JPS6241964A - Fuel injection device - Google Patents

Abstract

PURPOSE:To improve the rate of fuel consumption in a high speed rotation area by providing a timing control port through a plunger barrel and providing an opening/closing mechanism for opening and closing said timing control port. CONSTITUTION:A plunger 1 reciprocates inside a plunger barrel 3, on which a fuel feeding port 4 and a fuel draining port 4 are provided. A timing control port 7 is provided on the lower part of the fuel feeding port 4 on the plunger barrel 3, and is opened and closed by means of a control bar 8. When the control bar 8 is placed at the open position of the timing control port 7, a plunger chamber 6 is connected to a fuel chamber 10 via a timing control passage 9. Thereby, the rate of fuel consumption in a high speed rotation area can be improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a fuel injection device for a diesel engine.

[Conventional technology]

A conventional plunger and plunger parallel are shown in FIG. In the figure, 01 is a syringer, which is reciprocated within the plunger barrel 03 by a fuel cam (not shown). 02 is a notch provided in the plunger 01, 04
．． 05 is the oil supply hole and oil drain hole respectively provided in the plant barrel 03, 0ku is the plunger chamber, and the cylinder 01
This is a space surrounded by the upper surface of the plunger barrel 03 and the plunger barrel 03.

When the plunger 01 rises due to the rotation of the fuel t1 cam (the body shown in the figure), the oil supply hole 04 is opened on the side of the plunger.
And the oil drain hole 05 is gradually closed.

The oil pressure in the fuel chamber 06 increases by -L, and when this oil pressure increases to a certain level or more, fuel discharge begins.

After the oil supply hole 04 and oil drain hole 05 are completely closed.

Furthermore, the plunger lead 01 rises, and the plunger lead 02
When the oil is applied to the oil drain hole 05, an oil drain action occurs.

The oil pressure in the syringer chamber 06 decreases, and when the oil drain hole opens, the discharge of fuel ends.

[Problem that the invention seeks to solve]

However, the second one has the following drawbacks.

FIG. 9 shows the characteristics of injection delay and injection timing in a case with a fuel injection pipe, and FIG. 10 shows the characteristics of injection delay and injection timing in a case without a fuel injection pipe.

In the above-mentioned fuel injection device, automatic advance device (hereinafter referred to as “fuel advance device”)
- If you are too busy wearing a timer.

It is difficult to obtain appropriate injection timing over a wide range from low speed rotation to high speed rotation. That is, fuel injection devices are divided into those with fuel injection pipes and those without.

(1) For those with fuel injection pipes, the propagation time (per crank angle) of the high-pressure pressure wave compressed by the planter until it reaches the fuel injection valve increases as the rotation speed increases, and the propagation time (per crank angle) increases by 1 inch. Due to the fact that the residual pressure decreases as the engine speeds up, the injection delay increases as the rotation speed increases, resulting in the characteristics shown by the solid line in FIG. 9, and as a result, the fuel injection timing is delayed in the high speed rotation range.

(11) In an engine without a fuel injection pipe, the injection delay is almost constant with respect to the engine speed, resulting in a characteristic as shown by the solid line in FIG.

Due to the above-mentioned injection timing characteristics, if an auto-timer is not installed, the ignition timing of the fuel will be delayed as the rotation speed increases, resulting in a disadvantage that the fuel consumption rate will worsen in the high speed rotation range.

[Means for solving problems]

The object of the present invention is to provide a reciprocating plunger type combustion engine that can improve the injection timing, that is, advance the fuel injection timing in the high speed rotation range compared to the low speed rotation range;
The purpose of the present invention is to provide a timing control hole provided through the plunger barrel, a timing control passage provided in the plunger that communicates the plunger chamber with the timing control hole, and the above-mentioned timing control passage. It is equipped with an opening/closing mechanism that opens and closes the timing control hole.

[Effect]

In this case, the timing control hole opens and closes according to the total engine speed to control the grease discharge of fuel.

That is, the prestroke is made larger in the low speed rotation range than in the high speed rotation range.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a plunger barrel of a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line A--A in FIG. 1.

In the figure, 1 is a sylanger which reciprocates inside the plunger barrel 3 by a fuel cam (not shown), 2 is a plunger lead which is a notch provided in the sylanger 1;
Reference numerals 4 and 5 indicate an oil supply hole and an oil drain hole respectively provided in the plunger barrel 3. Reference numeral 6 indicates a silanger chamber, which is a space surrounded by the upper surface of the plunger 1 and the plunger barrel 3. Reference numeral 7 indicates a timing control hole, which is located in the plunger barrel. It is provided below the oil supply hole 4 and is opened and closed by a control rod 8. The control rod 8 is a rod that acts as a valve to open and close the timing control hole 7 according to the engine speed NE. When the control rod 8 is in the open position of the timing control hole 7, a timing control passage 9 connects the plunger chamber 6 and the oil supply chamber 10.

The timing control passage 9 is provided in the sylanger 1 and communicates the plunger chamber 6 with the timing control hole 7. The refueling chamber 10 is a space provided in the pump housing (not shown) and is used for refueling the fuel injection device. Fuel is sucked into and discharged from the system (all shown in the figure are composed of a fuel tank, a filter, a feed pump, etc.).

The operation in the case of the above configuration will be described.

FIGS. 3(a), 3(b), and 3(e) are cross-sectional views of the plunger barrel showing the static discharge start timing when the timing control hole is opened and closed.

