JP4424434B2 - IMPELLER FOR FUEL PUMP, FUEL PUMP AND FUEL SUPPLY DEVICE - Google Patents

Description

  The present invention relates to a fuel pump impeller applied to a fuel pump having a plurality of pump chambers, a fuel pump including the same, and a fuel supply apparatus to which the fuel pump is applied.

  Conventionally, a turbine-type fuel pump that is mounted in a fuel tank of a vehicle and pumps fuel to a vehicle travel engine is known.

  This type of fuel pump is generally reliable even when the liquid level of the fuel in the fuel tank is inclined, such as when the vehicle is turning or climbing, or when the liquid level of the fuel is lowered due to fuel consumption. It is mounted in a sub tank arranged at the bottom of the fuel tank so that fuel can be sucked and discharged. The sub tank is a fuel container that can store fuel at a liquid level independent of the liquid level in the fuel tank by filling the inside of the fuel in the fuel tank.

  As a means for filling the sub tank with fuel, for example, in Patent Document 1, the pump chambers of the fuel pump are formed in two rows on a concentric circle, and the outer pump chambers arranged on the outside are used as fuel for the vehicle running engine. It is disclosed that an inner pump chamber disposed inside is used for fuel filling into a sub tank.

  Further, Patent Document 2 discloses that the pump efficiency of the fuel pump is improved by defining the rearward tilt angle or the forward tilt angle of the rear surface located on the rear side in the rotational direction of the impeller blade groove. ing.

The rearward tilt angle of the rear surface is an angle formed by a line segment connecting the radially inner end and the radially outer end of the rear surface and a line segment extending radially from the radially inner end. The forward tilt angle refers to a line segment connecting the center portion of the rear surface in the rotational axis direction and one end portion of the rear surface in the rotational axis direction, and extends from the center portion of the rear surface in the rotational axis direction in the rotational tangential direction. The angle formed by the line segment.
US Pat. No. 5,596,970 JP 2007-132196 A

  By the way, when the pump chambers are formed in two rows concentrically as in Patent Document 1 and the inner pump chamber is used for fuel filling into the sub-tank, the inner pump chamber has an impeller peripheral to the outer pump chamber. Directional speed is reduced. Therefore, the suction negative pressure in the inner pump chamber is smaller than the suction negative pressure in the outer pump chamber.

  Therefore, for example, when the remaining amount of fuel in the fuel tank decreases, the fuel level in the fuel tank becomes lower than the pump mounting position, and there is no fuel in the inner pump chamber, the suction negative pressure in the inner pump chamber becomes extremely high. It becomes small and it becomes impossible to suck the fuel from the fuel tank into the inner pump chamber.

  Even if the fuel can be sucked into the inner pump chamber with a small negative suction pressure, the fuel cannot be pumped into the sub tank unless the pump effect is exhibited by exhausting the gas (air) in the inner pump chamber. .

  On the other hand, as a blade groove shape of the impeller for the inner pump chamber of Patent Document 1, a means for improving the pump efficiency by applying the blade groove shape disclosed in Patent Document 2 can be considered, but this means is adopted. Then, on the contrary, the fuel pumped up to the sub tank is excessively pressurized. And such excessive pressure | voltage rise leads to the increase in the drive torque of a fuel pump, and will cause the increase in a consumption current.

  In view of the above, the first object of the present invention is to provide a fuel pump impeller capable of pumping fuel with low torque even when no fuel is present in the pump chamber.

  A second object of the present invention is to provide a fuel pump that can pump fuel with low torque even when no fuel is present in the pump chamber.

  The present invention also provides a fuel supply device capable of pumping fuel to a sub-tank with low torque even when the fuel level in the fuel tank is low and there is no fuel in the pump chamber. The purpose of 3.

The present invention has been devised to achieve the above object, and is an impeller for a fuel pump applied to a fuel pump having an outer pump chamber (50a) and an inner pump chamber (50b) formed concentrically. There,
At least a portion corresponding to the inner pump chamber (50b) has a plurality of inner blade grooves (55, 55 ') in the rotation direction and a partition wall portion (55a) separating the adjacent inner blade grooves (55, 55'). Among the rear surfaces (55c, 55c ′) located on the rear side in the rotational direction of the inner blade grooves (55, 55 ′), at least the radially inner side is directed from the radially inner side to the radially outer side. A line segment (103) that is inclined rearward in the rotational direction and connects the radially inner end (55d) and the radially outer end (55e) of the rear surface (55c, 55c ′), and the radially inner end When the backward inclination angle formed by the line segment (104) extending in the radial direction from (55d) is α2,
30 ° ≦ α2 ≦ 80 ° ,
At least a part of the rear surface (55c ′) is inclined rearward in the rotational direction from one end side in the rotational axis direction to the other end side in the rotational axis direction, and the rear surfaces (55c ′) intersect each other. A line connecting a first end (551f) and a second end (551g) on the innermost peripheral side of the rear surface (55c ′). The inclination angle formed by the minute (105a) and the line segment (106a) extending in the tangential direction on the rear side in the rotational direction from the end portion (551f) on one end side is β1, and the outermost peripheral side of the rear surface (55c ′) A line segment (105b) connecting the end portion (552f) on one end side and the end portion (552g) on the other end side in FIG. When the inclination angle formed by (106b) is β2, the inclination angle an impeller for a fuel pump β1 and inclination angle β2 is different to the first feature.

  Since the fuel pump to which this kind of impeller is applied is a non-volumetric pump, if there is no liquid fuel in the pump chamber and the gas (air) is filled, the gas may be discharged from the pump chamber. difficult.

