JP6579986B2 - Fuel pump - Google Patents

Description

  The present invention relates to a fuel pump.

  Conventionally, as a fuel pump that pressurizes the fuel in a fuel tank and pumps it to an internal combustion engine such as an engine, a motor chamber in which a motor is built in a housing and a pump chamber in which an impeller driven by the motor is built are formed. There is something. In this case, the housing is one cylindrical member that forms both the outer wall portions of the motor chamber and the pump chamber. One end of the cylindrical member in the axial direction is on the motor chamber side, and the other end is pumped. Each part is fixed by caulking to the chamber side to improve the fuel sealing performance.

  In addition, the motor that is the drive source of the fuel pump is provided with a flow path (for example, a gap between the stator and the rotor) that allows the fuel to pass through the motor without providing a separate fuel flow path. The brushless motor (for example, patent document 1) and the motor with a brush (for example, patent document 2) are used.

  A brushless motor does not slide between a commutator and a brush like a motor with a brush, is less susceptible to motor characteristics due to fluctuations in contact resistance, and does not cause a voltage drop in the commutator or brush part. It is used for fuel pumps that are required to be small and highly efficient. The brushless motor as shown in Patent Document 1 can be used as a component part composed of one cylindrical member in which the housing is formed coaxially with the outer wall portions of the motor chamber and the pump chamber.

  On the other hand, in a motor with a brush, since a commutation action of current is generated by sliding the commutator and the brush, a special control circuit is not required and the structure is inexpensive. However, it is susceptible to motor characteristics due to variations in contact resistance. Moreover, in the motor with a brush of patent document 2, the magnet is attached to the housing and it uses as a magnetic path through which magnetic flux flows.

Japanese Patent Laying-Open No. 2015-86804 JP 2008-202592 A

  By the way, in the conventional fuel pump as described in the above-mentioned Patent Documents 1 and 2, the pump chamber in which the impeller for pumping the fuel is built in has a pump base on the motor chamber side of the impeller and the impeller. A pump cover is configured on the outer end side opposite to the sandwiched part, and a part of the housing is positioned on the outer periphery of the impeller.

  In this case, the gap between the impeller facing surface of the pump base and the impeller, and the gap between the impeller facing surface of the pump cover and the impeller (hereinafter referred to as impeller clearance) both have a significant effect on the quality of the fuel pump flow characteristics. give. Therefore, in the manufacture of the fuel pump, the processing accuracy and assembly of each component of the pump base, the pump cover, and the impeller are managed with high accuracy so that the impeller clearance becomes a predetermined value.

  In the process of manufacturing the fuel pump, after inserting the pump cover into the cylindrical member for constituting the housing, a caulking process is performed to bend the opening end of the cylindrical member on the pump cover side inward in the radial direction. A caulking portion is formed. As a result, the caulking portion of the cylindrical member comes into contact with the pump cover, and the pump cover is secured by caulking.

  When the caulking process is performed at normal temperature, the caulking portion of the cylindrical member formed by this springs back, so that the bending angle of the caulking portion is slightly smaller than the actually bent angle. As a result, the pressing force (hereinafter referred to as axial force) of the pump cover against the pump base is insufficient, the pump cover moves away from the impeller, the impeller clearance increases, and the flow characteristics of the fuel pump deteriorate. Will be invited.

  Therefore, in order to firmly fix the pump cover, it is necessary to increase the caulking load and form the caulking portion in consideration of the spring back when caulking the cylindrical member for housing formation at room temperature.

  However, when the caulking load is increased in this way, in order to pressurize only the outer diameter part of the pump cover locally, the outer diameter part side is pushed into the pump base side with respect to the inner diameter part of the pump cover, The pump cover is distorted, for example, when the pump cover is deformed into a drum shape. Along with this, slight distortion also occurs on the inner surface of the pump chamber that houses the impeller. And if a slight distortion occurs in the inner surface of the pump chamber, it becomes difficult for the impeller to rotate due to non-uniform force, or the impeller clearance varies and the fuel discharge efficiency of the fuel pump decreases. There is a problem that the pump characteristics fluctuate.

  As a countermeasure, in Patent Document 2, when the crimped portion is formed in the cylindrical member, the crimped portion is formed after the opening end of the cylindrical member is heated in advance. According to this, since the caulking part is heated before being caulked by the pump cover, the caulking part after caulking is thermally contracted due to a temperature drop. Therefore, it is possible to increase the axial force by the crimping portion without increasing the crimping load when the cylindrical member is crimped. Therefore, when caulking the cylindrical member, deformation of the pump cover due to excessive caulking load can be avoided, and the axial force by the caulking portion can be increased while suppressing an increase in the impeller clearance.

  However, when caulking the cylindrical member, it is difficult to locally heat the portion where the caulking portion is formed, and it is inevitable that the heat influences other than the caulking portion. And when the thermal effect reaches to places other than the caulking part, the in-plane variation of the impeller clearance occurs, and the fuel discharge efficiency of the fuel pump decreases, or the pump characteristics fluctuate, and other members There is a risk of causing deformation and deterioration of accuracy due to heat effects. Moreover, in the method of caulking after heating the caulking part, in addition to the caulking process of the cylindrical member, a process for heating the caulking part is required, and not only the caulking device but also caulking A heating device for heating the part is required, and there is a problem that an extra cost is increased in terms of productivity and equipment.

  The present invention has been made to solve the above problems, and its purpose is to suppress deformation of the pump cover while ensuring a sufficient axial force so that the pump cover does not separate from the pump base, An object of the present invention is to provide a fuel pump that can manage the impeller clearance with high accuracy, and that does not require large-scale equipment and has excellent productivity.

A fuel pump according to a first aspect of the present invention includes a housing in which a tubular portion and an end cover portion that closes one axially open end of the tubular portion are integrally formed, and the tubular portion of the housing is A locking portion protruding inward in the radial direction is formed in a part, and one end cover side in the axial direction sandwiching the locking portion is partitioned as a motor portion and the other opening end side is partitioned as a pump portion. And
The motor part is configured by housing a motor having a stator and a rotor inside the housing,
The pump part includes a pump cover that closes the other axially open end of the cylindrical part, and a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed, and the pump base Is fitted into the tubular portion of the housing with the annular portion facing the pump cover side and is locked to the axial end surface of the locking portion on the pump cover side, and the pump cover and the A pump chamber is formed inside the pump base, and one end side of the rotor shaft extends through the pump base inside the pump chamber, and an impeller is provided at the extended portion of the shaft. The pump cover has a suction hole for sucking fuel into the pump chamber, and the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor unit. The cover portion discharge hole for discharging the fuel boosted to the outside, are formed respectively,
A female screw mechanism portion is provided on the inner peripheral surface of the opening end on the pump cover side of the tubular portion of the housing, while a male screw portion is formed on the outer peripheral surface of the pump cover, and the male screw portion of the pump cover is The annular portion of the pump base is pressed by the opposing surface on the pump base side of the pump cover by being screwed to the female screw mechanism portion.

The fuel pump according to a second aspect of the present invention includes a housing in which a cylindrical portion and an end cover portion that closes one axially open end of the cylindrical portion are integrally formed, and the cylindrical shape of the housing A locking portion protruding inward in the radial direction is formed in a part of the portion, and one end cover side in the axial direction sandwiching the locking portion is a motor portion, and the other opening end side is a pump portion. The motor section is configured by housing a motor including a stator and a rotor inside the housing,
The pump part includes a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed, a push plate that closes an opening on the other end side in the axial direction of the housing, the pump base, and the push plate And the pump base is inserted into the cylindrical portion of the housing with the annular portion facing the pump cover side, and the pump cover of the locking portion. The pump cover is fitted into the cylindrical portion of the housing and faces the annular portion of the pump base. The pump base and the pump cover A pump chamber is formed in the enclosed interior, and one end side of the rotor shaft extends through the pump base inside the pump chamber, and an impeller is fixed to the extending portion of the shaft. Is configured,
The pump cover has a suction hole for sucking fuel into the pump chamber, the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor part, and the end cover part has fuel after boosting And a through hole for exposing the suction hole of the pump cover to the outside, respectively.
A female screw mechanism is provided on the inner peripheral surface of the open end of the cylindrical portion of the housing on the pump cover side, while a male screw portion is formed on the outer peripheral surface of the push plate, and the male screw portion of the push plate is The annular portion of the pump base is pressed by the opposing surface on the pump base side of the pump cover by being screwed to the female screw mechanism.

According to a third aspect of the present invention, a fuel pump includes a cylindrical casing and an end cover that closes one axially open end of the casing, and a part of the casing faces radially inward. A protruding locking part is formed, one end cover side in the axial direction sandwiching the locking part is partitioned as a motor part, and the other opening end side is divided as a pump part,
The motor unit is configured by housing a motor having a stator and a rotor inside the casing.
The pump part has a pump cover that closes the other opening end in the axial direction of the casing, and a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed. The annular portion is fitted into the casing with the pump cover side facing, and is locked to the axial end surface of the locking portion on the pump cover side, and is surrounded by the pump cover and the pump base. A pump chamber is formed inside, and one end side of the shaft of the rotor extends through the pump base inside the pump chamber, and an impeller is fixed to the extending portion of the shaft. ,
The pump cover has a suction hole for sucking fuel into the pump chamber, the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor unit, and the end cover has fuel after boosting. Discharge holes that discharge to the outside are formed respectively.
A female thread portion is formed on the inner peripheral surface of the opening end of the casing on the pump cover side, while a male screw portion is formed on the outer peripheral surface of the pump cover, and the male screw portion of the pump cover is screwed to the female screw portion. Thus, the annular portion of the pump base is pressed by the opposed surface of the pump cover on the pump base side.

A fuel pump according to a fourth aspect of the present invention includes a cylindrical casing and an end cover that closes one opening end in the axial direction of the casing, and a part of the casing protrudes inward in the radial direction. A locking part is formed, one end cover side in the axial direction sandwiching the locking part is partitioned as a motor part and the other opening end side as a pump part,
The motor unit is configured by housing a motor having a stator and a rotor inside the casing.
The pump part includes a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed, a push plate that closes the other opening end in the axial direction of the casing, the pump base, and the push plate And the pump base is fitted into the casing with the annular portion facing the pump cover, and is fitted to the axial end surface of the locking portion on the pump cover side. The pump cover is fitted into the casing and faces the annular portion of the pump base, and a pump chamber is formed inside the pump base and the pump cover. One end side of the shaft of the rotor extends through the pump base inside the pump chamber, and an impeller is fixed to an extension portion of the shaft.
The pump cover has a suction hole for sucking fuel into the pump chamber, the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor unit, and the end cover has fuel after boosting. A discharge hole for discharging to the outside, and a through hole for exposing the suction hole of the pump cover to the outside are formed in the push plate, respectively.
A female screw portion is formed on the inner peripheral surface of the opening end portion of the casing on the pump cover side, while a male screw portion is formed on the outer peripheral surface of the push plate, and the male screw portion of the push plate is screwed onto the female screw portion. By being stopped, the annular portion of the pump base is pressed by the opposing surface of the pump cover on the pump base side.

  According to this invention, since the pump cover is pressed against the pump base by the pump cover itself or the push plate, a sufficient axial force of the pump cover with respect to the pump base can be secured, and the pump characteristics can be improved by increasing the impeller clearance. Deterioration can be suppressed.

  In addition, the pump cover is not formed by performing a caulking process by bending the opening end portion of the cylindrical member for housing formation on the pump cover side inward in the radial direction as in the prior art. Since the pump cover is pressed against the pump base by the push plate itself, there is no local deformation of the pump cover, and the clearance with the impeller can be managed with high accuracy.

  Moreover, as the assembly work of the pump chamber, since it does not require large facilities and work such as a conventional caulking device and a heating device that heats the caulking part, it is sufficient to perform the work of tightening the screws. It is possible to provide a fuel pump that does not require time and is excellent in productivity.

It is a longitudinal cross-sectional view of the fuel pump of Embodiment 1 of this invention. It is a top view which shows the impeller of the fuel pump of Embodiment 1 of this invention. It is a top view of the pump base seen from the impeller side of the fuel pump of Embodiment 1 of this invention. It is a top view of the pump cover seen from the impeller side of the fuel pump of Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the modification of the fuel pump of Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the other modification of the fuel pump of Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the further another modification of the fuel pump of Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the further another modification of the fuel pump of Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the fuel pump of Embodiment 2 of this invention. It is a top view of the pump base seen from the impeller side of the fuel pump of Embodiment 2 of this invention. It is a top view of the pump cover seen from the impeller side of the fuel pump of Embodiment 2 of this invention. It is a longitudinal cross-sectional view which shows the modification of the fuel pump of Embodiment 2 of this invention. It is a longitudinal cross-sectional view of the fuel pump of Embodiment 3 of this invention. It is a longitudinal cross-sectional view which shows the modification of the fuel pump of Embodiment 3 of this invention. It is a longitudinal cross-sectional view which shows the other modification of the fuel pump of Embodiment 3 of this invention. It is a longitudinal cross-sectional view which shows the other modification of the fuel pump of Embodiment 3 of this invention.

Embodiment 1 FIG.
1 is a longitudinal sectional view of a fuel pump according to Embodiment 1 of the present invention, FIG. 2 is a plan view showing an impeller of the fuel pump of FIG. 1, and FIG. 3 is a pump base viewed from the impeller side of the fuel pump of FIG. FIG. 4 is a plan view of the pump cover as viewed from the impeller side of the fuel pump of FIG.

  The fuel pump 1 of the first embodiment is capable of sucking and boosting fuel and discharging it to the outside, and includes a housing 2. In the housing 2, a cylindrical tubular portion 2a and an end cover portion 2b that closes one opening end in the axial direction of the tubular portion 2a are integrally formed by molding. As a material of the housing 2 in this case, an insulating mold resin such as polyacetal (POM), polyphenylene sulfide (PPS), or the like is applied.

  The end cover portion 2b of the housing 2 is provided with a power supply terminal 3 for supplying electric power to a stator 9 of a motor 8 described later, and a bearing housing portion 2c is formed. A bearing 4 is press-fitted into the bearing housing portion 2c, and one end of a shaft 10b of a rotor 10 described later is mounted on the bearing 4 to hold the shaft 10b rotatably. Further, the end cover portion 2b is provided with a discharge hole 2d for discharging the pressurized fuel to the outside, and a check valve 5 is fitted into the discharge hole 2d. The check valve 5 is composed of a lid 5a and a spring 5b. When the fuel pressurized in the pump chamber 14 exceeds a predetermined pressure, the spring 5b contracts to move the lid 5a upward in FIG. Fuel is discharged from the discharge hole 2d.

  The cylindrical portion 2a of the housing 2 is provided with a female screw mechanism portion 6 on the inner peripheral surface of the opening end opposite to the end cover portion 2b. The female screw mechanism portion 6 includes a metal female screw component 7 having a thread formed on a cylindrical inner peripheral surface. The female screw component 7 is integrally fixed to the inner peripheral surface side of the cylindrical portion 2a. It is configured.

