the present embodiment, the outer diameter of the housing 41 is about 38 mm.

  As shown in FIG. 2, the pump casing 51 and the pump cover 52 have the impeller 6 rotatably accommodated in a position corresponding to the high-pressure pump blade portion 61, and an arcuate outer periphery along the blade portion 61. A high pressure pump flow path 7 as a pump flow path is formed, and a low pressure pump flow path 8 as an arcuate inner peripheral pump flow path is formed along the blade portion 62 at a position corresponding to the low pressure pump blade portion 62. ing.

  A suction port 72 as an outer peripheral suction port is formed at one end of the high-pressure pump flow path 7, and a high pressure as an outer peripheral suction passage extending downward from the lower surface 521 of the pump cover 52 is formed in the suction port 72. A pump suction pipe 74 is connected. A high-pressure pump suction filter 78 that filters the fuel sucked into the high-pressure pump flow path 7 is attached to the tip of the high-pressure pump suction pipe 74. The high-pressure pump suction filter 78 is configured by providing a collar portion 79 connected to the high-pressure pump suction pipe 74 in a bag-shaped material such as a nonwoven fabric.

  At the other end of the high-pressure pump flow path 7, a discharge port 73 is formed as an outer peripheral discharge port that discharges fuel sucked from the suction port 72. The discharge port 73 is formed on the upper surface of the pump casing 51. The formed high-pressure pump discharge passage 75 is connected. The high-pressure pump discharge passage 75 opens into the housing 41 that supports the pump unit 5.

  A suction port 82 as an inner peripheral suction port is formed at one end of the low-pressure pump flow path 8, and the suction port 82 serves as an inner peripheral suction passage extending downward from the lower surface 521 of the pump cover 52. The low-pressure pump suction pipe 84 is connected. A low pressure pump suction filter 88 that filters the fuel sucked into the low pressure pump flow path 8 is attached to the tip of the low pressure pump suction pipe 84. The low-pressure pump suction filter 88 is configured by providing a collar portion 89 connected to the low-pressure pump suction pipe 84 in a bag-like material made of vibration-absorbing material such as nonwoven fabric. The suction filter 88 is accommodated in the gap 35, and the collar portion 89 passes through the through hole 32 of the sub tank 3 and is connected to the low pressure pump suction pipe 84.

  A discharge port 83 as an inner peripheral discharge port for discharging the fuel sucked from the suction port 82 is formed at the other end of the low-pressure pump flow path 8, and the discharge port 83 has a lower surface of the pump cover 52. A low-pressure pump discharge passage 85 formed at 521 is connected.

  As the impeller 6 rotates, the high-pressure pump blade portion 61 moves from the suction port 72 of the high-pressure pump passage 7 toward the discharge port 73, and the low-pressure pump blade portion 62 also moves to the suction port 82 of the low-pressure pump passage 8. To the discharge port 83.

  When the high-pressure pump blade 61 moves in the high-pressure pump flow path 7, the fuel in the sub tank 3 is sucked into the high-pressure pump flow path 7 from the suction port 72. The fuel sucked into the high-pressure pump flow path 7 is increased in pressure by the movement of the high-pressure pump blade portion 61, and discharged from the discharge port 73 into the fuel chamber 411 in which the armature 91 is accommodated via the high-pressure pump discharge passage 75. The As shown in FIG. 1, the fuel discharged into the fuel chamber 411 is discharged from the fuel tank 2 through a discharge cylinder portion 414 formed on the end cover 412 and a hose (not shown) connected to the discharge cylinder portion 414. Supplied to the internal combustion engine.

  When the low-pressure pump blade portion 62 moves in the low-pressure pump flow path 8, fuel outside the sub tank 3 is sucked into the low-pressure pump flow path 8 from the suction port 82. The fuel sucked into the low pressure pump flow path 8 is discharged from the discharge port 83 to the sub tank 3 through the low pressure pump discharge passage 85 by the movement of the low pressure pump blade portion 62.

  Next, details of the arrangement of the high-pressure pump passage 7 and the low-pressure pump passage 8 formed in the pump casing 51 and the pump cover 52 will be described with reference to FIGS. 3 shows a cross section taken along line III-III in FIG. 2, and FIG. 4 shows a cross section taken along line IV-IV in FIG.

  As shown in FIG. 2, the impeller 6 is accommodated in a recess 511 formed on the lower surface of the pump casing 51. A high-pressure pump groove 71 and a low-pressure pump groove 81 that are part of the high-pressure pump flow path 7 and the low-pressure pump flow path 8 are formed on the bottom surface of the recess 511. A high pressure pump groove 71 and a low pressure pump groove 81 that are part of the high pressure pump flow path 7 and the low pressure pump flow path 8 are also formed on the upper surface of the pump cover 52 that covers the pump casing 51.

  The high-pressure pump flow path 7 is formed by the high-pressure pump groove 71 of the pump casing 51 and the high-pressure pump groove 71 of the pump cover 52 facing each other with the high-pressure pump blade portion 61 interposed therebetween. The low-pressure pump flow path 8 is formed by the low-pressure pump groove 81 of the pump casing 51 and the low-pressure pump groove 81 of the pump cover 52 facing each other with the low-pressure pump blade portion 62 interposed therebetween.

  A high pressure pump groove 71 and a low pressure pump groove 81 are formed between one axial side surface of the impeller 6 and the bottom surface of the recess 511 and between the other axial side surface of the impeller 6 and the top surface of the pump cover 52. The clearance of the portion that is not made is a clearance (for example, several μm to several tens μm) to the extent that fuel does not leak from the high pressure pump flow path 7 to the low pressure pump flow path 8.

  As shown in FIG. 3, the high-pressure pump groove 71 is an arc-shaped groove formed on the circumference of an imaginary circle centered on the rotation center 93 of the shaft 92, and the suction port side which is one end portion thereof A suction port 72 is formed at the end 76, and a discharge port 73 is formed at the discharge port side end 77 which is the other end (see FIG. 2 for the location of the discharge port 73). ).

  The low-pressure pump groove 81 is an arc-shaped groove formed on the circumference of an imaginary circle having a diameter smaller than the diameter of the imaginary circle with the rotation center 93 as the center, and is one end thereof. A suction port 82 is formed at the suction port side end portion 86, and a discharge port 83 is formed at the discharge port side end portion 87 which is the other end portion.

  In FIG. 3, the high-pressure pump groove 71 and the low-pressure pump groove 81 on the pump casing 51 side are not shown, but the description is omitted because they have the same configuration as the high-pressure pump groove 71 and the low-pressure pump groove 81 on the pump cover 52 side. To do.

  As shown in FIG. 4, the lower surface 521 of the pump cover 52 is formed with a high-pressure pump suction pipe 74 and a low-pressure pump suction pipe 84 connected to the suction ports 72 and 82 described in FIG. In this embodiment, the opening area of both pump suction pipes 74 and 84 is set to an area that can secure a discharge amount of 80 liters per hour as the discharge capacity of the pump unit 5, for example. The opening areas of both pump suction pipes 74 and 84 are larger than the opening areas of both suction ports 72 and 82.

  Since the two pump suction pipes 74 and 84 cannot be formed on the lower surface 521 of the pump cover 52 immediately below the two suction ports 72 and 82, as shown in FIG. 84 is formed by shifting in the circumferential direction. For this reason, as shown in FIG. 3, the high-pressure and low-pressure pump grooves 71 and 81 are formed so that the high-pressure pump groove 71 on the discharge port 73 side and the low-pressure pump groove 81 on the suction port 82 side wrap.

  Here, when the impeller 6 rotates, fuel is sucked into the pump flow paths 7 and 8 from the respective suction ports 72 and 82. The sucked fuel is pressurized as it goes to the respective discharge ports 73 and 83. The pressure in the high pressure pump flow path 7 is higher than the pressure in the low pressure pump flow path 8. Even in the high-pressure pump flow path 7, the pressure increases toward the discharge port side end 77.

As shown in FIG. 3, when the high-pressure pump flow path 7 on the discharge port 73 side and the low-pressure pump flow path 8 on the suction port 82 side wrap, the high-pressure pump flow path 7 and the low-pressure pump flow path 8 Since the distance is shortened, the fuel leaks from the high pressure pump flow path 7 toward the low pressure pump flow path 8. The leakage amount is a straight line connecting the discharge port-side end portion 77 of the rotation center 93 and the high-pressure pump flow path 7 of the impeller 6, an inlet side end portion 86 of the rotation center 93 and the low pressure pump channel 8 of the impeller 6 The larger the angle θ (lap angle θ) formed with the connected straight line , the larger the angle.

  FIG. 5 shows the relationship between the wrap angle θ and the overall efficiency of the fuel pump 4 expressed by (total efficiency%) = (P × L × 100) / (V × A). In the above formula, P is the pressure of the fuel discharged from the discharge port 73, L is the flow rate of the fuel discharged from the discharge port 73, V is the voltage applied to the motor unit 9, and A is the motor unit. This is the current applied to 9.

  As can be seen from FIG. 5, when the wrap angle θ increases, that is, when the leakage amount increases, the overall efficiency of the fuel pump 4 tends to decrease. When the wrap angle θ is larger than 58 °, as shown in FIG. 5, a jet having one pump flow path in the pump unit and pumping fuel into the sub tank from a part of the fuel flow discharged from the pump unit The total efficiency (20%) of the fuel pump of the type used for the pump drive source (see Patent Document 1) will be lower.

  In the present embodiment, the high pressure and low pressure pump flow paths 7 and 8 formed in the pump casing 51 and the pump cover 52 are the discharge port side end 77 of the high pressure pump flow path 7 and the suction port side of the low pressure pump flow path 8. Since the wrap angle θ with the end portion 86 is 58 ° or less, the fuel pump 4 can be operated with an overall efficiency of 20% or more.

  As shown in FIG. 5, when the wrap angle θ is reduced, the overall efficiency increases. However, as described above, the suction port 72 of the high-pressure pump channel 7 and the suction port 82 of the low-pressure pump channel 8 approach each other, and the pump The high pressure pump suction pipe 74 and the low pressure pump suction pipe 84 cannot be formed on the lower surface 521 of the cover 52. In the present embodiment, the pump suction pipes 74 and 84 can be formed on the lower surface 521 of the pump cover 52 by setting the wrap angle θ to 11 ° or more.

  As described above, in the fuel pump 4 in which the high pressure and low pressure pump flow paths 7 and 8 are formed in the pump casing 51 and the pump cover 52, the discharge port side end 77 of the high pressure pump flow path 7 and the low pressure pump flow path. 8, the wrap angle θ with respect to the suction port side end portion 86 is set to 11 ° to 58 °. Therefore, both pump suction pipes 74 and 84 can be formed on the lower surface 521 of the pump cover 52, and the overall fuel pump 4. A decrease in efficiency can be suppressed.

It is sectional drawing of the fuel supply apparatus using the fuel pump by one Embodiment of this invention. It is principal part sectional drawing of the fuel pump of FIG. It is sectional drawing of the III-III line | wire in FIG. It is sectional drawing of the IV-IV line | wire in FIG. It is a characteristic view which shows the relationship between a lap angle and the total efficiency of a fuel pump. It is sectional drawing of the 1st conventional fuel supply apparatus. It is sectional drawing of the 2nd conventional fuel supply apparatus. It is principal part sectional drawing of the fuel pump of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel supply apparatus 2 Fuel tank 3 Sub tank 4 Fuel pump 41 Housing 5 Pump part 51 Pump casing (pump case)
52 Pump cover (pump case)
521 Bottom 6 Impeller (Impeller)
61 High-pressure pump blade (outer blade)
62 Low pressure pump blade (inner blade)
7 High pressure pump flow path (peripheral pump flow path)
71 High-pressure pump groove 72 Suction port (outer peripheral suction port)
73 Discharge port (outer periphery discharge port)
74 High-pressure pump suction pipe (outer periphery suction passage)
75 High-pressure pump discharge passage 76 Suction port side end 77 Discharge port side end (outer periphery discharge port side end)
78 High-pressure pump suction filter 8 Low-pressure pump flow path (inner peripheral pump flow path)
81 Low pressure pump groove 82 Suction port (inner peripheral suction port)
83 Discharge port (inner discharge port)
84 Low-pressure pump suction pipe (inner suction passage)
85 Low pressure pump discharge passage 86 Inlet side end (inner peripheral inlet side end)
87 Discharge port end 88 Low pressure pump suction filter 9 Motor 92 Shaft 93 Rotation center

Claims (1)

In a fuel pump including a motor unit and a pump unit that boosts the sucked fuel driven by the rotational driving force of the motor unit and discharges the boosted fuel.
The pump part includes an outer peripheral blade part and an inner peripheral blade part, an impeller that is rotationally driven by the motor part, and an outer peripheral pump channel formed in an arc shape along the outer peripheral blade part. An outer peripheral pump passage that pressurizes fuel sucked from an outer peripheral suction port formed at one end and discharges it from an outer peripheral discharge port formed at the other end;
An inner peripheral pump flow path formed in an arc shape along the inner peripheral blade part, and pressurizes fuel sucked from an inner peripheral suction port formed at one end, and is formed at the other end. An inner peripheral pump flow path for discharging from the inner peripheral discharge port;
An outer peripheral suction passage formed on one side and communicating with the outer peripheral suction port;
An inner peripheral suction passage formed on the one side and communicating with the inner peripheral suction port;
Wherein the outer circumferential discharge opening side outer peripheral pump flow paths, in a configuration in which the inside and the inner circumferential pump channel in the circumferential inlet side overlap in the radial direction, the outer periphery of the outer peripheral pump channel with the center of rotation of the impeller and connecting the discharge port side end straight, angle of rotation center and connecting it straight to the inner peripheral inlet side end portion of the inner peripheral pump flow paths of the impeller is the 11 ° to 58 ° A fuel pump characterized by that.

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