JPWO2020149382A1 - Non-volumetric pump and liquid supply device - Google Patents

Abstract

The pump portion (4), which is a non-volumetric pump provided in the liquid supply device (1), is a first seal portion provided between the suction port (53) and the discharge port (48) in the circumferential direction of the impeller (40). It has (66) and a second seal portion (67). The angle between the two straight lines connecting both ends of each seal portion (66, 67) in the circumferential direction and the rotation center of the impeller (40) is 43 ° or more and 47 ° or less. Each seal portion (66, 67) has a size capable of closing at least two through flow paths (63) between both ends in the circumferential direction.

Description

The present invention relates to a non-volumetric pump and a liquid supply device.

The non-volumetric pump includes a substantially disk-shaped impeller and a pump case formed so as to cover the entire impeller. A plurality of blades are formed side by side in the circumferential direction on the impeller. A plurality of through passages that penetrate the impeller in the plate thickness direction are formed between the blade portions. The pump case rotatably houses the impeller. Further, the pump case has a suction port and a discharge port arranged on both sides of the impeller.
Such a non-positive displacement pump is used as a liquid supply device (fuel pump) for a vehicle such as a motorcycle or a four-wheeled vehicle, for example. This type of liquid feeder is located within the fuel tank.

Under such a configuration, when the impeller is rotated, fuel enters the through-passage of the impeller through the suction port of the pump case. The fuel that has entered the through-passage is sent to the discharge port while being compressed as the impeller rotates. After that, the fuel is discharged from the discharge port. As the impeller rotates, the fuel enters the through-passage where the fuel is discharged through the suction port again.

Here, a sealing portion is provided so that the discharge port and the suction port do not communicate with each other from the discharge port to the suction port in the rotation direction of the impeller. By providing the seal portion, it is possible to prevent the fuel in the discharge port from leaking to the suction port side. In addition, the flow rate characteristics of the non-volumetric pump are determined by the length of the seal portion in the circumferential direction. That is, if the length of the seal portion in the circumferential direction is short, the fuel drawn into the through-passage of the impeller is increased by this amount, so that the discharge flow rate of the non-volumetric pump is increased. On the other hand, if the length of the seal portion in the circumferential direction is long, the fuel drawn into the through-passage of the impeller is reduced by this amount, so that the discharge flow rate of the non-volumetric pump is reduced.

Japanese Patent No. 4952180 Japanese Patent Application Laid-Open No. 2015-86804

However, in the above-mentioned conventional technique, if the fuel cannot be completely discharged from the through-passage of the impeller at the discharge port and the fuel with high pressure is sent to the suction port as it is, the fuel suddenly becomes low pressure at the suction port. , There was a possibility of vacuum boiling. Noise may be generated due to the pressure fluctuation of the fuel at this time.

Therefore, one of the objects of the present invention is to provide a non-volumetric pump and a liquid supply device capable of reducing noise during driving while ensuring an appropriate discharge flow rate.

The non-volumetric pump according to the first aspect of the present invention is
With a disk-shaped impeller,
A pump case formed so as to cover the entire impeller and rotatably housed the impeller with the radial center of the impeller as the center of rotation is provided.
The impeller is
A plurality of blades formed side by side in the circumferential direction near the outer peripheral portion of the impeller, and
It has a plurality of through passages formed between the blade portions adjacent to each other in the circumferential direction and penetrating the impeller in the plate thickness direction.
The pump case is
A storage unit for storing the impeller and
A suction port that penetrates the storage portion and the outside of the pump case in the plate thickness direction of the impeller and communicates with the penetration flow path.
A discharge port that is arranged on the side opposite to the suction port with the impeller sandwiched between them, penetrates the storage portion and the outside of the pump case in the plate thickness direction, and communicates with the through flow path.
It has a seal portion provided between the suction port and the discharge port in the circumferential direction.
The angle between the two straight lines connecting both ends of the seal portion in the circumferential direction and the center of rotation is 43 ° or more and 47 ° or less.
The seal portion has a size capable of closing at least two of the through flow paths between the two ends.

With this configuration, it is possible to secure an appropriate discharge flow rate of the non-volumetric pump. In addition, the distance in the circumferential direction of the seal portion can be made appropriate, and the vacuum boiling of the liquid sent from the discharge port to the suction port can be suppressed. Therefore, it is possible to reduce the noise when driving the non-volumetric pump.

In the second aspect of the present invention, in the first aspect,
The pump case is
An upper case that is slidably contacted with one surface of the impeller and covers the one surface,
It has a lower case that is slidably contacted with another surface of the impeller opposite to the one surface and covers the other surface.
The storage portion is defined by the upper case and the lower case.
The upper case is
With the discharge port
It has an arc-shaped first flow path groove provided on the first sliding contact surface facing the impeller and communicating with the discharge port.
The lower case is
With the suction port
It has an arc-shaped second flow path groove provided on the second sliding contact surface facing the impeller and communicating with the suction port.
The seal portion is
It is between the discharge port and the suction port and on the rotation locus of the through flow path.