  Further, an annular locking portion 2e that protrudes radially inward is formed on a part of the cylindrical portion 2a of the housing 2, and one side (end cover) in the axial direction sandwiching the locking portion 2e is formed. The portion 2b side) is partitioned as a motor portion M, and the other opening end side (the pump cover 12 side described later) is partitioned as a pump portion P.

  Here, the motor part M is configured by housing a motor 8 (here, a brushless motor) in the housing 2. The motor 8 includes a stator 9 fixed to the housing 2 and a rotor 10 disposed concentrically with a predetermined gap from the stator 9. A gap between the stator 9 and the rotor 10 is secured as a fuel flow path.

  The stator 9 has an iron core 9a formed by arranging the magnetic pole portions in an annular shape, and a coil 9c wound around the iron core 9a via an insulating material 9b.

  The iron core 9a includes a back yoke (not shown), a tooth (not shown) protruding radially inward from the back yoke, and a magnetic attracting portion (see FIG. Not shown). The coil 9c is intensively wound around each tooth to which an insulating material is attached. In the distributed winding in which the wire is wound across a plurality of teeth, the axial dimension of the coil 9c is long, whereas in the first embodiment, the coil 9c is a concentrated winding, so the axial direction of the coil 9c is The dimensions can be shortened, and the amount of coil 9c used can be reduced.

  And the end cover part 2b is formed so that the axial direction end surface of the one side (FIG. 1 upper side) of the coil 9c may be covered. In the first embodiment, compared to the distributed winding, the concentrated winding in which the axial dimension of the coil 9c is shorter is adopted, so that the area covered by the end cover portion 2b is reduced, and the amount of resin material used in the end cover portion 2b is reduced. can do. In addition, since the axial dimension of the end cover portion 2b can be reduced, the fuel pump 1 can be reduced in size and weight, and fuel consumption can be improved. Further, the other axial end surface (the lower side in FIG. 1) opposite to the end cover portion 2b of the coil 9c is positioned in contact with the locking portion 2e.

  On the other hand, the rotor 10 includes a cylindrical permanent magnet 10a, and has a shaft 10b fixed through the central portion thereof in the axial direction. In this case, the permanent magnet 10a is a so-called plastic magnet in which a resin material (for example, polyacetal (POM), polyphenylene sulfide (PPS) or the like) is mixed with a magnet material (for example, ferrite, neodymium, iron, or boron), It can be manufactured by molding.

  As the rotor 10, a permanent magnet 10a (for example, ferrite, neodymium / iron / boron sintered magnet or plastic magnet) and a shaft 10b are made of resin (for example, polyacetal (POM), polyphenylene sulfide (PPS). ) Etc.) may be used.

  In general, sintered magnets contain a higher percentage of magnetic powder than plastic magnets and can obtain a high magnetic force, so that the flow rate and fuel pressure of fuel pump 1 can be increased by increasing motor torque. Can do. In addition, by using only a resin instead of a plastic magnet for the joint with the shaft 10b, it is possible to reduce the amount of magnet used at the portion used for joining with the shaft 10b, although it does not contribute to the surface magnetic flux.

  The pump part P includes a pump cover 12 that closes the other opening end in the axial direction of the cylindrical part 2a of the housing 2, and a pump base 13 that is interposed between the pump cover 12 and the motor part M in the axial direction. A pump chamber 14 is formed inside the pump cover 12 and the pump base 13, and one end side of the shaft 10 b of the rotor 10 extends through the pump base 13 in the pump chamber 14. An impeller 15 is fixed to the extending portion of the shaft 10b.

  Here, the pump base 13 is made of a metal material such as an aluminum material, and has a disc-shaped bottom plate portion 13a and an annular shape that protrudes in the axial direction toward the pump cover 12 side along the outer peripheral portion of the bottom plate portion 13a. It has a substantially bottomed cylindrical shape integrally formed with the portion 13b. A part of the outer periphery of the bottom plate portion 13a is cut out along the circumferential direction to form a step portion 13c, and a sealing material 16 (here, an O-ring) is fitted to the step portion 13c. The outer diameter of the annular portion 13b is formed to be substantially the same as the inner diameter located on the opening end side of the locking portion 2e of the cylindrical portion 2a of the housing 2.

  Further, a bearing hole 13d penetrating in the axial direction is provided at the center of the bottom plate portion 13a of the pump base 13, a bearing 17 is press-fitted into the bearing hole 13d, and the shaft 10b is inserted into the bearing 17. Further, an arcuate pressure groove 13e concentric with the annular portion 13b is formed on the inner surface of the annular portion 13b on the side of the bottom plate portion 13a facing the pump cover 12, and the end of the pressure groove 13e is formed. A discharge hole 13f for discharging fuel boosted by the impeller 15 to the motor part M is formed on the side, and the discharge hole 13f passes through the bottom plate part 13a and opens to the pump part P side.

  The pump base 13 is press-fitted into the cylindrical portion 2a of the housing 2 with the annular portion 13b facing the pump cover 12 side. Accordingly, the pump base 13 is locked to the locking portion 2e of the housing 2 by the axially opposed surfaces of the bottom plate portion 13a of the pump base 13 and the locking portion 2e of the housing 2 contacting each other. In that case, since the sealing material 16 is interposed between the stepped portion 13c provided on the outer periphery of the bottom plate portion 13a of the pump cover 12 and the locking portion 2e of the housing 2, airtight so that fuel does not leak from the motor portion M. Sex is maintained.

  The impeller 15 has a substantially disk shape as a whole. On the upper and lower opposing surfaces in the axial direction, blade grooves 15a that are continuous in the circumferential direction at a predetermined distance in the radial direction from the outer circumferential surface are formed in an annular shape. Is formed. Further, a substantially D-shaped engagement hole 15b is formed in the center of the impeller 15 in a plan view penetrating in the axial direction, and the shaft 10b is inserted into the engagement hole 15b.

  In other words, the outer diameter of the impeller 15 is larger than the inner diameter of the annular portion 13b of the pump base 13 so that a predetermined gap is formed between the impeller 15 and the inner peripheral surface of the annular portion 13b of the pump base 13 in the pump chamber 14. Is also formed small. Further, the impeller 15 is provided with a predetermined gap (i.e., clearance of the impeller 15) between the bottom plate portion 13a of the pump base 13 and the disc portion 12a of the pump cover 12, respectively. The axial thickness is set in advance.

  The pump cover 12 is made of a metal material such as an aluminum material, and a disc portion 12a and a projecting portion 12b projecting from the disc portion 12a to one side in the axial direction (opening end side of the housing 2) are integrally formed. Is. A flat bearing 18 is press-fitted into the center of the disk portion 12a on the pump chamber 14 side, and the other end side of the shaft 10b is attached to the flat bearing 18. An arc-shaped pressurization groove 12c concentric with the pressurization groove of the pump base 13 and having the same radius is formed on the disk portion 12a on the side facing the pump base 13, and the pressurization groove A suction hole 12d for sucking fuel is formed on the terminal end side of 12c. The suction hole 12d passes through the inside of the protruding portion 12b from the disc portion 12a and opens to the outside. Further, a male screw part 12 e is formed on the outer peripheral surface of the disc part 12 a of the pump cover 12, and this male screw part 12 e is formed on the female screw part 7 which is the female screw mechanism part 6 provided in the cylindrical part 2 a of the housing 2. It is screwed. In addition, the code | symbol 12f of FIG. 4 is the vent hole provided through the disc part 12a from the pressurization groove | channel 12c of the pump cover 12. As shown in FIG.

