JPH0311191A - Fuel supply pump - Google Patents

Abstract

PURPOSE:To enhance efficiency of a pump by setting an area of an inlet portion in a suitable range of a channel connected to an inlet hole in the most upstream larger than that of a channel in the downstream of the inlet portion in such a manner as to gradually become smaller toward the downstream. CONSTITUTION:When the first and second impellers 11, 12 of a pump 10 are rotated by the drive of a motor 2, fuel flows into a casing 1 through an inlet hole 25, a first channel 15, a communication hole, a second channel 16 and an outlet hole 30 via a fuel filter 31 so as to be discharged outside from a discharge port 32. There is provided an inlet portion 15a where a channel area gradually becomes larger toward the inlet hole 25 with the variation of a depth of channel grooves 23, 24. A connecting portion 33 of a pump body 17 to the channel groove 23 is formed in a gently curved surface. Therefore, the fuel flowing from the inlet hole 25 into the channel 15 is gradually increased in its pressure without any sharp change in the inlet portion 15a so as to be introduced to the channel on the downstream, thus restraining any generation of cavitation.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a fuel supply pump.

(Prior art) The fuel supply pump is rotatably driven and has an IJ@
at least one impeller having a blade groove of 0; a pump casing surrounding each of the impellers around the blade groove to form a circumferential flow path between the impeller and the blade groove; It is known that the pump part has a rag-type pump part, which has an inlet hole and an outlet hole, which are provided above and below each corresponding to each other, and are arranged at appropriate intervals in the circumferential direction. For example, in a multi-stage type with multiple impellers, the fuel that flows in from the inlet hole of the first stage is pressurized through the circumferential passage of the corresponding impeller, and then passes through the outlet hole of the second stage, i.e. The fuel passes through the second-stage inlet hole, passes through the circumferential flow path of the corresponding impeller, is further pressurized by I11, and then reaches the second-stage outlet hole, that is, the third-stage inlet hole. The pressure is increased one after another and discharged from the exit hole of the final stage.

Conventionally, in this type of pump, the flow path area is always set constant from the inlet hole to the outlet hole in each flow path.
Furthermore, the first-stage inlet hole, which is the fuel intake port, is set to be considerably larger than the flow path area.

(Problems to be Solved by the Invention) In conventional pumps, the area of the fuel flow path is rapidly narrowed from the first-stage inlet hole to the corresponding flow path. For this reason, the flow rate of the fuel changes rapidly, causing a pressure drop, and cavitation occurs, resulting in a decrease in pressure raising performance and a decrease in the flow M, resulting in a disadvantage of poor pump efficiency.

In addition, since the pressure decreases as described above, a large amount of fuel vapor is generated when the pump is avoided to be restarted at the tfA temperature, which has the drawback of poor high-temperature restartability.

(Means for Solving Problem 1) In order to solve the above problem, the fuel supply pump of the present invention is rotatably driven, and has at least one vane groove on the outer periphery.
a pump casing surrounding each of the impellers around the blade grooves to form a circumferential passage between the impeller and the blade groove; A fuel supply pump having an inlet hole and an outlet hole provided above and below and spaced apart from each other in the circumferential direction, the fuel supply pump being continuous with the inlet hole on the most upstream side behind the iyJ inlet hole. The area of the population section in an appropriate range of the flow path is set to be larger than the area of the flow path on the downstream side of the inlet portion, and the area of the inlet portion is set so that it gradually becomes smaller toward the downstream side. It is composed of

(Function) In the fuel supply pump of the present invention, the fuel that flows into the corresponding flow path from the most upstream inlet hole 1 of the inlet holes, that is, the fuel suction port undergoes a rapid change at the inlet of the flow path. The surface pressure gradually builds up without any accompanying movement, and the cod is guided into the flow path of the U'F cod.

(Embodiment) Next, a fuel supply pump according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 7.

In FIG. 1, a motor section 2, only a part of which is shown, is installed inside a cylindrical casing 1.
In 1Ji@, the motor section 2 has an armature 3 and a magnet 4 attached to the inner peripheral surface of the casing 1, and a terminal 5 provided on a cover (not shown) attached to the upper end of the casing 1. The structure is such that the armature 3 is rotated coaxially with the casing 1 by energizing the armature 3 through the casing 1. It should be noted that the configuration of such a motor section 2 is well known, and detailed explanation will be omitted. Further, as the motor section 2, other types than those shown can also be used. The lower part of the shaft 7 of the armature 3 of the motor section 2 is supported via a bearing 9 on a pump cover 8 (constituting a part of a pump casing 14 to be described later) which is caulked to the lower end of the casing 1. The shaft 7 passes through the bearing 9 and extends further downward.

