JPS644837U

JPS644837U -

Info

Publication number: JPS644837U
Application number: JP9967487U
Authority: JP
Priority date: 1987-06-29
Filing date: 1987-06-29
Publication date: 1989-01-12

Description

[Brief explanation of the drawing]

第１図は本考案のクレーム対応図、第２図は本
考案の一実施例を示す制御システム図、第３図と
第４図はこの実施例の噴射ポンプの要部断面図と
ポンプ後方から外形図、第５図はこの実施例の制
御内容を示す流れ図、第６図ないし第１２図は制
御に使用するメモリ値を示す特性図、第１３図と
第１４図はパイロツト噴射を行わない場合と行う
場合のそれぞれに付与される駆動パルスを示す波
形図、第１５図はパイロツト噴射を行う場合のこ
の実施例の作用を示す波形図、第１６図は他の実
施例の波形図である。第１７図は従来例のポンプ
断面図、第１８図Ａと第１８図Ｂはそれぞれ通常
噴射とパイロツト噴射時の燃料噴射特性を示す説
明図、第１９図はフエイスカムのカム速度特性図
、第２０図は従来例の作用を示す波形図である。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、１１……ローラ、１２……プラ
ンジヤ室、１３Ａ，１３Ｂ……分岐燃料戻し通路
、２１Ａ……大流量電磁弁、２１Ｂ……小流量電
磁弁、２２……機関回転数検出手段、２３……機
関負荷検出手段、２４……主噴射の制御量算出手
段、２５……領域判定手段、２６……パイロツト
噴射の制御量算出手段、２７Ａ，２７Ｂ……パル
ス数とパルス間隔の算出手段、２８Ａ，２８Ｂ…
…駆動パルス発生手段、２９Ａ，２９Ｂ……電磁
弁駆動手段、４１……角度パルス発生センサ、４
２……上死点センサ、４３……アクセル開度セン
サ、４４……コントロールユニツト、４５Ａ，４
５Ｂ……電磁弁駆動回路、４６Ａ，４６Ｂ……開
閉時期センサ。 Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a control system diagram showing an embodiment of the present invention, and Figs. 3 and 4 are sectional views of main parts of the injection pump of this embodiment, viewed from the rear of the pump. Figure 5 is a flowchart showing the control contents of this embodiment, Figures 6 to 12 are characteristic diagrams showing memory values used for control, and Figures 13 and 14 are when pilot injection is not performed. FIG. 15 is a waveform diagram showing the operation of this embodiment when pilot injection is performed, and FIG. 16 is a waveform diagram of another embodiment. FIG. 17 is a sectional view of a conventional pump, FIGS. 18A and 18B are explanatory diagrams showing fuel injection characteristics during normal injection and pilot injection, respectively, FIG. 19 is a cam speed characteristic diagram of a face cam, and FIG. The figure is a waveform diagram showing the effect of the conventional example. 1... Pump housing, 3... Plunger pump, 5... Pump chamber, 7... Plunger, 9...
... Face cam, 11 ... Roller, 12 ... Plunger chamber, 13A, 13B ... Branch fuel return passage, 21A ... Large flow solenoid valve, 21B ... Small flow solenoid valve, 22 ... Engine rotation speed detection means, 23 ... Engine load detection means, 24 ... Main injection control amount calculation means, 25 ... Region determination means, 26 ... Pilot injection control amount calculation means, 27A, 27B ... Pulse number and pulse interval calculation means, 28A, 28B...
...Drive pulse generation means, 29A, 29B...Solenoid valve drive means, 41...Angle pulse generation sensor, 4
2...Top dead center sensor, 43...Accelerator opening sensor, 44...Control unit, 45A, 4
5B...Solenoid valve drive circuit, 46A, 46B...Opening/closing timing sensor.

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 pump that opens and closes using a drive pulse is installed in the 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. The fuel injection pump is equipped with a valve, and the fuel injection start timing and injection period are variably controlled by the opening and closing of this solenoid valve.The fuel injection pump is divided into two injections, and the pilot injection is performed prior to the main injection. In the fuel injection control device for a diesel engine configured to perform A fuel injection control device for a diesel engine, characterized in that pilot injection is controlled by opening and closing a solenoid valve.