With such a configuration, it is possible to provide a non-volumetric pump capable of reducing noise during driving while ensuring an appropriate discharge flow rate with a simple structure.

The liquid supply device according to the third aspect of the present invention is
The non-volumetric pump according to the first aspect or the second aspect,
A motor unit for driving the non-volumetric pump is provided.
The rotation shaft of the motor unit and the impeller are connected so as not to rotate relative to each other.

With such a configuration, it is possible to provide a non-volumetric pump capable of reducing noise during driving while ensuring an appropriate discharge flow rate.

According to the present invention, an appropriate discharge flow rate of the non-volumetric pump can be ensured. In addition, the distance in the circumferential direction of the seal portion can be made appropriate, and the vacuum boiling of the liquid sent from the discharge port to the suction port can be suppressed. Therefore, it is possible to reduce the noise when driving the non-volumetric pump.

FIG. 1 is a perspective view of a liquid supply device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the axial direction of the liquid supply device according to the embodiment of the present invention. FIG. 3 is a perspective view of the impeller according to the embodiment of the present invention. FIG. 4 is a plan view of the upper case according to the embodiment of the present invention as viewed from the lower case side. FIG. 5 is a plan view of the lower case according to the embodiment of the present invention as viewed from the upper case side. FIG. 6 is a simplified view of a cross section of the pump portion along the axial direction according to the embodiment of the present invention. FIG. 7 is a graph comparing the fuel discharge flow rates when each seal portion in the embodiment of the present invention satisfies and does not satisfy the seal condition. FIG. 8 is a graph showing changes in the fuel discharge flow rate and the fuel sound pressure level in the embodiment of the present invention.

Next, an embodiment of the present invention will be described with reference to the drawings.

(Liquid supply device)
FIG. 1 is a perspective view of the liquid supply device 1. FIG. 2 is a cross-sectional view taken along the axial direction of the liquid supply device 1.
The liquid supply device 1 is used as a fuel pump for vehicles such as motorcycles and four-wheeled vehicles. The liquid supply device 1 is a so-called in-tank type fuel pump arranged in a fuel tank (not shown).

As shown in FIGS. 1 and 2, the liquid supply device 1 is fitted to a substantially cylindrical and metal housing 2 and an inner peripheral surface of the housing 2, and is arranged side by side in the axial direction of the housing 2, respectively. It includes a motor unit 3 and a pump unit 4. The housing 2, the motor unit 3, and the pump unit 4 are arranged coaxially.
The liquid supply device 1 is used with the pump unit 4 facing downward in the direction of gravity. Therefore, in the following description, the motor unit 3 side may be referred to as an upper portion, the pump portion 4 side may be referred to as a lower portion, or the like. Further, in the following description, the axial direction of the housing 2, the motor unit 3, and the pump unit 4 is simply the axial direction, the radial direction of the housing 2, the motor unit 3, and the pump unit 4 is simply the radial direction, and the housing 2, the motor unit. The circumferential direction of 3 and the pump unit 4 is simply referred to as a circumferential direction.

The housing 2 includes a motor fitting portion 11 into which the motor portion 3 is fitted, and a pump fitting portion 12 in which the diameter of the housing 2 is reduced from that of the motor fitting portion 11 and the pump portion 4 is fitted. Is integrally molded. A positioning convex portion 13 projecting inward in the radial direction is formed on the inner peripheral surface of the pump fitting portion 12. The positioning convex portion 13 is formed by pressing the housing 2 from the outside in the radial direction by, for example, pressing. The positioning convex portion 13 positions the housing 2 and the pump portion 4 in the circumferential direction. The positioning convex portion 13 is formed in a rectangular shape that is long in the axial direction when viewed in the radial direction.
Further, an inner flange portion 12a extending inward in the radial direction is bent and extended at the lower end of the pump fitting portion 12 in the housing 2. The positioning convex portion 13 and the inner flange portion 12a position the housing 2 and the pump portion 4 in the axial direction.

As the motor unit 3, for example, a motor with a brush is adopted. The motor unit 3 closes a substantially cylindrical yoke 5, a permanent magnet 8 provided on the inner peripheral surface of the yoke 5, an armature 6 rotatably provided in the yoke 5, and an upper opening 5a of the yoke 5. The main configuration is an outlet cover 7 and a brush 25 housed in the outlet cover 7. The outer peripheral surface of the yoke 5 is fitted to the inner peripheral surface of the housing 2.

The yoke 5 is a magnetic path through which the magnetic flux of the permanent magnet 8 passes. The upper opening 5a of the yoke 5 is fitted to the outer peripheral surface of the spigot portion 31 described later in the outlet cover 7. The positioning of the outlet cover 7 and the yoke 5 in the circumferential direction is performed by uneven fitting between the positioning convex portion (not shown) formed on the outlet cover 7 and the yoke positioning concave portion (not shown) formed on the yoke 5.

Two permanent magnets 8 are provided on the inner peripheral surface of the yoke 5. The permanent magnet 8 is formed in a substantially semicircular shape along the inner peripheral surface of the yoke 5 when viewed from the axial direction. The axial length of the permanent magnet 8 is set to be longer than the axial length of the armature core 15. Then, both ends in the axial direction of the permanent magnet 8 are arranged so as to protrude (overhang) from both ends in the axial direction of the armature core 15. The magnetic field orientation of the permanent magnet 8 is along the radial direction (thickness direction of the permanent magnet 8).
Such permanent magnets 8 are arranged so as to face each other in the radial direction about the rotation shaft 14. A minute gap is formed between the inner peripheral surface of the permanent magnet 8 and the radial outer end of the tooth 17 and the resin mold portion 22 described later in the armature core 15.

The armature 6 is fitted and fixed to the rotating shaft 14, the armature core 15 fitted and fixed to the outer peripheral surface of the rotating shaft 14, and the outer peripheral surface closer to the outlet cover 7 than the armature core 15 of the rotating shaft 14. The main configuration is a commutator 16.

The armature core 15 has a plurality of teeth 17 extending radially outward. A winding (not shown) is wound around these teeth 17. The end of the winding (not shown) is connected to the commutator 16.
The commutator 16 is a so-called disk-type commitator having a resin commitator main body 18 formed in a substantially disk shape. A plurality of segments 19 are arranged side by side in the circumferential direction on one surface 18a of the commutator main body 18 opposite to the armature core 15. At the radial outer end of the segment 19, a riser 21 that bends and extends toward the armature core 15 through the outer peripheral surface of the commutator body 18 is integrally molded. One end of a winding (not shown) is connected to each riser 21.

Most of the armature 6 thus formed is covered with the resin mold portion 22. The resin mold portion 22 is formed in a substantially columnar shape. Further, the resin mold portion 22 extends from the pump portion 4 side to the substantially center of the commutator main body 18 in the axial direction with respect to the armature core 15. In the armature core 15, only the radial outer end (outer peripheral surface) of the teeth 17 is exposed, and the winding (not shown) is embedded in the resin mold portion 22. A round chamfered portion 22a is formed at a corner portion at the end of the resin mold portion 22 on the pump portion 4 side. As a result, the end of the resin mold portion 22 on the pump portion 4 side is tapered.

The outlet cover 7 is formed in a substantially bottomed cylinder shape having an opening 7a on the armature core 15 side. A bearing cylindrical portion 23 projecting toward the armature core 15 side is integrally formed in the bottom portion 7b of the outlet cover 7 at substantially the center in the radial direction. The upper end portion 14a of the rotating shaft 14 is rotatably supported by the bearing cylindrical portion 23.

Further, a brush holder 24 is integrally molded on both sides of the bottom portion 7b of the outlet cover 7 with the bearing cylindrical portion 23 interposed therebetween. The brush holder 24 is formed in a box shape in which the commutator 16 side is opened. The brush 25 is housed in the brush holder 24 so as to be slidable along the axial direction. Further, the coil spring 26 is housed in the brush holder 24 in a form of being compressed and deformed. The brush 25 is urged toward the commutator 16 side by the coil spring 26. The tip of the brush 25 protrudes from the brush holder 24 and is slidably contacted with the segment 19.

Further, the bottom portion 7b of the outlet cover 7 is provided with a terminal 27 that penetrates the bottom portion 7b in the vertical direction. The brush 25 is connected to the terminal 27 via a pigtail (not shown). An external power supply (not shown) is connected to the terminal 27. As a result, external power is supplied to the windings (not shown) via the terminals 27, the pigtail (not shown), the brush 25, and the segment 19.
Further, a discharge port 28 projecting upward is integrally molded on the bottom portion 7b of the outlet cover 7. The discharge port 28 is a place where the fuel pumped up by the liquid supply device 1 is discharged, and is connected to a fuel flow path (not shown). Further, the inside and outside of the outlet cover 7 are communicated with each other via the discharge port 28.

A positioning piece 32 extending downward is integrally molded on the peripheral wall 7c of the outlet cover 7. The positioning piece 32 is interposed between the permanent magnets 8 to position the permanent magnet 8 (yoke 5) and the outlet cover 7.

Further, the peripheral wall 7c of the outlet cover 7 is formed so that the fitting ridge portion 29 projects radially outward on the outer peripheral surface over the entire circumference. The outer diameter of the fitting convex portion 29 is set to be substantially the same as the inner diameter of the motor fitting portion 11 in the housing 2. The outer peripheral surface of the fitting ridge portion 29 is fitted to the inner peripheral surface of the motor fitting portion 11. The upper opening edge portion 11a of the motor fitting portion 11 is caulked inward in the radial direction from above the fitting ridge portion 29 of the outlet cover 7. Further, the lower side of the peripheral wall 7c of the outlet cover 7 below the fitting convex portion 29 is an in-row portion 31 that is spigot-fitted with the yoke 5.

(Pump section)
The lower end of the rotating shaft 14 is inserted into the pump portion 4.
As the pump unit 4, a non-volumetric pump having an impeller 40 is used. The pump unit 4 is composed of an impeller 40 and a pump case 41 formed so as to cover the entire impeller 40. The pump case 41 is fitted to the pump fitting portion 12 of the housing 2.

(Impeller)
FIG. 3 is a perspective view of the impeller 40.
As shown in FIGS. 2 and 3, the impeller 40 is a member made of a resin material and formed in a substantially disk shape. An insertion hole 61 through which the lower end portion 14b of the rotating shaft 14 can be inserted is formed at substantially the center of the impeller 40 in the radial direction. Here, the lower end portion 14b of the rotating shaft 14 has a substantially D-shaped cross-sectional shape orthogonal to the axial direction. Further, the insertion hole 61 of the impeller 40 is formed in a substantially D shape when viewed from the axial direction so as to correspond to the cross-sectional shape of the lower end portion 14b of the rotating shaft 14. By inserting the lower end portion 14b of the rotating shaft 14 into such an insertion hole 61, the rotating shaft 14 and the impeller 40 are rotated together so as not to be relatively rotatable.

A plurality of blade portions 62 (see also FIG. 6) having a substantially L-shaped cross section along the axial direction are formed near the outer peripheral portion of the impeller 40. The blade portions 62 are arranged side by side at equal intervals in the circumferential direction so that the orientations in the circumferential direction are the same. A through flow path 63 is formed between the blade portions 62 adjacent to each other in the circumferential direction. The through flow path 63 is penetrated in the plate thickness direction of the impeller 40.

(Pump case)
As shown in FIG. 2, the pump case 41 that covers the entire impeller 40 is composed of an upper case 43, a middle case 44, and a lower case 42.

FIG. 4 is a plan view of the upper case 43 as viewed from the lower case 42 side (lower side).
As shown in FIGS. 2 and 4, the upper case 43 is arranged on the motor portion 3 side of the impeller 40. The upper case 43 is formed in a substantially disk shape so as to cover the upper surface of the impeller 40. The middle case 44 is joined to the outer peripheral portion of the upper case 43. The outer diameter of the upper case 43 is set to be slightly smaller than the outer diameter of the yoke 5.

An insertion hole 46 through which the lower end portion 14b of the rotating shaft 14 can be inserted is formed in the radial center of the upper case 43. A rotary shaft 14 is rotatably supported in the insertion hole 46 via a slide bearing 59.
Further, on the upper surface 43a of the upper case 43, a recess 47 having a substantially annular shape when viewed from the axial direction is formed so as to surround the periphery of the insertion hole 46. On the upper surface 43a of the upper case 43, the outer peripheral side of the recess 47 is the contact surface 43b with which the yoke 5 is abutted. Since the contact surface 43b has a sufficient space, even if the lower end of the yoke 5 is brought into contact with the contact surface 43b, it is possible to prevent the contact surface 43b and the yoke 5 from buckling and deforming. NS.

Further, on the upper surface 43a of the upper case 43, a discharge port 48 that penetrates the upper case 43 in the vertical direction is formed near the outer peripheral portion of the recess 47. On the lower surface 43c of the upper case 43, a recess 48a that widens the opening of the discharge port 48 is formed on the peripheral edge of the discharge port 48. The recess 48a is formed so as to expand toward the lower surface 43c of the upper case 43.

The lower surface 43c of the upper case 43 is the first sliding contact surface 43d that is slidably contacted with the impeller 40. On the first sliding contact surface 43d, a first flow path groove 64 having a substantially arc shape (substantially C-shaped) is formed at a position facing the through flow path 63 of the impeller 40 in the axial direction. .. One end of the first flow path groove 64 in the circumferential direction is communicated with the discharge port 48 (recessed portion 48a). A tapered portion 64a is formed at the other end of the first flow path groove 64 in the circumferential direction so as to be tapered when viewed from the axial direction.

The middle case 44 is formed in a substantially ring shape so as to surround the outer peripheral surface of the impeller 40. The middle case 44 is integrally formed with the upper case 43. The outer diameter of the middle case 44 is set to be slightly larger than the outer diameter of the upper case 43. The middle case 44 coincides the radial center of the impeller 40 with the axial center C of the rotating shaft 14. The thickness of the middle case 44 in the axial direction is formed so as to be substantially the same as or slightly thicker than the plate thickness of the impeller 40. As a result, predetermined clearances are formed between the impeller 40 and the upper case 43, and between the impeller 40 and the lower case 42, respectively.

FIG. 5 is a plan view of the lower case 42 as viewed from the upper case 43 side (upper side). For convenience of explanation, in FIG. 5, the position in the circumferential direction of the first seal portion 66 included in the upper case 43 shown in FIG. 4 and the position in the circumferential direction of the second seal portion 67 included in the lower case 42 shown in FIG. 5 are shown. The lower case 42 is illustrated so as to be in good agreement.
As shown in FIGS. 2 and 5, the lower case 42 is arranged below the impeller 40. The pump case 41 is formed so as to cover the entire impeller 40 by the upper case 43 in which the middle case 44 is integrally formed and the lower case 42. The lower surface 43c of the upper case 43 and the upper surface 42a of the lower case 42 form a storage portion 60 for accommodating the impeller 40.
The lower case 42 is formed in a substantially disk shape. The outer diameter of the lower case 42 is set to be substantially the same as the outer diameter of the middle case 44.

On the lower surface 42b of the lower case 42, a substantially cylindrical suction port 53 protruding downward is formed on the outer peripheral side. On the inner peripheral surface of the suction port 53, a tapered hole portion 53a is formed on the upper surface 42a side of the lower case 42 so that the opening area gradually increases toward the upper surface 42a.
Further, a step portion 49 is formed on the outer peripheral edge of the lower surface 42b of the lower case 42. The step portion 49 is formed by reducing the diameter of the lower surface 42b side of the lower case 42. The step portion 49 is formed at a position overlapping the inner flange portion 12a of the housing 2 when viewed from the axial direction.

The upper surface 42a of the lower case 42 is a second sliding contact surface 42c that is slidably contacted with the impeller 40. The upper surface 42a of the lower case 42 is formed with a bearing accommodating recess 54 facing the lower end portion 14b of the rotating shaft 14 at substantially the center in the radial direction. The thrust bearing 55 is housed in the bearing storage recess 54. The lower end portion 14b of the rotating shaft 14 is rotatably supported by the lower case 42 in a state of being in contact with the thrust bearing 55. The thrust bearing 55 receives the thrust load of the rotating shaft 14.

The second sliding contact surface 42c of the lower case 42 is approximately located at a position facing the through flow path 63 of the impeller 40 in the axial direction and at a position facing the first flow path groove 64 of the upper case 43 when viewed from the axial direction. An arc-shaped (substantially C-shaped) second flow path groove 65 is formed. One end in the circumferential direction of the second flow path groove 65 communicates with the suction port 53 (tapered hole portion 53a). A tapered portion 65a is formed at the other end of the second flow path groove 65 in the circumferential direction so as to be tapered when viewed from the axial direction.
Further, in the second flow path groove 65, a degassing hole 68 is formed through the lower case 42 in the plate thickness direction slightly closer to the suction port 53 than the center between the suction port 53 and the tapered portion 65a. The degassing hole 68 is a hole for discharging vapor (air bubbles) generated in the pump case 41.

Here, the discharge port 48 communicating with one end in the circumferential direction of the first flow path groove 64, the tapered portion 64a formed at the other end in the circumferential direction of the first flow path groove 64, and the second flow path groove 65. The suction port 53 communicating with one end in the circumferential direction and the tapered portion 65a formed at the other end in the circumferential direction of the second flow path groove 65 are arranged alternately. That is, the discharge port 48 faces the tapered portion 65a of the second flow path groove 65 in the axial direction. The suction port 53 faces the tapered portion 64a of the first flow path groove 64 in the axial direction.

Further, between the discharge port 48 (recessed portion 48a) on the first sliding contact surface 43d of the upper case 43 and the tapered portion 64a of the first flow path groove 64, fuel leakage from the discharge port 48 to the tapered portion 64a is suppressed. It becomes the first seal part 66 for this. The leakage of fuel from the tapered portion 65a to the suction port 53 is suppressed between the suction port 53 (tapered hole portion 53a) in the second sliding contact surface 42c of the lower case 42 and the tapered portion 65a of the second flow path groove 65. It becomes the second seal part 67 for this. The circumferential range (length) of the first seal portion 66 and the circumferential range (length) of the second seal portion 67 are the same. Details of the first seal portion 66 and the second seal portion 67 will be described later. As can be understood from FIG. 6, the first seal portion 66 and the second seal portion 67 are located between the discharge port 48 and the suction port 53 and on the rotation locus of the through flow path 63.

A square ring 50 as a sealing member is attached to the stepped portion 49 formed on the lower surface 42b of the lower case 42. The square ring 50 is a member made of a material having excellent oil resistance, such as fluororubber, which has a substantially rectangular cross section. The outer diameter of the square ring 50 is set to be slightly smaller than the outer diameter of the lower case 42. Therefore, the outer peripheral surfaces of the upper case 43, the middle case 44, and the lower case 42 are fitted to the pump fitting portion 12 of the housing 2. A minute gap is formed between the outer peripheral surface of the square ring 50 and the inner peripheral surface of the pump fitting portion 12 of the housing 2.

Under such a configuration, when the motor portion 3 and the pump portion 4 are housed in the housing 2, the square ring 50 is brought into contact with the inner flange portion 12a of the housing 2. At this time, the positioning convex portion 13 of the housing 2 is inserted into a concave portion (not shown) formed on the outer peripheral surface of the pump case 41. As a result, the housing 2 and the pump portion 4 are positioned in the circumferential direction.

Further, while the square ring 50 is slightly crushed by the stepped portion 49 and the inner flange portion 12a of the lower case 42, the upper opening edge portion 11a of the motor fitting portion 11 is fitted with the fitting convex portion of the outlet cover 7. Caulking inward in the radial direction from the top of 29. As a result, the pump portion 4 is fitted to the pump fitting portion 12 of the housing 2. Further, the motor portion 3 is fitted to the motor fitting portion 11 of the housing 2. Then, the motor unit 3 and the pump unit 4 are positioned with respect to the housing 2, and the housing 2, the motor unit 3, and the pump unit 4 are integrated. Further, the square ring 50 ensures a sealing property between the housing 2 and the pump portion 4.

(Operation of liquid supply device)
Next, the operation of the liquid supply device 1 will be described with reference to FIGS. 2 and 6.
FIG. 6 is a simplified cross-sectional view of the pump portion 4 along the axial direction.
As shown in FIGS. 2 and 6, when the rotating shaft 14 of the motor unit 3 is rotated, the impeller 40 is rotated integrally with the rotating shaft 14. Then, the fuel N is sucked up into the pump case 41 through the suction port 53. The sucked fuel N enters the through flow path 63 of the impeller 40, and further enters the first flow path groove 64 of the upper case 43 and the second flow path groove 65 of the lower case 42. Then, a swirling flow is generated between the impeller 40 and the pump case 41. By this swirling flow, the fuel in the through flow path 63 is boosted toward the discharge port 48.

The boosted fuel N is discharged into the yoke 5 of the motor unit 3 via the discharge port 48. That is, the pressure of the fuel N of the discharge port 48 is larger than the pressure of the fuel N of the suction port 53. A first seal portion 66 and a second seal portion 67 are provided between the discharge port 48 and the suction port 53. Therefore, the fuel N discharged from the discharge port 48 may leak to a portion of the suction port 53, the first flow path groove 64, and the second flow path groove 65 that intersects the suction port 53 in the axial direction. It is suppressed.
The fuel N discharged into the yoke 5 is pressure-fed to the discharge port 28 through a minute gap between the permanent magnet 8 and the resin mold portion 22 (the radial outer end of the teeth 17 in the armature core 15). After that, fuel is pumped to an engine or the like (not shown) via the discharge port 28.

Here, in the through flow path 63 of the impeller 40, the fuel N is not completely discharged on the discharge port 48 side, and the fuel N having a high pressure as it is is in the vicinity of the suction port 53, specifically, the suction port 53 and the first flow path groove 64. , And when the fuel leaks to a portion of the second flow path groove 65 that intersects the suction port 53 in the axial direction, the fuel N suddenly becomes low pressure at the suction port 53 and decompression boiling occurs, and the fuel N at this time Noise may occur due to pressure fluctuations. Therefore, in order to suppress such leakage of fuel N, the circumferential range (length) of the first seal portion 66 and the circumferential range (length) of the second seal portion 67 are set as follows. It is set.

That is, as shown in FIG. 4, the straight line connecting both ends in the circumferential direction of the first seal portion 66 and the axial center C of the rotating shaft 14 is defined as L1. Here, both ends in the circumferential direction of the first seal portion 66 are a portion where the straight line L1 passing through the axis C contacts the tapered portion 64a of the first flow path groove 64 and a portion where the concave portion 48a of the discharge port 48 contacts. ..
Further, as shown in FIG. 5, the straight line connecting both ends in the circumferential direction of the second seal portion 67 and the axial center C of the rotating shaft 14 is defined as L2. Here, both ends in the circumferential direction of the second seal portion 67 are a portion where the straight line L2 passing through the axis C contacts the tapered portion 65a of the second flow path groove 65 and a portion where the tapered hole portion 53a of the suction port 53 contacts. And.

Of the first sliding contact surface 43d of the upper case 43, a portion between the two straight lines L1 and axially facing the blade portion 62 and the penetrating flow path 63 of the impeller 40 constitutes the first seal portion 66. .. Further, of the second sliding contact surface 42c of the lower case 42, a portion between the two straight lines L2 and facing the blade portion 62 and the penetrating flow path 63 of the impeller 40 in the axial direction constitutes the second seal portion 67. do.

The angle θ1 between the two straight lines L1 and the angle θ2 between the two straight lines L2 are θ1 ≈ θ2 = 45 ° ± 2 ° ... (1).
It is set to meet. In other words, the angles θ1 and θ2 are set so that 43 ° ≦ θ1 ≦ 47 ° and 43 ° ≦ θ2 ≦ 47 °.
Further, as shown in detail in FIG. 6, the first seal portion 66 and the second seal portion 67 are formed in a size capable of closing at least two through flow paths 63 between both ends in the circumferential direction. The conditions of the sealing portions 66 and 67 having a size capable of closing at least two through-passage paths 63 and satisfying the above formula (1) are hereinafter referred to as sealing conditions.

Next, the effects of the sealing portions 66 and 67 that satisfy the sealing conditions will be described with reference to FIGS. 7 and 8.
In FIG. 7, when the vertical axis is the fuel discharge flow rate by the pump unit 4 (hereinafter, simply referred to as the fuel discharge flow rate) [L / h], the seal units 66 and 67 do not satisfy the seal condition. It is a graph comparing the discharge flow rate of fuel with the case.
In FIG. 7, “conventional” means that the angle θ1 between the two straight lines L1 of the first seal portion 66 is 22 °, and the angle θ2 between the two straight lines L2 of the second seal portion 67 is 24. If it is °. The "conventional" angles θ1 and θ2 do not satisfy the above equation (1). In FIG. 7, “45 ° -1” is a case where the angles θ1 and θ2 between the two straight lines L1 and L2 of the seal portions 66 and 67 are 45 ° -1, and the above equation (1) is used. Meet. In FIG. 7, “45 ° -2” is a case where the angles θ1 and θ2 between the two straight lines L1 and L2 of the seal portions 66 and 67 are 45 ° -2, and the above equation (1) is used. Meet. In FIG. 7, “67 °” means that the angles θ1 and θ2 between the two straight lines L1 and L2 of the seal portions 66 and 67 are 67 °, and does not satisfy the above equation (1).

As shown in FIG. 7, when the seal portions 66 and 67 satisfy the seal condition, the fuel discharge flow rate is slightly smaller than that of the conventional case, but the fuel discharge flow rate is larger than that of "67 °". Can be confirmed.

In FIG. 8, the vertical axis represents the fuel discharge flow rate [L / h], and the sound pressure level [dB] of the fuel in the vicinity of the suction port 53 when high-pressure fuel is sent to the suction port 53. It is a graph which shows the change of the discharge flow rate of fuel, and the sound pressure level of fuel when the axis is the angle θ1, θ2 [°] between two straight lines L1 and L2 of each seal part 66, 67.
As shown in FIG. 8, in the range where the angles θ1 and θ2 between the two straight lines L1 and L2 of the seal portions 66 and 67 satisfy the above equation (1), the fuel while satisfying the desired discharge flow rate range W. It can be confirmed that the sound pressure level of can be reduced. The discharge flow rate range W is defined as a range in which an acceptable sound pressure level and a practically desirable discharge flow rate can be achieved when the liquid supply device 1 of this type is actually used.
When each of the seal portions 66 and 67 satisfies the seal condition, the sound pressure level can be reduced as compared with the conventional case, and the flow rate condition can be satisfied as compared with "67 °". .. Therefore, when the sealing portions 66 and 67 satisfy the sealing condition, it can be confirmed that the performance balance in the flow rate and the sound pressure level is good.

Therefore, according to the above-described embodiment, when the seal units 66 and 67 satisfy the seal conditions, the pump unit 4 can secure an appropriate fuel discharge flow rate. Further, when the angles θ1 and θ2 between the two straight lines L1 and L2 of the seal portions 66 and 67 satisfy the above equation (1), the range (length) in the circumferential direction of the seal portions 66 and 67 is appropriate. Can be done. As a result, decompression boiling of the fuel sent from the discharge port 48 to the suction port 53 can be suppressed, the sound pressure level of the pump unit 4 can be reduced, and the noise during driving of the pump unit 4 can be reduced.

Further, the pump case 41 of the pump unit 4 has an upper case 43 that covers the upper surface of the impeller 40 and a lower case 42 that covers the lower surface of the impeller 40. The upper case 43 has a discharge port 48 for discharging fuel from the pump portion 4, and a first flow path groove 64 formed on the first sliding contact surface 43d. The lower case 42 has a suction port 53 for sucking fuel into the pump portion 4, and a second flow path groove 65 formed on the second sliding contact surface 42c. The first seal portion 66 is formed between the discharge port 48 (recessed portion 48a) on the first sliding contact surface 43d of the upper case 43 and the tapered portion 64a of the first flow path groove 64. Further, the second seal portion 67 is formed between the suction port 53 (tapered hole portion 53a) in the second sliding contact surface 42c of the lower case 42 and the tapered portion 65a of the second flow path groove 65. With such a configuration, fuel is pumped to the motor unit 3 by using the impeller 40, the first flow path groove 64, and the second flow path groove 65, and the leakage of fuel is surely suppressed by the seal portions 66 and 67. Therefore, the configuration of the pump unit 4 can be simplified.

The present invention is not limited to the above-described embodiment, and includes various modifications to the above-mentioned embodiment without departing from the spirit of the present invention.

For example, in the above-described embodiment, the liquid supply device 1 used as a fuel pump for vehicles such as motorcycles and four-wheeled vehicles has been described. However, the liquid supply device 1 can be used to pump various liquids.

Further, in the above-described embodiment, a case where, for example, a brushed motor is adopted as the motor unit 3 has been described. However, the present invention is not limited to this, and for example, a brushless motor can be adopted as the motor unit 3.

Further, in the above-described embodiment, the case where the pump case 41 is composed of the upper case 43, the middle case 44, and the lower case 42 has been described. However, the present invention is not limited to this, and the integrated upper case 43 and the middle case 44 may be referred to as one upper case 43. Further, the pump case 41 may have a storage portion 60 for rotatably storing the impeller 40, and may not be divided into an upper case 43 and a lower case 42. For example, the middle case 44 and the lower case 42 may be integrated, and the middle case 44 and the lower case 42 may be referred to as one lower case 42.

This application is based on a Japanese patent application filed on January 16, 2019 (Japanese Patent Application No. 2019-004877), the contents of which are incorporated herein by reference.

According to the non-volumetric pump and the liquid supply device of the present invention, for example, it is possible to suppress the vacuum boiling of the liquid leaked from the discharge port to the suction port while appropriately ensuring the discharge flow rate. The present invention exhibiting this effect is useful, for example, with respect to a fuel pump for a vehicle such as a motorcycle or a four-wheeled vehicle.

1 ... Liquid supply device, 3 ... Motor unit, 4 ... Pump unit (non-volumetric pump), 14 ... Rotating shaft, 40 ... Impeller, 41 ... Pump case, 42 ... Lower case, 42c ... Second sliding contact surface, 43 ... Upper case, 43d ... 1st sliding contact surface, 48 ... Discharge port, 53 ... Suction port, 60 ... Storage section, 62 ... Blade section, 63 ... Through flow path, 64 ... 1st flow path groove, 65 ... 2nd flow Road groove, 66 ... 1st seal part (seal part), 67 ... 2nd seal part (seal part), C ... axis center (center of rotation), L1, L2 ... straight line, θ1, θ2 ... angle

Claims (3)

With a disk-shaped impeller,
A pump case formed so as to cover the entire impeller and rotatably housed the impeller with the radial center of the impeller as the center of rotation is provided.
The impeller is
A plurality of blades formed side by side in the circumferential direction near the outer peripheral portion of the impeller, and
It has a plurality of through passages formed between the blade portions adjacent to each other in the circumferential direction and penetrating the impeller in the plate thickness direction.
The pump case is
A storage unit for storing the impeller and
A suction port that penetrates the storage portion and the outside of the pump case in the plate thickness direction of the impeller and communicates with the penetration flow path.
A discharge port that is arranged on the side opposite to the suction port with the impeller sandwiched between them, penetrates the storage portion and the outside of the pump case in the plate thickness direction, and communicates with the through flow path.
It has a seal portion provided between the suction port and the discharge port in the circumferential direction.
The angle between the two straight lines connecting both ends of the seal portion in the circumferential direction and the center of rotation is 43 ° or more and 47 ° or less.
The seal portion has a size capable of closing at least two of the through flow paths between the two ends.
Non-volumetric pump. In the non-volumetric pump according to claim 1,
The pump case is
An upper case that is slidably contacted with one surface of the impeller and covers the one surface,
It has a lower case that is slidably contacted with another surface of the impeller opposite to the one surface and covers the other surface.
The storage portion is defined by the upper case and the lower case.
The upper case is
With the discharge port
It has an arc-shaped first flow path groove provided on the first sliding contact surface facing the impeller and communicating with the discharge port.
The lower case is
With the suction port
It has an arc-shaped second flow path groove provided on the second sliding contact surface facing the impeller and communicating with the suction port.
The seal portion is
A non-volumetric pump located between the discharge port and the suction port and on the rotation locus of the through flow path. The non-volumetric pump according to claim 1 or 2,
A motor unit for driving the non-volumetric pump is provided.
The rotation shaft of the motor unit and the impeller are connected so as not to rotate relative to each other.
Liquid supply device.

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