Next, the configuration of the pump section 10 driven by the motor section 2 will be explained. The pump section 10 is of a Wesco type.
A first impeller 11 and a second impeller each having a disc shape are attached to the lower end of the shaft 7 of the rotor 2 at right angles to the shaft 7.
The impeller 12 is on the right. The first impeller 11 and the second impeller 12 have the same configuration, and each has a plurality of blade grooves 13 in the outer periphery of the upper and lower surfaces. Here, the lower end of the shaft 7 has a D-shaped cross section, and the first impeller 11 and the second impeller 12 have corresponding D-shaped holes in their centers so that the shaft 7 has a T! tiii! and the first impeller 1
The first and second impellers 12 are capable of following rotation with respect to the shaft 7 and are movable in the axial direction.

14 is a pump casing that recesses the first impeller 11 and the second impeller 12 to form circumferential 11% i passages 15 and 21st passages 16 around the blade m grooves 13, respectively; More pump body 17. First spacer 18. It is composed of a center plate 19, a second spacer 20, and the pump cover 8 described above, and these are connected to four screws 21 (
(Only one is shown in FIG. 1) are fixed to each other in an overlapping state.

Here, the pump body 17 and the center plate 19 have flow passages 1f 123 and 24, respectively, which form a downward wall surface of the first flow passage 15 on opposing sides.
The spacer 18 forms a wall surface of the first flow path 15 in the radial direction. The pump body 17 also has an inlet hole 25 to the 11th passage 15, that is, a fuel suction port, and the center plate 19 has an outlet hole 25 from the 1'FN passage 15 and a second passage 1.
Communication holes (not shown) which also serve as inlet holes to the inlet holes 6 and 6 are respectively provided, and as shown in FIG. 27 is formed.

Furthermore, the center plate 19 and the pump cover 8 have channel grooves 28 and 29 on opposing sides, respectively, which form the vertical wall surfaces of the second flow channel 16, and the second spacer 20 is arranged in the second flow channel 16. It forms the radial wall of the channel 16.

The pump cover 8 is also provided with an outlet hole 30 for the second flow path 16, and the second spacer 20 is provided with a partition wall (not shown) that partitions the second flow path 16 between the communication hole and the outlet hole 30. It is formed.

Further, a fuel filter 31 is connected to the inlet hole 25 of the first flow path 15, and when the first impeller 11 and the second impeller 12 of the pump section 10 are rotated by the drive IJJ of the motor section 2, the fuel is removed. The fuel flows into the casing 1 from the inlet hole 25 via the fuel filter 31, through the first flow path, the communication hole, and the second flow path 16, and from the outlet hole 30, and from the discharge port 32 provided at the upper end of the casing 1 to the outside. is discharged.

Here, as shown in FIG. 3, the first flow path 15 continuous to the inlet hole 25 has an angle θ (-7
0°) (see FIG. 2), an inlet portion 15a is provided whose flow path area gradually increases as it approaches the inlet hole 25. Such an expansion of the flow path area is achieved by keeping the width of the first flow path 15 constant and changing its height. Such a change in height is such that the passage grooves 23 of the pump body 17 and the passage grooves 24 of the center plate 19, which form the eleventh passage 15, reach the inlet hole 25 at the same ratio and gradually become deeper. This is achieved by forming the upper and lower flow paths of the first impeller 11 in the inlet portion 15a as well.

Changes in the cross-sectional shape in the direction perpendicular to the flow from the inlet portion 15a of the first flow path 15 configured as described above to the flow path portion on the downstream side are sequentially shown in FIGS. 4, 5, and 6. It is shown. Here, FIG. 4 shows the cross-sectional shape of the flow path at the upstream end of the inlet section 15a, FIG. 5 shows the cross-sectional shape of the flow path at the downstream end of the person 1" section 15a, and FIG.
The cross-sectional shape of the downstream flow path is shown, and the flow path area maintains a constant flow path area on the downstream side of the inlet portion 15a and reaches the next stage communicating hole.

Roughly returning to FIG. 3, the continuous portion 33 between the inlet hole 25 and the channel groove 23 of the pump body 17 that forms the first channel 15 is formed into a gently curved shape as shown in the figure. .

Further, as an example of preferable dimensions of the inlet portion 15a of the first flow path 15, for example, the diameter of the inlet hole 25 is 8- and the flow path groove 23.
The width of 4 is 3.6 mg+, and the entrance part 15 shown in FIG.
When the depth of the channel grooves 23 and 24 in the downstream channel section of a is 0.85 mm and the cross-sectional area is 2°1jW2,
The depth of the channel grooves 23 and 24 in the cross section shown in Fig. 4 is 2 taa and the cross-sectional area is 6°2llll, and the depth of the channel grooves 23 and 24 in the cross section shown in Fig. 5 is 1 layer and the cross-sectional area is 2
．． 6 layers m, respectively, and R of the continuous curved surface 133 is set to 1.5 layers m+.

In the fuel pump of this embodiment, the height of the flow path is changed within the range of angle θ (-70°) starting from the inlet hole 25, that is, the depth of the corresponding flow path 23.24 is changed. As a result, an inlet M15a is provided whose flow path area gradually increases toward the artificial hole 25, and a continuous portion 33 with the flow path groove 23 of the pump body 17 is formed in a gently curved shape. From the entrance hole 25, the first
The fuel that has flowed into the flow path 15 gradually increases in pressure at the inlet portion 15a without any sudden changes, and is guided to the downstream flow path.

As a result, the fuel pressure boosting ability is improved and the occurrence of cavitation is suppressed, and pump efficiency is improved as the pump ff1fll is increased.In addition, vapor generation at high temperature startup is suppressed and high temperature startability is improved. It has the advantage of improving.

FIG. 7 shows that the angle (angle in the flow direction of the first magic path 15 starting from the inlet hole 25>(deQ)-pressure (Kg/cj!>) of the fuel supply pump of the first embodiment is different from that of the conventional one. This is shown in comparison with a fuel pump.

The solid line in the figure shows the characteristics of this embodiment, and the broken line shows the characteristics of the conventional example. In this embodiment, there is no pressure drop immediately after the inlet hole 25 (as shown by hunting in the figure) in the conventional example, resulting in smooth pressure increase. is obtained.

Next, a second embodiment of the present invention will be described with reference to FIGS. 8 to 14.

The basic #4 structure of the fuel supply pump of this embodiment is the same as that of the fuel supply pump of the first embodiment, and similar members are given the same reference numerals and their explanations will be omitted.

As shown in FIG. 8, the first channel 1 is continuous with the inlet hole 25.
5, in the range of the first embodiment and the circumferential angle θ (=70'') (see FIG. 9) starting from the inlet hole 25,
An inlet portion 15b whose flow path area gradually increases toward the inlet hole 25 is provided. This expansion of the flow path area is achieved by keeping the height of the first flow path 15 constant and changing its width. This change in width is the first
This is achieved by forming the flow passage grooves 23 of the pump body 17 and the flow passage grooves 24 of the center plate 19, which form the flow passages 15, at the same ratio so that they gradually become wider as they reach the inlet hole 25. Flow path groove 23 at inlet portion 15b
The radially inner edge of the flow path tlt24 gradually moves inward from the radially inner edge of the blade groove 13 of the w11 impeller 11 as it moves toward the inlet hole 25, and the radially outer edge also moves toward the inlet hole 25. It is formed by gradually moving outward.

FIGS. 10 and 11 show changes in the cross-sectional shape in the direction 1'1 angle to the flow from the inlet portion 15b of the first flow path 15 configured as described above to the i-path portion on the downstream side.

These are sequentially shown in FIGS. 12 and 13. Here the first
Fig. 0 shows the cross-sectional shape of the flow path at the Δ mouth portion 15b, Fig. 11 shows the cross-sectional shape of the flow path at a portion adjacent to the downstream side of the inlet hole 25, and Fig. 12 shows the cross-sectional shape of the flow path at the downstream end of the inlet portion 15b. 13 shows the cross-sectional shape of the flow path downstream of the inlet portion 15b, and the flow path area is the same as that of the inlet portion 15b.
On the downstream side, a constant flow path area is maintained to reach the next stage's communication hole.

As described above, in this embodiment, the inlet portion 15 of the first flow path 15.
By changing the width of the corresponding channel grooves 23 and 24, the flow path cross-sectional area of b becomes gradually larger until it reaches the inlet hole 15.
The fuel that has flowed into the first flow path 15 from the inlet hole 25 gradually increases in pressure without any sudden change in the population portion 15b and is guided to the downstream flow path.

Therefore, as in the first embodiment, the valve pressure capacity of the fuel is increased, suppressing the occurrence of cavitation υ1, increasing the outflow of the cylinder 7 and improving the pump efficiency. This has the advantage that the occurrence of is suppressed and high-temperature startability is improved.