  In a state where the male screw part 12 e of the pump cover 12 is screwed to the female screw part 7, the discharge hole 13 f is formed in the bottom plate part 13 a of the pump base 13 and the disk part 12 a of the pump cover 12 is formed. The start end portion 12s opposite to the formation position of the suction hole 12d of the pressure groove 12c is positioned coaxially in the axial direction. Further, a start end portion 13s opposite to the discharge hole 13f of the pressurizing groove 13e formed in the bottom plate portion 13a of the pump base 13 and a suction hole 12d formed in the disc portion 12a of the pump cover 12 are axially arranged. At the same axis.

  In order to maintain such a positional relationship, the lengths of the pressure grooves 12c and 13e, the positions where the suction holes 12d and the discharge holes 13f are formed, and the internal threads 12e of the pump cover 12 and the internal threads for constituting the screw mechanism section. The screwing pitch of each thread of the component 7 is adjusted in advance.

  The operation of the fuel pump 1 having the above-described configuration will be described. When power is supplied to the coil 9c of the stator 9 through the power supply terminal 3, the shaft 10b of the rotor 10 rotates, and the impeller 15 in the pump chamber 14 is rotated accordingly. By rotating, the fuel passes through the inside of the projecting portion 12b of the pump cover 12 and is sucked into the pump chamber 14 from the suction hole 12d of the disc portion 12a. The fuel sucked into the pump chamber 14 is pressurized by the pressure groove 12 c of the pump cover 12, the blade groove 15 a of the impeller 15, and the pressure groove 13 e of the pump base 13, and from the discharge hole 13 f of the pump base 13 to the motor unit. M is discharged. The fuel discharged to the motor unit M passes through the gap between the stator 9 and the rotor 10 of the motor unit M, and is sent to the outside via the check valve 5.

  In order to manufacture the fuel pump 1 having the above configuration, the housing 2 is insert-molded with respect to the stator 9 of the motor 8, and the housing 2 and the stator 9 are integrally molded. Then, the rotor 10 is inserted from the open end side of the cylindrical portion 2a of the housing 2, and one end side of the shaft 10b of the rotor 10 is mounted on the bearing 4 provided on the end cover portion 2b.

  Next, the pump base 13 is press-fitted from the open end side of the tubular portion 2a of the housing 2 with the annular portion 13b facing the pump cover 12 side. At that time, the shaft 10b is inserted into the bearing 17 provided at the center of the bottom plate portion 13a. Subsequently, the shaft 10b extended through the pump base 13 is inserted into the engagement hole 15b of the impeller 15 to fix the impeller 15 to the shaft 10b. Finally, the male screw part 12e of the pump cover 12 is screwed to the female screw part 7, and the other end side of the shaft 10b is attached to the flat bearing 18.

  In this way, when the male screw part 12e of the pump cover 12 is screwed to the female screw mechanism part 6 (female screw part 7), the pump base 13 is pressed by the pump cover 12, and the engaging part 2e of the housing 2 is engaged. Stopped. That is, since the opposing surfaces of the bottom plate portion 13a of the pump base 13 and the locking portion 2e of the housing 2 are in contact with each other, the axial position of the bottom plate portion 13a of the pump base 13 is positioned by the locking portion 2e. At the same time, the opposed surfaces of the annular portion 13b of the pump base 13 and the disc portion 12a of the pump cover 12 come into contact with each other, so that the axial position of the annular portion 13b of the pump base 13 is regulated by the pump cover 12.

  Therefore, focusing on the pump chamber 14, when the pump chamber 14 is configured, the axial force with which the pump cover 12 is pressed against the pump base 13 is secured by screwing force. Sufficient axial force can be secured so as not to move away. Thereby, the distance between the opposing surfaces of the bottom plate portion 13a of the pump base 13 and the disc portion 12a of the pump cover 12 can be managed with high accuracy, and the clearance of the impeller 15 gradually changes to deteriorate the pump characteristics. Can be reliably prevented. In addition, since the disc portion 12a of the pump cover 12 is pressed against the annular portion 13b of the pump base 13 with a sufficient axial force, there is no gap between the annular portion 13b and the disc portion 12a. The airtightness of the pump chamber 14 can be improved. As a result, it is possible to improve the discharge amount of the fuel pump 1 and thus improve the characteristics of the fuel pump 1.

  In the fuel pump 1 having this configuration, the stator 9 is integrally fixed to the housing 2, one end of the shaft 10 b is attached to the bearing 4 of the end cover portion 2 b, and the other end of the shaft 10 b is the cylinder of the housing 2. The shaft 10b, the pump base 13, and the pump cover 12 are all coaxial with each other through the bearing 17 provided on the pump base 13 press-fitted into the shaped portion 2a and supported by the flat bearing 18 of the pump cover 12. The accuracy has been put out. Thereby, the inclination with respect to the axial direction of the shaft 10b is small, high coaxiality between the stator 9 and the rotor 10 can be ensured, and high coaxiality between the motor part M and the pump part P can be realized.

The female screw part 7 may be attached to the cylindrical portion 2a of the housing 2 by, for example, press-fitting assembly or heat fusion. However, the housing 2 is molded on the stator 9 and both are integrally formed. At the same time, the female screw part 7 may be integrally formed. Thereby, in the molding process of the housing 2, the female screw part 7 can be assembled at the same time, so that it is not necessary to provide a separate assembling process and productivity can be improved. Further, since the housing 2 and the female threaded part 7 are integrally formed, there is no gap between the housing 2 and the female threaded part 7, so that the assembly accuracy of the pump chamber 14 (the pump base 13 and the pump cover is high). 12), and the fuel does not leak from the gap between the cylindrical portion 2a of the housing 2 and the female threaded part 7. Therefore, the airtightness of the fuel pump 1 can be improved and high pump performance can be realized. .

  As described above, the fuel pump according to the first embodiment does not require large-scale equipment or work for crimping or heating a conventional cylindrical member for forming a housing at the time of manufacture. It can be assembled easily and has excellent productivity.

  In addition, since the cylindrical member that covers the outer shell of the fuel pump, which was necessary in the past, is no longer necessary, it is possible to reduce the weight of the fuel pump, reduce the number of parts, and reduce the amount of material used. A pump can be provided.

  Furthermore, even when using a motor with a long or short axial dimension in order to change the discharge flow rate of the fuel pump, it is not necessary to change the cylinder member and the pump chamber as in the conventional case. As a result, when manufacturing a plurality of types of fuel pumps, it is not necessary to prepare a plurality of types of cylindrical members as in the prior art, thereby reducing management costs. In addition, when the number of manufactured types varies greatly, the cost of the cylindrical member may vary greatly, but this can be solved by using the present invention.

  The following modifications can be considered for the fuel pump 1 having the configuration of the first embodiment (FIGS. 1 to 4).

Modification 1
As shown in FIG. 5, the female thread component 7 for constituting the female thread mechanism portion 6 not only forms a thread on the radially inner peripheral surface but also forms a thread-shaped groove 7a on the outer peripheral surface. May be. With such a configuration, when the female screw part 7 is integrally formed with the cylindrical part 2a of the housing 2, the groove 7a exhibits an anchor effect, so that it can be firmly fixed and the cylindrical part 2a. Since it is difficult for a gap to be formed between the female screw part 7 and the female screw part 7, high assembly accuracy of the pump chamber 14 (coaxiality between the pump base 13 and the pump cover 12) can be realized. In addition, since fuel does not leak from the gap between the cylindrical portion 2a of the housing 2 and the female screw part 7, the airtightness of the fuel pump 1 can be improved and high pump performance can be realized.

