CA2044950C - Fuel feed pump - Google Patents
Fuel feed pumpInfo
- Publication number
- CA2044950C CA2044950C CA 2044950 CA2044950A CA2044950C CA 2044950 C CA2044950 C CA 2044950C CA 2044950 CA2044950 CA 2044950 CA 2044950 A CA2044950 A CA 2044950A CA 2044950 C CA2044950 C CA 2044950C
- Authority
- CA
- Canada
- Prior art keywords
- casing
- sealing portion
- liquid sealing
- deairing
- vapor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 50
- 238000007789 sealing Methods 0.000 claims abstract description 36
- 239000007788 liquid Substances 0.000 claims abstract description 32
- 239000002828 fuel tank Substances 0.000 claims description 3
- 230000000052 comparative effect Effects 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000002093 peripheral effect Effects 0.000 description 4
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 230000005484 gravity Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 241000282320 Panthera leo Species 0.000 description 1
- 235000014676 Phragmites communis Nutrition 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Landscapes
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
A fuel feed pump for a motor vehicle, wherein a liquid sealing portion is formed in a position close to an impeller in a casing, an exhaust port is opened in the intermediate portion of the liquid sealing portion in a manner to communicate the inner space of the liquid sealing portion with the outside of the casing. The casing is opened therein with a deairing hole for communicating the liquid sealing portion with the outside of the casing. A deairing groove is formed at least on the upper end surface of the casing. One end of the deairing groove is communicated with the upper space of a generally annular groove path and the other end is communicated with the deairing hole, traversing the liquid seal portion.
Description
2 ~ a F~EL FEED PUMP
BACKGROUND OF THE INVENTION
1. Field of the Invention This invention relates to a fuel feed pump, and ntore partlcularly to a fuel feed pump of a frictional pump ~ype, e.g. one ef-~ectively used for an electronically controlled fuel inJection device.
2. Relnted Art Statement Since a frictional pump used in a fuel feed pump has no self-priming properties in general, as vapor quantity in a casing increases, discharge quantity ~ecreases, thus resulting in the vapor lock.
Therefore, it has been the common practice that, in the conventional fuel feed pump of this type, deairing holes are opened in a generally annular groove path ~ormed in an annular zone between an intake port and a discharge port except a liqu:ld sealing portion in a eas.lng,'whereby vapor is deaired through the deairing holes when the fuel is separated from the vapor by the cen~rifugal force.
The reason why the deairing holes have hereto-fore been downwardly opened resides in that, in order to wash and cool a commutator and brushes in a motor portion provided in the upper portion of the fuel feed pump, the interior of a housing of the motor portion is made to serve as a fuel path, whereby the interior of the housing of the motor portion is highly pressurized, therefore the vapor cannot be deaired through the deairing holes, so that the dea~ring holes are opened downwardly in order that the vapor does not intrude into the interior of the housing where the motor portion is ~llsposed~
~ lo~vever, recently, the number of component parts lloused Ln an engine room of a motor vehicle has increased highly, whereby, with the fuel feed pump in ~vhlch only the downwardly opened deairing holes are ~ormed in the intermediate portion of the groove path, the deairing effect has become insufficient.
Namely, as the number of the component parts in the en~lne room of the motor vehicle is increased highly, the temperature in the engine room tends to be raised.
In an electronically controlled fuel inJection device, a part o~ the fuel constantly circulates through the en~ine room and returns to a fuel tank, whereby the ~empernture of the f-uel in the tank tends to further ~asily increase. As the temperature of the fuel is rnised, boiling of the fuel itself and agitation of the fuel by the fuel feed pump produce a large quantity of vapor. When the large quantity of vapor is produced, 2 ~ ~ d ~a ,~ ~
the arrangemcnt in which only the deairing holes are opened ln the intermediate portion of the groove path can not deair the vapor sufficiently. Particularly, the vapor is lower in gravity than the fuel, whereby the vapor tends to accumulate in the upper space of the ~roove path, so that, in the conventional fuel feed pump in which the deairing holes are opened downwardly, the vap~r cannot be deaired sufficiently.
Then, even if it is tried to deair the vapor in-to t~he Lnterior of the motor portion from the upper space o~ the groove path, the vapor cannot be discharged upwardly because the vapor discharged from the deairing holes is lower in pressure than the highly pressurized fuel passing through the interior o-t' the motor por-tion.
Further, when the highly pressurized fuel and the vnpor ~hich has not been deaired return to the intake side, the pressure is abruptly lowered, whereby intake of the fuel through the intake port is disturbed by the nc~v production of the vapor and the expansion of the v~por, so that the vapor lock tends to occur.
SUMMARY OF THE INVENTION
An ob~ect of the present invention is to provide a ~uel feed pump, wherein the quantity o-f vapor produced in the vicinity of an intake port is reduced, and, even when the large quantity of vapor is produced, vapor can be deaired su~iciently.
Another object o~ the present invention is to provide a fuel feed pump wherein vapor produced in the upper portion of a groove path is discharged to the olltslde oE a casing, and returns of the remaining vapor whicll has not been deaired through deairing holes and a p~r~ o~ the hlghly pressurized ~uel are discharged through an exhaust hole formed in a sealing portion so ~s to suppress the production of vapor itself and to suEficiently deair vapor even when the large quantitY 0 vapor is produced.
The ~uel Eeed pump according to the present inventlon is characterized in that, in a fuel Eeed pump comprising: a casing immersed in a ~uel tank for a motor vehicle; an impeller rotatably installed in the casing ~nd provided on the outer periphery thereo~ with a plurality oE grooves; a liquid sealing portion -Eormed in position close to the impeller on rotating loci o~ a ~ronp oE the grooves oE the impeler in the casing; an lnt~ke port and a discharge port respectively opened in positions interposing the liquid sealing portlon in the circum~erential direction in the casing; and a generally annular groove path ~ormed between the intake port and the discahge port in a zone excluding the liquid sealing portion of the casing; an exhaust port is opened in the intermediate portion of the liquid sealing portion in a manner to be communicated with an inner space of this liquid sealing portion and this exhaust port is communicated with the outside of the casing.
Furthermore, the groove path is formed with deniring holes for communicating the interior of the ~roove path with the outside of a housing.
In the fuel feed pump according to the present invention, the exhaust port is opened in the liquid sealing portion, whereby the fuel is reduced in pressure here, so that new production of the vapor can be sllppressed. Furthermore, the remaining vapor which has not been discharged through the deairing holes can be deaired through this exhaust port. Accordingly, the quantity of the vapor produced in the vicinity of the intake port is decreased, so that the vapor lock can be ~voided.
Furthermore, another fuel feed pump according to the tnventton is characterized in that the deairing holes are opened in the casing in a manner to communicate the liquid sealing portion with the outside of the casing, and a deairing groove is formed at least in the upper end sur~ace of this casing in such a manner that one end thereof is communicated with the upper space o~ the groove path and the other end thereo-f is communicated with the deairing holes, passing throu~h the liquid sealing portion.
In the above-described fuel feed pump of another type according to the present invention, the deairin~
groove is communicated with the upper space of the ~roove path, so that the vapor which tends to accumulate In ~he upper space of the groove path can be very e~cctively deaired from the groove path by this deairing groove. Accordingly, the quantity of the vapor reaching the vicinity of the intake port is decreased and the intake port is constantly filled up with the fuel~ so that the vapor lock can be avoided.
Furthermore, the deairing groove traverses the llquid sealing portion, whereby the pressure in the li~uid sealing portion is reduced, so that the occurrence of the vapor lock can be further prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other obJects and features of the present invention will become more apparent when re~erred to the following descriptions given in conJunction with the accompanying drawings, wherein like reference numerals denote like elements, and in which:
Fig. 1 is a partially omitted plan sectional view J
taken along the line I-I in Fig. 3 showing an embodiment of the ~uel feed pump according to the present invention;
Fig. 2 is an enlarged partially sectional view taken along the line II-II in Fig. 1;
Fig. 3 is a front sectional view showing an embodiment of the fuel ~eed pump according to the present invention;
Fi~. 4 is a comparative graphic chart for e~plaining the actions;
Fig. 5 is a partially omitted plan sectional view showing another embodiment of the fuel -~eed pump ~ccording to the invention, taken along the line V-V in Fig~ 7;
Fig. 6 is an enlarged partially sectional view taken alon~ the line VI-VI in Fig. 5;
Fi~ 7 is a front sectional view showing the fuel rccd pump thereof;
Fig~ 8 is an enlarged partially sectional view sho~Yln~ n further embodlment of the present invention, corresponding to Fig. 7; and Fig. 9 is a comparative graphic chart explaining the actions.
DETAILED DESCRIPTION OF TEE PREFERRED EMBODIMENTS
i3 Embodiment 1 Referring to the drawings, in this Embodiment 1 shown in Fig. 1 through 4, a fuel feed pump according to the present invention 10 has a pump portion 12 and a motor portion 30, both portions being installed in a housing ll~ This fuel feed pump 10 is wholely immersed In n fuel tank, not shown, with the pump portion disposed below. A casing 13 of the pump portion 12 is fLxedly incorporated in the bottom end portion of the housing 11. The casing 13 has a pump plate 14 and a pump head 15, both of which are assembled into the housing 11 with the both members disposed back to back.
generally disk-shaped hollow pump chamber 16 is de~lned by surfaces of the pump plate 14 and the pump head 15 which face each other. The pump chamber 16 incorporates therein a disk-shaped impeller 17 rotatably and coa~ially therewith. A plurality of generally qu~-ter round-shaped grooves 18 being inwardly directed ~re disposed at equal intervals in the circumferent:Lal direction at opposite sides of the outer periphery of the impeller 17. Rotation of the impeller 17 makes this ~roup of grooves 18 move in the circumferential direction in a space formed on the outer periphery of the pump chamber 16. A motor shaft 31 to be described hereunder is inserted into the central axis of the $~
impeller 17, whereby the impeller 17 is rotatably driven by the motor shaft 31.
A liquid sealing portion 19 is -formed in a position very close to the outer peripheral surface o-f the impeller 17 on the inner periphery of an erected wall of the pump head 15. with the erected wall defining the inner peripheral surface of the pump chamber 16 in the caslng L3. And relatively, a gap portion 20 having sultable dimensions is formed on the inner periphery excluding the liquid sealing portion 19. Furthermore, the pump head 15 is provided with an intake port 21 which is disposed at the initial end in the rotating direction out of the opposite sides in the clrcllmferential direction of the liquid sealing portion 19 ~nd communicated with the pump chamber 16. The inta~e port 21 is communicated with the outside of the hollsin~ 11 through an intake hole 22 opened in the pump h~nd 15~
On the other hand, the pump plate 14 is provided with a discharge port 23 disposed on the side opposite to the intake port 21 of the liquid sealing portion 19 and communicated with the interior of the pump chamber 16. The discharge port 23 is communicated with the interior of the housing 11 through a discharge hole 24 opened in the pump plate 14.