In addition, especially in the inlet portion 15b of this embodiment, as shown in FIG. The pressure difference in IXl between the flow path section of 2511IJ and the flow path section on the opposite side disappears, and the pressure increases at the inlet section 1.
5b has the advantage of being carried out smoothly on both sides of the first impeller 11.

FIG. 14 shows that the angle (angle in the flow direction of the 12i passage 15 starting from the inlet hole 25) (deg) - pressure (KV/-) characteristic of the fuel supply pump of the second example is different from that of the conventional fuel. This is shown in comparison with a pump. The solid line in the figure shows the characteristics of this embodiment, and the broken line shows the characteristics of the conventional example. In this embodiment, as in the first embodiment, there is a pressure drop part (not shown in the figure) like the conventional example at the point where the inlet hole 25 directly penetrates. (indicated by hatching) is eliminated and smooth pressure increase is obtained.

Next, a third embodiment of the present invention will be described with reference to FIGS. 15 to 22.

The basic structure of the fuel supply pump of this embodiment is also the same as that of the fuel supply pump of the first embodiment, and similar members are given the same reference numerals and their explanations will be omitted.

FIG. 15 is a second cross-sectional view taken along the line ■-■ of the first embodiment.
As shown in the figure, the first flow path 15 continuous to the inlet hole 25 has an angle θ (-70") similar to h1 with respect to the first embodiment starting from the inlet hole 25. ), an inlet portion 15c is installed in which the channel area gradually increases as it approaches the inlet hole 25. Such an increase in the channel area is due to both the height and width of the first channel 15. 11.Here, the change in the height direction is such that the flow groove 23 of the pump body 17 forming the first flow passage 15 and the flow groove 24 of the center plate 19 are the same. By forming the groove so that it gradually becomes deeper until it reaches the inlet hole 25 at a ratio of
This is achieved by forming the inlet holes 1 and 4 at the same ratio so that they gradually become wider until they reach the inlet hole 25.
5b, the radially inner edges of the flow grooves 23 and 24 gradually move inward than the radially inner edges of the blade grooves 13 of the first impeller 11 toward the inlet hole 25, and , the radially outer edge is also formed to gradually move outward.

In addition, as shown in FIG. 16, the inlet hole 25 and the first flow path 1
A continuous portion 34 of the pump body 17 forming the flow path groove 23 is formed into a gently curved shape.

Inlet f'J11 of the first flow path 15 configured as described above
Figures 17 and 18 show changes in the cross-sectional shape in the direction perpendicular to the flow from 5c to the downstream flow path.

The water is sequentially shown in FIGS. 19 and 20. Here the first
7 shows the cross-sectional shape of the flow path at the inlet hole 25, and FIG. 18 shows the cross-sectional shape of the flow path at a portion adjacent to the downstream side of the inlet hole 25.
FIG. 19 shows the cross-sectional shape of the flow path at the downstream end of the inlet portion 15c, and FIG. 20 shows the cross-sectional shape of the flow path downstream of the inlet portion 15c.
A constant flow path area is maintained on the downstream side of c and reaches the next stage communicating hole.

Further, in the inlet portion 15c of this embodiment, as in the second embodiment, the width W between the tip of the first impeller 11 and the first spacer 18 at the inlet hole 25 is is large, so there is no pressure difference between the flow path portion on the artificial hole 25 side and the flow path portion on the opposite side, and the pressure is increased smoothly on both sides of the first impeller 11 at the inlet portion 15C. This embodiment is a combination of the configuration of the first embodiment and the configuration of the second embodiment.
The cross-sectional area of the flow path 5c competes with the inlet hole 15 and gradually increases, and the fuel that flows into the first flow path 15 from the inlet hole 25 gradually increases in pressure without a sudden change. and is guided to the downstream flow path.

Therefore, as in the first embodiment and the second actual IM example, the fuel pressure boosting ability is improved, the occurrence of cavitation is suppressed, and the pump efficiency is improved as the number of pump flow ports increases. This has the advantage that the generation of vapor at the time of starting is suppressed and high startability is improved.

Further, in particular, in this embodiment, since the flow path area of the inlet portion 15c is expanded in both the height direction and the width direction, it is possible to greatly expand the flow path area. Therefore, the advantages enumerated above are further improved, and in particular, the flow characteristics are significantly improved.

FIG. 21 shows that the angle (angle in the flow direction of the first flow path 15 starting from the inlet hole 25) (deQ)-pressure (Ky/ci) characteristic of the fuel supply pump of the third embodiment is different from that of the conventional fuel. This is shown in comparison with a pump. In the figure, the solid line indicates the characteristics of this embodiment, and the broken line indicates the characteristics of the conventional example. In this embodiment, as in the first and second embodiments, there is a pressure drop portion immediately after the inlet hole 25 as in the conventional example. (indicated by hatching in the figure) disappeared, and the first example and the second example
A smoother pressure increase can be obtained compared to the case of AVA.

Further, FIG. 22 shows the discharge pressure P <Kl/d>-flow mQ <j/[1] in the fuel supply pump of the third embodiment.
The characteristics are shown in comparison with a conventional fuel pump. F7!
4. The solid line shows the characteristics of this embodiment, and the broken line shows the characteristics of the conventional example.The fuel supply pump of this example shows a remarkable increase in flow ω at the same discharge pressure compared to the conventional pump.

(Effects) In the fuel supply pump of the present invention, the fuel that flows into the corresponding flow path from the fuel suction port gradually flows into the downstream flow path without any sudden change in the artificial part of the flow path. This improves the fuel pressure boosting ability and suppresses the occurrence of cavitation, which increases the pump flow rate and improves the pump efficiency.Furthermore, the generation of vapor during hot starts is suppressed, improving high temperature startability. Toshisada will improve.

In addition, in all of the above embodiments, two impellers were prepared.
Although the description has been made regarding a stage-type fuel supply pump, the same structure can be applied to a single-stage fuel supply pump having a single impeller or a fuel supply pump having three or more impellers.

[Brief explanation of the drawing]

1 to 7 show a first embodiment of the present invention, FIG. 1 is a vertical sectional view of a fuel supply pump, and FIG.
-■ line sectional view, Figure 3 is the ■-m line sectional view of Figure 2,
The figure is a sectional view taken along the line IV - + V in Fig. 2, Fig. 5 is a sectional view taken along the v-V line in Fig. 2, and Fig. 6 is a sectional view taken along the line Vr - VI Jl in Fig. 2.
The cross-sectional view, FIG. 7, shows the starting point of the inlet hole of the flow path that is continuous with the inlet hole on the most upstream side of the pump section shown in FIGS. 1 to 6.
Figures 8 to 14 show the second embodiment of the present invention, and Figure 8 shows a longitudinal cross-section of the fuel supply pump. Front view, No. 9
The figure is a sectional view taken along the line IX-XX of FIG. 8, FIG. 10 is a sectional view taken along the XX line of FIG. 9, FIG. 11 is a sectional view taken along the XJ-XX line of FIG. 9, and FIG. Xll-Xll line sectional view,
Figure 13 is a sectional view taken along the line Xllll-X1ll in Figure 9,
Figure 4 shows the seventh fuel supply pump shown in Figures 8 to 13.
15 to 22 show the third embodiment of the present invention, and FIG. 15 is a sectional view corresponding to FIG. 2 of the v5Fl supply pump, and FIG. 16 is a sectional view corresponding to FIG. Figure 15 XV
I-XVI 1llFii711.117aH1m1
Figure 5 (7) XV[I-XVIIlil sectional view, No. 18
The figure is a sectional view taken along the line XVIII-XVIII in Figure 15.
Figure 9 is the XIX-XIX @% view of Figure 15, No. 20
The figure is a sectional view taken on the line XXXX of Fig. 15, Fig. 21 is a characteristic diagram similar to Fig. 7 of the fuel supply pump shown in Figs. Discharge pressure P (Kg/ci) of the fuel supply pump shown in −Flow 1a (II/
h) A diagram showing characteristics in comparison with a conventional example. 10... Pump part 14... Pump casing 11... First impeller 12... Second impeller 13... Vane groove 15... First flow passages 15a, 15b, 15c... Inlet part 16...Second flow path 25...Inlet hole

Claims (1)

[Claims] At least one impeller that is rotationally driven and has a plurality of blade grooves on its outer periphery, and a pump casing that surrounds each of the impellers around the blade grooves to form a circumferential flow path between the impeller and the blade grooves. and an inlet hole and an outlet hole provided in the pump casing above and below each of the flow passages and arranged at appropriate intervals in the circumferential direction, the fuel supply pump comprising: The area of the inlet portion of the appropriate range of the flow path that is continuous with the most upstream inlet hole among the inlet holes is set to be larger than the area of the flow path downstream of the inlet portion, and the area of the inlet portion is A fuel supply pump characterized in that the fuel supply pump is set to gradually become smaller as it reaches the downstream side.