CN116696629A - Fuel injection pump - Google Patents
Fuel injection pump Download PDFInfo
- Publication number
- CN116696629A CN116696629A CN202310212800.9A CN202310212800A CN116696629A CN 116696629 A CN116696629 A CN 116696629A CN 202310212800 A CN202310212800 A CN 202310212800A CN 116696629 A CN116696629 A CN 116696629A
- Authority
- CN
- China
- Prior art keywords
- plunger
- suction
- fuel
- discharge port
- injection pump
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 88
- 238000002347 injection Methods 0.000 title claims abstract description 38
- 239000007924 injection Substances 0.000 title claims abstract description 38
- 238000005192 partition Methods 0.000 claims abstract description 20
- 238000000638 solvent extraction Methods 0.000 abstract description 2
- 230000002093 peripheral effect Effects 0.000 description 8
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
Abstract
The invention provides a fuel injection pump capable of pushing bubbles generated in a suction port out of the suction port without crushing, thereby reducing cavitation generated in the suction port of a plunger barrel. In a fuel injection pump (1) for introducing and pressurizing fuel into a pressurizing chamber (6) by the reciprocating motion of a plunger (7), the plunger (7) is provided with an axial fuel passage (7 b) communicating with the pressurizing chamber (6) and an inclined guide passage (7 a) communicating with the axial fuel passage (7 b) and capable of communicating with a suction/discharge port (5 b), and a partition (21) for partitioning the suction/discharge port (5 b) in the axial direction of the plunger (7) is provided inside the suction/discharge port (5 b) communicating with the pressurizing chamber (6) and a fuel reservoir (9).
Description
Technical Field
The present invention relates to a fuel injection pump for an internal combustion engine, and more particularly to a fuel injection pump for controlling an injection amount by a guide passage formed in a plunger.
Background
As a fuel injection pump for a fuel injection system of an internal combustion engine, there is a fuel injection pump in which a fuel reservoir is formed between a pump housing and a plunger cylinder, and a suction port communicating with the fuel reservoir is formed in a side wall of the plunger cylinder. In this fuel injection pump, a guide passage that communicates with the fuel pressurizing chamber and is capable of facing the suction/discharge port of the plunger cylinder is formed in the outer peripheral surface of the plunger. Such a fuel injection pump sucks fuel into the pressurizing chamber with the plunger being lowered, and closes the suction port with the plunger being raised to pressurize the fuel in the pressurizing chamber. When the pressure in the pressurizing chamber exceeds the opening pressure, the delivery valve opens, and the high-pressure fuel is pressure-fed to the injection nozzle. After that, when the plunger further rises and the guide passage formed in the plunger faces the suction/discharge port, the fuel in the pressurizing chamber is discharged to end the pressure feed.
In such a fuel injection pump, as shown in fig. 5, in the pressurization step in which the plunger 307 is raised, immediately before the tip of the plunger 307 closes the suction/discharge port 305a of the plunger cylinder 305, the fuel in the pressurization chamber 306 is pushed by the plunger 307 and overflows from the suction/discharge port 305a to the fuel reservoir 309. The overflow jet is abruptly depressurized in a region near the outer peripheral surface of the plunger 307 in the suction port 305a, and accordingly, bubbles are generated in the region of the suction port 305a and the generated bubbles expand and remain in the suction port 305 a.
After that, when the plunger 307 continues to rise and the pressure feed of the fuel to the injection nozzle is completed, as shown in fig. 6, the guide passage 307a formed on the outer peripheral surface of the plunger 307 faces the suction port 305a, and the fuel in the pressurizing chamber 306 returns from the guide passage 307a to the fuel reservoir 309 through the suction port 305 a. At this time, as shown in fig. 7, the high-pressure fuel in the pressurizing chamber 306 is changed from the guide passage 307a of the plunger 307 to a high-speed jet flow obliquely upward, and is discharged toward the suction port 305 a. By this high-speed jet flow, the trapped air bubbles are crushed and destroyed, and cavitation occurs in the suction/discharge port 305a of the plunger tube 305.
To reduce the occurrence of such cavitation, a fuel injection pump having an improved shape of a suction/discharge port is disclosed. For example, patent document 1 proposes a fuel injection pump in which the suction port includes a small-diameter hole having an opening surface through which the inside of the plunger tube can be seen, and a large-diameter hole communicating with the other end of the small-diameter hole, and the bottom of the early-stage control hole extends obliquely upward in a direction away from the opening surface, and the inner surface of the communicating end portion between the large-diameter hole and the small-diameter hole is a spherical surface portion.
Patent document 2 proposes to provide a spiral groove in the suction/discharge port, the spiral groove changing the flow of the high-pressure overflow jet and the return jet ejected from the pressurizing chamber to the suction/discharge port (introduction hole) into a spiral flow.
[ Prior Art literature ]
Japanese patent application laid-open No. 2005-248876
Japanese patent application laid-open No. 2000-38973 (patent document 2).
Problems to be solved by the invention
However, in the fuel injection pumps disclosed in patent documents 1 and 2, the flow of the high-pressure fuel at the moment of starting to return from the guide passage of the plunger to the suction/discharge port at the end of the pumping is directed to the wall surface on the side of the inner hole that is close to the sliding plunger among the wall surfaces of the suction/discharge port. Thus, the bubbles that remain are crushed in the suction port, and cavitation may occur in the sliding surface near the guide passage of the plunger and the suction port of the plunger barrel.
Disclosure of Invention
The invention provides a fuel injection pump capable of reducing cavitation generated in a suction port of a plunger barrel without crushing bubbles generated in the suction port and pushing out the bubbles to the outside of the suction port.
Means for solving the problems
In order to solve the above-described problems, according to an aspect of the present invention, there is provided a fuel injection pump including a pump housing; a plunger barrel mounted to the pump housing; a plunger slidably inserted in the plunger cylinder in an axial direction in a reciprocating manner; a fuel reservoir formed between the pump housing and the plunger barrel; a suction/discharge port formed in the plunger cylinder and communicating with the fuel reservoir; and a pressurizing chamber formed in the plunger cylinder and into which fuel is introduced and pressurized by the reciprocation of the plunger, wherein the plunger has an axial fuel passage communicating with the pressurizing chamber and an inclined guide passage communicating with the axial fuel passage and capable of communicating with the suction/discharge port, and a partition member for partitioning the suction/discharge port in the axial direction of the plunger is provided in the suction/discharge port.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention described above, the air bubbles generated in the suction port are pushed out of the suction port without being crushed, and cavitation generated in the suction port of the plunger cylinder can be reduced.
Drawings
Fig. 1 is a cross-sectional view showing an example of the structure of a fuel injection pump according to an embodiment of the present invention.
Fig. 2 is an enlarged cross-sectional view showing the periphery of the suction port of the fuel injection pump according to this embodiment.
Fig. 3 is a perspective view showing a fitting member constituting the separator according to the embodiment.
Fig. 4 is an explanatory view showing a suction port in which the partition according to this embodiment is disposed.
Fig. 5 is an explanatory diagram showing the flow of high-pressure fuel returning to the suction/discharge port immediately after the start of pressure feed in the conventional fuel injection pump.
Fig. 6 is an explanatory diagram showing the flow of high-pressure fuel returned to the suction port when the pressure feed in the conventional fuel injection pump is completed.
Fig. 7 is an enlarged cross-sectional view showing the periphery of a suction port of a conventional fuel injection pump.
Description of the reference numerals
1: fuel injection pump, 2: pump housing, 4: delivery valve, 5: plunger barrel, 5a: plunger insertion hole, 5b: suction and discharge port, 5ba: region 1, 5bb: region 2, 6: pressurization room, 7: plunger, 7a: inclined guide path, 7b: axial fuel passage, 9: fuel reservoir, 11: upper edge portion, 12: inclined edge portion, 14: opening portion, 15: plug, 20: fitting member, 21: separator, 23: and a supporting part.
Detailed Description
Hereinafter, embodiments of the fuel injection pump according to the present invention will be described in detail. However, this embodiment is an embodiment of the present invention, and is not limited to the present invention, and can be arbitrarily modified within the scope of the present invention. In the drawings, the same parts are denoted by the same reference numerals, and description thereof is omitted as appropriate.
Fig. 1 is a cross-sectional view showing an example of the structure of a fuel injection pump according to the present embodiment. In fig. 1, the components unnecessary for the description of the present invention are omitted.
The fuel injection pump 1 is a member for injecting and supplying pressurized high-pressure fuel to an internal combustion engine. The fuel injection pump 1 includes a pump casing 2, a plunger cylinder 5 fitted into the pump casing 2, a plunger 7, and a pressurizing chamber 6 partitioned by the plunger cylinder 5 and the plunger 7. Further, the delivery valve 4 and the retainer 17 are attached to the upper side of the plunger cylinder 5, and the retainer 17 is screwed to the pump housing 2.
The plunger barrel 5 is formed with a fuel suction/discharge port 5b. A fuel reservoir 9 is formed between the pump housing 2 and the plunger cylinder 5 at a position facing the suction port 5b. The plunger 7 is inserted into the plunger insertion hole 5a of the plunger tube 5 so as to be rotatable in the axial rotation direction and slidable in the up-down direction. The plunger 7 has an axial fuel passage 7b and an inclined guide passage 7a communicating with the axial fuel passage 7 b.
Further, the plunger 7 has an upper end edge 11 on the upper side and an inclined edge 12 on the lower side. The upper end edge 11 is constituted by an edge of the upper end surface of the plunger 7. The inclined edge portion 12 is formed by the upper end portion of the inclined guide path 7a. These upper end edge 11 and inclined edge 12 move on the opening 14 of the suction port 5b by the axial movement of the plunger 7. At this time, the opening 14 of the suction port 5b is closed by the upper end edge 11 at which the pressure feed is started, the fuel pressure feed is started, and the opening 14 of the suction port 5b is opened by the inclined edge 12 at which the pressure feed is ended, so that the fuel pressure feed is ended.
The inclined edge portion 12 is provided so as to be inclined with respect to the axial direction of the plunger 7, and by changing the phase of the axial rotation direction of the plunger 7, the timing at which the inclined edge portion 12 opens the opening portion 14 of the suction/discharge port 5b is changed, so that the pump-based fuel pressure feed amount can be adjusted. In the present embodiment, the suction and discharge ports 5b, the fuel reservoir 9, and the inclined edge portion 12 are provided in two groups with a phase difference of 180 °.
Further, a control sleeve S1 is fitted to the outer periphery of the plunger tube 5, and a groove St into which a collar 7c of the plunger 7 is fitted is formed in the lower portion of the control sleeve S1. Thus, by rotating the control sleeve S1 by the control bracket L1, the plunger 7 is displaced in the axial rotation direction, and the relative positions of the axial fuel passage 7b and the inclined guide passage 7a with respect to the suction port 5b are changed.
The elastic seat 8 is engaged with the lower end 7d of the plunger 7, and the plunger 7 is biased downward by the elastic force of the spring 29 via the elastic seat 8. The lower end portion 7d of the plunger 7 and the elastic seat 8 are pressed against the tappet 30, and the tappet 30 is pressed against a cam fixed to a cam shaft, not shown. The tappet 30 is pushed up by the cam lobe along with rotation of the cam shaft and the cam, and the tappet 30 is pushed down by the elastic force of the spring 29. Thereby, the plunger 7 reciprocates in the axial direction.
Fig. 2 is an enlarged view of the area Q enclosed by the one-dot chain line in fig. 1. Fig. 2 is a view corresponding to fig. 7 referred to in the description of the conventional high-pressure jet pump.
In the fuel injection pump 1 according to the present embodiment, a partition 21 that partitions the suction port 5b in the axial direction of the plunger 7 is provided in the suction port 5b. In the present embodiment, the partition 21 is provided in the suction port 5b by fixing the fitting member 20 having the partition 21 and the support portion 23 fitted to the inner periphery of the suction port 5b integrally with the partition 21 to the suction port 5b. Specifically, the suction port 5b is partitioned into an upper 1 st region 5ba and a lower 2 nd region 5bb by a partition 21.
Fig. 3 is a perspective view showing an example of the structure of the fitting member 20, and fig. 4 is an explanatory view of the suction port 5b in which the fitting member 20 is disposed, as seen in the axial direction.
The fitting member 20 has a shape similar to the cross-sectional shape of the inner periphery of the suction port 5b, and includes an annular support portion 23 pressed into the suction port 5b, and a plate-like spacer 21 integrally formed on the inner peripheral surface of the annular support portion 23 and having a length longer than the axial length of the support portion 23. The fitting member 20 is pushed into the suction port 5b from the outer peripheral surface side of the plunger tube 5, and the support portion 23 is fixed to the outer peripheral surface side of the plunger tube 5 in the interior of the suction port 5b. The partition 21 extends to the rear side (opening 14 side) of the suction port 5b than the support portion 23, and divides the entire suction port 5b including the vicinity of the opening 14 into the 1 st region 5ba and the 2 nd region 5bb.
The material constituting the partition 21 and the fitting member 20 is not particularly limited as long as it has a strength capable of withstanding the flow or pressure of the high-pressure fuel returned from the pressurizing chamber 6 or the inclined guide passage 7a to the suction/discharge port 5b.
By using such a fitting member 20 to partition the inside of the suction/discharge port 5b into the 1 st region 5ba and the 2 nd region 5bb, the partition 21 can be provided in the suction/discharge port 5b without accompanying design changes of the conventional fuel injection pump. In addition, when the separator 21 is broken, the repair can be easily performed by merely replacing the fitting member 20.
The separator 21 may divide the predetermined range into the 1 st region 5ba and the 2 nd region 5bb at least from the vicinity of the opening 14 toward the outer peripheral surface side of the plunger tube 5. More specifically, when the inclined edge portion 12 opens the opening 14 of the suction port 5b and the forced delivery of the fuel is completed, the range in which the flow of the high-pressure fuel is directed at the moment of starting to return from the inclined guide passage 7a to the suction port 5b may be divided into the 1 st region 5ba and the 2 nd region 5bb. Further, the 1 st region 5ba and the 2 nd region 5bb may not be completely liquid-tightly partitioned, and the partition 21 may be separated from the inner peripheral surface of the suction/discharge port 5b. That is, the separator 21 may be provided so as to block the flow of the high-pressure fuel at the moment when the return from the inclined guide passage 7a to the suction/discharge port 5b starts.
In this way, in the pressurizing step, it is possible to suppress bubbles that are generated when the high-pressure fuel returned from the inclined guide passage 7a to the suction/discharge port 5b at the end of the pressure feed and that remain in the upper portion in the suction/discharge port 5b when the fuel in the pressurizing chamber 6 overflows to the suction/discharge port 5b immediately before the tip end of the plunger 7 closes the suction/discharge port 5b. Thus, the possibility of cavitation caused by crushing of bubbles can be reduced.
In the fuel injection pump 1 of the present embodiment, the plug 15 is attached to the pump housing 2 so as to face the fuel reservoir 9 at a position facing the suction/discharge port 5b. The plug 15 is a member having high hardness, such as a member produced by carburizing and quenching carburized steel, and is less likely to be damaged by cavitation even if bubbles discharged from the suction and discharge port 5b into the fuel reservoir 9 collide. In addition, even when the plug 15 is damaged, only the plug 15 can be replaced.
As described above, the fuel injection pump 1 according to the present embodiment has the partition 21 that partitions the suction and discharge port 5b in the axial direction of the plunger 7. Therefore, it is possible to suppress crushing of the high-pressure fuel returned from the inclined guide passage 7a to the suction/discharge port 5b when the pressure feed ends, by the air bubbles that are generated by the overflow jet of the high-pressure fuel returned from the pressurizing chamber 6 to the suction/discharge port 5b at the start of the pressure feed and remain in the upper portion of the suction/discharge port 5b. Thus, the possibility of damage to the suction and discharge port 5b due to cavitation can be reduced.
The preferred embodiments of the present invention have been described in detail above with reference to the drawings, but the present invention is not limited to such examples. It is obvious that various modifications and modifications can be made within the scope of the technical idea described in the claims by those having ordinary knowledge in the technical field of the present invention, and it is needless to say that these modifications and modifications are also understood to fall within the technical scope of the present invention.
The configuration of the fuel injection pump described in the above embodiment is merely an example, and the configuration and shape of each constituent element may be different.
Claims (2)
1. A fuel injection pump (1),
the device is provided with: a pump housing (2); a plunger cylinder (5) mounted on the pump housing (2); a plunger (7) which is inserted into the plunger cylinder (5) so as to be capable of reciprocating and sliding in the axial direction; a fuel reservoir (9) formed between the pump housing (2) and the plunger cylinder (5); a suction/discharge port (5 b) formed in the plunger cylinder (5) and communicating with the fuel reservoir (9); a pressurizing chamber (6) formed in the plunger cylinder (5) and into which the fuel is introduced and pressurized by the reciprocation of the plunger (7),
introducing and pressurizing fuel into the pressurizing chamber (6) by the reciprocating motion of the plunger (7),
the fuel injection pump (1) is characterized in that,
the plunger (7) has an axial fuel passage (7 b) communicating with the pressurizing chamber (6), an inclined guide passage (7 a) communicating with the axial fuel passage (7 b) and capable of communicating with the suction/discharge port (5 b),
a partition (21) is provided inside the suction port (5 b) to partition the suction port (5 b) in the axial direction of the plunger (7).
2. The fuel injection pump (1) according to claim 1, characterized in that,
a fitting member (20) is fixed in the suction/discharge port (5 b), and the fitting member (20) has the partition (21) and a support portion (23) which is integrally fitted to the partition (21) and fitted to the inner periphery of the suction/discharge port (5 b).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022-031639 | 2022-03-02 | ||
| JP2022031639A JP2023127755A (en) | 2022-03-02 | 2022-03-02 | fuel injection pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116696629A true CN116696629A (en) | 2023-09-05 |
Family
ID=87844089
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310212800.9A Pending CN116696629A (en) | 2022-03-02 | 2023-02-28 | Fuel injection pump |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2023127755A (en) |
| CN (1) | CN116696629A (en) |
-
2022
- 2022-03-02 JP JP2022031639A patent/JP2023127755A/en active Pending
-
2023
- 2023-02-28 CN CN202310212800.9A patent/CN116696629A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JP2023127755A (en) | 2023-09-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4353288B2 (en) | Fuel pump | |
| JP5187255B2 (en) | High pressure pump | |
| JP4589382B2 (en) | High pressure pump for fuel injection device of internal combustion engine | |
| JP5251970B2 (en) | Fuel supply pump | |
| EP3088725A1 (en) | Fuel pump for a direct injection system with a reduced stress on the bushing of the piston | |
| KR20060127128A (en) | High pressure pump, in particular for a fuel injection device in an internal combustion engine | |
| KR20110083840A (en) | Injection device for fuel injectiojn pump | |
| CN116696629A (en) | Fuel injection pump | |
| JP3823819B2 (en) | Fuel injection pump | |
| JP5071401B2 (en) | Fuel supply device | |
| KR101931171B1 (en) | Hydraulic lash adjuster and method for using hydraulic lash adjuster | |
| JP5633387B2 (en) | Fuel supply pump | |
| JP2002523671A (en) | Control unit for controlling the pressure buildup in the pump unit | |
| JPS6146459A (en) | Fuel jet pump of internal combustion engine | |
| EP4286718A1 (en) | Fuel pump | |
| JP6806769B2 (en) | Fuel pump assembly | |
| JP2007023948A (en) | Fuel injection pump for internal combustion engine | |
| JP4098738B2 (en) | Fuel injection pump for internal combustion engines | |
| KR101909833B1 (en) | High pressure pump of engine for vehicle | |
| KR20060117566A (en) | The delivery valve of fuel injection pump for diesel engine | |
| JP3740742B2 (en) | Fuel injection pump | |
| JP6428361B2 (en) | pump | |
| JP2008280954A (en) | Fuel injection pump | |
| JP2021001587A (en) | Fuel injection pump | |
| EP4226036A1 (en) | Fuel pump |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |