JP3977040B2 - Manufacturing method of impeller for fuel pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an impeller for a fuel pump. ー It relates to a manufacturing method.
[0002]
[Prior art]
Conventionally, such an impeller for a fuel pump is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-64989.
[0003]
A front view of this type of fuel pump impeller is shown in FIG. The impeller 13 is made of a synthetic resin and is formed in a substantially disc shape having both front and back surfaces, and a shaft hole 14 into which a rotating shaft of a fuel pump (not shown) is fitted is provided in a substantially central portion. The shaft hole 14 has an arc portion 14a and a straight portion 14b.
[0004]
Further, as shown in FIGS. 9 and 10, a plurality of passages 16 are provided in the vicinity of the side peripheral wall portion of the impeller 13 along the outer peripheral direction of the impeller 13. In each passage 16, a rotor blade 17 composed of blade plates 17a and 17b that are integrally formed so as to be substantially V-shaped is disposed (see FIG. 10).
[0005]
As shown in FIG. 10 and FIG. 11 (partially enlarged view of FIG. 10), these blades 17a and 17b are rib portions that slightly protrude along the radial direction of the impeller 13 at substantially the center in each passage 16. 18 is formed integrally.
[0006]
Further, in the vicinity of the shaft hole 14, there are provided a plurality of small through holes 19 that surround the shaft hole 14 and penetrate both the front and back surfaces that are spaced apart from each other at substantially equal intervals. The passage 16, the blade plates 17 a and 17 b, and the small through hole 19 are formed simultaneously when the impeller 13 is molded from the molten resin.
[0007]
[Problems to be solved by the invention]
By the way, in the conventional impeller 13 described above, as shown in FIGS. 9 to 11, the burrs 20a to 20b are formed at the side portions, corner portions, or mold matching portions at the time of resin molding and at the time of cutting or grinding of both front and back surfaces. 20c was generated.
[0008]
These burrs 20a to 20c were removed by manual work such as brushing, but there was a problem that this deburring work required a lot of time.
[0009]
In addition, the deburring operation has a problem in that the radius of curvature of the side, corner, or die-matching portion of the deburring portion, that is, the intersection is increased.
[0010]
The present invention has been made to solve the above-described problems, and is a fuel pump impeller capable of minimizing the burr generated in the fuel pump impeller and minimizing the curvature radius of the intersection. ー An object is to provide a manufacturing method.
[0011]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a synthetic resin fuel pump impeller formed in a substantially disk shape and having both front and back surfaces, and a shaft hole for passing a rotating shaft for rotating the impeller. ,
A through hole formed in the vicinity of the shaft hole and penetrating both front and back surfaces;
A plurality of passages formed on the outer periphery of the impeller and having blades disposed therein;
The projection dimension by the burr | flash in the said shaft hole, the said through-hole, and the said some channel | path is 0.05 mm or less, and the curvature radius of each cross | intersection part is 0.05 or less, It is characterized by the above-mentioned.
[0012]
That is, the fuel pump impeller according to the present invention is configured such that there are almost no protrusions due to burrs and the edges of the intersections stand. For this reason, for example, it is possible to reliably and accurately fit the rotation shaft to the shaft hole. Further, in the fuel pump, since the fuel smoothly passes through the through hole, the pressure balance between the front and back of the impeller can be maintained in an appropriate range.
[0013]
Further, it becomes possible for the fuel to smoothly pass through the blades formed in the passage where the pump action is performed. Accordingly, it is possible to improve the pump efficiency by appropriately selecting the shape of the blade groove.
[0014]
Moreover, it is preferable that the blades arranged in the plurality of passages are formed so as to be substantially V-shaped. As a result, the substantially V-shaped slat has, for example, almost no burrs at the center even though the center is a mold-matching surface and is a deep part. In addition, the edges of the intersections are standing. For this reason, the generation of highly efficient eddy currents generated by the substantially V-shaped slats arranged in the passage is not hindered, and the pump efficiency performance can be extracted according to the shape of the slats. Become.
[0015]
The constituent material of the fuel pump impeller is preferably polyphenylene sulfide (PPS). This is because PPS is low in cost and can improve the moldability and shorten the molding cycle.
[0016]
Further, the present invention provides a fuel pump impeller made of a synthetic resin having a substantially disk shape and having both front and back surfaces. A shaft hole for passing a rotation shaft for rotating the impeller, a through hole formed in the vicinity of the shaft hole and penetrating both front and back surfaces, and formed on an outer periphery of the impeller, and a vane inside An impeller for a fuel pump, in which the blades disposed in the plurality of passages are formed so as to form a substantially V shape. In the manufacturing method, the first step of molding the molded product with the molding apparatus and the cutting of the molded product Is A second step of grinding to form a molded product, and cavitation is generated in the second liquid as the first liquid is injected into the second liquid from the injection nozzle, and the cavitation causes the cavitation to occur. And a third step of performing a deburring process on the molded article immersed in the second liquid, wherein the degassed liquid is used as the first liquid. .
[0017]
When the liquid deaerated beforehand by the deaeration means is ejected as a cavitation generating liquid, a high cavitation effect can be obtained. This is because, for example, when there is a large amount of dissolved gas such as tap water, the bubble diameter generated by cavitation increases, but when cavitation bubbles break, these large cavitation bubbles cause a cushioning action, and the impact force at the time of breakage Will weaken. However, since the liquid deaerated beforehand by the deaeration means has a remarkably low dissolved gas amount, the cushioning action is prevented as much as possible. For this reason, since the impact force at the time of cavitation bubble destruction is maximized without weakening, a high cavitation effect can be obtained. As a result, foreign matters and burrs can be efficiently removed from the molded product, and therefore, a good impeller with few burrs and a sharp edge can be easily manufactured.
[0018]
In this manufacturing method, it is preferable to deaerate the second liquid in advance. In this case, the above-described effect becomes more remarkable. The degassing means for degassing the second liquid may be the same as the degassing means for degassing the first liquid, or may be separate.
[0019]
The first liquid and the second liquid are preferably degassed water. This is because the working environment can be made safe by using water.
[0020]
Further, as the injection nozzle, it is possible to use a cylindrical member in which the inner peripheral wall portion and the tip wall portion form an angle of approximately 90 ° with each other, and the injection port provided in the tip wall portion is an orifice shape. preferable. In such an injection nozzle, a contracted flow is generated at the injection port. As a result, a large shearing stress that cannot be obtained by the conventional contraction nozzle is generated around the jet in the contraction portion, and generation of strong cavitation starts from the inside of the jet. For this reason, it is possible to obtain a greater erosion effect than conventional shrink nozzles, and more efficient cleaning and deburring of foreign matters, resulting in a fuel pump impeller with a better shape. Can do.
[0021]
Furthermore, it is preferable that the ejection nozzle has a projecting end portion surrounding the ejection port, and a discharge port communicating with the ejection port is provided at the projecting end portion, and the ejection port is tapered. It is more preferable to have a taper portion that is widened. By adopting such a configuration, the occurrence of cavitation is further promoted, so that a fuel pump impeller having a better shape can be obtained.
[0022]
Further, the present invention provides a fuel pump impeller made of a synthetic resin having a substantially disk shape and having both front and back surfaces. A shaft hole for passing a rotation shaft for rotating the impeller, a through hole formed in the vicinity of the shaft hole and penetrating both front and back surfaces, and formed on an outer periphery of the impeller, and a vane inside An impeller for a fuel pump, in which the blades disposed in the plurality of passages are formed so as to form a substantially V shape. In the manufacturing method, a first step of forming a molded product with a molding apparatus, a second step of cutting or grinding the molded product to form a molded product, and a first liquid from the injection nozzle as a second liquid A third step of generating cavitation in the second liquid as it is injected into the second liquid, and deburring the molded product immersed in the second liquid by the cavitation; The injection nozzle is a cylindrical member in which the inner peripheral wall portion and the tip wall portion form an angle of approximately 90 ° with each other, and the nozzle provided in the tip wall portion is an orifice. It is characterized by that.
[0023]
In short, in this case, even if the degassed liquid is not used, a fuel pump impeller having a good shape can be obtained.
[0024]
For the reasons described above, the injection nozzle preferably has a protruding end portion surrounding the injection port, and a discharge port communicating with the injection port is provided at the protruding end portion. It is more preferable that the discharge port has a tapered portion that expands in a tapered shape.
[0025]
In any of the production methods, it is preferable to produce the molded article using polyphenylene sulfide (PPS) as a raw material. As described above, since PPS is rich in moldability, it is possible to produce a molded product in a short time, and eventually, it is possible to efficiently produce a fuel pump impeller.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the impeller and the manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings. In addition, about the component shown by FIGS. 9-11, the same referential mark is attached | subjected and the detailed description is abbreviate | omitted.
[0027]
1 is a partially cutaway perspective view of an impeller according to the present embodiment, and FIG. 2 is an enlarged view of a main part thereof. The impeller 26 is configured in the same manner as the impeller 13 shown in FIGS. 9 to 11 except that the burrs 20a to 20c are not provided.
[0028]
That is, in the impeller 26 according to the present embodiment, the shaft hole 14, the passage 16, the blade plates 17 a and 17 b, the rib portion 18, and the small through hole 19 are provided in a shape substantially equivalent to the design shape. Specifically, the projection size due to burrs at these portions is 0.05 mm or less, and the burrs are as small as possible.
[0029]
The shaft hole 14 will be described as an example. As shown in an enlarged view in FIG. 2A, the radius of curvature R of the intersection of the arc portion 14a and the straight portion 14b is 0.05 or less. 2A is a cross-sectional view taken along the line AA in FIG. 2A, and the arc portion 14a and the front and back surfaces of the impeller 26 intersect each other substantially orthogonally, and the respective curvature radii R at the respective intersections. Is 0.05 or less. Similarly, the curvature radii R at the intersections as described above in the passage 16, the blades 17 a and 17 b, the rib portion 18 and the small through hole 19 in the impeller 26 are also 0.05 or less.
[0030]
In other words, the impeller 26 according to the present embodiment has almost no protrusions due to burrs, and the edges of the intersections stand. Such an impeller 26 has the following advantages. That is, first, the rotating shaft of the fuel pump (not shown) can be fitted into the shaft hole 14 with high accuracy.
[0031]
Further, in the fuel pump, since the fuel smoothly passes through the small through hole 19, the pressure balance between the front and back surfaces of the impeller 26 can be maintained in an appropriate range.
[0032]
Further, the fuel can smoothly pass through the blades 17a and 17b formed in the passage 16 that performs the pumping action. Accordingly, it is possible to improve the pump efficiency by appropriately selecting the shape of the blade groove.
[0033]
In addition, the impeller 26 is formed at the center position in the thickness direction of the impeller 26, that is, the intersecting portion of the blade plates 17a and 17b, the intersecting portion of the blade plates 17a and 17b and the rib portion 18, and the rib portion 18. , A burr 20b2 (see FIG. 11) is generated on this mold-matching surface, but the projection size due to the burr at such a part is also zero. .05 mm or less, and the curvature radius R of such an intersection is also 0.05 or less.
[0034]
Thus, even if it has a complicated shape in the deep part such as the central part of the substantially V-shaped blades 17a and 17b arranged in the passage 16, there is no protrusion due to burrs, and the edge Is composed of standing up. Therefore, the generation of the high-efficiency vortex generated by the substantially V-shaped blades 17a and 17b is not hindered, and the pump efficiency performance can be brought out according to the shape of the blades 17a and 17b. Become.
[0035]
The constituent material of the impeller 26 is not particularly limited. However, as will be described later, since the moldability is good, it is possible to produce a molded product in a short time. Therefore, polyphenylene sulfide (PPS) ) Is preferable.
[0036]
Next, a method for manufacturing the impeller 26 will be described with reference to FIG. As shown in FIG. 3, the manufacturing method includes a first step S1 for forming a molded product with a molding device, a second step S2 for cutting or grinding the molded product to form a molded product, and an injection nozzle. As the first liquid is injected into the second liquid, cavitation is generated in the second liquid, and burrs are formed on the molded product immersed in the second liquid by the cavitation. And a third step S3 for performing machining.
[0037]
First, in the first step S1, a mold apparatus comprising a first mold having a cavity having a shape corresponding to the shape of the blade plate 17a and a second mold having a cavity having a shape corresponding to the shape of the blade plate 17b. Then, the first mold and the second mold are closed, and the molten resin is introduced into the cavity formed thereby. A molded product having a shape corresponding to the impeller 26 is obtained by cooling and solidifying the molten resin.
[0038]
At this time, it is preferable to use a molten resin in which PPS is melted. Since PPS is rich in moldability compared to nylon resin and phenol resin, the time required for producing a molded product is shortened and the material cost is low. It is because it can manufacture at cost.
[0039]
Next, in the second step S2, both the front and back surfaces of the molded product are cut or ground to obtain a molded product, and then in a third step S3, burrs, machine oil, etc. adhering to the surface of the molded product are obtained. Foreign matter is washed away and burrs remaining on the molded product are removed.
[0040]
Here, FIG. 4 shows a schematic overall configuration of a cavitation generating apparatus used for performing cleaning and removing foreign substances and removing burrs. The cavitation generating device 30 is injected from the storage tank 32 for storing the immersion liquid L1 for immersing the molded product 26a of the impeller 26, the injection nozzle 34 for injecting the cavitation generation liquid L2, and the injection nozzle 34. A cavitation generating liquid L2 to be deaerated in advance, a supply tank 38 for storing the cavitation generating liquid L2 deaerated by the vacuum pump 36, and a cavitation generating liquid from the supply tank 38 to the injection nozzle 34. A first liquid feed pump 40 for feeding the liquid L2. In the present embodiment, pure water obtained by treating tap water with the water treatment device 42 is used as the immersion liquid L1 and the cavitation generating liquid L2.
[0041]
Hereinafter, the configuration of the cavitation generating device 30 will be described in order from the upstream side to which tap water is supplied.
[0042]
First, the water supply pipe 44 for supplying tap water is connected to the water treatment device 42. The water treatment device 42 has a function of removing pure chlorine or the like dissolved in tap water. That is, the water treatment device 42 performs a so-called water purification function, and specific examples thereof include activated carbon, a hollow fiber membrane, or a device having a reverse osmosis membrane. The water supply pipe 44 is provided with a valve 46.
[0043]
The water treatment device 42 is connected to the deaeration module 50 by a liquid feed pipe 48 connected to the water supply pipe 44 via a pipe joint. The pure water generated by the water treatment device 42 is deaerated in the deaeration module 50.
[0044]
As shown in FIG. 5, in this case, the deaeration module 50 has a substantially cylindrical container 52, and the liquid feeding pipe 48 is connected to the lower end of the container 52. In addition, a liquid supply pipe 54 that bridges the container 52 and the supply tank 38 is connected to the upper end of the container 52. Further, a joint pipe portion 56 is formed so as to protrude from the side wall portion of the container 52, and a communication hole 60 communicating with the inner chamber 58 of the container 52 is formed in the joint pipe portion 56. The vacuum pump 36 is connected to the joint pipe portion 56 via an exhaust pipe 62 (see FIG. 4). As will be described later, the gas dissolved in the pure water is separated from the pure water by the vacuum pump 36.
[0045]
A cylindrical hollow fiber membrane 64 is accommodated in the inner chamber 58 (see FIG. 5). A plurality of pores are provided in the longitudinal direction of the hollow fiber membrane 64, and the pure water introduced into the inner chamber 58 through the liquid feeding pipe 48 passes through the pores, and then the liquid feeding pipe. It is discharged from the container 52 through 54. Thus, while the pure water flows, the gas dissolved in the pure water is sucked in the diameter direction of the hollow fiber membrane 64 by the vacuum pump 36 and discharged through the exhaust pipe 62. The pure water flowing through the pores cannot permeate along the diameter direction of the hollow fiber membrane 64. Therefore, pure water is not accompanied with gas and discharged.
[0046]
The liquid feeding pipe 54 is branched so that pure water degassed by the degassing module 50 (hereinafter referred to as degassed pure water) can be individually supplied to the supply tank 38 and the storage tank 32. That is, the liquid feeding pipe 54 has branch pipes 66 and 68, and valves 70 and 72 are installed in the branch pipes 66 and 68, respectively.
[0047]
The supply tank 38 is a tank for temporarily storing degassed pure water. The degassed pure water supplied to the supply tank 38 via the branch pipe 66 is supplied from the supply tank 38 to the injection nozzle 34 by the first liquid supply pump 40, and from the injection nozzle 34, as will be described later. It is ejected as cavitation generating liquid L2. The degassed pure water is fed to the first liquid feed pump 40 through the liquid feed pipe 76 having the first filter 74 immersed in the supply tank 38.
[0048]
The storage tank 32 has a first horizontal portion 78, an inclined portion 80 inclined from the first horizontal portion 78, and a second horizontal portion 82 provided at a position deeper than the first horizontal portion 78 at the bottom. Among these, below the second horizontal portion 82, a liquid feed pipe 88 is connected that bridges the storage tank 32 and the second liquid feed pump 84 and is provided with a second filter 86. In addition, a clamp base 90 for fixing the molded product 26a is disposed in the first horizontal portion 78.
[0049]
In the above configuration, the liquid level detectors 92 and 94 and the temperature controllers 96 and 98 are installed in the supply tank 38 and the storage tank 32, respectively. A communication pipe 100 is bridged between the supply tank 38 and the storage tank 32, and a valve 102 is interposed in the communication pipe 100. The liquid level detectors 92 and 94, the valves 70, 72, and 102 and the temperature controllers 96 and 98 are electrically connected to a control unit (not shown). When the molded product 26a is made of PPS, the degassed pure water stored in the supply tank 38 and the storage tank 32 is held by the temperature controllers 96 and 98 within a range of 50 to 60 ° C., for example. The
[0050]
In addition, a plurality of floating members 104 made of plastic spheres float on the surfaces of the degassed pure water stored in the supply tank 38 and the storage tank 32 so as to cover the entire liquid surface. ing. The degassed pure water is stored in the supply tank 38 and the storage tank 32 in a state of being blocked from the atmosphere by the floating member 104.
[0051]
Here, the tip of the injection nozzle 34 is inserted into the immersion liquid L1 (degassed pure water) supplied and stored in the storage tank 32, and is directed to the molded product 26a. Therefore, the cavitation generating liquid L2 is sprayed from the spray nozzle 34 toward the molded product 26a in the immersion liquid L1.
[0052]
FIG. 6 shows a schematic cross-sectional configuration diagram of the tip portion of the injection nozzle 34. The injection nozzle 34 includes a cylindrical member 106 provided with a liquid path 105, and a discharge protruding end member 108 fitted to the distal end portion of the cylindrical member 106. That is, the cavitation generating liquid L2 discharged from the injection port 110 provided in the tip wall portion of the cylindrical member 106 is immersed in the immersion liquid L1 through the discharge port 112 of the discharge tip member 108 opened in the immersion liquid L1. Is injected into the inside.
[0053]
As can be understood from FIG. 6, the diameter of the liquid path 105 is substantially constant. The injection port 110 is also provided so that the diameter is substantially constant. For this reason, in the cylindrical member 106, the inner peripheral wall portion and the tip wall portion form an angle of approximately 90 ° with each other. That is, in the injection nozzle 34, the injection port 110 is provided in an orifice shape, and the injection nozzle proposed by the present applicant in the prior art from the liquid path 105 to the injection port 110 (hereinafter, this injection nozzle is referred to as a contraction nozzle). ) Is not provided.
[0054]
Further, a cylindrical hole 113 is provided at one end of the discharge protruding end member 108, and the discharge protruding end member 108 is fitted with the end of the cylindrical member 106 in the cylindrical hole 113. Thus, the cylindrical member 106 is fitted. Note that the tubular member 106 and the discharge protruding end member 108 are connected to each other by, for example, a screw (not shown).
[0055]
A discharge port 112 provided at the other end of the discharge tip member 108 has a small-diameter hole portion 114 and a tapered hole portion 116 that communicates with the small-diameter hole portion 114 and expands in a tapered shape. Among these, the small diameter hole portion 114 is provided at a position where the center portion substantially coincides with the center portion of the injection port 110.
[0056]
The diameter D of the small-diameter hole 114 is preferably set within 3 times the diameter d of the injection port 110. In addition, the angle θ formed by the tapered hole 116 is preferably set within a range of 30 ° to 70 °. As a constituent material of the ejection tip member 108, a material having good wear resistance, such as a quenched metal, a cemented carbide, ceramics, or the like is suitable.
[0057]
As shown in FIG. 7, the second filter 86 (see FIG. 4) has a filtration membrane 120 in which a flow path 118 is provided in a substantially central portion and a flow path 119 is provided in an outer peripheral portion. The degassed pure water discharged from the second horizontal portion 82 of 32 and introduced into the flow path 119 from the direction of the arrow Y1 passes through the flow path 118 in the direction of the arrow X1. To pass through. The degassed pure water that has passed through the filtration membrane 120 in this manner is returned to the liquid feed pipe 48 (see FIG. 4) by the second liquid feed pump 84 and degassed again by the degassing module 50, and then cavitation occurs. It is circulated and reused as working liquid L2 or immersion liquid L1.
[0058]
The branch pipe 122 branched from the liquid feed pipe 48 connected to the second liquid feed pump 84 is a pipe for feeding backwash water for backwashing the second filter 86. That is, as shown in FIG. 7, the backwash water is introduced through the flow path 118 of the filtration membrane 120 in the direction of the arrow X2, and passes in the direction outside the diameter of the filtration membrane 120 (the direction of the arrow Y2). After separating foreign matter and the like from the outer peripheral wall surface of the filtration membrane 120, the foreign matter and the like are circulated in the direction of arrow Y <b> 2 together with the foreign matter and discharged from the outlet (not shown) of the flow path 119.
[0059]
Cleaning and deburring of foreign matters and deburring of the molded product 26a by the cavitation generating device 30 are performed as follows. That is, first, the circulation of tap water is started when the valve 46 is opened. This tap water becomes pure water by removing chlorine and the like by the water treatment device 42. By using pure water, it is possible to avoid a processing mark called a watermark from remaining on the impeller 26.
[0060]
The obtained pure water is then introduced into the inner chamber 58 of the container 52 constituting the deaeration module 50 (see FIG. 5), and passes through the pores of the hollow fiber membrane 64 accommodated in the inner chamber 58. . Meanwhile, the dissolved gas in the pure water is sucked out of the diameter of the hollow fiber membrane 64 under the suction action of the vacuum pump 36 and, as a result, is discharged from the outer peripheral wall of the hollow fiber membrane 64, and then the container 52 is led out to the outside of the container 52 through the joint pipe portion 56 and the exhaust pipe 62. As described above, pure water does not permeate along the diameter direction of the hollow fiber membrane 64. That is, pure water is not discharged outside the container 52 under the suction action of the vacuum pump 36.
[0061]
As described above, the gas in the pure water is separated and removed. In other words, degassing is performed on pure water, and degassed pure water is thereby obtained. At this time, the amount of dissolved gas remaining in the degassed pure water is extremely small, for example, about 1.5 ppm.
[0062]
The degassed pure water is supplied to the supply tank 38 and the storage tank 32 through the liquid supply pipe 54 and the branch pipes 66 and 68 as the valves 70 and 72 are opened. At this time, the valve 102 may be opened. Then, the liquid level detectors 92 and 94 issue “liquid level upper limit” signals to the control units, respectively, so that the valves 70 and 72 are closed, thereby degassing the supply tank 38 or the storage tank 32. The supply of pure water is stopped.
[0063]
The floating members 104 float on the liquid surfaces of the degassed pure water stored in the supply tank 38 and the storage tank 32, respectively. The presence of these floating members 104 prevents the degassed pure water from being exposed to the atmosphere. For this reason, it can suppress that the gas from air | atmosphere melt | dissolves in deaeration pure water, and can finally maintain deaeration pure water in the state where the amount of dissolved gas is remarkably low.
[0064]
The degassed pure water stored in the supply tank 38 is fed to the injection nozzle 34 via the first liquid feed pump 40. In this case, the discharge pressure of the first liquid feed pump 40 is, for example, 30 to 200 kgf / cm. ² (2.9 to 19.6 MPa) may be set. If foreign matter is mixed in the degassed pure water, the foreign matter is removed by the first filter 74.
[0065]
The degassed pure water sent to the spray nozzle 34 is sprayed through the spray nozzle 34 into degassed pure water (immersion liquid L1) stored in the supply tank 38 as a cavitation generating liquid L2. That is, the degassed pure water flows through the liquid passage 105 of the cylindrical member 106 constituting the injection nozzle 34, and then is discharged from the injection port 110 provided in the cylindrical member 106, and further, the discharge tip member 108. Through the discharge port 112, the spray is directed toward the molded product 26 a immersed in the immersion liquid L 1 while being fixed to the clamp table 90. Many cavitations CA generate | occur | produce by the friction of the jet flow and immersion liquid L1 in this case. Due to the erosive force generated when the cavitation CA collides with the molded product 26a, chips and machine oil (foreign matter) are cleaned and removed from the molded product 26a, and burrs are removed. The
[0066]
Here, in the present embodiment, as described above, degassed pure water having a remarkably low dissolved gas amount is used as the cavitation generating liquid L2 and the immersion liquid L1. For this reason, a high cavitation effect can be obtained.
[0067]
This is because, for example, when there is a large amount of dissolved gas such as tap water, the bubble diameter generated by cavitation increases, but when cavitation bubbles break, these large cavitation bubbles cause a cushioning action, and the impact force at the time of breakage Will weaken. However, since the cavitation generating liquid L2 deaerated in advance by the vacuum pump 36 has a remarkably low dissolved gas amount, the cushioning action is prevented as much as possible. For this reason, since the impact force at the time of cavitation bubble destruction is maximized without weakening, a high cavitation effect can be obtained. Accordingly, the erosion force generated at this time is remarkably increased, so that foreign matters and burrs can be efficiently removed.
[0068]
In addition, in this case, as described above, since the cavitation CA has a remarkably large erosion force, for example, even in the passage 16 of the molded product 26a, burrs existing in the passage 16 are reliably removed. Of course, by adjusting the position where the cavitation CA collides with the molded product 26a, burrs existing in the shaft hole 14 and the small through hole 19 of the molded product 26a can be removed.
[0069]
At the time of the above-described injection, as shown in FIG. 8, since the injection port 110 of the cylindrical member 106 is rapidly throttled in an orifice shape with respect to the liquid path 105, Shrinkage CO is generated. When the contracted flow CO is generated in this way, a large shear stress that cannot be obtained by the conventional contraction nozzle is generated around the jet flow in the contracted CO portion, and generation of strong cavitation CA starts from the inside of the jet flow. For this reason, it becomes possible to obtain a larger erosion effect than the conventional shrink nozzle. Therefore, chips, machine oil (foreign matter), and burrs can be more reliably removed from the molded product 26a. Since the discharge pressure of the cavitation generating liquid L2 is set to 2.9 to 19.6 MPa, even if the jet of the cavitation generating liquid L2 collides with the molded product 26a, the molded product 26a is not damaged.
[0070]
The cavitation generating liquid L2 (degassed pure water) that has passed through the injection port 110 reaches the small-diameter hole portion 114 of the discharge tip member 108. Due to the presence of the small-diameter hole portion 114, the cavitation generating liquid L2 is in a tapered hole portion 116 even when the central axis of the tapered hole portion 116 and the central axis of the injection port 110 are misaligned. It is injected from the vicinity of the substantially central axis.
[0071]
At this time, a strong vortex V is generated around the jet in the tapered hole 116. For this reason, since generation | occurrence | production of cavitation CA is further accelerated | stimulated, a chip, a working oil (foreign matter), and a burr | flash can be removed still more reliably from the molded product 26a.
[0072]
Further, the cavitation generating liquid L2 and the immersion liquid L1 are held in the range of 50 to 60 ° C. by the temperature controllers 96 and 98. In this temperature range, chips, machine oil (foreign matter), and burrs are easily separated from the molded product 26a. That is, the removal efficiency of foreign matters and burrs is improved.
[0073]
As described above, as shown in FIG. 1, the burrs 20a to 20c (see FIGS. 9 to 11) are hardly present in the shaft hole 14, the passage 16, and the small through hole 19, and the edge is good. The impeller 26 is obtained.
[0074]
As described above, according to the manufacturing method according to the present embodiment, foreign substances and burrs are efficiently and reliably removed from the molded product 26a by using degassed pure water as the cavitation generating liquid L2 and the immersion liquid L1. Therefore, the impeller 26 having a good shape can be obtained.
[0075]
Most of the cavitation generating liquid L2 ejected from the ejection nozzle 34 is stored in the storage tank 32 as the immersion liquid L1.
[0076]
The foreign matters and burrs removed from the molded product 26a as described above are collected in the second horizontal portion 82 of the storage tank 32 under the suction action of the second liquid feeding pump 84. That is, the inclined portion 80 and the second horizontal portion 82 are trap portions that capture foreign matter and burrs. By capturing foreign matter and burrs in the trap portion in this way, it is possible to avoid the foreign matter and burrs from re-adhering to the molded product 26a after migrating in the immersion liquid L1.
[0077]
These foreign matters and burrs are filtered and separated from the immersion liquid L1 by the second filter 86. That is, the immersion liquid L1 containing burrs and foreign matters is introduced from the direction of the arrow Y1 into the flow path 118 of the filtration membrane 120 shown in FIG. Then, while burrs and foreign substances are blocked by the outer peripheral wall surface of the filtration membrane 120, only the immersion liquid L1 advances in the direction of the arrow X1 and permeates and passes through the filtration membrane 120.
[0078]
The immersion liquid L1 that has passed through the filtration membrane 120 is returned to the liquid supply pipe 48 (see FIG. 4) by the second liquid supply pump 84 and deaerated again by the deaeration module 50, and then the cavitation generating liquid L2 or immersion Recycled as liquid L1.
[0079]
The above circulation process is automatically performed by the control unit issuing a control signal based on a program. Then, after a predetermined time has elapsed, the injection of the cavitation generating liquid L2 from the injection nozzle 34 is stopped as the control unit issues a “stop operation” signal.
[0080]
In the above-described circulation process, when the liquid level of degassed pure water in the supply tank 38 or the storage tank 32 falls below a predetermined position, the liquid level detector 92 or the liquid level detector 94 A lower limit signal is sent to the control unit. Upon receiving this signal, the control unit issues a control signal for opening the valve 70, the valve 72, or the valve 102, whereby new deaerated pure water is supplied until a predetermined liquid level is reached.
[0081]
When the first filter 74 is clogged by repeating the above-described circulation process, the floating member 104 is removed, the first filter 74 is taken out, and the first filter 74 may be cleaned or replaced. Thus, since the spherical member is employed as the floating member 104, the floating member 104 can freely move when performing maintenance work such as cleaning or replacement of the first filter 74. ing. That is, a situation in which maintenance work becomes complicated and difficult is not caused.
[0082]
When the second filter 86 is clogged, the second filter 86 may be backwashed. That is, backwash water is introduced through the branch pipe 122 from the inner peripheral wall portion of the filtration membrane 120 (see FIG. 7) in the direction of the arrow Y2. When this backwash water enters the flow path 119, it mechanically separates foreign matter and the like adhering to the outer peripheral wall surface of the filtration membrane 120 and then circulates in the direction of the arrow Y2 with the foreign matter. It is discharged from an outlet (not shown).
[0083]
Further, when the discharge tip member 108 of the spray nozzle 34 is worn by the jet of the cavitation generating liquid L2, the discharge tip member 108 may be replaced with a new one. As described above, since the ejection tip member 108 can be replaced, it is not necessary to replace the injection nozzle 34 together with the tubular member 106. Therefore, the cost required for the injection nozzle 34 can be reduced.
[0084]
Furthermore, since water can be used as the immersion liquid L1 and the cavitation generating liquid L2, the burden on the environment is significantly reduced. Also, the work environment is safe. Moreover, since no abrasive grains are used, there is an advantage that a complicated process such as removal of abrasive grains is not required.
[0085]
In the above-described embodiment, the injection nozzle 34 in which the cylindrical member 106 and the ejection tip member 108 are separate members is exemplified as the injection nozzle. However, the injection nozzle 34 is formed so as to protrude from the cylindrical portion. Needless to say, the protruding end may be an injection nozzle made of the same member.
[0086]
In addition, when cavitation is generated using the injection nozzle 34 in which the injection port 110 is rapidly narrowed in an orifice shape, the liquid injected from the injection port 110 does not have to be degassed.
[0087]
Of course, it is also possible to use an injection nozzle whose injection port is rapidly narrowed in an orifice shape, and to inject the liquid deaerated beforehand by the deaeration means via this injection nozzle. Furthermore, in the above-described embodiment, pure water is used as the immersion liquid L1 and the cavitation generating liquid L2, but it goes without saying that water may be used.
[0088]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a good fuel pump impeller configured with almost no protrusions due to burrs and with the edges of the intersections standing.
[0089]
Further, according to the method for manufacturing the impeller for a fuel pump according to the present invention, the liquid previously deaerated by the deaeration means is injected, or the injection nozzle whose injection port is rapidly narrowed in an orifice shape is used. To generate cavitation. For this reason, since cavitation can be generated efficiently, foreign matters such as chips and machine oil adhering to the molded product can be efficiently washed and removed, and burrs of the molded product can be reliably removed. be able to. Eventually, the effect is achieved that a good fuel pump impeller that is clean and has almost no protrusion due to burrs and that has an edge at the intersection can be obtained.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view of a fuel pump impeller according to an embodiment of the present invention.
FIG. 2A is an enlarged view of a main part of FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A.
FIG. 3 is a flowchart of a method for manufacturing a fuel pump impeller according to the present embodiment.
FIG. 4 is a schematic overall configuration diagram of a cavitation generating device for performing a cleaning / deburring process on a molded product.
5 is a partially cutaway perspective view of a deaeration module constituting the cavitation generating device of FIG. 4. FIG.
6 is a schematic cross-sectional configuration diagram of a tip portion of an injection nozzle constituting the cavitation generating device of FIG. 4. FIG.
7 is a schematic cross-sectional configuration diagram of a second filter that constitutes the cavitation generating device of FIG. 4. FIG.
8 is a schematic cross-sectional configuration diagram illustrating a state in which cavitation generating liquid is ejected from the ejection nozzle of FIG. 6;
FIG. 9 is a front view of an impeller constituting a fuel pump.
10 is a partially cutaway perspective view of the impeller of FIG. 9. FIG.
11 is an enlarged view of a main part of FIG.
[Explanation of symbols]
13, 26 ... Impeller 14 ... Shaft hole
17 ... Rotating blades 17a, 17b ... Blades
18 ... rib part 19 ... small through-hole
20a-20c ... Burr 26a ... Molded product
30 ... Cavitation generator 32 ... Reservoir
34 ... Injection nozzle 36 ... Vacuum pump (deaeration means)
38 ... Supply tank 40, 84 ... Liquid feed pump (liquid feed mechanism)
42 ... Water treatment device 50 ... Deaeration module
52 ... Container 58 ... Interior
62 ... exhaust pipe 64 ... hollow fiber membrane
70, 72, 102 ... Valve 74, 86 ... Filter
80 ... Inclined part 82 ... Second horizontal part
90 ... Clamp base 92, 94 ... Liquid level detector
96, 98 ... Temperature controller 100 ... Communication pipe
104: floating member 105 ... liquid channel
106: Cylindrical member 108 ... Discharge tip member
110 ... Jet 112 ... Discharge port
113 ... Cylindrical hole 114 ... Small diameter hole
116: Tapered hole 120 ... Filtration membrane
L1 ... immersion liquid L2 ... cavitation generating liquid
CA ... Cavitation CO ... Shrinkage
V ... Eddy current

Claims (5)

It is a synthetic resin fuel pump impeller formed in a substantially disc shape and having both front and back surfaces,
A shaft hole for passing a rotating shaft for rotating the impeller;
A through hole formed in the vicinity of the shaft hole and penetrating both front and back surfaces;
A plurality of passages formed on the outer periphery of the impeller and having vanes disposed therein;
Have
In the method of manufacturing an impeller for a fuel pump, wherein the blades disposed in the plurality of passages are formed so as to be substantially V-shaped with each other.
A first step of forming a molded product having a shape corresponding to the fuel pump impeller with a molding device;
A second step of cutting or grinding the molded product to form a molded product;
Injecting the first liquid from the injection nozzle into the second liquid causes cavitation in the second liquid, and the molded product immersed in the second liquid by the cavitation A third step of performing a deburring process;
Have
In the third step, burrs generated in a deep part such as a central part of the substantially V-shaped blades disposed in the plurality of passages are minimized, and the radius of curvature of each intersection is Apply the deburring process to make it as small as possible,
The injection nozzle includes a cylindrical member in which an inner peripheral wall portion and a tip wall portion form an angle of approximately 90 ° with each other, and an orifice-like jet port provided in the tip wall portion, and a protruding end surrounding the jet port And
A method for manufacturing an impeller for a fuel pump , wherein the projecting end portion is provided with a discharge port that has a tapered portion that communicates with the injection port and expands in a tapered shape . 2. The method of manufacturing an impeller for a fuel pump according to claim 1, wherein a degassed liquid is used as the first liquid. 3. The manufacturing method according to claim 2 , wherein the second liquid is degassed in advance. 4. The method of manufacturing an impeller for a fuel pump according to claim 2 , wherein the first liquid and the second liquid are degassed water. The method for manufacturing an impeller for a fuel pump according to any one of claims 1 to 4 , wherein the molded article is manufactured using polyphenylene sulfide as a raw material.

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