  Therefore, for example, even in a fuel pump applied to a fuel supply device that pumps the fuel in the fuel tank to the sub-tank by the pumping action of the inner pump chamber (50b), the fuel level in the fuel tank is lowered, When there is no fuel, it is difficult to discharge the gas (air) in the inner pump chamber (50b).

  On the other hand, according to the fuel pump impeller of the first feature, the rearward inclination angle α2 of the rear surface (55c, 55c ′) is set to 30 ° ≦ α2 ≦ 80 °. Side gas can flow to the outer diameter side of the impeller along the rear surface (55c, 55c ′), and a larger suction negative pressure can be generated in the inner pump chamber (50b). As a result, even when there is no fuel in the pump chamber, the fuel can be pumped with low torque.

  According to the investigation by the present inventors, when α2 <30 °, the gas flowing from the impeller inner diameter side hits the rear surface (55c, 55c ′) and loses the flow velocity. For this reason, it has been found that the negative pressure generated in the pump chamber is reduced and a sufficient suction negative pressure cannot be obtained. On the other hand, if 80 °> α2, the rear surface (55c, 55c ′) cannot be formed.

Furthermore, by forming the rear surface (55c ′) in this way, even if the fuel liquid level is lower than the fuel pump impeller, the fuel is sucked into the inner pump chamber (50b), and the inner pump chamber (50b) ) Gas is discharged, the inner pump chamber (50b) is filled with liquid fuel, and the pump effect can be exerted.

  Furthermore, specifically, the inclination angle β1 may be β = 90 °, and the inclination angle β2 may be 55 ° ≦ β2 <90 °.

  Moreover, in this invention, let a fuel pump provided with the impeller (51) for fuel pumps of the above-mentioned 1st characteristic be the 2nd characteristic. According to this, since the fuel pump impeller of the first feature is provided, it is possible to provide a fuel pump capable of pumping fuel with low torque even when no fuel is present in the pump chamber.

  Further, in the present invention, the fuel pump (30) having the above-mentioned second characteristic and the fuel tank (10) for storing the fuel are disposed, and the fuel in the fuel tank (10) is filled therein. A sub-tank (20) configured to store fuel at a liquid level independent of the liquid level in the fuel tank, and the sub-tank (20) includes an inner pump chamber (50b) of the fuel pump (30). A third feature of the fuel supply device is that the fuel in the fuel tank (10) is filled by the pumping action.

  According to this, since the fuel pump (30) having the second feature is provided, the fuel level in the fuel tank (10) is lowered, and there is no fuel in the inner pump chamber (50b). However, it is possible to provide a fuel supply device that can pump fuel into the sub tank (20) with low torque.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

Hereinafter, embodiments of the present invention will be described. Of the first to eleventh embodiments described below, the eleventh embodiment is an embodiment of the invention described in the claims, and the first and second embodiments are the forms on which the present invention is based. Moreover, 3rd-10th embodiment is a form shown as a reference example.
(First embodiment)
The vehicle fuel supply device 1 of the present embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the fuel supply device 1, and upper and lower arrows indicate directions in a vehicle-mounted state. FIG. 2 is an enlarged cross-sectional view showing the main part of FIG. 1, specifically, an enlarged cross-sectional view showing the periphery of the pump part 50 of the fuel pump 30.

  As shown in FIG. 1, the fuel supply device 1 is accommodated in a fuel tank 10 and supplies fuel in the fuel tank 10 to a fuel consuming device (in this embodiment, a vehicle traveling engine) outside the fuel tank 10. It is. The fuel supply device 1 includes a sub tank 20 disposed at the bottom of the fuel tank 10 and a fuel pump 30 accommodated in the sub tank 20.

  The fuel tank 10 is a tank that stores fuel (in this embodiment, gasoline), and the sub tank 20 is disposed at the bottom of the fuel tank 10 and has a liquid level independent of the liquid level in the fuel tank 10. Is a fuel container capable of storing

  Specifically, the sub tank 20 is formed of a bottomed cylindrical or box-shaped (cylindrical in this embodiment) resin. A through hole 22 is provided in a bottom portion (hereinafter referred to as a sub tank bottom portion) 21 of the sub tank 20, and the inside of the fuel tank 10 and the sub tank 20 communicate with each other through the through hole 22.

  A gap space 23 is formed between the sub tank bottom 21 and the bottom of the fuel tank 10. The gap space 23 is formed in a size that can accommodate a suction filter 90 that filters the fuel flowing into the fuel pump 30 and removes foreign matter, and communicates with the fuel tank 10.

  An inner suction pipe 58 communicating with an inner pump chamber 50b of the fuel pump 30 described later is inserted into the through hole 22. The inner suction pipe 58 extends to the gap space 23 and is connected to the suction filter 90.

  In addition, a check valve 58 a that allows only fuel to flow from the gap space 23 side to the inner pump chamber 50 b side is provided inside the inner suction pipe 58. Thereby, the fuel in the sub tank 20 is prevented from flowing back into the fuel tank 10 via the inner pump chamber 50b and the inner suction pipe 58.

  In addition, a suction filter 91 that filters the fuel flowing into the fuel pump 30 to remove foreign matters is also disposed on the upper surface of the sub tank bottom 21 in the sub tank 20. The suction filter 91 is connected to an outer suction pipe 59 that communicates with an outer pump chamber 50a of the fuel pump 30 described later.

  The fuel pump 30 is a motor unit 40 that is rotated by being supplied with electric power, a pump unit 50 that obtains a rotational driving force from the motor unit 40 and sucks and discharges fuel, and a fuel pump that discharges fuel discharged from the pump unit 50 The resin cover end 70 and the like that form a discharge passage and the like leading from the inside of the fuel tank 10 to the outside of the fuel tank 10 are configured.

  First, the motor unit 40 is a known DC electric motor with a brush. Specifically, an armature 43 is rotatably arranged on the inner peripheral side of a permanent magnet 42 that is annularly arranged along the inner peripheral surface of a cylindrical housing 41. The armature 43 itself rotates by energizing (not shown). Of course, a brushless motor may be employed as the motor unit 40.

  The coil of the armature 43 includes a terminal of the connector portion 72 provided on the cover end 70, a brush disposed in the cover end 70, and a commutator provided on the armature 43 (not shown). Power is supplied from an external power source via The cover end 70 is fixed to one end side of the housing 41 (the upper end side in the mounting state shown in FIG. 1) by means such as caulking.

  The rotating shaft 44 of the armature 43 is supported by a bearing provided at the center of the cover end 70 and the pump unit 50, and the end of the rotating shaft 44 on the pump unit 50 side is the impeller of the pump unit 50. 51 is connected.

  Therefore, when the motor unit 40 is energized and the armature 43 is rotated, the impeller 51 rotates integrally with the armature 43 and causes the pump unit 50 to exert a pump action. The fuel flowing into the fuel chamber 45 in the housing 41 from the pump unit 50 by the pumping action of the pump unit 50 passes through the discharge passage formed in the cylindrical discharge port 71 of the cover end 70 and passes through the fuel tank 10. Out to the outside.

  The pump unit 50 includes an impeller 51, a pump chamber casing 52, and a pump chamber cover 53. More specifically, the impeller 51 is housed in a casing formed by the pump chamber casing 52 and the pump chamber cover 53 so as to be rotatable about the rotation shaft 44.

  Details of the impeller 51 will be described with reference to FIGS. 3A is an overall front view of the impeller 51 viewed from the rotation axis direction, FIG. 3B is an enlarged view of the outer periphery of the impeller 51 in FIG. 3A, and FIG. It is diagonal direction sectional drawing in the state which accommodated 51 in the casing.

  The impeller 51 is a disk-shaped member made of resin, and has a plurality of outer blade grooves 54 and inner blade grooves 55 for transmitting momentum to the fuel, as shown in FIG. These outer blade grooves 54 and inner blade grooves 55 are both arranged in two rows on a concentric circle in the rotational direction.

  More specifically, an annular portion 51 a is provided on the outermost periphery of the impeller 51, an outer blade groove 54 is disposed on the inner peripheral side of the annular portion 51 a, and further, on the inner peripheral side of the outer blade groove 54. An inner blade groove 55 is disposed.

  First, the outer blade groove 54 will be described. As shown in FIGS. 3 and 4, the outer blade grooves 54 adjacent to each other in the rotation direction rotate from substantially the center in the rotation axis direction (thickness direction) of the impeller 51 toward the end surfaces 51 b on both sides in the rotation axis direction of the impeller 51. It is partitioned off by a V-shaped partition wall 54a inclined forward in the direction. That is, the partition wall 54a is formed in a V shape in which both end surfaces 51b side incline forward in the rotation direction in the cylindrical cross section around the rotation axis.

  Further, the outer blade groove 54 is formed with a partition wall 54b that protrudes from the radially inner side of the outer blade groove 54 toward the radially outer side, and a part of the radially inner side of the partition wall 54b serves as a rotating shaft. It is partitioned in the direction. Therefore, both end surfaces 51b of the impeller 51 pass through on the radially outer side of the partition wall 54b of the outer blade groove 54.

  Furthermore, as shown in the enlarged view of the outer blade groove 54 in FIG. 5, among the rear surface 54 c located on the rear side in the rotational direction of the outer blade groove 54 (that is, the surface located on the front side in the rotational direction of the partition wall 54 a), At least the radially inner side is inclined backward in the rotational direction from the radially inner side toward the radially outer side.

  A line segment 101 connecting the radially inner end 54d and the radially outer end 54e of the rear surface 54c in a plane perpendicular to the rotation axis, and a straight line 102 extending in the radial direction of the impeller 51 from the radially inner end 54d, When the rearward tilt angle to be formed is α1, the angle is set to about 15 ° ≦ α1 ≦ 30 °.

  Next, the inner blade groove 55 will be described. The basic configuration of the inner blade groove 55 is the same as that of the outer blade groove 54. Therefore, the inner blade groove 55 adjacent to the rotation direction is partitioned by the V-shaped partition wall portion 55a inclined forward in the rotation direction, and a part of the inner blade groove 55 on the radially inner side is partitioned by the partition wall 55b. It has been.

  Furthermore, as shown in the enlarged view of the inner blade groove 55 in FIG. 6, among the rear surface 55c located on the rear side in the rotational direction of the inner blade groove 55 (that is, the surface located on the front side in the rotational direction of the partition wall 55a), At least the radially inner side is inclined backward in the rotational direction from the radially inner side toward the radially outer side.

  A line segment 103 connecting the radially inner end 55d and the radially outer end 55e of the rear surface 55c in a plane perpendicular to the rotation axis, and a straight line 104 extending in the radial direction of the impeller 51 from the radially inner end 55d, When the rearward tilt angle to be formed is α2, 30 ° ≦ α2 ≦ 80 °.

  Further, a D hole 51 c that penetrates both end surfaces 51 b of the impeller 51 is formed on the inner peripheral side of the inner blade groove 55 of the impeller 51. The rotary shaft 44 of the motor unit 40 is fitted into the D hole 51c.

  Next, the pump chamber casing 52 and the pump chamber cover 53 shown in FIG. 2 are formed of a metal typified by aluminum (for example, aluminum die casting) or a resin material having excellent fuel resistance and high strength. First, the pump chamber casing 52 is formed in a cylindrical shape to accommodate the impeller 51, and a recess 52a is formed therein.

  The depth of the recess 52a in the rotation axis direction is formed so as to be about 5 to 50 μm deeper than the thickness of the impeller 51, and the dimension of the casing in the rotation axis direction formed by the pump chamber casing 52 and the pump chamber cover 53 The gap between the impeller 51 and the rotational axis direction dimension is set to be a predetermined gap.

  Furthermore, an outer pump flow path 52b and an inner pump flow path 52c that allow fuel to pass along with the rotation of the impeller 51 are formed in an arc shape over a predetermined angle range on the surface of the recess 52a facing the impeller 51.

  The outer pump flow path 52b and the inner pump flow path 52c are formed at positions corresponding to the arrangement of the outer blade grooves 54 and the inner blade grooves 55 of the impeller 51, respectively. In addition, a fuel chamber discharge port 52 d that communicates with the fuel chamber 45 in the housing 41 is provided at the rotational direction end of the outer pump flow path 52 b of the pump chamber casing 52.

  On the other hand, the pump chamber cover 53 is formed in a substantially disc shape, and is positioned in a predetermined positional relationship with the pump chamber casing 52 along with the pump chamber casing 52 on the side where the cover end 70 of the housing 41 is attached. It is fixed by means such as caulking on the opposite side (lower end side in the mounting state shown in FIG. 1).

  On the surface of the pump chamber cover 53 facing the impeller 51, as shown in FIG. 2, an outer pump passage 53b and an inner pump passage 53c that allow fuel to pass through the rotation of the impeller 51 over a predetermined angular range are circular. It is formed in an arc shape. The outer pump flow path 53b and the inner pump flow path 53c are also formed at positions corresponding to the arrangement of the outer blade grooves 54 and the inner blade grooves 55 of the impeller 51, respectively.

  The pump chamber cover 53 is integrally formed with the outer suction pipe 59 and the inner suction pipe 58 described above. The rotation direction start end portion of the impeller 51 in the outer pump flow path 53b communicates with the suction passage in the outer suction pipe 59, and the rotation direction start end portion of the inner pump flow path 53c is the suction passage in the inner suction pipe 58. Communicated with. Further, a subtank discharge port 53d that communicates with the subtank 20 is provided at the rotation direction end of the inner pump flow path 53c.

  Therefore, the outer pump flow path 52b of the pump chamber casing 52, the outer blade groove 54 of the impeller 51, and the outer pump flow path 53b of the pump chamber cover 53 form an outer pump chamber 50a. The inner pump chamber 50 b is formed by the inner blade groove 55 of the impeller 51 and the inner pump flow path 53 c of the pump chamber cover 53.

  Further, in the present embodiment, as in the above-mentioned Patent Document 1, the inner pump chamber 50b is used for fuel filling from the fuel tank 10 to the sub tank 20, and the outer pump chamber 50a is pumped from the sub tank 20 to the fuel consuming device. It is used for.

  Next, the operation of this embodiment in the above configuration will be described. When a vehicle start switch (not shown) is turned on and electric power is supplied from the battery to the fuel pump 30 via the connector 72, the armature 43 of the motor unit 40 rotates. Then, the impeller 51 rotates together with the rotating shaft 44 of the armature 43.

  When the impeller 51 rotates and the inner pump chamber 50b exhibits a pumping action, the fuel in the fuel tank 10 flows into the clearance space 23 → the suction filter 90 → the inner suction pipe 58 → the inner pump chamber 50b → the sub tank discharge port 53d. The sub tank 20 is filled in order.

  Further, when the outer pump chamber 50a exhibits a pumping action, the fuel in the sub tank 20 flows in the order of the suction filter 91 → the outer suction pipe 59 → the outer pump chamber 50a → the fuel chamber discharge port 52d and is discharged into the fuel chamber 45. The The fuel discharged into the fuel chamber 45 passes around the armature 43 and is led out of the fuel tank 10 from the cylindrical discharge port 71 while cooling the armature 43.

  Here, the operation principle of the fuel pump 30 of the present embodiment will be described. Since the operating principle of the outer pump chamber 50a and the inner pump chamber 50b is basically the same, only the outer pump chamber 50 will be described based on FIG.

  The fuel sucked into the outer pump chamber 50a from the outer suction pipe 59 is moved in the outer pump flow paths 52b and 53b from the outer suction pipe 59 side to the fuel chamber discharge port 52d side as the impeller 51 rotates. Flowing. At this time, the flow of fuel is guided by the partition wall 54b described above, and a swirling flow 300 is generated that rotates on both sides of the impeller 51 in the rotation axis direction.

  The swirl flow 300 causes the fuel to repeatedly move in and out of the outer pump passages 52b and 53b and the outer blade groove 54, whereby the rotational momentum is transmitted from the outer blade groove 54 to the fuel. Is boosted.

  In the present embodiment, as described above, the rearward inclination angle α1 of the outer blade groove 54 is set to about 15 ° ≦ α1 ≦ 30. High pump efficiency can be exhibited in the pump chamber 50. On the other hand, the rearward inclination angle α2 of the inner blade groove 55 is 30 ° ≦ α2 ≦ 80 °, so that a stable negative suction pressure necessary for pumping fuel can be generated in the inner pump chamber 50b.

  This will be described in more detail with reference to FIG. FIG. 7 is a graph showing the relationship between the rearward tilt angle α2 of the inner blade groove 55 and the suction negative pressure. More specifically, when the fuel level 400 shown in FIG. 1 is lower than the pump mounting position 401 corresponding to the lowermost position of the impeller 51, the inner pump chamber 50b is filled with gas (air). This is a result of measuring the suction negative pressure when the impeller 51 is idled at 5000 rpm.

  As can be seen from FIG. 7, by setting the backward inclination angle α2 to 30 ° ≦ α2, it is possible to generate a stable suction negative pressure necessary for pumping up fuel in the inner pump chamber 50b. On the other hand, if α2 <30 °, the suction negative pressure is small, so that the fuel cannot be sucked up sufficiently and the subtank 20 cannot be filled with fuel.

  If 80 ° <α2, the rear surface 55c of the inner blade groove 55 is behind the tangent line of the inscribed circle 402 formed by the inner diameter side end portion of the inner blade groove shown in FIG. Therefore, the rear face 55c of the inner blade groove 55 cannot be formed. Therefore, as in this embodiment, by setting the rearward inclination angle α2 of the inner blade groove 55 to 30 ° ≦ α2 ≦ 80 °, even when no fuel is present in the inner pump chamber 50b, the fuel tank The fuel can be pumped from 10 to the sub tank 20.

  Further, since the inner pump chamber 50b is disposed on the inner peripheral side with respect to the outer pump chamber 50a, the outer pump chamber 50a efficiently boosts the fuel by using the peripheral speed of the impeller 51, and thereby sub tanks. The fuel can be pumped from 20 to the outside of the fuel tank 10, and the inner pump chamber 50b can prevent the fuel from being unnecessarily boosted.

  As a result, an increase in driving torque in the inner pump chamber 50b can be suppressed, and fuel can be pumped from the fuel tank 10 to the sub tank 20 with low torque.

(Second Embodiment)
In the first embodiment, the basic configuration of the inner blade groove 55 is the same as that of the outer blade groove 54, and the rearward inclination angles α1 and α2 are different from each other. However, in this embodiment, as shown in FIG. An example in which an inner blade groove 55 ′ having a configuration different from that of the groove 54 is employed will be described.

  FIG. 8 is a drawing corresponding to FIG. 3 of the first embodiment, and FIG. 8A is an overall front view of the impeller 51 of this embodiment viewed from the direction of the rotation axis, and FIG. These are the enlarged views of the outer peripheral part of the impeller 51 of (a). Moreover, in FIG. 8, the same code | symbol is attached | subjected to the same or equivalent part as 1st Embodiment. The same applies to the following embodiments.

  As shown in FIG. 8, the inner blade groove 55 'of the present embodiment is not provided with a partition wall 55b. Therefore, in the inner pump chamber 50b of the present embodiment, the swirl flow 300 described with reference to FIG. 4 is less likely to occur as compared with the first embodiment. Further, the rear surface 55c 'of the inner blade groove 55' is inclined rearward in the rotational direction from one end side in the rotational axis direction toward the other end side in the rotational axis direction.

  More specifically, as shown in FIG. 9, the cylindrical surface around the rotation axis is inclined rearward in the rotation direction from the end on the pump chamber cover 53 side toward the end on the pump chamber casing 52 side. . FIG. 9 is a cross-sectional view taken along the line AA in FIG. 8B (a cylindrical cross-sectional view around the rotation axis).

  In the cylindrical surface around the rotation axis, the line segment 105 connecting the end 55f ′ on the pump chamber cover 53 side of the rear surface 55c ′ and the end 55g ′ on the pump chamber casing 52 side and the end on the pump chamber cover 53 side are provided. When the inclination angle formed by the line segment 106 extending in the tangential direction on the rear side in the rotational direction from the portion 55f ′ is β, 65 ° ≦ β <90 ° is satisfied in the entire radial direction of the rear surface 55c ′. I have to.

  In the present embodiment, the inclination angle β is set to be substantially the same in the entire radial direction of the rear surface 55c ′. However, the inclination angle β on the radially inner circumferential cylindrical surface and the radially outer circumferential side are the same. The inclination angle β in the cylindrical surface may be different. For example, the inclination angle β may gradually decrease from the inner peripheral side toward the outer peripheral side.

  Other configurations are the same as those of the first embodiment. Accordingly, when the fuel supply device 1 of the present embodiment is operated, the outer pump chamber 50a operates in exactly the same manner as in the first embodiment.

  Further, in the present embodiment, since the inclination angle β of the inner blade groove 55 ′ is set to 65 ° ≦ β <90 °, the fuel liquid level 400 is lower than the pump mounting position 401, and it is in the inner pump chamber 50b. Even when the gas (air) is full, the air in the inner pump chamber 50b can be discharged, and the inner pump chamber 50b can exhibit the pump effect.

  This will be described with reference to FIG. FIG. 10 is a graph showing the relationship between the inclination angle β of the inner blade groove 55 ′ and the pumping flow rate of the inner pump chamber 50 b. The test conditions are the same as those in FIG. As is clear from FIG. 10, by setting the inclination angle β to 65 ° ≦ β <90 °, sufficient pumping from the fuel tank 10 to the sub tank 20 can be performed. On the other hand, if β <65 °, the pumping flow rate in the inner pump chamber 50b is significantly reduced.

  When the inclination angle β = 90 °, the rear surface 55c ′ is parallel to the rotation axis direction, and the rear surface 55c ′ of the inner blade groove 55 ′ is changed from one end side in the rotation axis direction to the other end side in the rotation axis direction. Although it does not incline backward in the rotation direction, it can be pumped from the fuel tank 10 to the sub tank 20 as shown in FIG.

  Therefore, according to this embodiment, even when there is no fuel in the inner pump chamber 50b, the fuel can be reliably pumped from the fuel tank 10 to the sub tank 20 with low torque.

(Third embodiment)
In this embodiment, an example in which a high pump efficiency ηb can be exhibited in the inner pump chamber 50b by defining the shape of the V-shaped partition wall portion 55a of the inner blade groove 55 relative to the first embodiment. Will be explained.

  Specifically, as shown in FIG. 11, a line connecting the central portion 55h of the rear surface 55c in the rotation axis direction and the one end portion 55i of the rear surface 55c in the rotation axis direction on the cylindrical surface around the rotation axis. When the forward tilt angle formed by the line segment 108 extending in the tangential direction on the front side in the rotation direction from the central portion 55h of the rotation axis direction of the minute portion 107 and the rear surface 55c is γ, 70 ° ≦ γ <90 °. I have to. FIG. 11 is a cross-sectional view corresponding to the AA cross-sectional view of FIG. 8B in the present embodiment.

  Other configurations are the same as those of the first embodiment. Accordingly, when the fuel supply device 1 of the present embodiment is operated, the outer pump chamber 50a operates in exactly the same manner as in the first embodiment.

  Further, in the present embodiment, the forward tilt angle γ of the inner blade groove 55 is set as 70 ° ≦ γ <90 °, so that the fuel liquid level 400 is lower than the pump mounting position 401 and enters the inner pump chamber 50b. Even when the gas (air) is full, the pump efficiency of the inner pump chamber 50b can be stably kept high.

  This will be described with reference to FIG. FIG. 12 is a graph showing the relationship between the forward tilt angle γ of the inner blade groove 55 and the pump efficiency ηb of the inner pump chamber 50b. The test conditions are the same as those in FIG. As can be seen from FIG. 12, by setting the forward tilt angle γ to 70 ° ≦ γ <90 °, the pump efficiency can be stably kept high.

  This is because when the forward tilt angle γ is set to 70 ° ≦ γ <90 °, an appropriate swirling flow is not generated in the inner pump passages 52c and 53c of the inner pump chamber 50b that does not require excessive pressure increase. This is because the fuel can be transported. On the other hand, if 70 ° <γ, a transient swirling flow is generated, and the pump efficiency is significantly reduced.

The pump efficiency ηb of the inner pump chamber 50b is expressed by the following formula F1.
ηb = (P × Q) / (Tb × R) (F1)
P is the discharge pressure of the inner pump chamber 50b, Q is the pumping flow rate of the inner pump chamber 50b, Tb is the driving torque of the inner pump chamber 50b, and R is the rotational speed of the motor unit 40. When the forward inclination angle γ = 90 °, the shape of the partition wall portion 55a of the inner blade groove 55 is not V-shaped, but high pump efficiency can be exhibited as shown in FIG.

  As described above, according to the present embodiment, even when there is no fuel in the inner pump chamber 50b, the fuel is supplied from the fuel tank 10 to the sub tank 20 with a low torque while keeping the pump efficiency ηb stable and high. Can be pumped up.

(Fourth to seventh embodiments)
The fourth to seventh embodiments are modifications of the first to third embodiments. That is, the rearward inclination angle formed by the line segment 103 connecting the radially inner end 55d and the radially outer end 55e of the rear surface 55c and the straight line 104 extending in the radial direction of the impeller 51 from the radially inner end 55d is expressed by α2. In this case, 30 ° ≦ α2 ≦ 80 °, but the surface shape that actually forms the rear surface 55c is changed.

  Specifically, in the fourth embodiment, as shown in FIG. 13, a corner portion of the outer peripheral shape of the inner blade groove 55 is formed in a chamfered shape. In the fifth embodiment, as shown in FIG. 14, out of the outer peripheral shape of the inner blade groove 55, the radially inner side is linear, and the radially outer side is arcuate.

  Moreover, in 6th Embodiment, as shown in FIG. 15, among the outer peripheral shape of the inner blade groove | channel 55, the radial inside is made into circular arc shape, and the radial direction outer side is made into linear form. Furthermore, in the seventh embodiment, as shown in FIG. 16, the outer peripheral shape of the inner blade groove 55 is a straight line.

  13 to 16 are enlarged views of the inner blade groove 55 in the fourth to seventh embodiments, corresponding to the above-described FIG. In the fourth to sixth embodiments, as shown in FIGS. 13 to 15, the radially inner end 55 d extends the arc formed by the inner diameter side end of the inner blade groove 55 and the linear portion of the rear surface 55 c. The radially outer end 55e is an intersection of an arc formed by the outer diameter side end of the inner blade groove 55 and an extension line extending the linear portion of the rear surface 55c.

  As shown in FIGS. 13 to 16, even if the outer peripheral shape of the inner blade groove 55 is changed, the same effect as the first to third embodiments can be obtained by setting the rearward inclination angle α2 to 30 ° ≦ α2 ≦ 80 °. Obtainable.

(Eighth to tenth embodiments)
The eighth to tenth embodiments are modifications of the second embodiment. That is, the line segment 105 connecting the end 55f ′ on the pump chamber cover 53 side and the end 55g ′ on the pump chamber casing 52 side of the rear surface 55c ′ on the cylindrical surface around the rotation axis and the end on the pump chamber cover 53 side. The inclination angle formed by the line segment 106 extending in the tangential direction on the rear side in the rotational direction from 55f ′ is set to be 65 ° ≦ β <90 °, but the rear surface 55c ′ is actually The surface shape to be formed is changed.

  Specifically, in the eighth embodiment, as shown in FIG. 17, the outer peripheral end portion of the rear surface 55c 'is formed by a plurality of straight lines. In the ninth embodiment, as shown in FIG. 18, the pump chamber cover 53 side of the rear surface 55c 'is formed with a curve. Furthermore, in the tenth embodiment, as shown in FIG. 19, only the rear surface 55c 'is inclined. 17 to 19 are cross-sectional views corresponding to the AA cross-sectional view of FIG. 8B in each embodiment.

  As shown in FIGS. 17 to 19, even if the outer peripheral end shape of the rear surface 55c ′ is changed, the same effect as that of the second embodiment is obtained by setting the inclination angle β to 65 ° ≦ β <90 °. be able to.

(Eleventh embodiment)
This embodiment is a modification of the second embodiment. In the second embodiment, the example in which the inclination angle β of the rear surface 55c ′ of the inner blade groove 55 ′ is set to substantially the same angle in the entire radial direction is described, but in this embodiment, as shown in FIGS. Next, an example will be described in which the inclination angle β1 on the radially inner periphery side of the rear surface 55c ′ and the inclination angle β2 on the radially outer periphery side of the rear surface 55c ′ are changed.

  FIG. 20 is an enlarged view of the outer peripheral portion of the impeller 51 of the present embodiment, and corresponds to FIG. 8B. FIG. 21 is a view as seen from the direction of the arrow B in FIG. 22, 23, and 24 are a CC sectional view, an EE sectional view, and a DD sectional view, respectively (cylindrical sectional view around the rotation axis) in FIG.

  In the present embodiment, the rear surface 55c 'is formed by a plurality of surfaces that are mutually configured. Specifically, the rear surface 55 c ′ is formed by two surfaces, an inner region surface 551 and an outer region surface 552. As shown in FIG. 21, the inner region surface 551 and the outer region surface 552 intersect at a bent portion 55j extending obliquely with respect to the radial direction.

  Further, the inner region surface 551 is formed by a plane parallel to the rotation axis direction. Therefore, as shown in FIG. 22, the line segment 105 a connecting the end 551 f on one end side in the axial direction and the end 551 g on the other end side in the axial direction on the radially innermost peripheral side of the rear surface 55 c ′, and the axial direction The inclination angle β1 formed by the line segment 106a extending in the tangential direction on the rear side in the rotation direction from the end portion 551f on the one end side is β1 = 90 °.

  On the other hand, the outer region surface 552 is formed as a flat surface that is inclined rearward in the rotational direction from the bent portion 55j. Furthermore, as shown in FIG. 24, a line segment 105b that connects an end 552f on one end side in the axial direction and an end 552g on the other end side in the axial direction on the radially innermost circumferential side of the rear surface 55c ′, and the axial direction The inclination angle β2 formed by the line segment 106b extending in the tangential direction on the rear side in the rotation direction from the end portion 552f on the one end side is 55 ° ≦ β2 <90 °.

  Since the inner region surface 551 and the outer region surface 552 obliquely intersect at the bent portion 55j, as shown in FIG. 23, one axial end on the outer peripheral side from the substantially central portion in the radial direction of the rear surface 55c ′. The line segment 105c connecting the end 553f on the side and the end 553g on the other end in the axial direction, and the line 106c extending in the tangential direction on the rear side in the rotational direction from the end 553f on the one end in the axial direction are formed. The angle β3 is also 55 ° ≦ β3 <90 °.

  Other configurations are the same as those of the second embodiment. Even if the inclination angle β1 and the inclination angle β2 of the rear surface 55c ′ are changed as in the present embodiment, the same effect as in the second embodiment is obtained by setting the inclination angle β2 to 55 ° ≦ β2 <90 °. be able to.

  This will be described with reference to FIG. FIG. 25 is a graph showing the relationship between the inclination angle β2 of the inner blade groove 55 'and the pumping flow rate of the inner pump chamber 50b. The test conditions are the same as those in FIG. As is clear from FIG. 25, by setting the inclination angle β to 55 ° ≦ β2 <90 °, sufficient pumping from the fuel tank 10 to the sub tank 20 can be performed. On the other hand, when β <55 °, the pumping flow rate in the inner pump chamber 50b is significantly reduced.

  Therefore, according to this embodiment, even when there is no fuel in the inner pump chamber 50b, the fuel can be reliably pumped from the fuel tank 10 to the sub tank 20 with low torque. Furthermore, with respect to the inclination angle β of the second and eighth to tenth embodiments, the inclination angle β2 can be set in a wide range, and the degree of freedom in design can be improved.

  In the present embodiment, the inner region surface 551 and the outer region surface 552 are formed as flat surfaces, but may be formed as curved surfaces. Alternatively, only the outer region surface 552 may be formed as a curved surface so that the inner region surface 551 and the outer region surface 552 intersect smoothly.

(Other embodiments)
In the first and third embodiments, the partition wall 55b is provided in the inner blade groove 55, but the partition wall 55b may be eliminated as in the second embodiment.

  In the first to third embodiments, the outer pump chamber 50a is used for pumping fuel from the sub tank 20 to the outside of the fuel tank 10, and the inner pump chamber 50b is used for fuel filling from the fuel tank 10 to the sub tank 20. When the outer pump chamber 50a is used for fuel filling and the inner pump chamber 50b is used for fuel pumping, the shapes of the outer blade groove 54 and the inner blade groove 55 may be reversed.

It is sectional drawing of the fuel supply apparatus of 1st Embodiment. It is an expanded sectional view of a pump part periphery of a fuel pump of a fuel supply device of a 1st embodiment. (A) is the whole front view of the impeller of 1st Embodiment, (b) is an enlarged view of (a). It is diagonal direction sectional drawing of the pump part of the fuel pump of 1st Embodiment. It is an enlarged view of the outer blade groove of the impeller of the first embodiment. It is an enlarged view of the inner blade groove of the impeller of the first embodiment. It is a graph which shows the relationship between the backward inclination angle (alpha) 2 and suction | inhalation negative pressure. (A) is the whole front view of the impeller of 2nd Embodiment, (b) is an enlarged view of (a). It is AA sectional drawing of FIG.8 (b). It is a graph which shows the relationship between inclination-angle (beta) and a pumping flow rate. It is sectional drawing equivalent to the AA cross section of FIG.8 (b) in 3rd Embodiment. It is a graph which shows the relationship between the forward inclination angle (gamma) and pump efficiency. It is an enlarged view of the inner blade groove | channel of the impeller of 4th Embodiment. It is an enlarged view of the inner blade groove | channel of the impeller of 5th Embodiment. It is an enlarged view of the inner blade groove | channel of the impeller of 6th Embodiment. It is an enlarged view of the inner blade groove | channel of the impeller of 7th Embodiment. It is sectional drawing equivalent to the AA cross section of FIG.8 (b) in 8th Embodiment. It is sectional drawing equivalent to the AA cross section of FIG.8 (b) in 9th Embodiment. It is sectional drawing equivalent to the AA cross section of FIG.8 (b) in 10th Embodiment. It is an enlarged view of the impeller of 11th Embodiment. It is a B arrow view of FIG. It is CC sectional drawing of FIG. It is EE sectional drawing of FIG. It is DD sectional drawing of FIG. It is a graph which shows the relationship between inclination-angle (beta) 2 and a pumping flow rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel tank 20 Subtank 30 Fuel pump 50a Outer pump chamber 50b Inner pump chamber 51 Impeller 55, 55 'Inner blade groove 55a Partition part 55c, 55c' Rear surface,
55d Radial inner end 55e Radial outer end 55h Center part α2 Back tilt angle β, β1, β2 Inclination angle γ Forward tilt angle

Claims (5)

A fuel pump impeller applied to a fuel pump having an outer pump chamber (50a) and an inner pump chamber (50b) formed concentrically,
At least a portion corresponding to the inner pump chamber (50b) includes a plurality of inner blade grooves (55, 55 ') in the rotation direction, and a partition wall section that partitions the adjacent inner blade grooves (55, 55') ( 55a) is provided,
Of the rear surfaces (55c, 55c ′) located on the rear side in the rotational direction of the inner blade grooves (55, 55 ′), at least the radially inner side is directed from the radially inner side toward the radially outer side toward the rear side in the rotational direction. Is inclined,
A line segment (103) connecting the radially inner end (55d) and the radially outer end (55e) of the rear surface (55c, 55c ′), and a line extending radially from the radially inner end (55d) When the backward tilt angle formed by the minute (104) is α2,
30 ° ≦ α2 ≦ 80 ° ,
At least a part of the rear surface (55c ′) is inclined rearward in the rotational direction from one end side in the rotational axis direction toward the other end side in the rotational axis direction,
Further, the rear surface (55c ′) is formed to have a plurality of surfaces (551, 552) intersecting each other,
A line segment (105a) connecting the end portion (551f) on the one end side and the end portion (551g) on the other end side on the innermost peripheral side of the rear surface (55c ′), and an end portion on the one end side The inclination angle formed by the line segment (106a) extending in the tangential direction on the rear side in the rotational direction from (551f) is β1,
A line segment (105b) connecting the end portion (552f) on the one end side and the end portion (552g) on the other end side on the outermost peripheral side of the rear surface (55c ′), and an end portion on the one end side ( 551f) and the inclination angle formed by the line segment (106b) extending in the tangential direction on the rear side in the rotational direction is β2,
The fuel pump impeller, wherein the inclination angle β1 and the inclination angle β2 are different. The inclination angle β1 is
The impeller for a fuel pump according to claim 1 , wherein β = 90 °. The inclination angle β2 is
The fuel pump impeller according to claim 1 or 2 , wherein 55 ° ≤ β2 <90 °. A fuel pump comprising the fuel pump impeller (51) according to any one of claims 1 to 3 . A fuel pump (30) according to claim 4 ;
Located in the fuel tank (10) for storing fuel, the fuel in the fuel tank (10) is filled inside, and the fuel can be stored at a liquid level independent of the liquid level in the fuel tank. A sub tank (20) configured in
The fuel supply device according to claim 1, wherein the sub tank (20) is filled with fuel in the fuel tank (10) by a pumping action of the inner pump chamber (50b) of the fuel pump (30).

Images