JPS6037314B2 - fuel injector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection device used in a diesel engine, particularly a multi-cylinder diesel engine.

Conventionally, in diesel engines equipped with a fuel injection device consisting of a Bosch-type fuel injection pump and a fuel injection nozzle, the amount of nitrogen oxides (N○x) contained in the exhaust gas increases as the combustion pressure and combustion temperature rise. Although it tends to increase as the fuel injection timing is advanced, the fuel injection timing is usually delayed using a timer. Further, in such diesel engines, consideration has been given to advancing the fuel injection timing at the time of starting to improve startability.

In order to ensure such fuel injection timing at startup, conventionally, the top lead shape of the plunger of the fuel injection pump has been processed. However, complicating the shape of the plunger lead,
This is not preferable because it becomes difficult to process.

The object of this invention is to provide a plunger without requiring any further processing to the upper lead shape, and without sacrificing engine performance such as fuel consumption, smoke, noise, etc.
An object of the present invention is to provide a fuel injection device for use in a multi-cylinder diesel engine that can reduce the amount of nitrogen oxides (N○x) contained in exhaust gas and improve startability.

In order to solve these problems, the fuel injection device of the invention was first formed into a plunger fitted with iron so that it could rotate and slide back and forth within a pump barrel, with one end attached to the top surface of the plunger and the other end attached to the plunger. A plunger side passageway opening in each side of the plunger, and a pump formed in the pump barrel so as to communicate with the plunger side passageway when the plunger is reciprocated within the pump barrel. - A plurality of Bosch fuel injection pumps that are equipped with a spin fuel take-out passage consisting of a barrel-side passage and are arranged in a diesel engine that has a plurality of cylinders, a counterfeit hole and a fuel reservoir that passes through the nozzle hole, and the fuel injection. A high-pressure fuel passage that guides the high-pressure fuel of the pump to its fuel reservoir;
a spin fuel passageway directing spin fuel of the fuel injection pump to the fuel sump, a nozzle needle valve seated in the fuel sump valve seat, and a nozzle needle valve seated in the fuel sump valve seat; It consists of a pressure regulating spring, a plurality of fuel injection nozzles arranged in the cylinder of the diesel engine, its spin fuel take-off passage of the fuel injection pump arranged in the cylinder to be immediately combusted, and the combustion immediately after the cylinder to be combusted immediately before. A plurality of pilot fuel communication passages are arranged between the fuel injection pump and the fuel injection nozzle so as to connect the fuel injection nozzle arranged in the cylinder, and each of the pilot fuel communication passages is arranged in the pilot fuel communication passages. pilot. The fuel injection system of the present invention includes a check valve, pre-injects spindle fuel, suppresses increases in combustion pressure and combustion temperature of the diesel engine, and reduces nitrogen oxide emissions. In addition to the above-described configuration, the device further includes a fuel cutoff electromagnetic valve arranged in the pilot fuel passage on the inlet side of the pilot check valve, and opens the electromagnetic valve only at startup to control the fuel injection timing. The engine is pre-injected with spin fuel, which is equivalent to advancing the engine, and improves the startability of the diesel engine while reducing nitrogen oxide emissions.During normal operation of the diesel engine, a timer delays the fuel injection timing. It is what makes it possible.

Hereinafter, preferred specific examples of the fuel injection device according to the present invention will be described with reference to the drawings.

Figures 1 and 5 show a tenth embodiment of the fuel injection device of the present invention, which is suitable for an eight-cylinder diesel engine of a truck. The fuel injection device 10 includes eight Botsch type fuel injection pumps 11, 12, which are arranged in a row.
13, 14, 15, 16, 17, 18, and eight fuel injection nozzles 19, 20, 21, 22 arranged in the cylinder.
, 23, 24, 25, 26 and their fuel injection pump 1
1, 12,..., 18 to those fuel injection nozzles 1
High pressure fuel passages 27, 28, 29, 30' 31, 32, 33, 3 that lead high pressure fuel to 9, 20, ..., 26
4, and a fuel injection pump 11 for the cylinder that burns immediately before.
Fuel injection nozzles 19, 20, . . . of the cylinders that burn immediately after 12, . . . , 18.
, 26, and a pilot fuel injection system that supplies spin fuel to the high pressure fuel passages 27, 28, 29, 30, 31, 32, 33,
34 is embodied in a high pressure fuel conduit.

The fuel injection pumps 11, 12, . It's possible to meet each other.

The pump barrel 37 has a suction hole 39 and a relief hole 40 in its upper part, and the suction hole 39 is connected to a fuel sump 4.
1, and the relief hole 40 is connected to the fuel return passage 4.
I'm letting Ren go through 2.

The fuel reservoir 41 is a feed. It is connected to the discharge side of a fuel pump (not shown) via a pipe 43, and the pipe 43 is provided with a fuel filter (not shown). The fuel return passage 42 is of course connected to a fuel tank (not shown), and is further connected to a fuel return pump/bypass passage (not shown) connected to the inlet side of the fuel filter. It continues. The pump barrel 37
Also, a discharge hole 44 is formed at the upper end, and the discharge hole 44
is connected to the high-pressure fuel connector 97 of the fuel injection nozzle 19 via the high-pressure fuel conduit 27, and a discharge valve 45 is disposed in the discharge hole 44.

The valve body 46 of the discharge valve 45 also has a pressure regulating spring 4
7 is seated on the valve seat of the discharge hole 44 to close the discharge hole 44. Also, the pump barrel 3
7 has a sleeve 48 fitted on the outside of the lower part.

The sleeve 48 has a gear 49 integrally formed at its upper end;
The gear 49 meshes with the rack 53 of the adjustment lever 52.

The sleeve 48 also has a pair of slots 5 at its lower end.
0 is formed, and the flange 51 at the lower end of the plunger 38 is loosened, and the plunger 38 is rotated around its own axis by the adjustment lever 52 to adjust the fuel injection amount. .

The plunger 38 has a groove 54 and an inclined notch 55 formed on the outer periphery of its upper end, and is reciprocated vertically within the pump barrel 37 via a jet roller 58 by a fuel cam 57 of a drive shaft 56. Ru.

Accordingly, the fuel supplied within the pump barrel 37 is forced open the discharge valve 45 as the plunger 38 reciprocates, and is pumped to the fuel injection nozzle. Also,
The plunger 38 is pressed down by a push-down spring 59 and constantly presses the plunger roller 58 against the cam surface of the fuel cam 57, causing the plunger 38 to move up and back in a reciprocating motion in cooperation with the fuel cam 57. is granted. The fuel injection pump 11,1
2,...,18 and its fuel injection nozzle 19,2
The pilot fuel injection system provided between the spill fuel extraction passage 60 and the pilot fuel communication passages 63, 64, 65, 66, 67, 68,
69, 70 and their pilot fuel lotus passages 63, 64
,…．・．． , seven rivers each have a pilot.
The check valve 71, the pilot fuel passages 63, 64, . It is composed of.

The spill fuel removal passage 60 is a plunger side passage 6
1 and a pump barrel side passage 62, the plunger side passage 61 has one end on the top surface of the plunger 38 and the other end on the upper outer peripheral surface of the plunger 38, that is,
The pump barrel side passage 62 is closed on each side, and the pump barrel side passage 62 is such that the plunger 38 is connected to the pump barrel 3.
Corresponding pilot fuel passages 63, 64, 37 are formed in the pump barrel 37 so as to communicate with the plunger side passage 61 when the pump barrel 37 is reciprocated in the vertical direction within the pump barrel 37.
・・・・・・7 rivers have been contacted.

The pilot fuel passageways 63, 64,...7
0 is the associated fuel injection nozzle 19, 20, ..., 2
6 spill fuel connector 97. The pilot check valve 71 is constructed similarly to the discharge valve 45, but the pressure regulating spring 72
is made weaker than the sea bream pressure spring 47 of the discharge valve 45,
The pressure regulating spring 72 seats the valve body 99 on the valve seat.

The fuel cutoff solenoid valve 73 has a cylinder bore 75 formed in the housing 35, and a cylinder bore 75 formed in the housing 35.
5, a movable iron core 77 fixed to the rod of the spool 76, an electromagnetic coil 78 for operating the movable iron core 77, and an electromagnetic coil 78 disposed at the bottom of the cylinder bore 75. The inlet boat 80 is connected to the upstream side of the pilot fuel communication passage, and the outlet boat 81 is connected to the downstream side of the pilot fuel communication passage. The electric circuit 74 that operates the fuel cutoff solenoid valve 73 is the fifth
As shown in the figure, it consists of a power supply 82, a manual switch 83, and an amplifier 84 supported by the electromagnetic coil 78 of the fuel cutoff electromagnetic valve 73.

The fuel injection nozzles 19, 20, ..., 26 are the third
As shown in the figure, a nozzle holder 86, a nozzle 86 fixed to the tip of the nozzle holder 86 by a cap-shaped returning nut 87, and a nozzle disposed within the nozzle 85. It includes a needle valve 88 , a push rod 89 and a pressure regulating spring 90 built into the nozzle holder 86 to push the nozzle needle valve 88 , and an regulating screw 9 to adjust the opening pressure of the nozzle needle valve 88 .
It is adjusted with 1.

The nozzle 85 also has a fuel reservoir 92 which is communicated via high pressure fuel passages 93 and 94 to a high pressure fuel connector 97 and via spill fuel passages 95 and 96 to a spill fuel connector 98, respectively. ing.

Since the fuel injection device 10 is configured as described above, now,
When starting a diesel engine, first press manual switch 8.
3 is closed, and its fuel cutoff solenoid valve 73 is operated.

That is, with the closing operation of the manual switch 83,
The electromagnetic coil 78 is excited, the movable iron core 77 is moved downward,
Along with the upward movement of the movable iron core 77, the spool 76 is moved upward against the spool spring 79, and the inlet boat 8
0 and exit boat 81. In that way, in advance,
Spilled fuel in the pump barrel 37 is allowed to flow from the relief hole to the pilot fuel passageway.

Then start the diesel engine.

When the diesel engine is started, the drive shaft 56 is rotated so that initially, for combustion in the first cylinder,
As the drive shaft 56 rotates, the fuel cam 57, tabet
Via the roller 58, the plunger 38 is moved upward in the pump barrel 37, and from the suction hole 39 the plunger 38 is moved up into the pump barrel 37.
7 is compressed, the compressed high-pressure fuel opens the discharge valve 45, flows through the high-pressure fuel conduit 27 to the fuel injection nozzle 19, and enters the first cylinder through the hole in the nozzle 85. It is injected and combusts there. Also, at the end of the upward movement of the plunger 38, the plunger side passage 61 is fully connected to the pump barrel side passage 62, so the discharge valve 45 is closed and the high pressure fuel in the pump barrel 37, that is, the spilled fuel. , flows through the spill fuel removal passage 60, and then pushes open the pilot check valve 71.

The fuel flows through the fuel passageway 63, passes through the spill fuel connector 98, the spill fuel passages 96 and 95, and then flows into the fuel reservoir 92.
Further, the nozzle/needle valve 88 is pushed open and the liquid is injected into the eighth cylinder through the air hole. The spill fuel injected in this way is of course in an amount that does not lead to explosive combustion, and the pre-injection of this spill fuel corresponds to advancing the injection timing, resulting in improved startability of the diesel engine. Improve the quality of nitrogen oxides (N○x) and reduce nitrogen oxide (N○x) emissions.

Thereafter, the pilot check valve 71 is closed, and the spilled fuel from the fuel injection pump 11 ends being injected into the eighth cylinder.

Further, the fuel injection pump 18 for the eighth cylinder operates in the same manner as the fuel injection pump 11 for the first cylinder, and injects high-pressure fuel into the eighth cylinder from the fuel injection nozzle 26 and also injects high-pressure fuel into the eighth cylinder. The high-pressure spill fuel in its own pump barrel is pre-injected from the fuel injection nozzle 22 into the fourth cylinder via the fuel passage 70.

In sequence, the fuel injection pumps 14, 12, 17, 13, 16 and 15 for the fourth, second, seventh, third, sixth and fifth cylinders operate similarly to the fuel injection pump 11 for the first cylinder. , fuel injection nozzles 22, 20, 25, 21,
High pressure fuel is injected from 24 and 23 into the corresponding 4th, 2nd, 7th, 3rd, 6th and 5th cylinders, and also through associated pilot fuel passages 66, 64, 69, 65, 68 and 67. Pre-inject high pressure spill fuel in its own pump barrel into cylinders 2, 7, 3, 6, 5 and 1.

When starting a diesel engine, the fuel injection device operates as described above to improve the startability of the diesel engine.

Further, after starting, if the diesel engine is transferred to normal operation, the manual switch 84 is opened, the fuel cutoff solenoid valve 73 is closed, and each pilot fuel passage 63,
64,..., 7 rivers are cut off.

Therefore, fuel injection pumps 11, 12, ..., 1
8 is determined by an automatic type (not shown), and in the fuel injection device 10, the fuel injection timing is determined by the automatic type (not shown).
High-pressure fuel in the barrel escapes through a hole 40 and a fuel return passage 42
The fuel is then returned to the fuel tank.

Further, during normal operation of the diesel engine, the fuel injection device 10 may be operated with the manual switch 83 closed; In this case, the fuel cutoff solenoid valve 73 may be omitted.

As described above, the fuel injection device of the present invention is formed in a steel plunger which is rotatably and reciprocally slidably fitted in a pump barrel, and has one end attached to the top surface of the plunger.
a plunger side passageway opening at the other end into each side of the plunger; A plurality of Bosch type fuel injection pumps arranged in a diesel engine having a plurality of cylinders are provided with a spill fuel take-off passage consisting of a pump barrel side passage formed, and a fuel flow is passed through a counterfeit hole and its fin hole. a high-pressure fuel passage that guides high-pressure fuel from the fuel injection pump to the fuel sump; a spill fuel passage that leads spill fuel from the fuel injection pump to the fuel sump;
A plurality of fuels arranged in the cylinders of the diesel engine, consisting of a nozzle needle valve seated on the valve seat of the fuel sump and a pressure regulating spring that seats the nozzle needle valve on the valve seat of the fuel sump. The fuel is injected so as to connect the injection nozzle with the spill fuel outlet passage of the fuel injection pump disposed on the immediately preceding combustion cylinder and the fuel injection nozzle disposed on the immediately subsequent combustion cylinder. It is composed of a plurality of pilot fuel passages arranged between an injection pump and its fuel injection nozzle, and a pilot check valve arranged in each of these pilot fuel passages. The fuel injection device of the present invention is constructed by adding a fuel cutoff electromagnetic valve that is placed in each pilot fuel passage on the inlet side of the valve and is opened only when the diesel engine starts. , without sacrificing engine performance such as smoke, noise, etc., increases in combustion pressure and combustion temperature are suppressed, the amount of nitrogen oxides (N○x) contained in the exhaust gas is reduced, and , it becomes possible to advance the fuel injection timing of the fuel injection pump without further processing the shape of the plunger's upper lead and without operating the automatic timer, improving the startability of diesel engines. This makes it particularly useful for direct injection diesel engines.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a fuel injection pump for a first cylinder of a fuel injection device according to the present invention, and FIG.
FIG. 3 is a partial cross-sectional view of the pilot fuel injection system of the fuel injection pump shown in FIG. 1; FIG. 1 is a diagram showing the connection relationship of the fuel injection device shown in FIG. 1, and FIG. 5 is an electric circuit diagram of the fuel cutoff electromagnetic valve. 10. ...Fuel injection device, 1 1, 12,...
,18. ．． ．． Bosch type fuel injection pump, 19,20,
…． ．． 、． 26...Fuel injection nozzle, 27, 28,.
．．・・・．・34... High pressure fuel conduit, 60... Spill fuel removal passage, 61... Plunger side passage, 62...
... Pump barrel side passage, 63, 64, ...
, 70... Pilot fuel passage, 71... Pilot check valve, 73... Solenoid valve for fuel cutoff, 74... Electric circuit. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. A plunger side that is formed in a plunger that is rotatably and reciprocally slidably fitted into the pump barrel, and that has one end opening on the top surface of the plunger and the other end opening on the side surface of the plunger. a spill fuel removal passageway formed in the pump barrel so as to communicate with the plunger passageway when the plunger is reciprocated within the pump barrel; a plurality of bottle-type fuel injection pumps disposed in a diesel engine having a plurality of cylinders;
A nozzle hole and a fuel reservoir communicating with the nozzle hole, a high-pressure fuel passage that leads high-pressure fuel from the fuel injection pump to the fuel reservoir, a spill fuel passage that leads spill fuel from the fuel injection pump to the fuel reservoir, and the fuel A plurality of fuel injection nozzles arranged in the cylinders of the diesel engine, comprising a nozzle needle valve seated on the valve seat of the sump, and a pressure regulating spring that seats the nozzle needle valve on the valve seat of the fuel sump. and the fuel injection pump so as to connect the spill fuel outlet passage of the fuel injection pump disposed in the cylinder to be immediately combusted and the fuel injection nozzle disposed in the cylinder to be combusted immediately after the cylinder to be combusted immediately before. A fuel injection device including a plurality of pilot fuel communication passages disposed between the fuel injection nozzle and a pilot check valve disposed in each of the pilot fuel communication passages. 2. A plunger side passage formed in a plunger that is rotatably and reciprocally slidably fitted in the pump barrel, and having one end opened at the top surface of the plunger and the other end opened at the side surface of the plunger, and the plunger A spill fuel take-off passage formed in the pump barrel is formed in the pump barrel so as to communicate with the plunger side passage when the fuel is reciprocated into the pump barrel, and the plurality of cylinders a plurality of bottle-type fuel injection pumps disposed in a diesel engine having
A nozzle hole and a fuel reservoir communicating with the nozzle hole, a high-pressure fuel passage that leads high-pressure fuel of the fuel injection pump to the fuel reservoir, a spin fuel passage that leads spin fuel of the fuel injection pump to the fuel reservoir, and the fuel reservoir. a nozzle needle valve seated in the valve seat of the diesel engine; and a pressure regulating spring seating the nozzle needle valve in the valve seat of the fuel sump; The fuel injection nozzle connects the spin fuel take-off passage of the fuel injection pump located in the immediately preceding combustion cylinder with the fuel injection nozzle located in the immediately preceding combustion cylinder of the immediately preceding combustion cylinder. A plurality of pilot fuel communication passages disposed between the pump and its fuel injection nozzle, a pilot check valve disposed in each of the pilot fuel communication passages, and a pilot check valve disposed on the inlet side of the pilot check valve. A fuel injection device including a fuel cutoff solenoid valve that is disposed in each pilot fuel communication passage and is opened only when the diesel engine starts.