JPH01157236U

JPH01157236U -

Info

Publication number: JPH01157236U
Application number: JP5241988U
Authority: JP
Priority date: 1988-04-19
Filing date: 1988-04-19
Publication date: 1989-10-30

Description

[Brief explanation of the drawing]

第１図はこの考案の一実施例の分配型噴射ポン
プの断面図、第２図は第１図のＡ―Ａ線断面図、
第３図Ａ、第３図Ｂは第２図の通路２２部の拡大
図、第４図Ａ、第４図Ｂは第１図の通路２２部の
拡大図である。第５図は他の実施例のデイストリ
ビユータヘツド１７部の断面図、第６図Ａは第５
図のＡ部の拡大図、第６図Ｂは第６図ＡのＡ―Ａ
線断面図、第７図ないし第１０図はこの実施例の
作用を説明するためのスプール弁位置を示す図、
第１１図はこの実施例の基準パルスと制御信号と
を示す波形図である。第１２図Ａと第１２図Ｂは
それぞれ電磁弁１４の開弁状態と閉弁状態におけ
る開閉時期センサの構成図、第１３図は同センサ
の出力特性図である。第１４図は従来ポンプの断
面図、第１５図は従来ポンプによる駆動パルスと
噴射特性との関係を説明するための波形図である
。１……ポンプハウジング、３……プランジヤポ
ンプ、５……ポンプ室、７……プランジヤ、９…
…フエイスカム、１２……プランジヤ室、１３…
…燃料戻し通路、１４……電磁弁、１７……デイ
ストリビユータヘツド、２１……第２の燃料戻し
通路、２２，２３……通路、２５……電磁弁、２
６……バルブ、３１……第２の燃料戻し通路、３
２〜３４……通路、３５……スプール弁、４０…
…ラツク、４１……ピニヨン、４２……ステツプ
モータ。 Fig. 1 is a sectional view of a distribution type injection pump according to an embodiment of this invention, Fig. 2 is a sectional view taken along the line A--A in Fig. 1,
3A and 3B are enlarged views of the passage 22 portion of FIG. 2, and FIGS. 4A and 4B are enlarged views of the passage 22 portion of FIG. 1. FIG. 5 is a sectional view of the distributor head 17 of another embodiment, and FIG.
An enlarged view of part A in the figure, Figure 6B is A-A of Figure 6A
Line sectional views, FIGS. 7 to 10 are views showing the spool valve position for explaining the operation of this embodiment,
FIG. 11 is a waveform diagram showing the reference pulse and control signal of this embodiment. 12A and 12B are configuration diagrams of the opening/closing timing sensor in the open and closed states of the solenoid valve 14, respectively, and FIG. 13 is an output characteristic diagram of the sensor. FIG. 14 is a sectional view of a conventional pump, and FIG. 15 is a waveform diagram for explaining the relationship between drive pulses and injection characteristics of the conventional pump. 1... Pump housing, 3... Plunger pump, 5... Pump chamber, 7... Plunger, 9...
...Face cam, 12... Plunger chamber, 13...
...Fuel return passage, 14... Solenoid valve, 17... Distributor head, 21... Second fuel return passage, 22, 23... Passage, 25... Solenoid valve, 2
6... Valve, 31... Second fuel return passage, 3
2 to 34... passage, 35... spool valve, 40...
...Rack, 41... Pinyon, 42... Step motor.

Claims

[Scope of utility model registration request]

A low-pressure feed pump and a high-pressure plunger pump that rotate in synchronization with engine rotation are provided, and an electromagnetic field that opens and closes using a drive pulse is installed in a fuel return passage that communicates the low-pressure pump chamber of the feed pump formed in the pump housing with the high-pressure plunger chamber of the plunger pump. In a fuel injection pump for a diesel engine, which is equipped with a valve and whose fuel injection start timing and injection period are variably controlled by opening and closing the solenoid valve, a low-pressure pump is branched from a fuel return passage upstream of the solenoid valve. a second fuel return passage communicating with the chamber;
A fuel injection pump for a diesel engine, comprising a valve mechanism that opens and closes the second fuel return passage in response to a signal from an ignition switch.