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Generally annular groove paths 25 are recessedly formed extending from the intake port 21 and the discharge port 23 respectively on the outer periphery portions of end surfaces of the pump chamber 16 in the casing 13, both outer periphery portions of end sur-~aces of the pump chamber 16 being defined by the outer periphery portions of end surfaces of the pump plate 14 and the pump head 15. Two deairing holes 26 are d~sposed at generally central portions o-f the c:lrellmferential length of the groove paths 25, communicating the interiors of the groove paths 25 with the outside of the housing 11.
In this Embodiment 1, the pump head 15 is provided with an exhaust port 27, which is disposed in the :in~ermediate portion of the liquid sealing portion 19, -faces the outer peripheral surface of the impeller 17 and is communicated with the interior o-f the pump chamber 16. This exhaust port 27 is communicated with the outside o~ the housing 11 through an exhaust hole 28 opened ~n the pump head 15.
On the other hand, in the motor portion 30, the mo-~or s~la~t 31 having fixed thereto with the impeller 17 ls disposed in the central axis of the housing 11 and rotatably supported. An armature 32 and a commutator 33 are fixedly mounted to the motor shaft 31. A plurality 2 ~ :~L L~ ,J ,~ ~
of magnets 34 are fixedly provided on the inner peripheral surface of the housing 11 at equal intervals in the circumferential direction thereo-f and opposed to the armature 32. A brush holder stay 35 is fixedly mounted to the top end portion in the housing in such a mallner that brush holders 36 mounted thereto are opposed t;o ~he commutator 33. Brushes 37 housed in the brush llolders 36 are in sliding contact with the commutator 33~ An end bracket 38 is coupled and f'ixed to the top end portion of the housing 11. A discharge pipe path 39 communicated with a fuel in~ection device, not shown, is integrally projected from the end bracket 38 in a manner t~ be disposed at the central portion and communicated with the interior of the housing 11. The discharge pipe path 39 incorporates therein a check valve 40. A relief valve 41 is integrally pro~ected from the end bracket 38 in a manner to be disposed at a portion of the outer periphery of the end bracket 38 and communicate the tntertor with the exterior of the housing 11. The relief valve 41 incorporates therein a depressurization valve 42.
Action of this Embodiment 1 will hereunder be described.
Rotation of the motor sha~t 31 in the motor portion 30 makes the impeller 17 fixedly mounted thereto be rotatably driven. When the impeller 17 rotates, the ~uel is taken into the group o-f the grooves 18 formed on the outer periphery of the impeller 17 through the intake port 21 and discharged ~rom the discharge port ~3~ The fuel discharged from the discharge port 23 is disellnrged into the interior of the housing 11 through the dlscharge hole 24, and delivered to the fuel in~jection device, not shown, through a discharge pipe p~t~l 39.
During this pump operation, the vapor produced in the groove paths 25 is deaired to the outside of the llollsing 11 through the deairing holes 26 opened in the intermediate portions of the groove paths 25.
~ urthermore, the exhaust port 27 is opened in the liquid sealing portion 19 in this Embodiment 1, whereby the vapor which has not been deaired through the denlrlng holes 26 opened in the intermediate portions of ~hn groove paths 25 is passed through the exhaust port ~7 ~nd the exhaust hole 28 and exhausted to the outside o-~ the housin~ ll. At this time, pressure is reduced in the exhaust port 27 o~ the liquid sealing portion 19, whereby the vapor is exhausted effectively, so that the vapor can be prevented from being produced in the vicinity of the intake port 21 after passing the exhaust port 27. As the result, the intake port 21 is 2 ~
constantly filled up with the fuel, so that the vapor lock can be prevented from occurring.
Fig. 4 is the comparative graphic chart showin~ the decrease of the discharge quantity o~ the fuel reed pump with the rise in the temperature of the fuel, wherein a solid curve shows the case of this Embodiment 1 and a broken curve shows the conventional example~
As shown in Fig~ 4, in the case of this Embodiment .~ as compared with the conventional example, the temperature at which the discharge quantity of the pump is decreased and the temperature at which the vapor lock is caused are raised, so that the decrease of the discharge quantity of the pump relative to the temperature of the fuel can be improved~
As described above, in the above Embodiment 1 of the present invention, the exhaust port is opened in the llquid sealing portion, so that the vapor can be exhnusted effectively and the vapor lock can be prevented from occurring~
~mbodiment 2 The second embodiment of the present invention as sho~Yn in Figs~ 5 through 7 will hereunder be described~
Almost all of the construction of this Embodiment 2 is similar to that in the above Embodiment 1~
In this Embodiment 2, an upper groove path 25A and .
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a lo~ver groove path 25B are resessedly provided in generally annular shapes from the intake port 21 to the discharge port 23 respectively on the outer periphery portions of the end surfaces of the pump plate 14 and the pnmp head 15, both of which define the upper and lowe~ outer periphery portions of the end surfaces of tlle pump chamber 16 in the casing 13. A plurality o~
downwardly directed deairing holes 26 are disposed in the generally central portion of the circumferential length of the lower groove path 25B and opened downwardly in a manner to communicate the interior of the lower groove path 25B with the outside of the h~uslng 11. Furthermore, in this Embodiment 2, a deairing groove 127 is recessedly provided in a generally circularly arcuate shape on the inner surface of the pump plate 14 which is opposed to the upper sllrface of the impeller 17, the initial end portion 127a o~ this deairing groove 127 is communicated with the generally central portion of the circumferential length o~ ~he upper groove 25~, and the tail end thereof traverses the liquid sealing portion 19 and is communicated with the inner end portion of a deairing hole 128 to be described hereunder~
In this Embodiment 2, the deairing hole 128 is disposed in the vicinity of the generally central 2 ~
portion of the liquid sealing portion in the casing 13, opened in a manner to be communicated with the outside of the housing 11 from the pump plate 14 to the pump head 15, and the tail end of the deairing groove 127 traverses the liquid sealing portion 19 and is fluidally connected to the inner end portion of this deairing hole 1~8 on the side of the pump plate 14.
Action of the Embodiment 2 will hereunder be described.
Rotation of the motor shaft 31 in the motor portion makes the impeller 17 fixedly mounted thereto be rotatably driven. When the impeller 17 rotates, the el is taken into the group of grooves 18 formed on the outer periphery of the impeller 17 through the intake port 21, and discharged from the discharge port 23 by the centrifugal force. The fuel discharged from the discharge port 23 is discharged into the interior of the h~usin~ 11 through the discharge hole 24, and passes through the discharge pipe path 39 and is delivered -to the fuel inJection device, not shown.
Dur.lng this pump operation, the vapor produced in the upper groove path 25A is taken into the deairing ~roove 127 opened in the intermediate portion of the upper groove path 25A, delivered into the deairing hole 1~8, and then, deaired to the outside of the housing 11.
Furthermore, the vapor produced in the lower groove path 25B is directly deaired to the outside of the housing 11 through the downwardly directed deairing holes 26 opened in the intermediate portion o~ the lower groove path ~B.
Now, the vapor is lower in gravity than the fuel, whcrcby the vapor tends to accumulate in the upper ~roove paths 25A out o~ the both upper and lower groove paths 25A and 25B. Then, in this Embodiment 2, the deairing groove 127 is opened to be communicated with the interior of the upper groove path 25A, so that the vapor accumulated in the upper ~roove path 25A can be very effectively deaired from the groove path, i.e. the pump chamber 16. Accordingly, the vapor is prevented ~rom being produced in the vicinity of the intake port 21 after the vapor has passed the discharge port 23. As the result, the intake port 21 is constantly filled up with the fuel, so that the vapor lock can be prevented -~rom occurring.
Furthermre, the deairing groove 127 traverses the liquid sealing portion 19, whereby pressure in the liquid sealing portion is reduced and production of the vapor due to the pressure reduction is eliminated, so that the vapor lock can be further prevented from occurring.
2 ~
Embodiment 3 A further embodiment of the present invention will hereunder be described with re-ference to Figs. 8 and 9.
Fig. 8 is the enlarged partially sectional view showing the Embodiment 3 of the present invention, corresponding to Fig. 7.
The difference of this Embodiment 3 from the above Embodiment 2 resides in that the deairing groove 127B is also provlded on the side o-f the pump head 15 and the ~.11 end of this deairing groove 1~7B is connected to the deairing hole 128. In this Embodiment 3, the do~vnwardly directed deairing holes 26 are omitted.
Fig. 9 is the comparative graphic chart showing the Aecrease of the discharge quantity of the fuel feed pump with the rise of the temperature of the ~uel, wherein Ehc solid curve shows the case of this Embodiment 3 and the broken curve shows the case of the conventional e~ample~
As shown in Fig~ 9, in the case of this Embodiment ~s compared wi-th the conventional example, the Eemperature at which the discharge quantity of the pump l~ decreased and the temperature at which the vapor lock ls caused are raised, so that the discharge quantity of the pump relative to the temperature can be improved.
As has been described hereinabove, according to the 2 ~ 3 present invention, the vapor can be exhausted e~fectively and the vapor lock can be prevented -~rom occurring.
The present invention should not be limited to the above embodiments, various modi~ications may be adopted.
nnd these modi~ications should be included within the ~cope o~ the present invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention This invention relates to a fuel feed pump, and ntore partlcularly to a fuel feed pump of a frictional pump ~ype, e.g. one ef-~ectively used for an electronically controlled fuel inJection device.
2. Relnted Art Statement Since a frictional pump used in a fuel feed pump has no self-priming properties in general, as vapor quantity in a casing increases, discharge quantity ~ecreases, thus resulting in the vapor lock.
Therefore, it has been the common practice that, in the conventional fuel feed pump of this type, deairing holes are opened in a generally annular groove path ~ormed in an annular zone between an intake port and a discharge port except a liqu:ld sealing portion in a eas.lng,'whereby vapor is deaired through the deairing holes when the fuel is separated from the vapor by the cen~rifugal force.
The reason why the deairing holes have hereto-fore been downwardly opened resides in that, in order to wash and cool a commutator and brushes in a motor portion provided in the upper portion of the fuel feed pump, the interior of a housing of the motor portion is made to serve as a fuel path, whereby the interior of the housing of the motor portion is highly pressurized, therefore the vapor cannot be deaired through the deairing holes, so that the dea~ring holes are opened downwardly in order that the vapor does not intrude into the interior of the housing where the motor portion is ~llsposed~
~ lo~vever, recently, the number of component parts lloused Ln an engine room of a motor vehicle has increased highly, whereby, with the fuel feed pump in ~vhlch only the downwardly opened deairing holes are ~ormed in the intermediate portion of the groove path, the deairing effect has become insufficient.
Namely, as the number of the component parts in the en~lne room of the motor vehicle is increased highly, the temperature in the engine room tends to be raised.
In an electronically controlled fuel inJection device, a part o~ the fuel constantly circulates through the en~ine room and returns to a fuel tank, whereby the ~empernture of the f-uel in the tank tends to further ~asily increase. As the temperature of the fuel is rnised, boiling of the fuel itself and agitation of the fuel by the fuel feed pump produce a large quantity of vapor. When the large quantity of vapor is produced, 2 ~ ~ d ~a ,~ ~
the arrangemcnt in which only the deairing holes are opened ln the intermediate portion of the groove path can not deair the vapor sufficiently. Particularly, the vapor is lower in gravity than the fuel, whereby the vapor tends to accumulate in the upper space of the ~roove path, so that, in the conventional fuel feed pump in which the deairing holes are opened downwardly, the vap~r cannot be deaired sufficiently.
Then, even if it is tried to deair the vapor in-to t~he Lnterior of the motor portion from the upper space o~ the groove path, the vapor cannot be discharged upwardly because the vapor discharged from the deairing holes is lower in pressure than the highly pressurized fuel passing through the interior o-t' the motor por-tion.
Further, when the highly pressurized fuel and the vnpor ~hich has not been deaired return to the intake side, the pressure is abruptly lowered, whereby intake of the fuel through the intake port is disturbed by the nc~v production of the vapor and the expansion of the v~por, so that the vapor lock tends to occur.
SUMMARY OF THE INVENTION
An ob~ect of the present invention is to provide a ~uel feed pump, wherein the quantity o-f vapor produced in the vicinity of an intake port is reduced, and, even when the large quantity of vapor is produced, vapor can be deaired su~iciently.
Another object o~ the present invention is to provide a fuel feed pump wherein vapor produced in the upper portion of a groove path is discharged to the olltslde oE a casing, and returns of the remaining vapor whicll has not been deaired through deairing holes and a p~r~ o~ the hlghly pressurized ~uel are discharged through an exhaust hole formed in a sealing portion so ~s to suppress the production of vapor itself and to suEficiently deair vapor even when the large quantitY 0 vapor is produced.
The ~uel Eeed pump according to the present inventlon is characterized in that, in a fuel Eeed pump comprising: a casing immersed in a ~uel tank for a motor vehicle; an impeller rotatably installed in the casing ~nd provided on the outer periphery thereo~ with a plurality oE grooves; a liquid sealing portion -Eormed in position close to the impeller on rotating loci o~ a ~ronp oE the grooves oE the impeler in the casing; an lnt~ke port and a discharge port respectively opened in positions interposing the liquid sealing portlon in the circum~erential direction in the casing; and a generally annular groove path ~ormed between the intake port and the discahge port in a zone excluding the liquid sealing portion of the casing; an exhaust port is opened in the intermediate portion of the liquid sealing portion in a manner to be communicated with an inner space of this liquid sealing portion and this exhaust port is communicated with the outside of the casing.
Furthermore, the groove path is formed with deniring holes for communicating the interior of the ~roove path with the outside of a housing.
In the fuel feed pump according to the present invention, the exhaust port is opened in the liquid sealing portion, whereby the fuel is reduced in pressure here, so that new production of the vapor can be sllppressed. Furthermore, the remaining vapor which has not been discharged through the deairing holes can be deaired through this exhaust port. Accordingly, the quantity of the vapor produced in the vicinity of the intake port is decreased, so that the vapor lock can be ~voided.
Furthermore, another fuel feed pump according to the tnventton is characterized in that the deairing holes are opened in the casing in a manner to communicate the liquid sealing portion with the outside of the casing, and a deairing groove is formed at least in the upper end sur~ace of this casing in such a manner that one end thereof is communicated with the upper space o~ the groove path and the other end thereo-f is communicated with the deairing holes, passing throu~h the liquid sealing portion.
In the above-described fuel feed pump of another type according to the present invention, the deairin~
groove is communicated with the upper space of the ~roove path, so that the vapor which tends to accumulate In ~he upper space of the groove path can be very e~cctively deaired from the groove path by this deairing groove. Accordingly, the quantity of the vapor reaching the vicinity of the intake port is decreased and the intake port is constantly filled up with the fuel~ so that the vapor lock can be avoided.
Furthermore, the deairing groove traverses the llquid sealing portion, whereby the pressure in the li~uid sealing portion is reduced, so that the occurrence of the vapor lock can be further prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other obJects and features of the present invention will become more apparent when re~erred to the following descriptions given in conJunction with the accompanying drawings, wherein like reference numerals denote like elements, and in which:
Fig. 1 is a partially omitted plan sectional view J
taken along the line I-I in Fig. 3 showing an embodiment of the ~uel feed pump according to the present invention;
Fig. 2 is an enlarged partially sectional view taken along the line II-II in Fig. 1;
Fig. 3 is a front sectional view showing an embodiment of the fuel ~eed pump according to the present invention;
Fi~. 4 is a comparative graphic chart for e~plaining the actions;
Fig. 5 is a partially omitted plan sectional view showing another embodiment of the fuel -~eed pump ~ccording to the invention, taken along the line V-V in Fig~ 7;
Fig. 6 is an enlarged partially sectional view taken alon~ the line VI-VI in Fig. 5;
Fi~ 7 is a front sectional view showing the fuel rccd pump thereof;
Fig~ 8 is an enlarged partially sectional view sho~Yln~ n further embodlment of the present invention, corresponding to Fig. 7; and Fig. 9 is a comparative graphic chart explaining the actions.
DETAILED DESCRIPTION OF TEE PREFERRED EMBODIMENTS
i3 Embodiment 1 Referring to the drawings, in this Embodiment 1 shown in Fig. 1 through 4, a fuel feed pump according to the present invention 10 has a pump portion 12 and a motor portion 30, both portions being installed in a housing ll~ This fuel feed pump 10 is wholely immersed In n fuel tank, not shown, with the pump portion disposed below. A casing 13 of the pump portion 12 is fLxedly incorporated in the bottom end portion of the housing 11. The casing 13 has a pump plate 14 and a pump head 15, both of which are assembled into the housing 11 with the both members disposed back to back.
generally disk-shaped hollow pump chamber 16 is de~lned by surfaces of the pump plate 14 and the pump head 15 which face each other. The pump chamber 16 incorporates therein a disk-shaped impeller 17 rotatably and coa~ially therewith. A plurality of generally qu~-ter round-shaped grooves 18 being inwardly directed ~re disposed at equal intervals in the circumferent:Lal direction at opposite sides of the outer periphery of the impeller 17. Rotation of the impeller 17 makes this ~roup of grooves 18 move in the circumferential direction in a space formed on the outer periphery of the pump chamber 16. A motor shaft 31 to be described hereunder is inserted into the central axis of the $~
impeller 17, whereby the impeller 17 is rotatably driven by the motor shaft 31.
A liquid sealing portion 19 is -formed in a position very close to the outer peripheral surface o-f the impeller 17 on the inner periphery of an erected wall of the pump head 15. with the erected wall defining the inner peripheral surface of the pump chamber 16 in the caslng L3. And relatively, a gap portion 20 having sultable dimensions is formed on the inner periphery excluding the liquid sealing portion 19. Furthermore, the pump head 15 is provided with an intake port 21 which is disposed at the initial end in the rotating direction out of the opposite sides in the clrcllmferential direction of the liquid sealing portion 19 ~nd communicated with the pump chamber 16. The inta~e port 21 is communicated with the outside of the hollsin~ 11 through an intake hole 22 opened in the pump h~nd 15~
On the other hand, the pump plate 14 is provided with a discharge port 23 disposed on the side opposite to the intake port 21 of the liquid sealing portion 19 and communicated with the interior of the pump chamber 16. The discharge port 23 is communicated with the interior of the housing 11 through a discharge hole 24 opened in the pump plate 14.
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, 2 ~
Generally annular groove paths 25 are recessedly formed extending from the intake port 21 and the discharge port 23 respectively on the outer periphery portions of end surfaces of the pump chamber 16 in the casing 13, both outer periphery portions of end sur-~aces of the pump chamber 16 being defined by the outer periphery portions of end surfaces of the pump plate 14 and the pump head 15. Two deairing holes 26 are d~sposed at generally central portions o-f the c:lrellmferential length of the groove paths 25, communicating the interiors of the groove paths 25 with the outside of the housing 11.
In this Embodiment 1, the pump head 15 is provided with an exhaust port 27, which is disposed in the :in~ermediate portion of the liquid sealing portion 19, -faces the outer peripheral surface of the impeller 17 and is communicated with the interior o-f the pump chamber 16. This exhaust port 27 is communicated with the outside o~ the housing 11 through an exhaust hole 28 opened ~n the pump head 15.
On the other hand, in the motor portion 30, the mo-~or s~la~t 31 having fixed thereto with the impeller 17 ls disposed in the central axis of the housing 11 and rotatably supported. An armature 32 and a commutator 33 are fixedly mounted to the motor shaft 31. A plurality 2 ~ :~L L~ ,J ,~ ~
of magnets 34 are fixedly provided on the inner peripheral surface of the housing 11 at equal intervals in the circumferential direction thereo-f and opposed to the armature 32. A brush holder stay 35 is fixedly mounted to the top end portion in the housing in such a mallner that brush holders 36 mounted thereto are opposed t;o ~he commutator 33. Brushes 37 housed in the brush llolders 36 are in sliding contact with the commutator 33~ An end bracket 38 is coupled and f'ixed to the top end portion of the housing 11. A discharge pipe path 39 communicated with a fuel in~ection device, not shown, is integrally projected from the end bracket 38 in a manner t~ be disposed at the central portion and communicated with the interior of the housing 11. The discharge pipe path 39 incorporates therein a check valve 40. A relief valve 41 is integrally pro~ected from the end bracket 38 in a manner to be disposed at a portion of the outer periphery of the end bracket 38 and communicate the tntertor with the exterior of the housing 11. The relief valve 41 incorporates therein a depressurization valve 42.
Action of this Embodiment 1 will hereunder be described.
Rotation of the motor sha~t 31 in the motor portion 30 makes the impeller 17 fixedly mounted thereto be rotatably driven. When the impeller 17 rotates, the ~uel is taken into the group o-f the grooves 18 formed on the outer periphery of the impeller 17 through the intake port 21 and discharged ~rom the discharge port ~3~ The fuel discharged from the discharge port 23 is disellnrged into the interior of the housing 11 through the dlscharge hole 24, and delivered to the fuel in~jection device, not shown, through a discharge pipe p~t~l 39.
During this pump operation, the vapor produced in the groove paths 25 is deaired to the outside of the llollsing 11 through the deairing holes 26 opened in the intermediate portions of the groove paths 25.
~ urthermore, the exhaust port 27 is opened in the liquid sealing portion 19 in this Embodiment 1, whereby the vapor which has not been deaired through the denlrlng holes 26 opened in the intermediate portions of ~hn groove paths 25 is passed through the exhaust port ~7 ~nd the exhaust hole 28 and exhausted to the outside o-~ the housin~ ll. At this time, pressure is reduced in the exhaust port 27 o~ the liquid sealing portion 19, whereby the vapor is exhausted effectively, so that the vapor can be prevented from being produced in the vicinity of the intake port 21 after passing the exhaust port 27. As the result, the intake port 21 is 2 ~
constantly filled up with the fuel, so that the vapor lock can be prevented from occurring.
Fig. 4 is the comparative graphic chart showin~ the decrease of the discharge quantity o~ the fuel reed pump with the rise in the temperature of the fuel, wherein a solid curve shows the case of this Embodiment 1 and a broken curve shows the conventional example~
As shown in Fig~ 4, in the case of this Embodiment .~ as compared with the conventional example, the temperature at which the discharge quantity of the pump is decreased and the temperature at which the vapor lock is caused are raised, so that the decrease of the discharge quantity of the pump relative to the temperature of the fuel can be improved~
As described above, in the above Embodiment 1 of the present invention, the exhaust port is opened in the llquid sealing portion, so that the vapor can be exhnusted effectively and the vapor lock can be prevented from occurring~
~mbodiment 2 The second embodiment of the present invention as sho~Yn in Figs~ 5 through 7 will hereunder be described~
Almost all of the construction of this Embodiment 2 is similar to that in the above Embodiment 1~
In this Embodiment 2, an upper groove path 25A and .
.. . .
. .
.. : .
.
.: . . ' ' : ' ~ ~l'3,~
a lo~ver groove path 25B are resessedly provided in generally annular shapes from the intake port 21 to the discharge port 23 respectively on the outer periphery portions of the end surfaces of the pump plate 14 and the pnmp head 15, both of which define the upper and lowe~ outer periphery portions of the end surfaces of tlle pump chamber 16 in the casing 13. A plurality o~
downwardly directed deairing holes 26 are disposed in the generally central portion of the circumferential length of the lower groove path 25B and opened downwardly in a manner to communicate the interior of the lower groove path 25B with the outside of the h~uslng 11. Furthermore, in this Embodiment 2, a deairing groove 127 is recessedly provided in a generally circularly arcuate shape on the inner surface of the pump plate 14 which is opposed to the upper sllrface of the impeller 17, the initial end portion 127a o~ this deairing groove 127 is communicated with the generally central portion of the circumferential length o~ ~he upper groove 25~, and the tail end thereof traverses the liquid sealing portion 19 and is communicated with the inner end portion of a deairing hole 128 to be described hereunder~
In this Embodiment 2, the deairing hole 128 is disposed in the vicinity of the generally central 2 ~
portion of the liquid sealing portion in the casing 13, opened in a manner to be communicated with the outside of the housing 11 from the pump plate 14 to the pump head 15, and the tail end of the deairing groove 127 traverses the liquid sealing portion 19 and is fluidally connected to the inner end portion of this deairing hole 1~8 on the side of the pump plate 14.
Action of the Embodiment 2 will hereunder be described.
Rotation of the motor shaft 31 in the motor portion makes the impeller 17 fixedly mounted thereto be rotatably driven. When the impeller 17 rotates, the el is taken into the group of grooves 18 formed on the outer periphery of the impeller 17 through the intake port 21, and discharged from the discharge port 23 by the centrifugal force. The fuel discharged from the discharge port 23 is discharged into the interior of the h~usin~ 11 through the discharge hole 24, and passes through the discharge pipe path 39 and is delivered -to the fuel inJection device, not shown.
Dur.lng this pump operation, the vapor produced in the upper groove path 25A is taken into the deairing ~roove 127 opened in the intermediate portion of the upper groove path 25A, delivered into the deairing hole 1~8, and then, deaired to the outside of the housing 11.
Furthermore, the vapor produced in the lower groove path 25B is directly deaired to the outside of the housing 11 through the downwardly directed deairing holes 26 opened in the intermediate portion o~ the lower groove path ~B.
Now, the vapor is lower in gravity than the fuel, whcrcby the vapor tends to accumulate in the upper ~roove paths 25A out o~ the both upper and lower groove paths 25A and 25B. Then, in this Embodiment 2, the deairing groove 127 is opened to be communicated with the interior of the upper groove path 25A, so that the vapor accumulated in the upper ~roove path 25A can be very effectively deaired from the groove path, i.e. the pump chamber 16. Accordingly, the vapor is prevented ~rom being produced in the vicinity of the intake port 21 after the vapor has passed the discharge port 23. As the result, the intake port 21 is constantly filled up with the fuel, so that the vapor lock can be prevented -~rom occurring.
Furthermre, the deairing groove 127 traverses the liquid sealing portion 19, whereby pressure in the liquid sealing portion is reduced and production of the vapor due to the pressure reduction is eliminated, so that the vapor lock can be further prevented from occurring.
2 ~
Embodiment 3 A further embodiment of the present invention will hereunder be described with re-ference to Figs. 8 and 9.
Fig. 8 is the enlarged partially sectional view showing the Embodiment 3 of the present invention, corresponding to Fig. 7.
The difference of this Embodiment 3 from the above Embodiment 2 resides in that the deairing groove 127B is also provlded on the side o-f the pump head 15 and the ~.11 end of this deairing groove 1~7B is connected to the deairing hole 128. In this Embodiment 3, the do~vnwardly directed deairing holes 26 are omitted.
Fig. 9 is the comparative graphic chart showing the Aecrease of the discharge quantity of the fuel feed pump with the rise of the temperature of the ~uel, wherein Ehc solid curve shows the case of this Embodiment 3 and the broken curve shows the case of the conventional e~ample~
As shown in Fig~ 9, in the case of this Embodiment ~s compared wi-th the conventional example, the Eemperature at which the discharge quantity of the pump l~ decreased and the temperature at which the vapor lock ls caused are raised, so that the discharge quantity of the pump relative to the temperature can be improved.
As has been described hereinabove, according to the 2 ~ 3 present invention, the vapor can be exhausted e~fectively and the vapor lock can be prevented -~rom occurring.
The present invention should not be limited to the above embodiments, various modi~ications may be adopted.
nnd these modi~ications should be included within the ~cope o~ the present invention.
Claims (4)
1. A fuel feed pump comprising:
a casing immersed in a fuel tank for a motor vehicle;
an impeller rotatably installed in the casing and provided on the outer peripheries thereof with a plurality of grooves;
a liquid sealing portion formed in a position close to the impeller on rotating loci of a group of the grooves of the impeller in the casing;
an intake port and a discharge port respectively opened in positions interposing the liquid sealing portion in the circumferential direction in the casing;
a generally annular groove path formed between the intake port and the discharge port in a zone excluding the liquid sealing portion of the casing; and an exhaust port opened in the intermediate portion of the liquid sealing portion in a manner to be communicated with an inner space of the liquid sealing portion and said exhaust port is communicated with the outside of the casing.
a casing immersed in a fuel tank for a motor vehicle;
an impeller rotatably installed in the casing and provided on the outer peripheries thereof with a plurality of grooves;
a liquid sealing portion formed in a position close to the impeller on rotating loci of a group of the grooves of the impeller in the casing;
an intake port and a discharge port respectively opened in positions interposing the liquid sealing portion in the circumferential direction in the casing;
a generally annular groove path formed between the intake port and the discharge port in a zone excluding the liquid sealing portion of the casing; and an exhaust port opened in the intermediate portion of the liquid sealing portion in a manner to be communicated with an inner space of the liquid sealing portion and said exhaust port is communicated with the outside of the casing.
2. The fuel feed pump as set forth in claim 1, wherein:
said groove path is formed with deairing holes for communicating the interior of said groove path with the outside of a housing.
said groove path is formed with deairing holes for communicating the interior of said groove path with the outside of a housing.
3. The fuel feed pump as set forth in claim 1, wherein:
deairing holes are opened in said casing in a manner to communicate the liquid sealing portion with the outside of said casing.
deairing holes are opened in said casing in a manner to communicate the liquid sealing portion with the outside of said casing.
4. The fuel feed pump as set forth in claim 1, wherein:
a deairing groove is formed at least in the inner surface of said casing opposed to an upper surface of the impeller in such a manner that one end thereof is communicated with the upper space of the groove path and the other end thereof is communicated with said deairing holes, traversing the liquid sealing portion.
a deairing groove is formed at least in the inner surface of said casing opposed to an upper surface of the impeller in such a manner that one end thereof is communicated with the upper space of the groove path and the other end thereof is communicated with said deairing holes, traversing the liquid sealing portion.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2-69052 | 1990-04-26 | ||
| JP16477090A JPH0454271A (en) | 1990-06-22 | 1990-06-22 | Fuel supply pump |
| JP2-164770 | 1990-06-22 | ||
| JP6905290U JPH0540296Y2 (en) | 1990-06-29 | 1990-06-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2044950A1 CA2044950A1 (en) | 1991-12-23 |
| CA2044950C true CA2044950C (en) | 1999-02-23 |
Family
ID=26410230
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2044950 Expired - Fee Related CA2044950C (en) | 1990-06-22 | 1991-06-19 | Fuel feed pump |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2044950C (en) |
| IT (1) | IT1248343B (en) |
-
1991
- 1991-06-19 CA CA 2044950 patent/CA2044950C/en not_active Expired - Fee Related
- 1991-06-20 IT ITRM910444A patent/IT1248343B/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| IT1248343B (en) | 1995-01-05 |
| ITRM910444A0 (en) | 1991-06-20 |
| ITRM910444A1 (en) | 1992-12-20 |
| CA2044950A1 (en) | 1991-12-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |