JP6584468B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a fuel supply device that sucks up and pressurizes fuel and supplies the fuel to equipment such as an engine.

  2. Description of the Related Art In recent years, in a fuel supply apparatus that sucks fuel from a fuel tank using a pump having a rotating body such as an impeller, there is a movement to apply a brushless motor that is expected to be downsized as a pump drive source. In such a fuel supply device, it is necessary to form a flow path for the fuel to pass through the motor portion along the axial direction and to prevent the fuel from leaking to the outside.

In view of this, a fuel supply device has been proposed in which an end cover is press-fitted into a metal housing having the stator core outer periphery in close contact with the inner peripheral side, and an end of the metal housing is bent to prevent and seal (for example, (See Patent Document 1). On the other hand, in the brushless motor, the magnetic circuit housing as a yoke is not required, the fuel supply system is covered with a resin that integrates the stator core and the end cover has been proposed (e.g., see Patent Document 2.).

Japanese Patent Laying-Open No. 2005-110478 (paragraphs 0013 to 0016, FIG. 1, paragraphs 0027 to 0028, FIG. 3) JP 2007-104871 A (paragraphs 0011 to 0018, FIGS. 1 and 2)

  However, even if the end portion of the metal housing is bent and sealed, it is conceivable that a gap is formed with time and the fuel leaks from there. Also, when the stator core is covered only with the resin, even if the sealing property can be secured, the resin is less rigid than the metal, so it is difficult to firmly fix the positional relationship in the axial direction between the stator core and the pump. It becomes difficult to obtain stable ejection performance. That is, it has been impossible to achieve both suppression of fuel leakage and stable discharge performance.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain a highly reliable fuel supply apparatus that suppresses fuel leakage and has stable discharge performance.

A fuel supply device of the present invention is housed so as to be sandwiched from both sides in the axial direction by a cylindrical metal housing, a pump case fixed to an inner peripheral surface on one end side in the axial direction of the metal housing, and the pump case. The other end of the metal housing formed by winding a coil around a stator core that is a laminated body in which electromagnetic steel plates are laminated in the axial direction. A stator that is press-fitted and fixed to the inner peripheral surface on the side, a motor portion that is disposed to face the inner peripheral surface of the stator and that has a rotor whose rotation shaft is continuous with the impeller, and an open end on the other end side of the metal housing. A resin end cover that covers the other end side and opens a discharge port of fuel supplied from the pump unit on the other end side, and a surface along the axial direction of the laminate. And a fuel flow path formed so as to communicate the pump unit and the discharge port, and the stator has a predetermined distance from an end surface on the other end side of the stator core to a predetermined distance in the axial direction. each of the outer peripheral surface of the electromagnetic steel plates stacked in area, of the outer circumferential surface of Rutotomoni the metal housing is formed so as to have a gap between the metal housing over the entire circumference, from the tip portion of the other end The portion up to the second predetermined distance is formed with a step so that the outer diameter is smaller than the other portion, and the end cover is an integrally molded product with respect to the metal housing into which the stator is press-fitted. and wherein the resin constituting the end cover to the biting portion bites into the gap is formed Rutotomoni the step from the other side over the circumference is filled That.

According to the fuel supply device of the present invention, the biting portion of the end cover formed by integral molding suppresses the generation of a gap between the metal portion and the resin, and configures the end cover at the step on the outer peripheral surface of the metal housing. Since the positional relationship in the axial direction of the stator and the pump can be firmly fixed by filling the resin to be used, a highly reliable fuel supply device that suppresses fuel leakage and has stable discharge performance can be obtained.

It is sectional drawing along the rotating shaft of the fuel supply apparatus concerning Embodiment 1 of this invention. It is sectional drawing perpendicular | vertical to the rotating shaft in the stator intermediate part of the fuel supply apparatus concerning Embodiment 1 of this invention. It is sectional drawing perpendicular | vertical to the rotating shaft in the stator upper end part vicinity of the fuel supply apparatus concerning Embodiment 1 of this invention. It is an expanded sectional view in alignment with the rotating shaft of the stator right side part of the fuel supply apparatus concerning Embodiment 1 of this invention. It is a schematic diagram which shows the state which press-fits the stator of the fuel supply apparatus concerning Embodiment 1 of this invention to a metal housing. It is a partial expanded sectional view along the rotating shaft near the stator upper end part of the fuel supply apparatus concerning Embodiment 2 of this invention. It is a partial expanded sectional view along the rotating shaft of the stator upper end part vicinity of the fuel supply apparatus concerning Embodiment 3 of this invention. It is sectional drawing perpendicular | vertical to the rotating shaft in the stator upper end part vicinity of the fuel supply apparatus concerning Embodiment 4 of this invention. It is sectional drawing along the rotating shaft of the fuel supply apparatus concerning Embodiment 5 of this invention, and an expanded sectional view of a stator right side part. It is a partial expanded sectional view along the rotating shaft of the stator right side part of the fuel supply apparatus concerning Embodiment 6 of this invention.

Embodiment 1 FIG.
FIGS. 1-5 is for demonstrating the structure of the fuel supply apparatus concerning Embodiment 1 of this invention, and FIG. 1 is sectional drawing which cut | disconnected the fuel supply apparatus along the rotating shaft of a motor. 2 shows a cross section of the fuel supply device perpendicular to the rotational axis at the intermediate portion in the axial direction of the stator, and is a cross sectional view corresponding to the AA section of FIG. 1, and FIG. 3 shows the axial direction of the stator. FIG. 4 is a cross-sectional view of the fuel supply device perpendicular to the rotation axis in the vicinity of the upper end portion of FIG. 1, corresponding to the BB cut surface of FIG. 1, and FIG. FIG. 2 is an enlarged cross-sectional view of a portion, corresponding to a region C in FIG. 5 is a schematic view showing a state in which the stator of the fuel supply device is press-fitted into the metal housing. FIG. 5A is a perspective view of the stator and the metal housing before press-fitting, and FIG. FIG. 2 is an end view of the stator and metal housing corresponding to the cross-sectional view of FIG. 1. In FIG. 5A, for the sake of simplification, drawing of bobbins and coils of the stator is omitted, and only the stator core is drawn.

  As shown in FIG. 1, the fuel supply device 1 according to the first exemplary embodiment of the present invention includes a pump unit 2, a motor unit 3 that drives the pump unit 2, and an end cover 6 arranged in this order from the lower side in the axial direction. Has been. And the metal housing 7 is arrange | positioned so that the pump part 2 and the motor part 3 may be enclosed from the outer side of radial direction.

  The motor unit 3 has a stator 4 and a rotor 5. The stator core 43 of the stator 4 is formed by laminating electromagnetic steel plates 44 while caulking in the motor axial direction. As shown in FIGS. 2 and 3, six teeth 43t are arranged in the circumferential direction. It is formed at equal intervals. Each tooth 43t has a bobbin 41 attached to both ends in the axial direction, and a coil 42 is wound on the bobbin 41.

  In the rotor 5, a permanent magnet 51 and a shaft 52 are fixed by a resin member 53 and installed on the inner peripheral side of the stator 4. The coil 42 wound around each tooth 43t of the stator 4 is electrically connected to a power supply terminal 81 and a neutral point terminal 82 for electrical connection with a control board (not shown). The drive circuit formed on the control board controls the rotational drive by performing commutation control that reverses the energization according to the rotational position of the rotor 5. That is, the motor unit 3 of the fuel supply device 1 according to the present embodiment is a so-called brushless motor that is driven to rotate without using a brush.

  The pump unit 2 is configured by a pump case including a pump base 21 and a pump cover 22 so that the impeller 23 is sandwiched from both sides in the axial direction. A fuel discharge port 2px is formed in the pump base 21 and a fuel suction port 2pi is formed in the pump cover 22. When the pump base 21 and the pump cover 22 are combined, a space S2 for accommodating the impeller 23 is formed therebetween. Yes. Then, the pump base 21 is press-fitted and fixed to the inner peripheral side of the cylindrical metal housing 7 from the lower side in the figure, the impeller 23 is inserted into the inner peripheral portion, the pump base 21 is covered, and one end of the metal housing 7 is inserted. It is fixed by crimping (lower end in the figure).

  Here, a shaft 52 bearing is press-fitted into the pump base 21 and a thrust bearing is press-fitted into the pump cover 22. The impeller 23 is rotatably accommodated in the space S <b> 2, and a central portion is formed in a D-shaped cross section and is engaged with a notch 52 n formed in the shaft 52. Thereby, the impeller 23 rotates in accordance with the driving of the rotor 5.

  The impeller 23 is formed with a plurality of blades (not shown) in the circumferential direction, and the pump base 21 is formed with a C-shaped groove (not shown) along the arrangement of the blades on the surface facing the impeller 23. A communication hole communicating with the fuel discharge port 2 px is formed at the end of the groove in the rotation direction of the rotor 5 in the upward direction (z-axis direction). Similarly, a C-shaped groove is formed along the arrangement of the blades on the surface of the pump cover 22 facing the impeller 23, and a communication point communicating with the fuel inlet 2pi is provided at the starting point in the rotational direction of the groove. A hole is formed. By combining these two C-shaped grooves and the spaces between the blades of the impeller 23, a pump flow path is formed from the fuel suction port 2pi to the fuel discharge port 2px. In other words, a basic configuration of the cascade-type pump unit 2 is formed in which fluid is sucked from the fuel suction port 2pi and discharged from the fuel discharge port 2px.

  Next, the stator 4 and the metal housing 7 of the motor unit 3 which are characteristic parts of the fuel supply device 1 according to the first embodiment of the present invention will be described. As shown in FIG. 4, the stator core 43 that is a main component of the stator 4 is an outer peripheral surface of a predetermined region Rue from the upper end surface Feu on the opposite side of the lower end surface Fep on the pump unit 2 side in the motor shaft direction to a predetermined length. Fo4 is configured to be smaller than the outer peripheral surface Fo4 of other regions. Specifically, an electromagnetic steel sheet 44 having an outer diameter equal to or larger than the inner diameter of the metal housing 7 is laminated in a portion corresponding to a region other than the predetermined region Rue, and a metal housing is formed in a portion corresponding to the predetermined region Rue. The stator core 43 is configured by laminating electromagnetic steel plates 44 having an outer diameter smaller than the inner diameter of the inner diameter 7.

  Then, for example, as shown in FIG. 5, the outer peripheral surface Fo4 of the stator core 43 is opposed to the inner peripheral surface Fi7 of the metal housing 7, and the stator 4 is press-fitted into the metal housing 7 until reaching a predetermined position in the axial direction. Then, a frictional force acts between the outer peripheral surface Fo4 of the stator core 43 other than the predetermined region Rue and the inner peripheral surface Fi7 of the metal housing 7, and the axial position between the stator core 43 and the metal housing 7 is fixed. The That is, the axial position of the stator 4 with respect to the metal housing 7 is fixed, and the coaxial relationship between the stator 4 and the metal housing 7 is also fixed. At this time, a gap G47 having a predetermined interval T6g is formed between the outer peripheral surface Fo4 of the stator core 43 and the inner peripheral surface Fi7 of the metal housing 7 in a portion corresponding to the predetermined region Rue.

In this way, the positional relationship in the radial direction and the axial direction is fixed, and the metal housing 7 integrated with the stator 4 (not shown in FIG. 5 but including the bobbin 41 and the coil 42) is molded by molding. The end cover 6 is formed. For example, the metal housing 7 into which the stator 4 is press-fitted is fixed to a mold (not shown) with its axis aligned. Then, polyacetal (POM: Poly Oxy Methylene) is molded as an insulating resin material, and the end cover 6 is formed by insert molding the bearing 61 and the stator 4 when the shaft 52 rotates. In this case, among the stator core 43, in a portion of the predetermined area Rue, as shown in FIG. 3, crowded flow the insulating resin material in a gap G47 between the inner circumferential surface Fi7 of the outer circumferential surface Fo4 metal housing 7 of the stator core 43, metal The housing 7 constitutes a part of the end cover 6. Therefore, the end cover 6, to the part of the predetermined region Rue, in a state having a predetermined thickness corresponding to between the gaps G47 interval (= T6g), biting bite between the outer periphery of the metal housing 7 and the stator core 43 The portion 6i is formed.

  Next, the operation will be described. In this fuel supply apparatus 1, the rotor 5 is rotated by supplying a controlled current to a power supply terminal (not shown). Then, the impeller 23 connected to the shaft 52 rotates following, and fluid such as gas or liquid between the plurality of blades also flows in the flow path of the pump at high speed. At this time, the fluid vortexes many times in the flow path of the pump due to the kinetic energy received from the blades and the centrifugal force caused by the circumferential flow. Then, the pressure increases as it goes downstream along the C-shaped groove, while the upstream side becomes a negative pressure.

  As a result, the fuel is sucked from the suction port 2pi of the pump cover 22 and is sent out from the discharge port 2px of the pump base 21 toward the motor unit 3 inside the metal housing 7 in a high pressure state. The fuel sent to the motor unit passes through the gap between the inner peripheral surface Fi4 of the stator core 43 and the outer peripheral surface Fo5 of the rotor 5, and is then discharged from the discharge port 6px of the end cover 6.

  The pressure of the pump varies depending on the application, but a pressure of several hundred kPa is assumed for a vehicle. That is, an internal pressure of several hundred kPa is generated in the space S <b> 2 in the pump unit 2 and acts in a direction in which the pump cover 22 and the pump base 21 are separated from each other. The motor unit 3 also acts in a direction away from the pump unit 2.

  However, in the fuel supply device 1 according to the present embodiment, as shown in FIG. 2, the outer peripheral surface Fo4 of the stator core 43 and the inner peripheral surface of the metal housing 7 are axially moved by press-fitting as shown in FIG. It is firmly fixed in the direction. Further, the end cover 6 also has a thickness corresponding to T6g up to the predetermined region Rue, and bites between the metal housing 7 and the outer periphery of the stator core 43. Accordingly, the end cover 6 can be used without dropping from the metal housing 7 even under a high pressure state of 500 kPa level as used in a direct injection type engine.

  Further, the pump part 2 is fixed by crimping so that the pump base 21 is fitted into a step (not shown in the drawing without reference) provided in the metal housing 7 and the pump cover 22 is pressed against the motor part 3 side. ing. Therefore, the pump cover 22 is prevented from moving in the direction away from the motor unit 3 in the axial direction, and the position in the axial direction with respect to the pump base 21 is also fixed. That is, even if the internal pressure changes due to the pump operation, the positional relationship in the axial direction between the pump unit 2 and the motor unit 3 and the positional relationship in the axial direction of the members in the pump unit 2 are not broken.

  On the other hand, the stator core 43 is laminated without caulking metal plates, but the mating surfaces of the electromagnetic steel plates 44 are continuous from the inner peripheral surface Fi4 to the outer peripheral surface Fo4. Therefore, a part of the fuel that passes through the gap between the inner peripheral surface Fi4 of the stator core 43 and the rotor 5 penetrates into the stator core 43 from the inner peripheral surface Fi4 of the stator core by capillary force or the like, and is on the outer peripheral surface Fo4 side of the stator core. Ooze out. At this time, when the fuel that has flowed to the outer peripheral surface Fo4 of the stator core leaks out of the fuel supply device 1, it moves along the axial direction toward the end cover 6 side.

  However, in the predetermined region Rue portion located on the outlet side in the axial direction, a biting portion 6i in which the insulating resin member forming the end cover 6 has a predetermined thickness is formed. The biting part 6i does not enter in a solid state like press-fitting, but is formed by molding and entering in a molten state and curing. Therefore, the biting portion 6i penetrates into the fine irregularities on the surface as if it were welded to the outer peripheral surface Fo4 of the stator core 43 and the inner peripheral surface Fi7 of the metal housing 7. This state is formed over the entire circumference in the predetermined region Rue.

  As a result, even if the fuel reaches the predetermined region Rue in the axial direction, it is between the outer peripheral surface Fo4 of the stator core 43 and the biting portion 6i and between the inner peripheral surface Fi7 of the metal housing 7 and the biting portion 6i. Are completely in close contact with each other, so the path in the axial direction is cut off and cannot be further advanced. Even when the adhesion between the outer peripheral surface Fo4 of the stator core 43 and the biting portion 6i or between the inner peripheral surface Fi7 of the metal housing 7 and the biting portion 6i is reduced, the boundary surface between the two is not flat. There are no complicated irregularities. Therefore, the path along which the fuel travels along the axial direction becomes longer, and the leakage of the fuel to the outside can be suppressed and the sealing performance can be improved as compared with the case where the end cover is inserted by press fitting.

  Moreover, since the biting part 6i has predetermined thickness (T6g) and is formed over the perimeter, the end cover 6 is continuing in the state which maintained rigidity to the front-end | tip of the biting part 6i. It will be. Therefore, the end cover 6 and the metal housing 7 and the end cover 6 and the stator core 43 are mechanically firmly fixed, the concentricity of the bearing 61 can be maintained, and the rotational stability of the rotor 5 and the impeller 23 is maintained. Can be maintained. In addition, although the example which used POM as a molding material which forms the end cover 6 was shown, it is not restricted to this, For example, if it is resin which has oil resistance (fuel) resistance and mechanical stability, such as PPS Applicable.

As the range of the predetermined region Rue (location of the end of the lower Fe p-side of the predetermined area Rue), it is desirable that the center in the axial direction of the stator core 43 in the upper end face Feu side.
More desirably, the end point is located closer to the upper end face Feu than the center in the axial direction.

  Further, in the present embodiment and each of the following embodiments, the example in which the fuel flow path is formed between the inner peripheral surface Fi4 of the stator core 43 and the outer peripheral surface Fo5 of the rotor 5 has been described. There is nothing. For example, the stator core 43 (each electromagnetic steel plate 44) itself may be provided with a through hole that extends in the axial direction to form a fuel flow path.

  As described above, according to the fuel supply device 1 according to the first embodiment of the present invention, the cylindrical metal housing 7 and the pump case fixed to the inner peripheral surface Fi7 on one end side in the axial direction of the metal housing 7. (Pump base 21, pump cover 22), an impeller 23 that is accommodated in the pump case so as to be sandwiched from both sides in the axial direction, and a pump part 2 having a fuel inlet 2 pi open at one end side, and an electromagnetic A stator 4 formed by winding a coil 42 around a stator core 43 that is a laminated body in which steel plates 44 are laminated in the axial direction, and press-fitted and fixed to an inner peripheral surface Fi7 on the other end side of the metal housing 7, and an inner periphery of the stator 4 A brushless motor (motor unit 3) having a rotor 5 disposed opposite to the surface Fi4 and having a rotation shaft connected to the impeller 23, and an open end on the other end side of the metal housing 7, The end cover 6 made of resin in which the discharge port 6px of the fuel supplied from the pump unit 2 opens to the end side is in contact with the surface along the axial direction of the laminate, and the pump unit 2 and the discharge port 6px are communicated with each other. The stator 4 is a magnetic steel sheet 44 laminated in a predetermined region Rue from the end surface (upper end surface Feu) on the other end side of the stator core 43 to a predetermined distance in the axial direction. Each of the outer peripheral surfaces Fo4 is formed so as to have a gap G47 between the outer peripheral surface Fo4 and the metal housing 7, and the end cover 6 is an integrally molded product with respect to the metal housing 7 into which the stator 4 is press-fitted. Since the biting portion 6i that bites into the gap G47 from the other end side is formed, the fuel reaches the predetermined region Rue portion through the laminated surfaces of the electromagnetic steel plates 44. Even if the path where the fuel advances in the axial direction is cut off by the biting part 6i or the path becomes longer, the leakage of the fuel to the outside is suppressed as compared with the case where the end cover is inserted by press-fitting, Sealability can be improved. Further, the biting portion 6i strengthens the mechanical connection between the end cover 6 and the metal housing 7, maintains coaxiality, and enables stable discharge. In addition, since both the pump unit 2 and the motor unit 3 are press-fitted into the inner peripheral surface Fi7 of one metal housing 7, axial displacement is suppressed, and more effective and stable discharge is possible.

  At this time, if the predetermined distance is set to be less than half the length of the stator core 43 in the axial direction, the end cover 6 can be molded without impairing the coaxiality between the stator 4 and the metal housing 7.

  In particular, if the predetermined distance is set to be less than a quarter of the length of the stator core 43 in the axial direction, the stator 4 and the metal housing 7 can be molded without impairing the coaxiality.

Embodiment 2. FIG.
The fuel supply apparatus according to the second embodiment is obtained by changing the shape of the inner peripheral surface of the metal housing with respect to the fuel supply apparatus described in the first embodiment. The configurations other than the inner peripheral surface and the portion related to the shape of the inner peripheral surface such as the biting portion are the same as those described in the first embodiment. FIG. 6 is a partially enlarged cross-sectional view along the rotation axis in the vicinity of the upper end of the stator of the fuel supply apparatus according to the second embodiment, and corresponds to the upper half region of FIG. 4 used in the description of the first embodiment. Is.

  As shown in FIG. 6, the fuel supply device 1 according to the second embodiment is provided with a circumferentially extending groove 7 c in at least a portion corresponding to the predetermined region Rue on the inner peripheral surface Fi 7 of the metal housing 7. I made it.

  As a result, the contact area between the biting portion 6i and the inner peripheral surface Fi7 of the metal housing 7 is increased, and the positional relationship in the axial direction is more firmly fixed. As a result, even if there is a change in the dimensional relationship due to the difference in linear expansion coefficient between the resin and the metal member when the temperature changes, the displacement of both is forcibly suppressed, and the inner peripheral surface Fi7 of the metal housing 7 and the bite. The adhesion with the part 6i can be further stabilized. Further, even when the adhesion between the inner peripheral surface Fi7 of the metal housing 7 and the biting portion 6i is lowered, the path along which the fuel travels along the axial direction is more due to the unevenness along the axial direction of the boundary surface by the groove 7c. It becomes longer, the leakage of fuel to the outside can be suppressed, and the sealing performance can be further enhanced.

  In the figure, an example in which two grooves 7c are formed is shown, but a single groove or three or more grooves may be used. Moreover, although it is desirable to form the groove 7c over the entire circumference, there may be a portion that is interrupted in the circumferential direction. In that case, it is desirable that the other groove 7c formed at a different position in the axial direction is formed so as not to overlap with a portion interrupted in the circumferential direction. Alternatively, the groove 7c may be formed in a spiral shape that moves in the axial direction as it advances in the circumferential direction.

  As described above, according to the fuel supply device 1 according to the second embodiment, the groove 7c extending in the circumferential direction is formed in the portion corresponding to the predetermined region Rue on the inner peripheral surface Fi7 of the metal housing 7. Therefore, the contact area between the biting portion 6i and the inner peripheral surface Fi7 of the metal housing 7 is increased, and the positional relationship in the axial direction is more firmly fixed. In addition, the path along which the fuel travels along the axial direction becomes longer, so that leakage of the fuel to the outside can be suppressed and the sealing performance can be further improved.

Embodiment 3 FIG.
The fuel supply device according to the third embodiment is obtained by changing the shape of the outer peripheral side of the upper end portion of the metal housing from the fuel supply device described in the first embodiment. The configuration other than the portion related to the outer peripheral shape is the same as that described in the first embodiment. FIG. 7 is a partially enlarged cross-sectional view along the rotation axis in the vicinity of the upper end portion of the stator of the fuel supply device according to the third embodiment, and corresponds to FIG. 6 used in the description of the second embodiment.

  As shown in FIG. 7, the fuel supply device 1 according to the third exemplary embodiment includes a portion having a predetermined length from the end portion 7eu on the end cover 6 side of the outer peripheral surface Fo7 of the metal housing 7 from other portions. A step 7s is provided so that the outer diameter is reduced. The step 7 s portion is covered with a covering portion 6 p formed of an insulating resin member that forms the end cover 6. That is, the end portion 7eu on the end cover 6 side of the metal housing 7 is sandwiched from both sides in the radial direction by the biting portion 6i and the covering portion 6p. At that time, the inner peripheral surface Fi7, the end surface, and the outer peripheral surface Fo7 are continuously in close contact with the resin member constituting the end cover 6.

  As a result, the distance of the connection surface between the end cover 6 and the metal housing 7 that connects the outer peripheral surface Fo4 of the stator core 43 and the outside is longer than in the case where there is no step 7s. Therefore, the path through which the fuel leaked to the outer peripheral surface Fo4 of the stator core 43 leaks to the outside of the pump becomes long, and leakage can be suppressed.

  On the other hand, the resin material of the end cover 6 has a larger linear expansion coefficient than the metal material of the metal housing 7. Therefore, the end cover 6 is relatively more radially inward than the metal housing 7 when the temperature is low, and the end cover 6 is relatively more radially outward than the metal housing 7 when the temperature is high. Is displaced. However, in the present embodiment, the material of the end cover 6 sandwiches the metal housing 7 from both sides in the radial direction. Therefore, no matter how the temperature changes, either the inner peripheral surface Fi7 or the outer peripheral surface Fo7 of the metal housing 7 exerts a force in the direction of pressing against the material of the end cover 6, so that the metal housing 7 and the end cover Even when peeling occurs at the interface with 6, sealing performance can be maintained.

  The shape of the outer peripheral side of the upper end portion of the metal housing shown in the third embodiment can also be applied to the fuel supply device shown in the second embodiment.

  As described above, according to the fuel supply device 1 according to the third exemplary embodiment, other portions of the outer peripheral surface Fo7 of the metal housing 7 from the tip portion on the end cover 6 side to the second predetermined distance A step 7s is formed so that the outer diameter is small with respect to the portion, and the step 7s is filled with the resin constituting the end cover, so that the resin material sandwiches the metal member from both sides in the radial direction, and the temperature change Even if there is, there can be maintained sealing performance.

Embodiment 4 FIG.
The fuel supply device according to the fourth embodiment is a shape on the outer peripheral side of the electromagnetic steel sheet used for the portion of the stator core that is press-fitted into the inner peripheral surface of the metal housing with respect to the fuel supply device described in the first embodiment. Is a change. The configuration other than the portion related to the outer peripheral shape of the stator core is the same as that described in the first embodiment. FIG. 8 is a cross-sectional view perpendicular to the axis of the intermediate portion in the axial direction of the stator of the fuel supply apparatus according to the fourth embodiment, and corresponds to FIG. 2 used in the description of the first embodiment.

  As shown in FIG. 8, the fuel supply device 1 according to the fourth embodiment has the shape of the electromagnetic steel plate 44 used for a layer of the stator core 43 other than the predetermined region Rue having a predetermined length from the upper end surface Feu. The shape is different from the shape described in FIG. 2 of the first embodiment. Specifically, a protrusion 43p that is in contact with the inner peripheral surface Fi7 of the metal housing 7 is provided only at a portion of the outer peripheral surface Fo4 where the teeth 43t are disposed in the circumferential direction. The diameter was reduced so as not to contact the peripheral surface Fi7.

  Thereby, the circumferential direction length of the outer peripheral surface Fo4 of the stator core 43 which contacts the metal housing 7 at the time of press fitting is shorter than the fuel supply apparatus 1 concerning each embodiment. That is, the contact area between the metal housing 7 and the stator core 43 is smaller than that of the fuel supply device 1 according to each embodiment at the time of press-fitting, and a load required at the time of press-fitting is reduced. As a result, the stress on the inner peripheral surface Fi7 of the metal housing 7 generated during press-fitting is also reduced, and the stress load on the metal housing 7 can be reduced.

  On the other hand, between the protrusion 43p and the protrusion 43p in the circumferential direction, when the end cover 6 is formed, an extension 6ix extending further downward from the biting portion 6i of the predetermined region Rue is formed. For example, if the gap between the metal housing 7 other than the protrusion 43p is made the same as the gap G47 in the predetermined region Rue, the biting portion 6i and the extension portion 6ix are continuous without losing rigidity, and the end cover The anchor effect on the metal housing 7 of 6 is further enhanced.

  In the present embodiment, by providing the protrusion 43p for each tooth 43t, the effect of improving the concentricity of the inner peripheral surface Fi7 of the metal housing 7 and the inner peripheral surface Fi4 of the stator core 43 is achieved. I was able to. However, the present invention is not limited to this, and the effect of reducing the stress load described above can also be achieved by distributing and disposing portions with small outer diameters in the circumferential direction. At this time, it is desirable that the portion corresponding to the protrusion 43p is disposed so as not to be biased in the circumferential direction.

  Note that the shape of the stator core 43 shown in the fourth embodiment is also applicable to the fuel supply devices shown in the second and third embodiments.

  As described above, according to the fuel supply device 1 according to the fourth embodiment, the inner peripheral surface Fi7 of the metal housing 7 is included in the electromagnetic steel sheet 44 used in the region other than the predetermined region Rue of the stator core 43. If the part (projection part 43p) in contact with each other is intermittently dispersed in the circumferential direction, the load required for press-fitting is reduced, and the stress load on the metal housing 7 can be reduced. .

Embodiment 5 FIG.
The fuel supply device according to the fifth embodiment is not in contact with the inner peripheral surface of the metal housing in the region of the intermediate portion in the axial direction of the stator core with respect to the fuel supply devices described in the first embodiment. In addition, an electromagnetic steel sheet having a reduced outer diameter is used. The configuration other than the portion related to the outer peripheral shape of the stator core is the same as that described in the first embodiment. FIG. 9 is a view for explaining the configuration of a fuel supply apparatus according to Embodiment 5 of the present invention. FIG. 9A is a cross-sectional view of the fuel supply apparatus taken along the rotation axis of the motor, and FIG. ) Is an enlarged cross-sectional view of the right side portion of the stator and corresponds to the region D in FIG.

As shown in FIG. 9, the fuel supply device 1 according to the fifth embodiment includes an electromagnetic whose outer diameter is reduced so as not to contact the inner peripheral surface of the metal housing 7 in the intermediate portion of the stator core 43 in the axial direction. A steel plate 44 was used . As the electrical steel sheet 44 having a reduced outer diameter, the same electrical steel sheet 44 corresponding to the predetermined region Rue described in FIG. 3 of the first embodiment was used from the viewpoint of component efficiency. Thereby, the length in the axial direction in which the outer peripheral surface Fo4 of the stator core 43 is press-fitted into the inner peripheral surface of the metal housing 7 is shorter than the case described in the first embodiment.
In other words, the contact area between the metal housing 7 and the stator core 43 is smaller than that of the fuel supply device 1 according to the first to third embodiments at the time of press-fitting, and a load necessary for press-fitting is reduced. As a result, the stress on the inner peripheral surface Fi7 of the metal housing 7 generated during press-fitting is also reduced, and the stress load on the metal housing 7 can be reduced.

Here, the arrangement in the axial direction of the magnetic steel sheet 44 having a small outer diameter and not in contact with the metal housing 7 will be examined. For example, even if the layers that do not contact the metal housing 7 are concentrated only on the upper end surface Feu side in the axial direction and further formed to an enlarged region that is enlarged beyond the center, it is possible to reduce the load during press-fitting. Is possible. In other words, even if the layers in contact with the metal housing 7 are concentrated only on the lower end face Fep side in the axial direction, it is possible to reduce the load during press-fitting.

However, when the end cover 6 is integrally formed with the metal housing 7 into which the stator core 43 is press-fitted, the resin member is circumferentially dependent on the position of the gate for injecting resin during molding and the shape of the end cover 6. It is assumed that it is filled in an uneven manner. At this time, if the enlarged region is set, the outer peripheral portion of the stator core 43 and the inner peripheral surface of the metal housing 7 are not in contact with each other in the vicinity of the end surface portion on the end cover 6 side. In this case, the stator core 43 is pushed to the inner peripheral side by the resin, and the metal housing 7 is pushed to the outer peripheral side.

  As a result, the gap between the outer periphery of the stator core and the metal housing at the location that is axially symmetric with respect to the location where the resin is initially filled becomes narrow, making it difficult to fill the resin, and the resin may not be sufficiently filled, resulting in a gap. There is. Furthermore, the metal housing and the stator core shaft may be shaken to prevent smooth rotation.

On the other hand, in the fuel supply device according to the fifth embodiment, a region where the outer peripheral surface Fo4 of the stator core 43 is in contact with the inner peripheral surface Fi7 of the metal housing 7 is present on the upper end surface Feu side from the intermediate portion in the axial direction. That is, as viewed from the center in the axial direction, there are regions in contact with the inner peripheral surface Fi7 of the metal housing 7 on each of the upper end surface Feu side and the lower end surface Fep side. Therefore, in the predetermined region Rue, biased in the circumferential direction even when the resin is filled, to suppress the inclination of the stator core 43 and the metal housing 7 can Rukoto to maintain the concentricity.

  In addition, disposing only the layer of the electromagnetic steel sheet 44 that does not contact the metal housing from the center in the axial direction to one end side causes troubles such as inclination as described above. However, if the stator core 43 is configured so that a layer of the electromagnetic steel sheet 44 that contacts the metal housing 7 is disposed in each of the one end region and the other end region as viewed from the center in the axial direction, The arrangement can be changed as appropriate. At that time, the distance between the farthest layers among the layers of the electromagnetic steel sheet 44 in contact with the metal housing 7 is at least 1/2 of the axial length (distance between the upper end surface Feu and the lower end surface Fep). Is desirable.

The electromagnetic steel plate 44 in the region Ra that does not contact the metal housing 7 is not limited to the same shape as that corresponding to the predetermined region Rue. However, if the shape is the same as that corresponding to the predetermined region Rue, there is no need to increase the types of patterns of the electromagnetic steel sheet 44.

  In the fourth embodiment, the case where the electromagnetic steel sheet 44 having a portion not in contact with the metal housing is arranged in all layers other than the predetermined region Rue has been described. In this case, the metal housing is dispersed at positions distributed in the circumferential direction. Since it is in contact with 7, the problem of tilt does not occur. However, in the fourth embodiment, as described in the fifth embodiment, it may be arranged so as to be appropriately dispersed in the axial direction.

  The form of the stator core shown in the fifth embodiment can also be applied to the fuel supply devices shown in the second and third embodiments.

  As described above, according to the fuel supply device 1 according to the fifth embodiment, the electromagnetic steel sheet 44 having an outer diameter smaller than the inner peripheral surface Fi7 of the metal housing 7 is used for the intermediate portion in the axial direction of the stator core 43. If so, the load required for press-fitting is reduced, and the stress load on the metal housing 7 can be reduced.

Embodiment 6 FIG.
The fuel supply device according to the sixth embodiment has an inner diameter in the region of the intermediate portion in the axial direction of the metal housing so as not to contact the outer peripheral portion of the stator core, compared to the fuel supply device described in the first embodiment. An enlarged concave portion is provided. The configuration other than the portion related to the shape of the region of the intermediate portion of the inner peripheral surface of the metal housing is the same as that described in the first embodiment. FIG. 10 is an enlarged cross-sectional view of the right portion of the stator of the fuel supply device according to the sixth embodiment of the present invention, and corresponds to FIG. 9B of the fifth embodiment.

  As shown in FIG. 10, the fuel supply device 1 according to the sixth embodiment has a concave portion 7 d having an inner diameter increased so as not to come into contact with the stator core 43 at an intermediate portion in the axial direction of the inner peripheral surface Fi 7 of the metal housing 7. Is provided. More specifically, in the region facing the stator core 43, a concave portion 7d that does not contact the stator core 43 is provided in an intermediate portion away from the predetermined region Rue and the lower end surface Fep.

  Thereby, the length in the axial direction in which the outer peripheral surface Fo4 of the stator core 43 is press-fitted into the inner peripheral surface of the metal housing 7 is shortened as in the case described in the fifth embodiment. In other words, the contact area between the metal housing 7 and the stator core 43 is smaller than that of the fuel supply device 1 according to the first to third embodiments at the time of press-fitting, and a load necessary for press-fitting is reduced. As a result, the stress on the inner peripheral surface Fi7 of the metal housing 7 generated during press-fitting is also reduced, and the stress load on the metal housing 7 can be reduced.

  In the present embodiment, the example in which the concave portion 7d is provided in the intermediate portion away from the lower end surface Fep is shown, but it may be configured to reach the lower end surface Fep. However, in that case, from the viewpoint of preventing the shaft from shaking, the farthest distance between the layers of the electromagnetic steel sheet 44 in contact with the metal housing 7 is the axial length (distance between the upper end surface Feu and the lower end surface Fep). It is desirable to set so that it becomes more than / 2.

Moreover, the form of the metal housing shown in the sixth embodiment is also applicable to the fuel supply device shown in the second to fourth embodiments. In addition, although there is no necessity to combine, it is applicable also to the fuel supply apparatus shown in Embodiment 5.

  As described above, according to the fuel supply device 1 according to the sixth embodiment, the concave portion 7d whose inner diameter is increased so as not to contact the stator core 43 at the intermediate portion in the axial direction of the inner peripheral surface Fi7 of the metal housing 7. As a result, the load required for press-fitting is reduced, and the stress load on the metal housing 7 can be reduced.

1: fuel supply device, 2: pump unit, 2pi: suction port,
3: Motor part (brushless motor), 4: Stator, 5: Rotor,
6: End cover, 6i: Biting part, 6px: Discharge port, 7: Metal housing,
7c: Groove, 7s: step 21: Ponpube scan, 22: Ponpukaba over,
23: Impeller, 42: Coil, 43: Stator core, 43p: Projection
44: Electrical steel sheet, Feu: Upper end surface on the end cover side of the stator core,
Fi7: inner peripheral surface of the metal housing, Fo4: outer peripheral surface of the stay data, G47: gap,
Rue: Predetermined area

Claims (4)

A cylindrical metal housing;
A pump case fixed to an inner peripheral surface on one end side in the axial direction of the metal housing, and an impeller accommodated so as to be sandwiched from both sides in the axial direction by the pump case, and a fuel inlet on the one end side An opening pump part;
A stator core, which is a laminated body in which electromagnetic steel sheets are laminated in the axial direction, is formed by winding a coil, and is press-fitted and fixed to the inner peripheral surface on the other end side of the metal housing, and is disposed opposite to the inner peripheral surface of the stator And a motor unit having a rotor whose rotating shaft is connected to the impeller, and
A resin end cover that covers the open end of the metal housing on the other end side and that opens the discharge port of fuel supplied from the pump unit on the other end side;
A fuel flow path that is in contact with a surface along the axial direction of the laminated body and is formed so as to communicate the pump unit and the discharge port;
In the stator, each outer peripheral surface of the electromagnetic steel sheets laminated in a predetermined region from the end surface on the other end side of the stator core to a position at a predetermined distance in the axial direction is spaced from the metal housing over the entire periphery. of the outer peripheral surface of the formed Rutotomoni the metal housing so as to have the portion of the tip portion of the other end to a second predetermined distance, a step such that the outer diameter becomes smaller than the other portions Formed,
Said end cover, said a stator integral molding relative to the metal housing that is press-fit, forming the end cover to the other end biting portion bites into the gap is formed from the side Rutotomoni the step over the entire periphery A fuel supply device filled with resin . Among the electromagnetic steel sheets used for the portion excluding the predetermined region of the stator core, there is one in which a portion in contact with the inner peripheral surface of the metal housing is intermittently dispersed in the circumferential direction. The fuel supply device according to claim 1 . The fuel supply apparatus according to the intermediate portion, to claim 1 where the outer diameter than the inner peripheral surface of the metal housing is characterized by using a small magnetic steel sheets in the axial direction of the stator core. 3. The fuel supply device according to claim 1, wherein a concave portion having an increased inner diameter is formed in an intermediate portion in an axial direction of an inner peripheral surface of the metal housing so as not to contact the stator core.

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