JPH0180662U

JPH0180662U -

Info

Publication number: JPH0180662U
Application number: JP1987174942U
Authority: JP
Priority date: 1987-11-18
Filing date: 1987-11-18
Publication date: 1989-05-30

Description

[Brief explanation of the drawing]

第１図は第２図のパイロツト噴射装置の詳細図
、第２図は本考案によるパイロツト噴射装置を取
りつけた燃料噴射ポンプを示す断面図、第３図は
閉弁時の状態を示す第１図の要部拡大断面図、第
４図は第３図と同じく開弁時の状態を示す断面図
、第５図は開弁圧の変化を説明するための説明図
、第６図は燃料の温度と粘度との関係を示す図、
第７図は本考案と従来の油たまりの残留圧力の発
生及びその結果としてのパイロツト噴射量の変化
を説明する説明図、第８図は本考案の第２実施例
を示す第３図と同様の断面図、第９図は第８図と
同じく開弁時の状態を示す断面図、第１０図は第
８図のリリーフ通路を設けたアキユムレートピス
トンの断面図、第１１図はリリーフ通路を変形さ
せた例の第１０図と同様の断面図、第１２図は第
１１図のリリーフ通路を採用したアキユムレート
ピストンの側面図、第１３図は第１２図のアキユ
ムレートピストンの変形例を示す側面図である。１０……燃料噴射ポンプ、１２……パイロツト
噴射装置、１８……プランジヤ、２２……燃料加
圧室、３２……燃料噴射弁、３８……アキユムレ
ートピストンガイド、４０……小孔、４２……油
たまり、４４……シリンダ、４６……アキユムレ
ートピストン、４８……弁部材、６８……リター
ンスプリング、７０……リリーフ通路。 Fig. 1 is a detailed view of the pilot injection device shown in Fig. 2, Fig. 2 is a sectional view showing a fuel injection pump equipped with the pilot injection device according to the present invention, and Fig. 3 is Fig. 1 showing the state when the valve is closed. Figure 4 is a cross-sectional view showing the state when the valve is open, similar to Figure 3, Figure 5 is an explanatory diagram to explain changes in valve opening pressure, Figure 6 is a diagram showing fuel temperature. A diagram showing the relationship between and viscosity,
Fig. 7 is an explanatory diagram illustrating the generation of residual pressure in the oil pool and the resulting change in the amount of pilot injection according to the present invention and the conventional method, and Fig. 8 is the same as Fig. 3 showing the second embodiment of the present invention. Figure 9 is a cross-sectional view showing the state when the valve is open, similar to Figure 8, Figure 10 is a cross-sectional view of the accumulation piston with the relief passage shown in Figure 8, and Figure 11 is a relief passage. FIG. 12 is a side view of an accumulation piston adopting the relief passage shown in FIG. 11, and FIG. 13 is a modification of the accumulation piston shown in FIG. 12. It is a side view which shows an example. 10...Fuel injection pump, 12...Pilot injection device, 18...Plunger, 22...Fuel pressurization chamber, 32...Fuel injection valve, 38...Accumulate piston guide, 40...Small hole, 42 ... Oil pool, 44 ... Cylinder, 46 ... Accumulate rate piston, 48 ... Valve member, 68 ... Return spring, 70 ... Relief passage.

Claims

[Scope of utility model registration request]

In a fuel injection device having a fuel pressurizing chamber into which a reciprocating plunger is inserted, an oil pool communicates with the fuel pressurizing chamber through a small hole, and the small hole communicates with the fuel pressurizing chamber through a small hole. An accumulation piston provided with a valve member that can open and close a hole, a fuel relief passage connected to the oil pool, and a fuel relief passage that blocks the relief passage when the valve member opens and closes the valve. 1. A pilot fuel injection device comprising: a pilot injection device having means for opening the pilot fuel injection device.