KR101138680B1 - Fluid pump - Google Patents

Abstract

(σ'/θ 의 평균)

0.30, 0.15

C'

0.35 를 만족한다. (Problem) Provides a technique for further reducing the sound generated from the fluid pump.
(Solution means) The fuel pump sucks fluid into the pump casing by rotating the impeller and discharges the fluid out of the pump casing. In this fuel pump, the impeller has n wing grooves (n is an integer of 2 or more) formed at its outer peripheral edge. The pitch angles between the wing grooves are nonuniform, and each pitch angle has a pitch angle equal to one or more angles. Pitch angle of vane groove is 0.05

(average of σ '/ θ)

0.30, 0.15

C '

0.35 is satisfied.

Description

Fluid Pump {FLUID PUMP}

In this specification, a technique for reducing sound generated from a fluid pump is disclosed.

BACKGROUND ART Fluid pumps are known which have an impeller having a plurality of wing grooves formed on the outer circumferential edge thereof. In this type of fluid pump, the impeller rotates so that fluid is sucked into the pump casing from the inlet of the pump casing, the sucked fluid is boosted while flowing through the fluid flow path in the pump casing, and the boosted fluid is pumped from the outlet of the pump casing. It is discharged out of the casing. Since the pressure of the fluid in the fluid flow path on the discharge port side is higher than the pressure of the fluid in the fluid flow path on the suction port side, it is necessary to prevent the fluid from flowing from the fluid flow path on the discharge port side toward the fluid flow path on the suction port side. For this reason, a partition wall is formed in the pump casing to isolate the fluid flow path on the discharge port side and the fluid flow path on the suction port side near the outer peripheral edge of the impeller. Therefore, in a fluid pump having an impeller formed at a constant pitch angle, when the impeller rotates, the wing grooves periodically pass through the partition wall. As a result, a loud sound is generated from the fluid pump by the frequency determined by the rotational speed of the impeller and the pitch angle θ of the blade groove. Here, pitch angle (theta) means the angle which the two line segments which respectively connected the center of rotation of the impeller and the center of the circumferential direction of the adjacent blade | wing groove, when an impeller is seen in plan view. In order to solve the said problem, the technique which reduces the sound generated from a fluid pump is developed (for example, patent document 1).

The fluid pump of patent document 1 is provided with the impeller in which pitch angle (theta) of a blade groove is all different, and is formed so that pitch angle (theta) of a blade groove may satisfy | fill predetermined conditions. As a result, a deviation occurs in the period in which the blade passes the partition wall, and the sound of the fluid pump can be reduced.

Japanese Patent Application Laid-Open No. 11-50990

However, also in the technique of the said patent document 1, although noise can be reduced to some extent, the implementation of the technique which can reduce a noise more is desired. The present specification provides a technique for further reducing the sound generated from the fluid pump.

As a result of earnestly examining in order to reduce the sound (sound pressure) generated from the fluid pump, the inventors have found that the sound generated from the fluid pump and the pressure fluctuation of the fluid in the wing grooves are correlated, and thus the sound generated from the fluid pump. In order to reduce the pressure, it was found that reducing the spectral peak value of the pressure fluctuation of the fluid in the wing groove is effective. In addition, the inventors found an index strongly correlated with the spectral peak value of the pressure fluctuation of the fluid, and examined the relationship between the found index and the spectral peak value of the pressure fluctuation, thereby reducing the spectral peak value of the pressure fluctuation. Was specified.

(σ'/θ 의 평균)

0.30, 0.15

C'

0.35 를 만족한다. 단, σ', θ 의 평균 및 C' 는 이하에 정의된다. 또한, 날개 홈의 번호는, 복수의 날개 홈 중 어느 1 개의 날개 홈을 1 번째로 설정하고, 임펠러의 회전 방향 또는 반회전 방향으로 나열되어 있는 순서대로, 승순 (昇順) 으로 설정한다. The technique provided by this specification is a fluid pump which pressurizes a fluid in a pump casing by the rotation of an impeller, and pressurizes and discharges a pressurized fluid out of a pump casing. In this fluid pump, n impeller grooves are formed in the outer peripheral edge of the impeller. When the impeller is viewed from the plane, the line segment connecting the center of rotation of the impeller and the center of the circumferential direction of the wing groove of the i th (integer of i = 1 to n), the center of rotation of the impeller and the i + 1 th (where i + 1 = n + 1 In this case, when the angle formed by the line segments connecting the centers in the circumferential direction of the blade groove of i + 1 = 1) is set to the pitch angle θi, and the difference between the adjacent pitch angles is set to σ i = θi + 1? Θi, the pitch angle θi is In addition to the nonuniformity, at least one pitch angle θk (an integer of k = 1 to n and an integer other than i) is present at each pitch angle θi. And 0.05

(average of σ '/ θ)

0.30, 0.15

C '

0.35 is satisfied. However, (sigma) ', the average of (theta), and C' are defined below. In addition, the number of the blade | wing groove sets the blade groove | channel of any one of several wing groove | channels to 1st, and sets it in ascending order in the order arrange | positioned in the rotation direction or the semi-rotation direction of an impeller.

[Equation 1]

[Equation 2]

&Quot; (3) "

&Quot; (4) "

[Equation 5]

&Quot; (6) "

The inventors found that (average of σ '/ θ) and C' correlate strongly with the spectral peak value of the pressure fluctuation of the fluid in the wing groove. Then, when (average of? '/ Θ) and C' satisfy the above range, it was found that the sound generated from the fluid pump can be reduced as compared with the prior art. Moreover, one or more other pitch angles θk (an integer of k = 1 to n and an integer other than i) are equal to each pitch angle θi (i = 1 to n) of the impeller wing of the impeller described above. Is formed to exist. When there is only one pitch angle θ i, when the impeller rotates, pressure fluctuation occurs by the pitch angle θ i, and the pressure fluctuation by the pitch angle θ i is not reduced. In other words, the sound component due to θ i is not reduced in the pitch angle. On the other hand, when there are a plurality of pitch angles having the same angle, for example, when the pitch angle θi and the pitch angle θk are the same, sound components generated when the wing groove formed by the pitch angle θi passes through the partition wall are different pitch angles θk. It becomes possible to attenuate by the sound component which generate | occur | produces by the wing groove formed in this way through a partition. By satisfying this condition and the above-described conditions (average of? '/ Θ) and C', the noise caused by the specific pitch angle θi can be reduced.

It is preferable that this impeller satisfies 0.1 <(number of pitch angles with the same pitch angle) / n <0.5. According to this configuration, the sound generated from the fluid pump can be reduced without significantly reducing the pump efficiency of the fluid pump.

According to the technology provided by this specification, the sound produced from a fluid pump can be reduced. For example, the fluid pump provided by this specification can be used suitably for the fuel pump which supplies the fuel of an automobile to an engine. This fluid pump is useful for reducing sound in automobiles in which staticity is required.

1 is a longitudinal sectional view of a fuel pump;
FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1. FIG.
3 is a graph showing the correlation between the analysis results and the experimental results.
4 is an isometric view showing the correlation between (average of σ '/ θ) and C' and spectral peak values of pressure fluctuations.
Fig. 5 is an isometric view showing the correlation between the number of vane grooves having the same pitch angle and the spectral peak value of the pressure fluctuation.
6 is an isometric view showing the correlation between the number of vane grooves having the same pitch angle and the pump efficiency.
7 is a graph showing experimental results of negative pressure generated by a fuel pump including an equal pitch impeller.
8 is a graph showing experimental results of sound pressure generated by a fuel pump including an uneven pitch impeller.

Carrying out the invention  Form for

Embodiments embodying the technology provided by the present specification will be described with reference to the drawings. The fuel pump of this embodiment is an automobile fuel pump, used in a fuel tank, and used to supply fuel to an engine of an automobile. As shown in FIG. 1, the fuel pump 10 includes a motor portion 12 and a pump portion 14. The motor part 12 and the pump part 14 are accommodated in the housing 16, and are comprised. The motor unit 12 has a rotor 18. The rotor 18 includes a shaft 20, a laminated iron core 22 fixed to the shaft 20, a coil (not shown) wound around the laminated iron core 22, and an end portion of the coil. Has a commutator 24 connected thereto. The shaft 20 is rotatably supported by the bearings 26 and 28 with respect to the housing 16. Inside the housing 16, the permanent magnet 30 is fixed so as to surround the rotor 18. A terminal (not shown) is formed in the top cover 32 attached to the upper portion of the housing 16, and electricity is supplied to the motor unit 12. When the coil is energized through the brush 34 and the commutator 24, the rotor 18 and the shaft 20 rotate.

(σ'/θ 의 평균)

0.30, 및 0.15

C'

0.35 를 만족하고 있다. 단, σ', θ 의 평균 및 C' 는, 이하에 정의된다. The pump part 14 is accommodated in the lower part of the housing 16. The pump part 14 is equipped with the substantially disk shaped impeller 36. As shown in FIG. As shown in FIG. 2, the through hole 39 is formed in the center of the impeller 36, and the shaft 20 is engaged with the through hole 39 so that relative rotation is impossible. For this reason, when the shaft 20 rotates, the impeller 36 also rotates. At the outer peripheral edge of the impeller 36, n (n = 41) wing grooves 37 are formed. In FIG. 2, the wing groove 37 shown by the wing groove 37 (1) means the 1st wing groove 37. As shown in FIG. Similarly, the wing grooves 37 represented by the wing grooves 37 (2) and 37 (n) mean the second and n (41) -th wing grooves 37, respectively. That is, in this embodiment, the order is set in ascending order from the first wing groove 37 in the order of rotation in the impeller 36 (arrow 60 in the drawing). The n (41) wing grooves 37 are arranged side by side at the outer circumferential edge of the impeller 36, and are arranged at the same time as the outer circumferential edge of the impeller 36. A blade 37a is formed between two adjacent wing grooves 37. That is, in the impeller 36, the wing 37a of the same number as the wing groove 37 is formed. The n (41) wings 37a are all formed in the same shape. The blade groove 37 is formed so that the pitch angle θ between two adjacent blade grooves 37 becomes uneven. The pitch angle θ is 2 in the case where two adjacent blade grooves 37 draw a straight line from the midpoint along the outer circumferential edge of the impeller 36 of each blade groove 37 to the rotation center of the impeller 36. Angle between two straight lines. In the impeller 36, the pitch angles of the i-th wing groove 37 and the i + 1 th wing (i is an integer of 1 to n, where i = n, where i (n) + 1 = 1) When θ i is defined, at least one pitch angle θ m exists that satisfies the pitch angle θ i = θ m (m is an integer of 1 or more, and m ≠ i) in each of i = 1 to n. And also 0.05

(average of σ '/ θ)

0.30, and 0.15

C '

0.35 is satisfied. However, (sigma) ', the average of (theta), and C' are defined below.

Here,? 'Means the standard deviation of the difference? I =? I + 1?? I of the adjacent pitch angles. (average of? '/ θ) is an index for evaluating the deviation of adjacent pitch angles. The larger (average of? '/ θ) is, the larger the deviation of adjacent pitch angles is. (average of? '/ θ) mainly contributes to the loudness of the fundamental frequency ((total number of blade grooves) x (number of rotations of the impeller)). Moreover, C 'is an index which evaluates the deviation of the pitch angle over the perimeter of an impeller. The closer C 'is to 0, the larger the deviation of the pitch angle over the entire circumference of the impeller. C 'mainly contributes to the loudness of frequencies lower than the fundamental frequency.

In addition, the blade groove 37 satisfies 0.1 <(number of pitch angles / number of total wing grooves n (= 41)) <0.5 having the same pitch angle.

The pump casing containing the impeller 36 is composed of a discharge side casing 38 and a suction side casing 40. In the discharge-side casing 38, the groove 38a is formed in the area | region which opposes the outer peripheral edge of the impeller 36. As shown in FIG. The groove 38a opposes the outer circumferential surface of the impeller 36 and the upper surface of the outer circumferential edge. The groove 38a is formed in a substantially C shape extending from the upstream end to the downstream end along the rotational direction of the impeller 36. The discharge side casing 38 is provided with a discharge port 50 extending from the downstream end of the groove 38a to the upper surface of the discharge side casing 38. The discharge port 50 communicates the inside of the pump casing with the outside (the internal space of the motor portion 12).

In the suction side casing 40, the groove 40a is formed in the area | region which opposes the outer peripheral edge of the impeller 36. As shown in FIG. A part of the groove 40a faces the lower surface of the outer circumferential edge of the impeller 36 and is connected to the groove 38a on the outer circumferential side of the impeller 36. Similar to the groove 38a, the groove 40a is formed in a substantially C shape extending from the upstream end to the downstream end in the rotational direction of the impeller 36. The suction side casing 40 is formed with a suction port 42 extending from the lower surface of the suction side casing 40 to an upstream end of the groove 40a. The suction port 42 communicates the inside of the pump casing with the outside (outside of the fuel pump). The pump flow path 44 is formed by the blade | wing groove 37, the groove 38a, and the groove 40a so that the outer peripheral edge of the impeller 36 may be covered.

In the casings 38 and 40, partition walls 41 are formed between the suction port 42 and the discharge port 50. The partition 41 is formed in order to prevent fuel from flowing from the discharge port 50 side toward the suction port 42 side. Therefore, the surface which opposes the outer peripheral edge of the impeller 36 of the partition 41 is compared with the other surface of the casing 38 and 40 which opposes the outer peripheral edge of the impeller 36, and the outer periphery of the impeller 36 It is close to the edge.

When the impeller 36 rotates in the pump casings 38 and 40, fuel is sucked from the intake port 42 into the pump portion 14 and introduced into the pump flow path 44. The fuel boosted while flowing through the pump flow path 44 is sent from the discharge port 50 to the motor portion 12 side. The fuel sent to the motor unit 12 passes through the motor unit 12 and is sent out from the port 48 formed in the top cover 32.

(σ'/θ 의 평균)

0.30, 및 0.15

C'

0.35 를 만족하고 있다. 이 때문에, 연료 펌프 (10) 에서는, 날개 홈의 피치각 θ 이 균일하게 형성되어 있는 임펠러를 구비하는 연료 펌프와 비교하여, 발생하는 소리가 저감된다. In the fuel pump 10, the wing groove 37 of the impeller 36 is 0.05.

(average of σ '/ θ)

0.30, and 0.15

C '

0.35 is satisfied. For this reason, in the fuel pump 10, the sound which generate | occur | produces is reduced compared with the fuel pump provided with the impeller in which pitch angle (theta) of a wing groove is formed uniformly.

Moreover, in the fuel pump 10, the blade groove 37 of the impeller 36 satisfies 0.1 <(number of pitch angles / number of total blade grooves n (= 41)) <0.5. For this reason, in the fuel pump 10, compared with the fuel pump provided with the impeller in which the pitch angle (theta) of a wing groove is formed uniformly, the sound which generate | occur | produces is reduced and the reduction of pump efficiency is suppressed.

In the fuel pump 10, at least one pitch angle θk (i ≠ k) that satisfies the pitch angle θi = θk is present. Thereby, the sound component which arises from the blade | wing groove 37 corresponding to pitch angle (theta) i is attenuated by the blade groove | channel 37 corresponding to pitch angle (theta) k. Thereby, the sound which arises from the blade | wing groove 37 corresponding to pitch angle (theta) i can be reduced.

(Analysis to examine the relationship between the pitch angle of the wing groove and the sound generated from the fuel pump)

Hereinafter, the analysis result performed by the present inventors is demonstrated. First, the analysis result which examined the relationship between the pitch angle (theta) of the blade groove 37 and the sound produced from the fuel pump 10 is demonstrated.

(Determination method of arrangement of pitch angle of wing groove)

First, how to determine the arrangement of the wing grooves 37 of the impeller 36 used in the present analysis will be described. In this analysis, the difference of the number of the blade grooves 37 of the impeller 36, the minimum pitch angle (theta) min, the maximum pitch angle (theta) max, and the pitch angle was determined, and the number for every pitch angle was determined. Table 1 shows an example of the number of pitch angles θ determined when the number of wing grooves 37 is 41, θmin is 8.0 degrees, θmax is 10.5 degrees, and the difference in pitch angles is 0.5 degrees. .

By the above method, 10,000 types of combinations were determined. Subsequently, it was determined how to arrange the pitch angles, that is, the pitch angles in which the number was determined, in the impeller 36. By this method, an array of 100,000 pitch angles was determined on average for each of the above 10,000 combinations. That is, in this analysis, the analysis was performed about the impeller (henceforth pitch pitch impeller) 36 from which the arrangement of 10,000x100,000 pitch angles differs.

(Interpretation method)

In this analysis, first, a CAE analysis was performed on a fuel pump provided with an impeller (hereinafter referred to as an equal pitch impeller) 36 having a wing groove arranged at a uniform pitch angle θ = 7.5 degrees. In this CAE analysis, the pressure variation of the fuel with respect to time was calculated. The pressure fluctuation of the fuel is the time course of the fuel pressure in the blade groove 37 when the blade groove 37 of the impeller 36 passes from the discharge port 50 side of the partition 41 to the suction port 42 side. It means change. Next, using the calculation result of the pressure fluctuation, the pressure fluctuation of the fuel with respect to time in each unequal pitch impeller 36 was computed according to the determined pitch angle arrangement. Specifically, the time axis was adjusted to match the magnitude of the pitch angles arranged, and the pressure waveform when the uneven pitch impeller 36 was rotated one by one was calculated.

Subsequently, FFT (Fast Fourier Transform) analysis was performed on the pressure fluctuation waveform of the fuel over time calculated according to the pitch angle arrangement, and the pressure fluctuation was spectrally resolved to calculate the spectral peak value of the pressure fluctuation.

(Review of Correlation between Analysis and Experiment)

Next, the correlation between the experimental result (measurement result in real product) and the analysis result which performed the said analysis method about the impeller used for the experiment was examined, and the validity of the said analysis method was confirmed. Here, the correlation between the spectral peak value of the pressure fluctuation of the fuel obtained by this analysis and the spectral peak value of the negative pressure generated from the fuel pump 10 obtained in the experiment were examined. 3 is a graph showing a correlation between the spectral peak value of the sound pressure obtained by the experiment and the spectral peak value of the pressure fluctuation obtained by the present analysis. 3 represents the spectral peak value of the pressure fluctuation obtained by this analysis, and the vertical axis | shaft has shown the spectral peak value of the sound pressure obtained by experiment. As can be seen from the graph of FIG. 3, the spectral peak value of the sound pressure obtained in the experiment was almost proportional to the spectral peak value of the pressure fluctuation obtained by the analysis. Moreover, the correlation coefficient of the spectral peak value of the sound pressure obtained by the experiment and the spectral peak value of the pressure fluctuation obtained by analysis was 0.79. As mentioned above, it turned out that the spectral peak value of the sound pressure obtained by experiment and the spectral peak value of the pressure fluctuation obtained by analysis have strong correlation, and could confirm the effectiveness of the said analysis method. Moreover, from the above examination results, it was found that the smaller the spectral peak value of the pressure fluctuation obtained by the analysis, the smaller the sound generated from the fuel pump 10 in the actual product.

(Review of (average of σ '/ θ) and C' for pressure fluctuations)

Next, from the analysis result obtained by this analysis, the correlation of said (average of (σ '/ (theta)) and C') with the spectral peak value of the pressure fluctuation of a fuel was examined. 4 is an isometric diagram showing the relationship between (average of σ '/ θ) and C' and the spectral peak value of the pressure fluctuation. In Fig. 4, the horizontal axis represents (average of? '/ Θ), and the vertical axis represents C'. In FIG. 4, 20-log10 (PI / PR) (where PR is the analysis result (constant value) of the spectral peak value of the pressure fluctuation of the fuel pump 10 provided with the equal pitch impeller 36 mentioned above, PI) Is an analysis result of the value of the spectrum peak value of the pressure fluctuation of the fuel pump 10 provided with the inequality pitch impeller 36).

(σ'/θ 의 평균)

0.30 또한 0.15

C'

0.35 이면, 등피치 임펠러 (36) 를 구비하는 연료 펌프와 비교하여, 압력 변동의 스펙트럼 피크값을 저감시킬 수 있는 것을 알 수 있었다. 이것으로부터, 0.05

(σ'/θ 의 평균)

0.30 또한 0.15

C'

0.35 이면, 연료 펌프 (10) 가 발생하는 소리를 저감시킬 수 있는 것을 알 수 있었다. 도 4 로부터 알 수 있는 바와 같이, 특히, 0.20

(σ'/θ 의 평균)

0.30 또한 0.20

C'

0.30 의 경우, 소리를 저감시키는 효과가 높아지고 있다. As shown in FIG. 4, it was found that the spectral peak value of the pressure fluctuation had a strong correlation with (average of σ '/ θ) and C'. And also 0.05

(average of σ '/ θ)

0.30 or 0.15

C '

When 0.35, it turned out that the spectral peak value of a pressure fluctuation can be reduced compared with the fuel pump provided with the equal pitch impeller 36. From this, 0.05

(average of σ '/ θ)

0.30 or 0.15

C '

If 0.35, it turned out that the sound which the fuel pump 10 generate | occur | produces can be reduced. As can be seen from FIG. 4, in particular, 0.20

(average of σ '/ θ)

0.30 or 0.20

C '

In the case of 0.30, the effect of reducing the sound is increased.

(Review of the number of equivalent pitch angles for pressure fluctuations)

Subsequently, the relationship between the number of equivalent pitch angles and the spectral peak value of the pressure fluctuation of fuel was examined from the analysis result obtained by this analysis. Here, when the number of equal pitch angles is set to N, the minimum value of N is defined as Nmin, and the maximum value is defined as Nmax, Nmin / n (where n = total number of blade grooves) and Nmax / n are used as indexes. The spectral peak value of the variation was evaluated. Taking Table 1 as an example, when pitch angle θ = 8 degrees, N = 5 pieces. Similarly, in the case of pitch angles of 8.5, 9, 9.5, 10, and 10.5 degrees, N = 6, 8, 10, 6, and 4, respectively. In this case, Nmin = 4 and Nmax = 10. FIG. 5: shows the isoline diagram which shows the relationship with the spectral peak value of the pressure fluctuation which arises from the fuel pump 10 using Nmin / n and Nmax / n as an index | index. 5, the horizontal axis represents Nmin / n, and the vertical axis represents Nmax / n. In FIG. 5, the isoline of 20 log10 (PI / PR) value is shown similarly to FIG. Moreover, even if Nmin and Nmax were the same, the spectral peak value (= PI) of a pressure fluctuation might differ by the arrangement | positioning of a pitch angle. For this reason, 20 log10 (PI / PR) was computed employ | adopting the average value of the peak spectrum value of several pressure fluctuations when Nmin and Nmax are the same.

0.5 인 경우에, 20?log10 (PI/PR) 의 값이 작아졌다. 이것으로부터, N/n

0.5 를 만족하는 임펠러 (36) 를 구비하는 연료 펌프 (10) 이면, 등피치 임펠러 (36) 를 구비하는 연료 펌프 (10) 와 비교하여, 압력 변동의 스펙트럼 피크값을 크게 저감시킬 수 있다고 할 수 있다. 즉, 본 해석 결과로부터, N/n

0.5 이면, 연료 펌프 (10) 가 발생하는 소리를 저감시킬 수 있다. As shown in FIG. 5, Nmax / n

In the case of 0.5, the value of 20 log10 (PI / PR) became small. From this, N / n

If it is the fuel pump 10 provided with the impeller 36 which satisfy | fills 0.5, it can be said that compared with the fuel pump 10 provided with the equal pitch impeller 36, the spectral peak value of a pressure fluctuation can be reduced significantly. have. That is, from this analysis result, N / n

If it is 0.5, the sound which the fuel pump 10 generate | occur | produces can be reduced.

(Review of the number of equal pitch angles for pump efficiency)

Then, the relationship between the number of equivalent pitch angles and pump efficiency was examined from the analysis result obtained by this analysis. Here, the pump efficiency of the fuel pump 10 was evaluated using Nmin / n and Nmax / n as an index. FIG. 6 shows an isometric view showing the relationship between the pump efficiency of the fuel pump 10 with Nmin / n and Nmax / n as indices. 6, the horizontal axis has shown Nmin / n, and the vertical axis has shown Nmax / n. In FIG. 6, (ηI / ηR) (where ηR is an analysis result (constant value) of the pump efficiency of the fuel pump 10 having the above-described equal pitch impeller 36, and ηI is the unequal pitch impeller 36. Is an analysis result of the pump efficiency of the fuel pump 10 provided with the same value).

N/n 를 만족하는 임펠러 (37) 를 구비하는 연료 펌프 (10) 이면, 등피치 임펠러 (36) 를 구비하는 연료 펌프 (10) 와 비교하여, 펌프 효율이 저하되는 것을 억제할 수 있다고 할 수 있다. 이상의 결과로부터, 0.1

N/n

0.5 이면, 펌프 효율의 저하를 억제하면서, 연료 펌프가 발생하는 음압을 저감시킬 수 있는 것을 알 수 있었다. As shown in FIG. 6, when 0.1 <Nmin / n, it turned out that the value of 20-log10 ((eta) / (eta) R) is comparatively large. 0.1 from this

If it is the fuel pump 10 provided with the impeller 37 which satisfy | fills N / n, compared with the fuel pump 10 provided with the equal pitch impeller 36, it can be said that it can suppress that a pump efficiency falls. have. From the above result, 0.1

N / n

When 0.5 was found, it was found that the negative pressure generated by the fuel pump could be reduced while suppressing the decrease in pump efficiency.

(Comparison in Actual Products of Fuel Pumps with Equal Pitch Impellers and Fuel Pumps with Equal Pitch Impellers)

By using the fuel pump 10 having the equal pitch impeller 36 and the fuel pump 10 having the uneven pitch impeller 36, the fuel pump 10 is actually operated at a speed of 3000 to 9000 rpm, which is the rotation speed at which the fuel pump 10 is used. When the impeller 36 was rotated at an intermediate 6000 rpm, the experiment which compared the sound emitted from the fuel pump 10 was performed.

(σ'/θ 의 평균)

0.30 또한 0.15

C'

0.35 를 만족하고 있다. In the pitch pitch impeller 36 prepared in this experiment, the pitch angle was 7.5 degrees. Moreover, in the pitch pitch impeller 36 prepared in this experiment, the blade | wing groove 37 was formed in the pitch angle shown in Table 2. As shown in FIG. The pitch angle of the wing groove 37 of the inequality pitch impeller 36 is 0.05

(average of σ '/ θ)

0.30 or 0.15

C '

0.35 is satisfied.

FIG. 7 shows measurement results of sound generated from the fuel pump 10 including the equal pitch impeller. In addition, about the fuel pump 10 provided with the equal pitch impeller 36, five fuel pumps 10 were prepared and the measurement about each fuel pump 10 was carried out. The measurement result of the five fuel pumps 10 provided with the equal pitch impeller 36 is included. FIG. 8 has shown the measurement result of the sound produced from the fuel pump 10 provided with the impeller 36 in which the blade | wing groove 37 was formed in the pitch angle of the said Table 2. 7, 8 represents the frequency of sound, and the vertical axis represents the loudness (dB) of sound. The broken line 100 of FIG. 8 has shown the peak value of the sound produced from the fuel pump 10 provided with the equal pitch impeller 36. 7, 8, in the fuel pump 10 provided with the unequal pitch impeller 36, the frequency of the sound which generate | occur | produces compared with the fuel pump 10 provided with the equal pitch impeller 36 is disperse | distributed, The peak value of sound was small. From this, it was found that in the fuel pump 10 having the inequality pitch impeller 36, the generated sound becomes smaller as compared with the fuel pump 10 having the equal pitch impeller 36.

(σ'/θ 의 평균)

0.30, 및 0.15

C'

0.35 를 만족함으로써, 연료 펌프 (10) 가 발생하는 소리를 저감시킬 수 있는 것을 알 수 있었다. 또, 연료 펌프 (10) 에서는, 임펠러 (36) 의 날개 홈 (37) 이 0.1＜(피치각이 동일한 피치각의 수/총 날개 홈 수 (= 43))＜0.5 를 만족함으로써, 날개 홈의 피치각 θ 이 균일하게 형성되어 있는 임펠러 (36) 를 구비하는 연료 펌프 (10) 와 비교하여, 펌프 효율의 저감을 억제함과 함께, 연료 펌프 (10) 가 발생하는 소리를 저감시킬 수 있는 것을 알 수 있었다. From the analysis results, in the fuel pump 10, the wing groove 37 of the impeller 36 is 0.05

(average of σ '/ θ)

0.30, and 0.15

C '

By satisfying 0.35, it turned out that the sound which the fuel pump 10 generate | occur | produces can be reduced. In the fuel pump 10, the blade groove 37 of the impeller 36 satisfies 0.1 &lt; (number of pitch angles / number of total wing grooves (= 43)) &lt; Compared with the fuel pump 10 provided with the impeller 36 in which the pitch angle θ is formed uniformly, it is possible to suppress the reduction of the pump efficiency and to reduce the sound generated by the fuel pump 10. Could know.

The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

For example, the technology provided by the present specification can be applied to various fluid pumps in addition to fuel pumps that suck and discharge fuel.

Moreover, the technique illustrated in this specification or drawing achieves several objectives simultaneously, and has technical utility in itself by achieving one of the objectives.

The inventors found that (average of σ '/ θ) and C' correlate strongly with the spectral peak value of the pressure fluctuation of the fluid in the wing groove. Then, when (average of? '/ Θ) and C' satisfy the above range, it was found that the sound generated from the fluid pump can be reduced as compared with the prior art. Moreover, one or more other pitch angles θk (an integer of k = 1 to n and an integer other than i) are equal to each pitch angle θi (i = 1 to n) of the impeller wing of the impeller described above. Is formed to exist. When there is only one pitch angle θ i, when the impeller rotates, pressure fluctuation occurs by the pitch angle θ i, and the pressure fluctuation by the pitch angle θ i is not reduced. In other words, the sound component due to θ i is not reduced in the pitch angle. On the other hand, when there are a plurality of pitch angles having the same angle, for example, when the pitch angle θi and the pitch angle θk are the same, sound components generated when the wing groove formed by the pitch angle θi passes through the partition wall are different pitch angles θk. It becomes possible to attenuate by the sound component which generate | occur | produces by the wing groove formed in this way through a partition. By satisfying this condition and the above-described conditions (average of? '/ Θ) and C', the noise caused by the specific pitch angle θi can be reduced.

10: fuel pump
12: motor unit
14: pump unit
36 impeller
37: wing home
41: bulkhead
42: suction port
50: discharge port

Claims (2)

A fluid pump which is boosted by suction of a fluid in a pump casing by rotation of an impeller, and discharges the boosted fluid out of the pump casing.
The impeller,
N wing grooves are formed at the outer peripheral edge thereof,
When the impeller is viewed in plan, a line segment connecting the center of rotation of the impeller and the center of the circumferential direction of the blade groove of the i th (an integer of i = 1 to n), the center of rotation of the impeller and the i + 1 th (end , i + 1 = n + 1, the angle formed by the line connecting the center of the circumferential direction of the blade groove of i + 1 = 1) is set to the pitch angle θ _i , and the difference between adjacent pitch angles is σ _i = θ _{i + 1} ? θ _{When i}
While the pitch angle θ _i is nonuniform, at least one other pitch angle θ _k (any integer of k = 1 to n and an integer other than i) is present at each pitch angle θ _i ,
0.05

(average of σ '/ θ)

0.30
0.15

C '

0.35
only,
[Equation 1]

[Equation 2]

[Equation 3]

[Equation 4]

&Quot; (5) &quot;

&Quot; (6) &quot;

To meet the fluid pump. The method of claim 1,
A fluid pump satisfying 0.1 <(number of pitch angles with the same pitch angle) / n <0.5.

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