JP4177602B2 - Turbine type fuel pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a turbine type fuel pump suitably used for supplying fuel to, for example, an injection valve of a vehicle engine.
[0002]
[Prior art]
In general, a vehicle such as a passenger car is equipped with an electronically controlled fuel injection device for supplying fuel to the engine. The fuel injection device includes an injection valve that injects fuel toward the combustion chamber of the engine, The fuel tank etc. which are provided in the rear part etc. are comprised with the fuel pump etc. which discharge and supply the fuel in the fuel injection valve toward the said injection valve.
[0003]
Further, as the fuel pump, a turbine type fuel pump provided with an impeller is widely used. The turbine type fuel pump includes a cylindrical casing that houses an electric motor, an upper cover provided at one end of the casing, and the other casing so as to support the electric motor between the upper cover. A pump housing provided on an end side and having an annular fuel passage between a fuel suction port and a discharge port; and the suction port that is rotatably provided in the pump housing and rotated by the electric motor And an impeller that pumps the fuel sucked from the fuel passage toward the discharge port.
[0004]
The impeller is formed in a disc shape, and blades extending in the radial direction of the impeller are arranged in the circumferential direction on the outer peripheral side thereof. Then, by rotating the impeller blades in the fuel passage, the fuel can be pumped toward the discharge port.
[0005]
Here, the impeller blades are parts that are greatly related to the efficiency of fuel discharge, so-called pump efficiency. For example, in Japanese Patent Laid-Open No. 7-189773 (hereinafter referred to as the prior art), the front surface of each blade By providing chamfers and the like at the corners of the side surfaces and at the corners of the rear and side surfaces, the fuel is smoothly flowed around the blades to obtain good pump efficiency.
[0006]
[Problems to be solved by the invention]
By the way, the above-described conventional turbine type fuel pump has chamfered portions formed at the front and side corners of the blades provided at the impeller, and at the rear and side corners.
[0007]
However, in the impeller according to the prior art, only a chamfered portion is formed for a plurality of blades, so there is a possibility that vortex flow may occur around the blades, and good pump efficiency cannot always be obtained. There's a problem.
[0008]
The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a turbine type fuel pump that can smoothly flow fuel around blades and improve pump efficiency. There is to do.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, the blades arranged on the outer peripheral side of the impeller extend in the radial direction of the impeller, the front surface located on the front side in the rotational direction of the impeller, the rear surface located on the rear side in the rotational direction, and the front surface A plate-like body having a substantially square cross section consisting of a pair of side surfaces located between the rear surfaces, and at the base side of each blade, the corners between the side surfaces and the rear surface are cut diagonally. A chamfered portion that is formed and extends in the radial direction of the impeller is provided, and a length dimension H of the chamfered portion is (2/5 to 3/5) × L with respect to a radial dimension L of the fuel passage provided in the pump housing. The chamfered portion is substantially constant over a range of dimension (1/5 to 4/5) × H from the root side end portion with respect to the length dimension H of the entire chamfered portion. A root chamfer formed with a chamfer width and the root chamfer The front end side chamfering portion is formed by gradually reducing the chamfering width from the front end side of the portion .
[0010]
As a result, when the impeller blades are rotated in the fuel passage, the fuel that has flowed in between the blades at the suction port flows out into the fuel passage from the front end side between the blades due to centrifugal force. The fuel flows into the base side between the blades, and by repeating such a flow, the fuel becomes a swirl flow and is pumped through the fuel passage toward the discharge port.
[0011]
At this time, the chamfered portion provided on the base side of the blade has a length H in the range of (2/5 to 3/5) × L with respect to the radial dimension L of the fuel passage, that is, in the fuel passage. Is formed so as to extend to almost the center position when the fuel flows as a swirling flow, so that the chamfered portion smoothly flows the fuel to the base side between the blades corresponding to the flow of the fuel that has become the swirling flow. Can be allowed to flow into. Therefore, eddy currents can be prevented from occurring around each blade by the chamfered portion, fuel flow resistance can be reduced, and pump efficiency can be improved.
[0012]
Moreover, the chamfered portion with respect to length H of the entire chamfer, which is formed with a substantially constant chamfer width over a range of dimensions (1 / 5~4 / 5) × H from its root end Since the base side chamfered portion and the tip side chamfered portion formed by gradually reducing the chamfering width from the tip side of the base side chamfered portion, the root side chamfered portion is formed from the root side of the blade. The fuel can smoothly flow between the blades, and the resistance of the fuel can be reduced. The tip side chamfered portion can smoothly connect the rear surface, side surface, and root side chamfered portion of the blade, and can smoothly flow the fuel therebetween.
[0014]
Further, according to the invention of claim 2 , since the base side chamfering portion is formed with an inclination angle of 30 to 70 degrees with respect to the side surface, the angle when the fuel flows between the blades and the base side chamfering portion. Therefore, the fuel can flow along the root chamfered portion, and the flow resistance of the fuel can be reduced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a turbine type fuel pump according to an embodiment of the present invention will be described in detail with reference to FIGS.
[0016]
In the figure, reference numeral 1 denotes a cylindrical casing constituting the outer shell of the fuel pump. The casing 1 is closed at both axial ends by a discharge cover 2 and a pump housing 9 which will be described later.
[0017]
Reference numeral 2 denotes a covered cylindrical discharge cover provided on one end side of the casing 1, and the discharge cover 2 is provided with a discharge port 2A and a connector portion 2B protruding upward as shown in FIG. 2 is provided with a bearing cylinder 2 </ b> C extending downward.
[0018]
3 is a check valve for maintaining the residual pressure provided in the discharge port 2A. The check valve 3 is opened by the fuel flowing through the casing 1 when the electric motor 7 described later rotates, and this fuel is It is allowed to be discharged from the discharge port 2A into an external fuel pipe (not shown). The check valve 3 is closed when the electric motor 7 is stopped, and the fuel in the fuel pipe is prevented from returning inside the casing 1, thereby maintaining the fuel pipe in a predetermined residual pressure state. It is.
[0019]
Reference numeral 4 denotes a bush provided to be fitted in the bearing cylinder 2C of the discharge cover 2, and reference numeral 5 denotes a bush provided to be fitted in a stepped hole 12D of the inner housing 12 to be described later. A bearing that rotatably supports a rotating shaft 6 to be described later is configured.
[0020]
Reference numeral 6 denotes a rotating shaft that is pivotally supported between the discharge cover 2 and the pump housing 9 via bushes 4 and 5. The rotating shaft 6 is formed in the casing 1 along the axis OO shown in FIG. It extends in the direction, and supports a rotor 7B and the like of an electric motor 7 described later so as to be rotatable in the casing 1. Further, as shown in FIG. 3, a chamfered portion 6 </ b> A is formed on the lower end side of the rotating shaft 6 to be fitted to an impeller 17 described later in a non-rotating state.
[0021]
Reference numeral 7 denotes an electric motor housed in the casing 1, and the electric motor 7 is located between the discharge cover 2 and the pump housing 9 and is fitted in the casing 1, and is a stator made of a permanent magnet. A cylindrical yoke 7A that supports a rotor (not shown), a rotor 7B and a commutator 7C that are inserted inside the yoke 7A with a gap and are attached to the rotary shaft 6 so as to rotate integrally therewith, and the commutator It is comprised by a pair of brush (not shown) etc. which slidably contact 7C.
[0022]
When the electric motor 7 is supplied with power to the rotor 7B via the connector portion 2B of the discharge cover 2, the brush, and the commutator 7C, the rotor 7B rotates integrally with the rotary shaft 6, thereby causing an impeller described later. 17 is driven to rotate at a speed of about 5000 to 8000 rpm, for example.
[0023]
Reference numeral 8 denotes a fuel passage formed between the yoke 7A and the rotor 7B of the electric motor 7, and the passage 8 receives fuel discharged into the casing 1 from a discharge port 14 of a pump housing 9 described later. Then, it is circulated to the discharge cover 2 side through a gap between the yoke 7A and the rotor 7B.
[0024]
9 is a pump housing provided on the other end (lower end) side of the casing 1, and the pump housing 9 is configured by abutting an outer housing 10 and an inner housing 12, which will be described later, in the upward and downward directions, An impeller 17 described later is rotatably provided inside.
[0025]
Reference numeral 10 denotes an outer housing of the pump housing 9, and the outer housing 10 is attached to the lower end side of the casing 1 in a fitted state using means such as caulking as shown in FIGS. It is blocked from. The outer housing 10 is integrally formed with a fuel inlet 11.
[0026]
Further, the outer housing 10 is formed with a circular recessed portion 10A on the axial center (axis OO) side, and the outer housing 10 has a circumferential direction around the axis OO at a position on the outer peripheral side of the impeller 17. An arc groove 10B having a substantially semicircular cross section is formed.
[0027]
Reference numeral 12 denotes an inner housing provided on the upper side of the outer housing 10, and the inner housing 12 is fitted and attached in the casing 1 in a state of being abutted with the outer housing 10. Further, as shown in FIG. 2, the inner housing 12 is formed as a flat covered cylindrical body by a cylindrical portion 12A that is a cylindrical peripheral wall and a lid portion 12B that covers the cylindrical portion 12A from the upper side. The inner peripheral side of 12 </ b> A is a circular turbine accommodating recess 13 that opens to the abutting surface 12 </ b> C side with the outer housing 10.
[0028]
Further, a fuel passage 15 (described later) is formed in the cylindrical portion 12A so as to be located on the inner peripheral side thereof. Further, a stepped hole 12D into which the bush 5 is inserted is formed in the lid portion 12B, and a discharge port 14 (shown by a two-dot chain line in FIGS. 1 and 2) is formed upward and downward on the outer peripheral side. It is extended and drilled.
[0029]
An annular fuel passage 15 is formed in the pump housing 9 and is located on the outer peripheral side of the turbine housing recess 13. The fuel passage 15 includes an arc groove 10B of the outer housing 10 as shown in FIGS. In addition, the passage is configured as a longitudinally long C-shaped passage extending in the circumferential direction around the position of the axis OO (axial center O).
[0030]
Here, the fuel passage 15 is formed in an arc shape at both ends in the upper and lower directions, and the fuel flows while turning along the arc shape as indicated by arrows in FIG. The vicinity of the center position of the part is the passage center C when the fuel is pumped in the fuel passage 15. The position of the passage center C of the fuel passage 15 with respect to the radial dimension L about the axis O from the inner diameter side end portion 15A to the outer diameter side end portion 15B of the fuel passage 15 is the inner diameter side end portion 15A. The distance dimension L1 is about ½ of the distance.
[0031]
The start end side of the fuel passage 15 communicates with the suction port 11, and the terminal end side communicates with the discharge port 14. The fuel passage 15 has a suction passage portion 15 </ b> C at the start end side, and the suction passage portion 15 </ b> C smoothly guides the fuel sucked from the suction port 11 into the fuel passage 15.
[0032]
Reference numeral 16 denotes a seal partition provided on the cylindrical portion 12A side of the inner housing 12, and the seal partition 16 protrudes from the cylindrical portion 12A of the inner housing 12 to a position close to the outer periphery of the impeller 17, as shown in FIG. It is formed as an arc-shaped convex part. The seal partition 16 seals the outer peripheral side of the impeller 17 between the suction port 11 and the discharge port 14 to compensate for the fuel sucked from the suction port 11 flowing along the fuel passage 15. it can.
[0033]
Next, reference numeral 17 denotes an impeller according to the present embodiment. The impeller 17 is formed in a substantially disc shape by, for example, a reinforced plastic material, and is rotatably provided in the turbine housing recess 13 of the pump housing 9. The impeller 17 is rotated in the direction indicated by the arrow A in FIG. 3 by the electric motor 7, thereby pumping the fuel sucked from the suction port 11 toward the discharge port 14 from the fuel passage 15.
[0034]
Further, the impeller 17 is provided with a fitting hole 18 in which the rotating shaft 6 is fitted at the rotation center (axis line OO), and a plurality of, for example, three transparent holes are provided around the fitting hole 18. A hole 19 is provided. Further, as shown in FIGS. 5 and 6, a large number of blades 20, 20,... Extending in the radial direction of the impeller 17 are arranged in the circumferential direction on the outer peripheral side of the impeller 17. Further, a pair of arc-shaped recesses 21, 21 are provided between each blade 20 so as to form a mountain shape, and these arc-shaped recesses 21 substantially correspond to the arc shape of the fuel passage 15 in the pump housing 9. It is formed with curvature.
[0035]
The impeller 17 is float-sealed between the upper surface of the outer housing 10 and the lower surface of the lid portion 12B of the inner housing 12 in the turbine housing recess 13. In this state, the electric motor 7 is integrated with the rotary shaft 6. It is rotationally driven by. Further, each through hole 19 of the impeller 17 has a function of equalizing the fuel pressure and the like between the recessed portion 10 </ b> A of the outer housing 10 and the stepped hole 12 </ b> D side of the inner housing 12.
[0036]
Here, as shown in FIG. 5 and FIG. 6, each blade 20 includes a front surface 20 </ b> A located on the front side in the rotational direction of the impeller 17 (arrow A direction), a rear surface 20 </ b> B located on the rear side in the rotational direction, and the front surface 20 </ b> A. It is formed as a plate-like body having a substantially square cross section composed of a pair of side surfaces 20C, 20C located between the rear surfaces 20B.
[0037]
Further, the blade 20 has a straight blade portion 22 whose root side extends linearly in the radial direction of the impeller 17, and a curved blade portion whose front end side is curved in an arc shape toward the front side in the rotation direction of the impeller 17 (arrow A direction). 23. And the linear blade | wing part 22 and the curved blade | wing part 23 are each formed in the length dimension of the half of the full length of the blade | wing 20 respectively.
[0038]
24 and 24 are a pair of chamfered portions provided on the base side of each blade 20, and each chamfered portion 24 is an angle between the side surface 20C and the rear surface 20B, as shown in FIGS. The corners are formed so as to be cut obliquely and extend in the radial direction of the impeller 17. Further, the overall length dimension H of the chamfered portion 24 is substantially the same as the distance dimension L1 from the inner diameter side end portion 15A to the passage center C of the fuel passage 15, that is, with respect to the radial dimension L of the fuel passage 15. It is set to dimension (2/5 to 3/5) × L as shown in the following equation (1).
[0039]
[Expression 1]
2/5 ≦ (H / L) ≦ 3/5
[0040]
Further, the overall length C of the chamfered portion 24 is a dimension (9/20 to 11/20) × L as shown in the following equation 2 in the range of H / L set in the above equation 1. It is preferable to set the range.
[0041]
[Expression 2]
9/20 ≦ (H / L) ≦ 11/20
[0042]
Furthermore, the length dimension H of the entire chamfered portion 24 within the range of the above formulas (1) and (2) is optimally a place having a value of ½ of the radial dimension L of the fuel passage 15. As a result, the chamfered portion 24 is formed to extend to the passage center C, which is the central position when the fuel swirls and flows in the fuel passage 15, so that the fuel flows smoothly between the blades 20. Can be best exhibited.
[0043]
Further, the chamfered portion 24 has a substantially rectangular base side chamfered portion 24A formed on the base side and having a substantially constant chamfered width, and the chamfered width is gradually reduced from the front end side of the root chamfered portion 24A. It is comprised by the substantially triangular front-end | tip side chamfer 24B formed in this way.
[0044]
The base side chamfer 24A is cut out with a substantially constant chamfering width so that the fuel smoothly flows into the blades 20 from the root side of the blades 20 to reduce the resistance of the fuel. Further, the front end side chamfer 24B gradually reduces the chamfer width toward the front end side, thereby smoothly connecting the rear surface 20B and the side surface 20C of the blade 20 and the root side chamfer 24A. The fuel flows smoothly.
[0045]
Here, the shape of the root side chamfer 24 </ b> A constituting the chamfer 24 will be described in detail. First, the base side chamfer 24A sets the inclination angle α with respect to the side surface 20C of the blade 20 shown in FIG. 7 within a range of 30 to 70 degrees as shown in the following equation (3).
[0046]
[Equation 3]
30 ≦ α ≦ 70
[0047]
Further, the inclination angle α set in the above equation 3 is preferably set in the range of 40 to 60 degrees as in the following equation 4.
[0048]
[Expression 4]
40 ≦ α ≦ 60
[0049]
Further, the base side chamfer 24A is set such that the length H1 with respect to the total length H of the chamfer 24 shown in FIG. 4 is set to a dimension (1/5 to 4/5) × H as shown in the following formula 5. Yes.
[0050]
[Equation 5]
1/5 ≦ (H1 / H) ≦ 4/5
[0051]
Further, the length dimension H1 of the base side chamfer 24A is a dimension (2/5 to 3/5) × H as shown in the following expression 6 in the range of H1 / H set in the above expression 5. It is preferable to set in the range.
[0052]
[Formula 6]
2/5 ≦ (H1 / H) ≦ 3/5
[0053]
The turbine type fuel pump according to the present embodiment has the above-described configuration. Next, the operation thereof will be described.
[0054]
First, when power is supplied from the outside through the connector portion 2B of the discharge cover 2, the electric motor 7 rotates the rotor 7B integrally with the rotary shaft 6 by supplying a drive current to the rotor 7B, and the pump housing 9, the impeller 17 is driven to rotate. Then, by rotating the impeller 17, the fuel in the fuel tank (not shown) is sucked into the fuel passage 15 from the suction port 11 and is pumped along the fuel passage 15 by the blades 20 of the impeller 17. , Discharged from the discharge port 14 into the casing 1.
[0055]
Thus, the fuel that has flowed into the casing 1 flows through the casing 1 toward the discharge cover 2 via the passage portion 8 and the like, and opens the check valve 3 in the discharge port 2A. For example, a discharge pressure of 200 to 500 kPa (kilopascals) and a discharge flow rate of 30 to 200 L / h (liters) are discharged from the discharge port 2A to an injection valve (none of which is shown) on the engine body via an external fuel pipe. Per hour).
[0056]
Here, as a result of intensive studies on the inclination angle α of the root chamfer 24A with respect to the side surface 20C of the blade 20, the inventors have a range of 30 to 70 degrees as shown in the equation (3), preferably the equation (4). As shown in FIG. 8, it was confirmed that a high pump efficiency as shown by the characteristic line shown in FIG. 8 was obtained under the conditions of a discharge pressure of 300 kPa and a discharge flow rate of 80 L / h.
[0057]
In this case, the ratio of the length dimension H1 of the base side chamfer 24A to the total length H of the chamfer 24 is about ½. As a result, the inclination angle α of the root side chamfer 24A can be made substantially the same as the angle at which the fuel flows from the side 20C side to the rear surface 20B side of the blade 20, and the fuel is moved along the root chamfer 24A. It can flow smoothly and reduce resistance.
[0058]
Further, as a result of earnest research on the ratio of the length dimension H1 of the base side chamfer 24A to the total length dimension H of the chamfer 24, the ratio of the length dimension H1 of the root chamfer 24A to the total length H of the chamfer 24 (H1 / H) is set to a numerical value range of 1/5 to 4/5 as shown in the formula 5, preferably 2/5 to 3/5 as shown in the formula 6. Was 300 kPa and the discharge flow rate was 80 L / h, and it was confirmed that high pump efficiency was obtained as indicated by the characteristic line shown in FIG.
[0059]
In this case, the inclination angle α of the base side chamfer 24A with respect to the side surface 20C of the blade 20 is about 50 degrees. As a result, the root chamfered portion 24A can suppress a vortex that tends to occur on the root side of the blade 20 by a large notch of a certain width, and can reduce resistance when the fuel flows.
[0060]
Furthermore, in the above research results, the tip side chamfered portion 24B whose chamfering width is gradually reduced toward the tip side smoothly connects the rear surface 20B and side surface 20C of the blade 20 and the root side chamfered portion 24A. It has been found that the fuel can smoothly flow from the side surface 20C of the blade 20 toward the base side chamfer 24A and from the base side chamfer 24A toward the rear surface 20B, and high pump efficiency can be obtained.
[0061]
Thus, the ratio (H / L) of the length dimension H of the entire chamfered portion 24 to the radial dimension L of the fuel passage 15 is set to 1/2 which is within the range of 9/20 to 11/20. The inclination angle α of the base side chamfer 24A with respect to the side surface 20C of the blade 20 is set to 50 degrees within the range of 40 to 60 degrees, and the length dimension H1 of the root chamfer 24A relative to the total length H of the chamfer 24 is set. It has been found that the pump efficiency becomes the highest when the ratio (H1 / H) is set to 1/2 which is in the range of 2/5 to 3/5.
[0062]
Therefore, according to the present embodiment, the chamfered portion 24 that is located on the base side of the blade 20 of the impeller 17 and that is formed so as to obliquely cut off the corner between the side surface 20C and the rear surface 20B is provided on the impeller 17. The overall length dimension H extending in the radial direction is set to 9/20 to 11/20 (1/2) with respect to the radial dimension L of the fuel passage 15, and the base side chamfered portion with respect to the side surface 20 </ b> C of the blade 20. The inclination angle α of 24A is set to 40 to 60 degrees (50 degrees), and the length dimension H1 of the base side chamfer 24A is set to 2/5 to 3/5 (1 / 2).
[0063]
As a result, the chamfered portion 24 (the root of the chamfered portion 24 (the root of the chamfered portion 24) corresponds to the position when the fuel flows into the blades 20 from the fuel passage 15 and the size and angle necessary for the fuel to flow smoothly). The position and length of the side chamfer 24A) and the inclination angle of the root chamfer 24A can be set.
[0064]
As a result, when the impeller 17 is rotated, the chamfered portion 24 causes the fuel to smoothly flow along the root side chamfered portion 24A and the tip side chamfered portion 24B, and resistance when the fuel flows around the blade 20 Therefore, the fuel can be efficiently pumped toward the discharge port 14 in the fuel passage 15 and the pump efficiency can be improved.
[0065]
In the embodiment, the fuel passage 15 is described as an example in which the fuel passage 15 is formed as a vertically long passage having a C-shaped cross section. However, the present invention is not limited to this. For example, as in the first modification shown in FIG. 10, the fuel passage 31 has an annular projecting portion 32 projecting radially inward in an intermediate portion in the upper and lower directions. It is good also as a structure which divides | segments into the back side flow path 33 and the collision side flow path 34 into upper and lower two by providing.
[0066]
Further, in the embodiment, each blade 20 of the impeller 17 has a straight blade portion 22 that extends linearly in the radial direction of the impeller 17 at the root side, and the tip side is curved in an arc shape toward the front side in the rotation direction of the impeller 17. The case where the curved blade portion 23 is used has been described as an example. However, the present invention is not limited to this. For example, as in the blade 41 according to the second modification shown in FIG. 11, the entire configuration from the root side to the tip side may be formed linearly.
[0067]
Furthermore, the blades 20 may be configured so that the entire portion from the base side to the tip side is curved in an arc shape toward the front side in the rotation direction.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a turbine type fuel pump according to an embodiment of the present invention.
FIG. 2 is an enlarged vertical sectional view of a main part showing an enlarged view of a pump housing, an impeller, and the like in FIG.
3 is a cross-sectional view of the inner housing and the impeller as viewed from the direction of arrows III-III in FIG.
4 is an enlarged vertical cross-sectional view of a main part showing an enlarged fuel passage, blades, chamfered portion, etc. in FIG. 2;
FIG. 5 is an enlarged perspective view of the main part showing the impeller blades in an enlarged manner.
FIG. 6 is an enlarged plan view of the main part showing the impeller blades in an enlarged manner.
7 is a cross-sectional view showing impeller blades from the direction of arrows VII-VII in FIG. 6;
FIG. 8 is a characteristic diagram showing the relationship between the inclination angle of the base side chamfer and the pump efficiency.
FIG. 9 is a characteristic diagram showing the relationship between the length of the base side chamfer and the pump efficiency.
10 is an enlarged longitudinal sectional view of a main part of a fuel passage according to a first modification of the present invention as seen from the same position as in FIG. 4;
FIG. 11 is an enlarged perspective view of a main part of a blade of an impeller according to a second modification of the present invention as seen from the same position as in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Casing 2 Discharge cover 6 Rotating shaft 7 Electric motor 9 Pump housing 10 Outer housing 11 Suction port 12 Inner housing 14 Discharge port 15, 31 Fuel passage 15A Inner diameter side edge 15B Outer diameter side edge 17 Impeller 20, 41 Blade 20A Front 20B Rear surface 20C Side surface 24 Chamfered portion 24A Root side chamfered portion 24B Tip side surface chamfered portion OO Axis A Rotation direction of impeller C Fuel passage passage center L Fuel passage radial dimension L1 From inner diameter side end portion to fuel passage passage center Distance dimension to H Length dimension of the entire chamfered part H1 Length dimension of the base chamfered part α Inclination angle of the base chamfered part with respect to the side of the blade

Claims (2)

A cylindrical casing that houses the electric motor, a pump housing that is provided in the casing and has an annular fuel passage between a fuel suction port and a discharge port, and the electric motor that is rotatably provided in the pump housing A turbine-type fuel pump comprising a disk-shaped impeller in which blades that pump fuel in the fuel passage while being rotated by
Each blade of the impeller extends in the radial direction of the impeller, and includes a front surface positioned on the front side in the rotation direction of the impeller, a rear surface positioned on the rear side in the rotation direction, and a pair of side surfaces positioned between the front surface and the rear surface. Formed as a rectangular plate,
And on the root side of each blade, a chamfered portion that is formed by obliquely notching a corner between the side surface and the rear surface and extending in the radial direction of the impeller is provided,
The length dimension H of the chamfered portion is set to a range of (2/5 to 3/5) × L with respect to the radial dimension L of the fuel passage provided in the pump housing .
The chamfered portion is a base side surface formed with a substantially constant chamfer width over a range of dimension (1/5 to 4/5) × H from the base side end with respect to the length dimension H of the entire chamfered portion. A turbine-type fuel pump comprising: a chamfered portion; and a tip side chamfered portion formed by gradually reducing the chamfer width from the tip side of the base side chamfered portion . The turbine-type fuel pump according to claim 1 , wherein the base side chamfered portion is formed with an inclination angle of 30 to 70 degrees with respect to the side surface.

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