JPH0710072Y2 - Trochoid type fuel pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a trochoid type fuel pump provided with measures for suppressing the pulsation of fuel pumped from a trochoid pump section.

[Conventional technology]

A conventional trochoid fuel pump will be described with reference to FIGS. 4 to 8.

In the figure, reference numeral 1 denotes a tubular casing main body having a fuel discharge passage inside, and 2 denotes an upper cover for covering the upper end side of the casing main body 1.

Reference numeral 3 denotes a trochoid pump portion which is provided in a lower portion of the casing main body 1, covers the lower end side of the main body 1, and is driven by a motor portion 12 described later to suck fuel in a fuel tank (not shown). Then, the trochoid pump unit 3 is
A lower cover 4 which serves as a lower backing plate for the pump portion 3 and has a suction port 4A and a relief port 4B for sucking fuel.
And a pump housing 5 provided in contact with the upper surface of the lower cover 4 and having an eccentric circular pump chamber 5A,
An outer rotor 6 rotatably mounted in the pump chamber 5A of the pump housing 5 and having 11 inner teeth 6A, an inner rotor 7 mounted in the outer rotor 6 and having 10 outer teeth 7A, and an outer rotor. 6 and the inner rotor 7, the upper plate 8 that contacts the upper surface of the pump housing 5 and seals the inside of the pump chamber 5A of the pump housing 5, the lower cover 4, the pump housing 5, and the upper plate 8 are integrated. And a bolt 9 for fixing it physically. A fixed shaft 10 is provided on the lower cover 4, and an inner rotor 7 is rotatably attached to the fixed shaft 10. The inner rotor 7 is formed with an engagement hole 7B into which three engagement claws 20A of the motor section 12 described later are inserted so as to drive the inner rotor 7 to rotate.

The number of outer teeth 7A of the inner rotor 7, that is, ten, is set under the following conditions. The volume of the plurality of fuel pumping chambers 11 defined by the inner teeth 6A of the outer rotor 6 and the outer teeth 7A of the inner rotor 7 can be increased as the number of the inner teeth 6A and the outer teeth 7A is decreased to increase the discharge amount. However, the pulsation at the time of fuel discharge becomes large. On the other hand, if the number of the internal teeth 6A and the external teeth 7A is increased and the volume of the fuel pumping chamber 11 is reduced, the pulsation is reduced, but the discharge amount is reduced. The number of outer teeth 7A of the inner rotor 7 is set in consideration of the above two conditions.

Reference numeral 12 denotes a motor portion that is provided between the upper cover 2 and the trochoid pump portion 3 and is provided in the casing body 1, and drives the trochoid pump portion 3. The motor portion 12 has a yoke 13 in the casing body 1. A pair of stators fixed via
14, 14 and a rotor 1 rotatably arranged on each stator 14.
It is composed of 5 and. Here, the rotor 15
Is an armature 16 rotatably supported on the inner circumference of the stator 14 and a coil wound around the armature 16.
It is composed of 17 and. Reference numeral 18 denotes a support shaft that is inserted into the armature 16 and rotatably supports the armature 16. The support shaft 18 has its upper end rotatably or fixedly supported in an engagement hole 2A provided in the upper cover 2. And is arranged so as to hang down in the axial direction. Reference numeral 19 denotes a flange portion fixedly provided on the upper part of the armature 16 so as to pass through the support shaft 18. Is provided. Reference numeral 20 denotes a tubular portion fixedly provided at a lower portion of the armature 16. The tubular portion 20 is rotatably fitted to the fixed shaft 10 and is provided at a lower end portion thereof on the inner rotor 7 of the trochoid pump portion 3. Engaging claws 20A to be inserted into the formed engaging holes 7B are provided.

Reference numeral 21 is a flat commutator for supplying power to the coil 17 of the rotor 15, and the flat commutator 21 is a substantially circular circle formed of a plurality of fan-shaped segments 21A, 21A, ... It is formed in a plate shape. 22,2
2 is a pair of brush sliding holes 2 provided in the upper cover 2
A pair of brushes slidably inserted into B and 2B and having a lower end side in sliding contact with each segment 21A of the flat commutator 21, and each brush 22 supplies power to the coil 17 of the rotor 15 via the commutator 21. It is like this.

In the conventional trochoidal fuel pump configured as described above, each brush 22 is energized from the external wiring (not shown), and the coil 17 of the rotor 15 is energized via the commutator 21 slidingly contacting each brush 22. As a result, the rotor 15 rotates, and the inner rotor 7 is driven to rotate via the engagement claw 20A and the engagement hole 7B of the tubular portion 20. Then, the rotation of the inner rotor 7 causes the outer rotor 6 rotatably mounted in the pump chamber 5A of the pump housing 5 to rotate, and the inner teeth 6A
And the volume of each fuel pumping chamber 11 defined by the external teeth 7A is changed, the fuel is sucked from the suction port 4A,
After being discharged into the casing body 1, the upper cover 2 passes through the outer circumference of the collar portion 19 to which the commutator 21 is attached.
It is pumped to the outside from the discharge port 2C.

[Problems to be Solved by the Invention] By the way, in the above-mentioned conventional technique, the trochoid pump portion 3 for pumping fuel is provided with the ten outer teeth 7A on the outer circumference of the inner rotor 7 of the pump portion 3 as shown in FIG. In addition, since the pulsation is generated 10 times in one cycle, the vibration due to the pulsation causes resonance of the fuel pipe and the like, which causes abnormal noise.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a trochoid fuel pump that suppresses pulsation generated in the trochoid pump unit and prevents generation of abnormal noise due to resonance.

[Means for Solving the Problems]

The structure adopted by the present invention to solve the above-mentioned problems is a cylindrical casing body having a fuel discharge passage inside, a trochoid pump portion provided in the casing body, and a motor for driving the pump portion. A stator that is provided inside the casing body, and a rotor that is rotatably provided inside the stator and that drives a trochoid pump unit that is located at one axial end. A trochoidal fuel pump comprising a flat commutator provided at the other axial end of the rotor for supplying electric power to a coil of the rotor, and a pair of brushes slidably contacting the flat commutator, the outer periphery of the flat commutator An agitating member is provided on the agitator to agitate the fuel passing around the flat commutator, and the fuel is pressed from the trochoid pump section into the casing body. In that a configuration of suppressing the pulsation of the time being.

[Action]

With the above configuration, when the fuel pumped with pulsation from the trochoid pump section passes through the casing body and around the flat commutator, the stirring member agitates the fuel to suppress the pulsation.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. The overall structure of the trochoidal fuel pump of this embodiment is substantially the same as that of the above-described conventional technique, and therefore, the same members are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 31 is a rotor according to the present embodiment, and the rotor 31 includes an armature 32 and an armature 32 as in the prior art.
And a coil 33 wound around. 34 is a flange portion provided on the upper part of the armature 32, in which a substantially disk-shaped flat commutator 35 formed by combining a plurality of fan-shaped segments 35A, 35A, ... Is embedded like the prior art. The whole is formed in a disk shape, and an annular recess 34A for fixedly supporting the flat commutator 35 is formed on the upper surface thereof. Further, a turbine portion 36 as an agitating member for agitating the fuel passing around the collar portion 34 is integrally formed on the outer peripheral edge portion of the collar portion 34. The turbine section 36 is a collar section.
Blades 36A, 36B formed on the upper and lower sides of the outer peripheral edge of 34
The blade portions 36A and 36B are configured to stir the fuel passing around the collar portion 34.

The shape and the number of blades 36A and 36B of the turbine unit 36 are set under the following conditions.

The rotor 31 drives the trochoid pump part 3 and at the same time rotates the collar part 34 attached to the rotor 31,
The pulsation cycle generated in the trochoid pump unit 3 is synchronized with the rotation of the turbine unit 36. Therefore, the pulsation generated in the trochoid pump unit 3 is set to have a shape and number that can most effectively suppress the pulsation.

The trochoid fuel pump according to this embodiment is constructed as described above, and its operation will be described below. The operation of the entire trochoidal fuel pump is not different from that of the above-described conventional technique, and therefore its description is omitted here.

When the trochoid pump unit 3 is driven, the fuel is pressure-fed in the casing body 1 to the upper end side with pulsation, and passes through the outer periphery of the collar unit 34 in which the flat commutator 35 is embedded. At this time, the fuel passing through the turbine portion 36 at the outer peripheral edge of the collar portion 34 is agitated to suppress the pulsation thereof to a small level.

Here, using specific numerical values as an example, the magnitude of fuel pulsation by the trochoidal fuel pump of the related art (8th
In the figure, ΔP ′) was about 0.1 kg / cm, but in the trochoid fuel pump of this example, the pulsation magnitude (ΔP in FIG. 3) was about 0.03 kg / cm. Was reduced to.

As a result, the fuel pipe connected to the trochoidal fuel pump resonates, and the fuel pipe and the plate portion to which the fuel pipe is attached resonate with each other to prevent abnormal noise (resonance) from occurring. can do.

In the above embodiment, as the stirring member, the turbine portion 36 in which the blade portions 36A and 36B are formed on both upper and lower outer peripheral portions of the collar portion 34 is used, but the present invention is not limited to this. Any other shape such as a screw propeller may be used as long as it can stir the fuel passing through the outer peripheral edge of the flange 34.

[Effect of device]

As described in detail above, according to the present invention, a stirring member is provided on the outer periphery of the flat commutator to stir the fuel passing around the flat commutator to suppress the pulsation generated in the trochoid pump section. By suppressing the pulsation of the fuel pumped from the section, it is possible to significantly reduce the generation of abnormal noise due to the resonance of the fuel pipe or the like.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention. FIG. 1 is a perspective view showing a rotor including a collar portion for fixing and supporting a flat commutator, and FIG. 2 is a longitudinal sectional view of the rotor of FIG. 3 and 4 are characteristic diagrams showing the relationship between the rotor cycle of the trochoidal fuel pump and the fuel pressure, FIGS. 4 to 8 relate to the prior art, and FIG. 4 is a longitudinal section of the trochoidal fuel pump. 5 and FIG. 5 are longitudinal sectional views as seen from the direction of the arrows VV in FIG. 4, FIG. 6 is a bottom view of the trochoidal fuel pump of FIG. 4, and FIG. 7 is VII- of FIG. FIG. 8 is a sectional view as seen from the direction of the arrow VII, and FIG. 8 is a characteristic diagram showing the relationship between the cycle of the trochoid fuel pump rotor and the fuel pressure. DESCRIPTION OF SYMBOLS 1 ... Casing body, 3 ... Trochoid pump part, 12 ... Motor part, 14 ... Stator, 15 ... Rotating, 22 ... Brush, 31 ... Rotor, 34 ... Collar part, 35 ... Flat commutator, 36 ... Turbine (stirring) Element).

Claims (1)

[Scope of utility model registration request] 1. A cylindrical casing body having an interior serving as a fuel discharge passage, a trochoid pump portion provided in the casing body, and a motor portion for driving the pump portion, the motor portion comprising: A stator provided in the casing body, a rotor rotatably provided in the stator, which drives a trochoid pump portion located at one end in the axial direction, and a coil of the rotor to be supplied with electric power. In a trochoidal fuel pump comprising a flat commutator provided at the other axial end of the rotor and a pair of brushes slidingly contacting the flat commutator, a stirring member is provided on the outer periphery of the flat commutator, The fuel passing through the surroundings is agitated to suppress the pulsation when the fuel is pressure-fed in the casing body from the trochoid pump section. Trochoid fuel pump characterized by and.