  5 is not limited to the case where the thread-shaped groove 7a is formed on the outer peripheral surface of the female screw part 7, but is integrated with the housing 2 such as forming a groove by forming a notch in a part of the outer peripheral surface. Any shape can be used as long as the anchor effect at the time of molding can be enhanced.

Modification 2
Further, in order to prevent loosening of the screwed portion of the pump cover 12 due to vibration or the like during use of the fuel pump 1, as shown in FIG. 6, the female screw provided on the cylindrical portion 2 a of the housing 2 as shown in FIG. After screwing on the component 7, the screw thread portion 7 b may be formed by crushing the thread of the portion where the female screw component 7 is exposed to the outside along the axial direction.

  In this way, even if vibrations or fuel pressure fluctuations occur during use of the fuel pump 1, no loosening occurs at the screwing location, so that changes in the clearance of the impeller 15 can be suppressed. Moreover, since the said effect can be implement | achieved by the easy process of crushing a screw thread, a large-scale installation is unnecessary and it is excellent in productivity.

  Here, the thread removal part 7b is formed by crushing all the threads of the female screw part 7 that are exposed to the outside along the axial direction. If it is a form which can suppress, the same effect is produced.

Modification 3
In order to prevent loosening of the screwed portion of the pump cover 12 due to vibration or the like during use of the fuel pump 1, after screwing the pump cover 12 to the cylindrical portion 2a of the housing 2, as shown in FIG. A bent portion 7c that is bent inward in the radial direction may be formed by caulking a portion where the female screw part 7 is exposed to the outside along the axial direction.

  By adopting such a configuration, it is possible to prevent loosening at the screwing portion as described in the second modification example, and thus the clearance of the impeller 15 can be maintained with high accuracy over a long period of time.

Modification 4
In the configuration shown in FIG. 1, the pump cover 12 is integrally formed with a disc portion 12 a and a projecting portion 12 b that projects from the disc portion 12 a toward the opening end side of the housing 2. A configuration as shown in FIG.

  That is, the pump cover 12 shown in FIG. 8 includes a disc portion 12a having a male screw portion 12e formed on the outer peripheral surface thereof, and a projecting portion 12b projecting from the disc portion 12a toward the opening end side of the housing 2 in the axial direction. In addition, an annular portion 12h is integrally formed along the outer peripheral portion of the disc portion 12a and protruding in the axial direction toward the pump base 13.

  With such a configuration, the male screw part 12 e of the pump cover 12 is screwed to the female screw part 7, so that the annular part 12 h of the pump cover 12 abuts on the annular part 13 b of the pump base 13. The axial position of the annular portion 12 h is positioned by the annular portion 13 b of the pump base 13. Thereby, the clearance of the impeller 15 in the pump chamber 14 is ensured with high accuracy.

  In addition, in this case, the place where the pump base 13 and the pump cover 12 are in contact with each other is the opposing surfaces of the annular portions 13b and 12h of both, and the area of contact with each other is limited. Therefore, when tightened with the same axial force, the surface pressure (axial force / abutting area) applied to the abutting surface is equal. However, in the pump cover 12 shown in FIG. 8, the rigidity of the pump cover 12 at the portion that receives the axial force is increased by the height of the annular portion 12h as compared with the configuration shown in FIG. Since the deformation of the cover 12 is suppressed, the influence of the clearance of the impeller 15 can be suppressed. Further, since the rigidity of the pump cover 12 is increased, a higher axial force can be applied without deforming the pump cover 12. As a result, it is possible to improve the discharge amount of the fuel pump 1 and thus improve the characteristics of the fuel pump 1.

Embodiment 2. FIG.
9 is a longitudinal sectional view of the fuel pump according to the second embodiment of the present invention, FIG. 10 is a plan view of the pump base viewed from the impeller side of the fuel pump of FIG. 9, and FIG. 11 is from the impeller side of the fuel pump of FIG. It is the top view of the pump cover which looked. In addition, the same code | symbol is attached | subjected to the component corresponding to the fuel pump of Embodiment 1. FIG.

  The fuel pump 1 according to the second embodiment is characterized in that an annular portion 13b of the pump base 13 has a positioning projection 13g protruding toward the pump cover 12 side. The disc cover 12a of the pump cover 12 is formed with a positioning recess 12g into which the positioning protrusion 13g is fitted at a location facing the positioning protrusion 13g provided on the annular portion 13b of the pump base 13.

  Also, in the case of the second embodiment, the pressure grooves 12c, 13e, the discharge holes 13f, and the suction holes 12d are maintained in the same positional relationship as in the case of the first embodiment. The length of 13e, the positions where the suction holes 12d and the discharge holes 13f are formed, and the positions where the positioning convex portions 13g of the pump base 13 and the positioning concave portions 12g of the pump cover 12 are formed are adjusted in advance.

  Further, the male screw portion as in the first embodiment is not formed on the outer peripheral surface of the disc portion 12a of the pump cover 12, and the outer peripheral surface of the disc portion 12a and the cylindrical portion 2a of the housing 2 are locked. The outer diameter of the disk portion 12a is slightly smaller than the inner diameter of the cylindrical portion 2a of the housing 2 so that a slight gap is formed between the inner peripheral surface located on the opening end side of the portion 2e. Is formed.

  Further, in the second embodiment, a disk-shaped push plate 21 that closes the open end of the cylindrical portion 2a of the housing 2 is provided. The push plate 21 is formed with a through hole 21a that passes through the protruding portion 12b of the pump cover 12 and exposes the suction hole 12d to the outside, and the outer peripheral surface of the push plate 21 serves as a female screw mechanism portion 6 provided in the housing 2. A male screw portion 21 b that is screwed into the female screw component 7 is formed.

  When manufacturing the fuel pump 1 having the above configuration, first, when the housing 2 is insert-molded, the stator 9 of the motor 8 is also molded at the same time, and the housing 2 and the stator 9 are integrated. Then, the rotor 10 is inserted from the open end side of the cylindrical portion 2a of the housing 2, and one end side of the shaft 10b is attached to the bearing 4 provided on the end cover portion 2b.

  Next, the pump base 13 is press-fitted from the open end side of the tubular portion 2a of the housing 2 with the annular portion 13b facing the pump cover 12 side. At that time, the shaft 10b is inserted through a bearing provided at the center of the bottom plate portion 13a. Subsequently, the shaft 10b extended through the pump base 13 is inserted into the engagement hole 15b of the impeller 15 to fix the impeller 15 to the shaft 10b.

  Next, the pump cover 12 is fitted from the open end side of the cylindrical part 2a of the housing 2, and the positioning convex part 13g provided in the annular part 13b of the pump base 13 is fitted into the positioning concave part 12g provided in the disk part 12a. Then, the pump cover 12 and the pump base 13 are positioned, and the other end of the shaft 10b is attached to the flat bearing 18. Here, by fitting the positioning convex portion 13g to the positioning concave portion 12g, the radial and circumferential positions of the pump base 13 and the pump cover 12 are accurately positioned.

  Finally, after the protruding portion 12b of the pump cover 12 is inserted into the through hole 21a of the push plate 21, the male screw portion 21b is screwed to the female screw component 7 provided in the cylindrical portion 2a of the housing 2.

  As described above, in the first embodiment, the pump base 13 is directly pressed by the pump cover 12 by the male screw portion 12e of the pump cover 12 being screwed to the female screw part 7, and the locking portion of the housing 2 is thus engaged. In the second embodiment, the pump base 13 is indirectly pressed by the pump cover 12 when the male screw portion 21b of the push plate 21 is screwed to the female screw component 7 in the second embodiment. And is locked to the locking portion 2e of the housing 2.

  In that case, since the pump base 13 and the pump cover 12 are positioned in a state in which the opposing surfaces of the bottom plate portion 13a and the disc portion 12a are parallel to each other, the pump base 13 and the pump cover 12 are positioned. Should the male screw part 21b of the push plate 21 be screwed to the female screw part 7 provided on the cylindrical part 2a of the housing 2, even if the push plate 21 is slightly inclined due to the position of the screw, There is no local deformation of the pump cover 12, and the clearance of the impeller 15 in the pump chamber 14 can be managed with high accuracy. Therefore, the clearance can be easily managed by the dimensional accuracy of components such as the pump base 13, the pump cover 12, and the impeller 15.

  In the configuration of the first embodiment, the male screw part 12e of the pump cover 12 is precisely cut in advance so that the male screw part 12e of the pump cover 12 is screwed to the female screw part 7 so that the pump The discharge hole 13f of the base 13 and the position of the start end 12s of the pressure groove 12c of the pump cover 12, and the start end 13s of the pressure groove 13e of the pump base 13 and the suction hole 12d of the pump cover 12 are coaxial in the axial direction. There was a need to match to be on top.

On the other hand, in the second embodiment, the positioning of the pump base 13 and the pump cover 12 in the radial direction and the circumferential direction is performed by fitting the positioning convex portion 13g of the pump base 13 with the positioning concave portion 12g of the pump cover 12. Since it can be easily achieved with high accuracy, the threading accuracy of the male screw portion 21b of the push plate 21 can be relaxed.
Since other configurations and operational effects are the same as those in the first embodiment, detailed description thereof is omitted here.

  The following modifications can be considered for the fuel pump 1 having the configuration of the second embodiment (FIGS. 9 to 11).

Modification 1
Also in the second embodiment, as described as the first modification (FIG. 5) of the first embodiment, a thread-shaped groove is formed on the outer peripheral surface of the female screw component 7 for constituting the female screw mechanism portion 6. Alternatively, the anchor effect when integrally formed with the housing 2 can be made, such as forming a groove by forming a cut in a part of the outer peripheral surface of the female screw part 7.
The effect in that case is the same as that described in the first modification of the first embodiment, and detailed description thereof is omitted here.

Modification 2
Also in the second embodiment, as in the case of the second modification of the first embodiment (FIG. 6), in order to prevent loosening of the screwed portion of the push plate 21 due to vibration or the like during use of the fuel pump 1. After the pressing plate 21 is screwed to the female screw part 7 provided on the cylindrical portion 2a of the housing 2, the screw thread of the part where the female screw part 7 is exposed to the outside along the axial direction is crushed, or one of the screw threads The screw may be prevented from being loosened by damaging the part.
The effect in that case is the same as that described in the second modification of the first embodiment, and detailed description thereof is omitted here.

Modification 3
Also in the second embodiment, as in the case of the third modification (FIG. 7) of the first embodiment, in order to prevent loosening of the screwed portion of the push plate 21 due to vibration or the like during use of the fuel pump 1. 12, after the pressing plate 21 is screwed to the cylindrical portion 2 a of the housing 2, the internal thread component 7 is radially inward by caulking the portion exposed to the outside along the axial direction. The bent portion 7c may be formed by bending toward it.
The effect in that case is the same as that described in the third modification of the first embodiment, and detailed description thereof is omitted here.

Modification 4
Also in the second embodiment, as in the case of the fourth modification of the first embodiment (FIG. 8), the pump cover 12 is configured from the disk portion 12a to the opening end side of the housing 2 from the disk portion 12a. The protruding portion 12b protruding may be integrally formed, and the annular portion 12h protruding in the axial direction toward the pump base 13 along the outer peripheral portion of the disc portion 12a may be integrally formed.
The effect in that case is the same as that described in the fourth modification of the first embodiment, and detailed description thereof is omitted here.

Embodiment 3 FIG.
13 is a longitudinal sectional view of a fuel pump according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the component corresponding to the fuel pump of Embodiment 1. FIG.

  The feature of the fuel pump 1 of the third embodiment is that the housing 2 is configured by integrally forming the cylindrical portion 2a and the end cover portion 2b by molding as in the first and second embodiments. Rather, a cylindrical casing 22 and an end cover 23 that is a separate body and closes one opening end of the casing 22 in the axial direction are provided.

  The end cover 23 is made of an insulating mold resin (for example, polyacetal (POM) or polyphenylene sulfide (PPS)). The end cover 23 is provided with a discharge hole 23a and is provided with a power supply terminal 3, a bearing 4, and a check valve 5. The configuration thereof is the same as that in the first embodiment.

  The casing 22 is made of, for example, steel, and is crimped so that one opening end side on the end cover 23 side is bent inward in the radial direction to form a crimping stop portion 22e. As a result, even when the fuel pressure in the fuel pump 1 fluctuates, the crimping portion 22e provides the effect of preventing the end cover 23 from being detached and the effect of improving the airtightness by suppressing the leakage of the fuel pump 1.

  In addition, the casing 22 has a female screw portion 22 a in which a screw thread is formed on the inner peripheral surface of the other opening end opposite to the end cover 23. Further, an annular locking portion 22b protruding inward in the radial direction is formed in a part of the casing 22, and one opening end side (end cover 23 side) in the axial direction sandwiching the locking portion 22b is formed. ) Is a motor part M, and the other opening end side (the pump cover 12 side) is partitioned as a pump part P.

  In the motor unit M, the motor 8 including the stator 9 and the rotor 10 is housed in the casing 22, and one end side in the axial direction of the iron core 9 a constituting the stator 9 is the locking portion of the casing 22. The position in the axial direction is positioned by being locked by 22b. The configuration of the motor 8 is the same as that in the first embodiment.

  The pump part P includes a pump cover 12 that closes the other opening end of the casing 22 in the axial direction, and a pump base 13 that is interposed between the pump cover 12 and the motor part M in the axial direction. A pump chamber 14 is formed inside the cover 12 and the pump base 13. In the pump chamber 14, one end side of the shaft 10b of the rotor 10 extends through the pump base 13, and an impeller 15 is fixed to the extending portion of the shaft 10b.

  Here, the pump base 13 is integrally formed with a disc-shaped bottom plate portion 13a and an annular portion 13b that protrudes in the axial direction toward the pump cover 12 along the outer peripheral portion of the bottom plate portion 13a. It has a bottom cylindrical shape, and a part of the outer periphery of the bottom plate portion 13a is cut out along the circumferential direction to form a step portion 13c.

The outer diameter of the outer peripheral surface of the step portion 13 c is formed to be substantially the same as the inner diameter of the locking portion 22 b of the casing 22, while the outer diameter of the annular portion 13 b is the locking portion 22 b of the casing 22. It is formed so as to be slightly smaller than the inner diameter located on the pump cover 12 side. Therefore, in a state where the pump base 13 is fitted to the casing 22, the opposing surfaces of the stepped portion 13 c and the locking portion 22 b of the casing 22 come into contact with each other, whereby the pump base 13 is locked to the locking portion of the casing 22. It is locked to 22b. As a result, the pump base 13 is accurately positioned at the radial and axial positions, and is kept airtight so that fuel does not leak from the motor unit M.
Since the other structure of this pump base 13 is the same as that of Embodiment 1, detailed description is abbreviate | omitted here.

  Further, the pump cover 12 has a male screw portion 12 e formed on the outer peripheral surface of the disc portion 12 a, and this male screw portion 12 e is screwed to a female screw portion 22 a provided in the casing 22. Since the configuration of the pump cover 12 is the same as that of the first embodiment, detailed description thereof is omitted here.

  When the fuel pump 1 having the above configuration is manufactured, first, the end cover 23 is insert-molded with respect to the stator 9 of the motor 8 so that the stator 9 and the end cover 23 are integrated. Then, the end cover 23 in which the stator 9 is integrated is press-fitted from one opening end side of the casing 22. As a result, one end portion of the stator 9 in the axial direction is locked to the locking portion 22 b of the casing 22. In this state, the casing 22 and the end cover 23 are further integrated by crimping the opening end portion of the casing 22 on the end cover 23 side to form the crimping stop portion 22e.

  On the other hand, the rotor shaft 10 b is inserted from the other open end side of the casing 22, and one end side of the shaft 10 b is attached to the bearing 4 provided on the end cover 23. Next, the pump base 13 is press-fitted with the annular portion 13b facing the pump cover 12 side. At that time, the pump base 13 is locked to the locking portion 22 b of the casing 22 by the mutually facing surfaces of the step portion 13 c of the pump base 13 and the locking portion 22 b of the casing 22 abutting each other. Thereby, each position of the radial direction of the pump base 13 and the circumferential direction is positioned. Further, the shaft 10b is inserted through the bearing 17 provided at the center of the bottom plate portion 13a.

  Next, the shaft 10b extended through the pump base 13 is inserted into the engagement hole 15b of the impeller 15 to fix the impeller 15 to the shaft 10b. Finally, the male screw portion 12e of the pump cover 12 is screwed to the female screw portion 22a of the casing 22, and the other end side of the shaft 10b is attached to the flat bearing 18.

  As described above, in the fuel pump 1 according to the third embodiment, the opposed surfaces of the step portion 13c of the pump base 13 and the locking portion 22b of the casing 22 are in contact with each other. Fuel leakage is prevented. Further, since the disc portion 12a of the pump cover 12 is pressed against the annular portion 13b of the pump base 13 with a sufficient axial force, the clearance of the impeller 15 can be ensured with high accuracy, and the annular portion 13b and the disc portion are also secured. Since no gap is generated between 12a, the airtightness of the pump chamber 14 can be improved. As a result, it is possible to improve the discharge amount of the fuel pump 1 and thus improve the characteristics of the fuel pump 1.

  Moreover, in the fuel pump 1 of the third embodiment, since all components such as the stator 9, the rotor 10, and the impeller 15 are housed in the casing 22, the rigidity of the fuel pump 1 itself can be improved. The fuel pump 1 with low vibration and low noise can be provided.

Further, the end cover 23 in which the stator 9 is integrated is press-fitted into the casing 22, and one end of the shaft 10 b is attached to the bearing 4 of the end cover 23, and the other end of the shaft 10 b is the same as the inside of the casing 22. The shaft 10 b, the pump base 13, and the pump cover 12 are all adjusted to be coaxial with each other through the bearing 17 of the pump base 13 that is press-fitted into the shaft and supported by the flat bearing 18 of the end cover 23. Yes. Thereby, the inclination with respect to the axial direction of the shaft 10b is small, high coaxiality between the stator 9 and the rotor 10 can be ensured, and high coaxiality between the motor part M and the pump part P can be realized.
In the case of the configuration of the third embodiment, the assembly of the pump chamber 14 by a screw mechanism can also be adopted for the fuel pump with a brush.
Since other configurations and operational effects are the same as those in the first embodiment, detailed description thereof is omitted here.

The following modifications can be considered for the fuel pump 1 having the configuration of the third embodiment ( FIG. 13 ).

Modification 1
Also in the third embodiment, as in the case of the second modification of the first embodiment (FIG. 6), in order to prevent loosening of the screwed portion of the pump cover 12 due to vibration or the like during use of the fuel pump 1. As shown in FIG. 14, after screwing the pump cover 12 to the female threaded portion 22a of the casing 22, the female threaded portion 22a is crushed in the axially exposed portion to form a screw removing portion 22c. Or loosening a part of the thread may be prevented.
The effect in that case is the same as that described in the second modification of the first embodiment, and detailed description thereof is omitted here.

Modification 2
In the third embodiment, as in the case of the third modification (FIG. 7) of the first embodiment, in order to prevent loosening of the screwed portion of the pump cover 12 due to vibration or the like during use of the fuel pump 1. 15, after the pump cover 12 is screwed to the female screw portion 22 a of the casing 22, the female screw portion 22 a is directed radially inward by, for example, crimping a portion exposed to the outside along the axial direction. A bent portion 22d that is bent may be formed.
The effect in that case is the same as that described in the third modification of the first embodiment, and a detailed description thereof is omitted here.

Modification 3
Also in the third embodiment, as in the case of the fourth modification of the first embodiment (FIG. 8), as shown in FIG. 16, the pump cover 12 is connected to the disc portion 12a and the disc portion 12a to the shaft. And a projecting portion 12b projecting toward the opening end of the housing in the direction, and an annular portion 12h projecting in the axial direction toward the pump base 13 along the outer periphery of the disc portion 12a. It can be.
The effect in that case is the same as that described in the fourth modification of the first embodiment, and a detailed description thereof is omitted here.

Modification 4
In the third embodiment (FIG. 13), the pump cover 12 is screwed directly to one open end of the casing 22, but the present invention is not limited to this and is the same as in the second embodiment (FIG. 9). The push plate 21 having the above structure is provided, and the pump cover 12 is pressed and fixed to the pump base 13 side by screwing the push plate 21 into the female screw portion 22 a of the casing 22.

In order to employ this configuration, a positioning convex portion is inserted into the pump base 13 and this positioning convex portion is inserted into the pump cover 12 as in the case of the second embodiment with respect to the configuration shown in FIG. Each positioning recess may be formed, and the male screw portion 12e on the outer peripheral surface of the disc portion 12a of the pump cover 12 may be omitted so as to be fitted inside the casing 22.
The operational effects when such a configuration is employed are the combined operational effects of the second embodiment and the third embodiment.

  The present invention is not limited to the configurations of the first to third embodiments described above, and a part of the configurations of the first to third embodiments may be changed without departing from the spirit of the present invention. Or the configuration thereof can be omitted, and the configurations of the first to third embodiments can be combined.

1 fuel pump, 2 housing, 2a cylindrical part, 2b end cover part,
2d discharge hole, 2e locking portion, 6 female screw mechanism, 7 female screw component, 7a groove,
7b Screw removal part, 7c bending part, M motor part, P pump part, 8 motor,
9 Stator, 10 Rotor, 10b Shaft, 12 Pump cover, 12a Disc part, 12b Protruding part, 12d Suction hole, 12e Male thread part, 12h Annular part,
13 pump base, 13a bottom plate part, 13b annular part, 13c step part,
13f Discharge hole, 14 Pump chamber, 15 Impeller, 16 Sealing material, 21 Push plate,
21b Male thread part, 22 Casing, 22a Female thread part, 22b Locking part,
22c Screw removal part, 22d bending part, 23 end cover, 23a discharge hole.

Claims (13)

A fuel pump capable of sucking and boosting fuel and discharging it to the outside,
A tubular part and an end cover part that closes one axially open end of the tubular part are integrally formed, and a part of the tubular part of the housing is directed radially inward. A locking portion protruding in this manner is formed, one end cover side in the axial direction sandwiching the locking portion is partitioned as a motor portion, and the other opening end side is partitioned as a pump portion,
The motor part is configured by housing a motor having a stator and a rotor inside the housing,
The pump part includes a pump cover that closes the other axially open end of the cylindrical part, and a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed, and the pump base Is fitted into the tubular portion of the housing with the annular portion facing the pump cover side and is locked to the axial end surface of the locking portion on the pump cover side, and the pump cover and the A pump chamber is formed inside the pump base, and one end side of the rotor shaft extends through the pump base inside the pump chamber, and an impeller is provided at the extended portion of the shaft. It is configured to be fixed
The pump cover has a suction hole for sucking fuel into the pump chamber, the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor part, and the end cover part has fuel after boosting Each has a discharge hole for discharging
A female screw mechanism portion is provided on the inner peripheral surface of the opening end on the pump cover side of the tubular portion of the housing, while a male screw portion is formed on the outer peripheral surface of the pump cover, and the male screw portion of the pump cover is The fuel pump, wherein the annular portion of the pump base is pressed by an opposing surface on the pump base side of the pump cover by being screwed to the female screw mechanism. A fuel pump capable of sucking and boosting fuel and discharging it to the outside,
A tubular part and an end cover part that closes one axially open end of the tubular part are integrally formed, and a part of the tubular part of the housing is directed radially inward. A locking portion protruding in the direction is formed, one end cover side in the axial direction sandwiching the locking portion is partitioned as a motor portion, and the other open end side is divided as a pump portion, and the motor portion is arranged inside the housing. On the other hand, a motor having a stator and a rotor is housed and configured.
The pump part includes a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed, a push plate that closes an opening on the other end side in the axial direction of the housing, the pump base, and the push plate And the pump base is inserted into the cylindrical portion of the housing with the annular portion facing the pump cover side, and the pump cover of the locking portion. The pump cover is fitted into the cylindrical portion of the housing and faces the annular portion of the pump base. The pump base and the pump cover A pump chamber is formed in the enclosed interior, and one end side of the rotor shaft extends through the pump base inside the pump chamber, and an impeller is fixed to the extending portion of the shaft. Is configured,
The pump cover has a suction hole for sucking fuel into the pump chamber, the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor part, and the end cover part has fuel after boosting And a through hole for exposing the suction hole of the pump cover to the outside, respectively.
A female screw mechanism is provided on the inner peripheral surface of the open end of the cylindrical portion of the housing on the pump cover side, while a male screw portion is formed on the outer peripheral surface of the push plate, and the male screw portion of the push plate is The fuel pump, wherein the annular portion of the pump base is pressed by the opposed surface of the pump cover on the pump base side by being screwed to the female screw mechanism portion. A fuel pump capable of sucking and boosting fuel and discharging it to the outside,
A cylindrical casing; and an end cover that closes one opening end in the axial direction of the casing. A locking portion that protrudes radially inward is formed in a part of the casing, and the locking One end cover side in the axial direction sandwiching the part is partitioned as a motor part and the other opening end side as a pump part,
The motor unit is configured by housing a motor having a stator and a rotor inside the casing.
The pump part has a pump cover that closes the other opening end in the axial direction of the casing, and a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed. The annular portion is fitted into the casing with the pump cover side facing, and is locked to the axial end surface of the locking portion on the pump cover side, and is surrounded by the pump cover and the pump base. A pump chamber is formed inside, and one end side of the shaft of the rotor extends through the pump base inside the pump chamber, and an impeller is fixed to the extending portion of the shaft. ,
The pump cover has a suction hole for sucking fuel into the pump chamber, the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor unit, and the end cover has fuel after boosting. Discharge holes that discharge to the outside are formed respectively.
A female thread portion is formed on the inner peripheral surface of the opening end of the casing on the pump cover side, while a male screw portion is formed on the outer peripheral surface of the pump cover, and the male screw portion of the pump cover is screwed to the female screw portion. Thus, the annular portion of the pump base is pressed by the opposed surface of the pump cover on the pump base side. A fuel pump capable of sucking and boosting fuel and discharging it to the outside,
A cylindrical casing; and an end cover that closes one opening end in the axial direction of the casing. A locking portion that protrudes radially inward is formed in a part of the casing, and the locking One end cover side in the axial direction sandwiching the part is partitioned as a motor part and the other opening end side as a pump part,
The motor unit is configured by housing a motor having a stator and a rotor inside the casing.
The pump part includes a bottomed cylindrical pump base in which a bottom plate part and an annular part are integrally formed, a push plate that closes the other opening end in the axial direction of the casing, the pump base, and the push plate And the pump base is fitted into the casing with the annular portion facing the pump cover, and is fitted to the axial end surface of the locking portion on the pump cover side. The pump cover is fitted into the casing and faces the annular portion of the pump base, and a pump chamber is formed inside the pump base and the pump cover. One end side of the shaft of the rotor extends through the pump base inside the pump chamber, and an impeller is fixed to an extension portion of the shaft.
The pump cover has a suction hole for sucking fuel into the pump chamber, the pump base has a discharge hole for discharging fuel boosted by the impeller to the motor unit, and the end cover has fuel after boosting. A discharge hole for discharging to the outside, and a through hole for exposing the suction hole of the pump cover to the outside are formed in the push plate, respectively.
A female screw portion is formed on the inner peripheral surface of the opening end portion of the casing on the pump cover side, while a male screw portion is formed on the outer peripheral surface of the push plate, and the male screw portion of the push plate is screwed onto the female screw portion. The fuel pump, wherein the annular portion of the pump base is pressed by the opposed surface of the pump cover on the pump base side. 2. The pump cover according to claim 1, wherein an annular portion protruding in an axial direction toward the pump base is formed on an outer peripheral portion of the pump cover, and the annular portion and the annular portion of the pump cover are in contact with each other. The fuel pump according to claim 2. The pump cover is formed with an annular portion protruding in the axial direction toward the pump base at a peripheral portion thereof, and the annular portion of the pump base and the annular portion of the pump cover are in contact with each other. The fuel pump according to claim 3 or claim 4. The said female screw mechanism part is comprised by integrally fixing the cylindrical female screw component by which a screw thread is formed in an internal peripheral surface at the internal peripheral surface side of the said cylindrical part of the said housing. 2,5 fuel pump according to any one of. The fuel pump according to claim 7, wherein a groove is formed in an outer peripheral surface in a radial direction of the female screw part. 9. The fuel pump according to claim 7, wherein the female screw part is formed such that a portion of the housing that is exposed to the outside in the axial direction from the cylindrical portion is bent radially inward. The part of the female screw portion formed at the opening end portion of the casing on the pump cover side that is exposed to the outside in the axial direction is bent toward the inner side in the radial direction. The fuel pump described in 1. The fuel pump according to any one of claims 1, 2, 5, 7, and 8, wherein a portion of the female screw mechanism portion exposed to the outside in the axial direction from the cylindrical portion of the housing is crushed. . The fuel pump according to any one of claims 3, 4, and 6, wherein a threaded portion is crushed in a portion where the female thread portion formed at the opening end portion on the pump cover side of the casing is exposed to the outside in the axial direction. . A seal material is provided between the locking portion formed on the cylindrical portion of the housing and a pump base facing the locking portion. 11. The fuel pump according to any one of 11 above.

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