(1) In the case of high-speed rotation range, the drive device (
(not shown), the timing control hole 7 is closed in this case. In this state, when the plunger 1 is raised by the rotation of a fuel cam (not shown), the oil supply hole 4 and the oil drain hole 5 are gradually closed on the side of the plunger, and the oil pressure in the syringer chamber 6 increases. When the oil pressure increases beyond a certain level, fuel discharge begins. in this case.

The static (or geometric) discharge start timing is shown in Figure 3 (a).
), the top surface of the plunger is in the position where the oil supply hole and oil drain hole are closed, similar to the conventional one.

After the oil supply hole and oil extraction hole are completely closed, the sylanger is further raised to -, and when the plant gear lead 2 is applied to the oil drain hole, an oil drain action occurs, and the oil pressure in the sylanger chamber decreases.
Further, when the oil drain hole opens, fuel discharge ends.

(11) In the case of a low speed rotation range In a low speed rotation range, the control rod 8 is positioned so that the timing control hole 7 is opened by the drive device for the control rod 8. In this state, even if the sylanger 1 is raised by the rotation of the fuel cam and the oil supply hole 4 and oil drain hole 5 are completely closed on the side of the plunger (as shown in FIG. 3(b)), the timing control passage 9
The plunger chamber 6 and the oil supply chamber 10 are in communication with each other through the timing control hole 7, and therefore the oil pressure in the syringe chamber does not rise sufficiently, and no fuel is discharged. When the plunger further rises and communication between the timing control passage and the timing control hole is cut off (as shown in FIG. 3(C)), the oil pressure in the plunger chamber increases and fuel discharge begins.

When the plunger further rises, the f plunger lead 2 is engaged with the oil drain hole, thereby causing an oil draining action, reducing the oil pressure in the plunger chamber, and ending fuel discharge.

FIG. 6 is a sectional view showing a plunger barrel according to a second embodiment of the present invention, and FIG. 7 is a sectional view taken along line A--A in FIG. 6.

In the figure, numerals 1 to 6 and 9 and 10 are the same as those in the first embodiment.

Reference numeral 7 denotes a timing control hole, which is provided in the plunger barrel 3 and is opened and closed by rotation of the control ring 8. When the control ring 8 is in the open position of the timing control hole, the timing control passage 9 connects the syringe chamber 6 and the oil supply chamber 10.
Connect with.

The control ring 8 is a ring for opening and closing the timing control hole 7 according to the total engine rotation speed NE.

Structurally, the control rod of the first embodiment of L1 is simply replaced with a control ring, and one function is the same as that of the first embodiment.

〔Effect of the invention〕

Figure 4 shows the injection timing characteristics of a device with a fuel injection pipe, (a) when the timing control hole is opened and closed discontinuously, and (b) when the opening area of the timing control hole is completely continuously changed. It is.

In the case of the first embodiment, the fuel discharge stroke changes depending on the engine speed due to the above-mentioned effect.

That is, high-speed rotation range: the same prestroke h as before.

Low speed rotation range: The glue stroke increases, h. -+-h
, 1, and therefore, in the low speed rotation range, the fuel injection timing is delayed by θp1 (angle corresponding to hpl) compared to the conventional one. Therefore, if the injection timing is changed in advance so that the fuel injection timing is the same as the conventional one in the low-speed rotation range, the fuel injection timing will be advanced by θ, 1 in the high-speed rotation range compared to the conventional one. Become. This is shown in FIGS. 4 and 5.

Here, (,) is a case where the timing control hole is discontinuously opened and closed at a certain rotation speed, and (b) is a case where the opening area of the timing control hole is continuously changed.

As a result, the fuel consumption rate in the high speed range is improved.

The effects of the second embodiment are the same as those of the first embodiment.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a plunger barrel of a first embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1,
Figures 3(a), (b), and (e) are cross-sectional views of the plunger barrel showing the static discharge start timing when the timing control hole is opened and closed, and Figures 4(a) and (b) are for fuel injection. Figures 5(a) and 5(b) are diagrams showing the injection timing characteristics of the fuel injection pipe with no fuel injection pipe, and Figure 6 is a diagram showing the injection timing characteristics of the fuel injection pipe with no fuel injection pipe. A sectional view showing the plunger barrel, Fig. 7 is a sectional view taken along the line A-A in Fig. 6, Fig. 8 is an explanatory view showing a conventional fuel injection installation, and Fig. 9 is an injection delay although it has a fuel injection pipe. FIG. 10 is a diagram showing characteristics of injection delay and injection timing when all fuel injection pipes are present and not. 1... Siranja, 3... Plunger barrel, 4...
... Oil supply hole, 5 ... Oil drain hole, 6 ... Plunger chamber,
7... Timing control hole, 8... Control rod, 9...
Timing control passage. Figure 1 NE'/? Moved from C Fig. 2 (a) Fig. 3 Engine rotation speed NE (b) 匡 ax engine rotation speed NE (a) Engine rotation speed NE (b) Wataru engine rotation speed NE (a) Fig. 5 Fig. 6 Fig. Figure 7 Engine speed NE Figure 9

Claims (1)

[Claims] 1. A fuel injection system having a plunger barrel, a plunger that reciprocates within the plunger barrel, a plunger chamber formed by the upper surface of the plunger and the plunger barrel, and an oil supply hole and an oil drain hole respectively provided in the plunger barrel. The device includes a timing control hole provided through the plunger barrel, a timing control passage provided in the plunger that communicates the plunger chamber with the timing control hole, and an opening/closing mechanism that opens and closes the timing control hole. A fuel injection device characterized by: