JPS5958150A - Fuel injection valve - Google Patents

Abstract

PURPOSE:To satisfy the cut-off of fuel injection, by arranging, around a main needle valve, an auxiliary needle valve provided with an oil sump and a spring, an oil passage branched off from a fuel introduction passage and led to the oil sump in the auxiliary needle valve, a check valve disposed in the oil passage and a restrictor disposed in parallel with the check valve. CONSTITUTION:When pressure in an oil sump 101 exceeds a valve opening pressure P0 due to pressure wave from a fuel injection pump, a main needle valve 3 is lifted so that a check valve 10 is opened to make a restrictor ineffective and pressure in the oil sump becomes also the valve opening pressure P0. As a result, an auxiliary needle valve 13 is also lifted simultaneously with the main needle valve 3, thereby fuel is injected from an injection port 8. After the completion of a discharge by the fuel injection pump, the main needle valve 3 is seated. During this stage, the check valve is still opened so that a decrease in the volume of the oil sump 101 is absorbed by the volume of the auxiliary needle valve. On the auxiliary needle valve side the check valve 10 is closed by a spring 11 dut to pressure drop, and therefore, fuel is subjected to restriction by the restrictor 12. Therefore, by suitably selecting a restricting value, the rate of pressure drop may be controlled so that the auxiliary needle valve 13 is lowered after the main needle valve 3 is seated. Accordingly, the portion of fuel of volume variation upon descent of the auxiliary needle valve 13 is not injected through the injection port 8 so that the cut-off of fuel injection is made satisfactory.

Description

[Detailed description of the invention] The present invention relates to a fuel injection valve for an internal combustion engine.

A conventional fuel injection valve of this type is shown in FIG. In the figure,
01 is the fuel injection valve body, 02 is the oil path inside the fuel injection valve, 0
A needle valve 3 is slidably inserted into the fuel injection valve body 0.1. 04 is the needle valve push rod.

05 is a needle valve spring, and the spring force is applied via a push rod 04 to press the needle valve 03 to the inside of the nozzle 08 and to the r seat 01 (12). 06 is a valve opening pressure adjustment screw, and 07 is a spring chamber. The nozzle 08 communicates the oil reservoir (l I 01) with the combustion chamber (not shown) in the cylinder of the ennon. 09 is the discharge port.

Fuel injection, I? The fuel oil is compressed by a knob (not shown) and reaches a high pressure while passing through an injection pipe (not shown), an oil passage 02 in the fuel injection valve, and an oil sump 0101. The needle valve 03 is pressed against the valve seat 0102 by the spring 05, and the fuel oil pressure in the oil reservoir 0101 is constant pressure, that is, the valve opening pressure P. An initial spring force is set by the valve opening pressure adjusting screw 06 so that the valve does not open unless the valve opening pressure exceeds the above value. Therefore, the high pressure wave sent from the type injection pump reaches the valve opening pressure P in the oil sump 0101.

When the pressure exceeds the pressure, the needle valve 03 rises by 2, and the oil sump 010 rises.
The volume of part 1 increases, part of the fuel is sent from the fuel injection pump 0 and part of the fuel is spent on this, and the rest is injected from the injection pump 18 into the combustion chamber and ignites and burns to produce output. Suzensai (
Futona l□, I? When the discharge of pump 0 is completed, the oil sump (l
The pressure within 1.01 drops and this pressure becomes the valve closing pressure F'
When the needle valve 03 is pushed down by the spring 05, the volume of the oil pool decreases by 0.1 (l),
A part of it is injected from the nozzle 08, and when the needle valve ();3 is seated on the valve seat 0102, the injection ends.

Note that leakage from the sliding portion of the needle valve ( ) 3 during this period reaches the spring chamber 07 and is discharged through the discharge port ( ) 9 .

Shikaji soil n (U for 2: It has the following drawbacks.

In order to reduce the noise, the 8th point is to reduce the fuel energy and IM during the fire delay period, and this is achieved from the fuel injection side. As one method to prevent this, it is said to be effective to suppress the injection rate at the beginning of the injection to a low level.In the conventional method, the volume of the oil reservoir increases due to the rise of the needle valve, so the fuel injection A portion of the fuel sent from Ponfu 0 is spent on this,
The rest will be ejected from the nozzle.

The injection rate at the initial stage of injection is suppressed, but on the other hand, when the needle valve descends due to a drop in pressure, the volume of the oil pool decreases, and some of it is injected from the nozzle, so even in the latter stage of injection after the main injection ends. As shown in FIG. 2, there is a drawback that low-pressure, low-injection-rate injection continues incessantly, resulting in poor smoke exhaust.

The purpose of the present invention is to focus on the above points and to suppress the injection rate at the initial stage of injection, that is, to secure a long-term low injection rate of 311J.

Moreover, it prevents low-pressure, low-injection-rate injection in the latter half of the main injection period.
Toshi provides a hot stone injection valve that can improve the sharpness of injection, and its features include an oil reservoir in the main needle valve into which fuel from the fuel injection pump is introduced, and four oil reservoirs. A fuel injection valve for an internal combustion engine that has a nozzle communicating with a seven-ring combustion chamber, and a main needle valve that opens and closes the nozzle by attaching to and removing from a valve seat provided inside the nozzle.
It is slidably housed in the space around the main needle valve.
, an auxiliary hook valve with an oil sump on the i side and a spring on the other end, and an oil branching from the fuel introduction path to the oil sump of the main hook valve and leading to the oil sump of the 10 sub-valves. The sub-needle valve is opened at approximately the same pressure as the opening pressure of the main needle valve provided in the same oil passage, and the sub-needle valve is opened in the direction of increasing the volume of the oil M of the sub-needle valve. ] A reverse city valve that closes when the main needle valve closes at a pressure equal to or lower than the closing pressure of the main needle valve. It is equipped with a throttle that gradually reduces the pressure in the oil sump.

In this case, sub<pl valve and this movement! ii! I! −
If combined with Toichiben and aperture.

(1) At the beginning of injection, the auxiliary needle valve is displaced in synchronization with the opening of the main needle valve in a direction that increases the amount of oil in the sump of the auxiliary needle valve, and (2
) In the latter stage of injection, after the main) I valve has arrived, the secondary needle valve (1) is activated.
) in the opposite direction.

If the shape is such that two valves are combined on the same axis, it will be a convergent configuration, which is convenient in terms of waves.

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

FIG. 3 is a cross-sectional view showing a fuel injection method I' according to the present invention.

In the figure, 1 is the main body of the fuel injection valve, 2 is the oil passage that introduces fuel 1 from the fuel oil injection pump into the oil aqt 101 of the main thruster, and 3 is the main needle valve, which is the fuel oil injection valve. In the wooden body 1, there is a ``skull eye'' inserted into the Noh. 4 is the main senben.

5 is a main needle valve spring, and the spring force presses the main needle valve 3 to the valve pressure 102 provided in the nozzle 8 (ill) through the push rod 4. 6 is a valve opening pressure adjustment screw, and 7 is a valve opening pressure adjustment screw. It is a spring chamber.
Reference numeral 8 communicates the oil reservoir p I (l+) of the main needle valve with the combustion chamber (not shown) in the 7-ring of the engine. 9 is a discharge port.

■3 is the secondary needle valve, around the main needle valve! ! It is accommodated in a sliding capacity between R, and has an auxiliary needle valve oil M (16) on one end and an auxiliary needle valve spring 14 on the other end. 15 is an auxiliary needle valve stopper.

10 is a check valve, 12 is a throttle, and both of these are the /llll reservoir of the sub-needle valve branched from the oil passage 2 via the annular oil passage 17]
The oil passages are lined up in the middle of the oil passages reaching 6.

11 is a check valve spring.

The operation in the case of the above tf11 configuration will be described.

・Kakebetsu injection month? The fuel oil is 1f due to the horn (not shown)
: The fuel is compressed and is sent to the injection pipe (not shown) while being under high pressure, passes through the oil path 2 in the fuel injection valve and branches into an annular oil path 11 and oil path 17, one of which reaches the oil sump +01 of the main needle valve. .

A:, the side valve 3 is connected by the main needle valve spring 5 and the auxiliary needle valve 1
3 is pressed by the width needle valve spring I/I, with a constant pressure,
That is, the valve opening pressure P. Unless it becomes higher than that, it will not rise to the second level. Therefore, the high pressure wave sent from the fuel injection pump 0 to the main needle valve oil reservoir Jol causes the valve opening pressure P. When it comes to 1, the main t + 3 is ten eyebrows and 1 year old. At this time, it is reverse 1, jV l
(Since l opens, the throttle 12 does not work, and when the pressure of the main side non-oil ld1 101 becomes P., the monthly zero force of the sub-side valve oil holder 10 also becomes P., and the main needle valve 3 (almost the same) 11j
The secondary needle valve 13 also rises to 11 degrees. Therefore, the increase in volume when the needle valve 3 rises by 1 is the sum of the increases in the oil reservoir 1 (ml) and 16. The fuel is injected into the combustion chamber (not shown) and ignites and burns to produce output.

If the fuel injection pump does not finish discharging the fuel, the pressure in the raw metal valve oil reservoir 101 decreases, and when this pressure falls below the valve closing pressure, the main needle valve 3 is pushed down by the main needle valve spring 5. He descends and sits down. During this time, the reverse one-tooth valve 10 is still in the open state, and the decrease in the volume of the main needle valve oil reservoir 101 due to the descent of the main needle valve 3 is absorbed by the volume on the auxiliary needle valve side. On the auxiliary needle valve side, when the discharge of the fuel injection pump ends and the pressure in the oil passage decreases, the check valve 10 is closed by the check valve spring 11, and the fuel is subjected to a throttling action by the throttle 2. For this reason, the pressure drop in the sub needle valve oil reservoir 16 becomes gradual, and the size of the orifice,
The rate of pressure drop is controlled by appropriate selection of the shape, and if the pressure in the secondary valve oil reservoir 16 is made below the valve closing pressure after the main needle valve 3 is seated, the secondary valve oil reservoir 16 will be closed after the main needle valve 3 is seated. Valve 13 is lowered. Therefore, the fuel corresponding to the change in volume when the auxiliary needle valve 13 descends is not injected from the injection port 8. In addition, during this time, the main needle valve 3
The leakage from the >d moving part of the secondary needle valve 1; 3 reaches the spring chamber 7 and is discharged through the discharge 1''19.
If the shape Q of 3 and the F part are made into a conical shape and seated on the cone part, the valve closing pressure can be made smaller than the valve opening pressure, and the start of descent of the secondary needle valve 3 is delayed. This makes it even more effective.

If we focus on the fuel injection rate and reduce the above effect to 1.

The next 'two' becomes.

(+) u7 "At the beginning of one injection, the main 91 valve and the sub needle valve are loaded almost simultaneously, resulting in a large volume increase, and the fuel sent from the fuel injection 1 injection and the fuel injection 0. Since the amount spent on the inner Jl increases, the injection rate at the initial stage of injection can be suppressed to a low level.

(2) At 1υ1 after injection, the decrease in volume of the main side non-oil M1 is absorbed by the sub needle valve 41111, and
Since the auxiliary needle valve descends 1: after '14, the change in volume has no bearing on fuel injection. Therefore, it is possible to prevent the low-pressure, low-injection-rate injection from continuing sluggishly after the end of the main injection, and the sharpness of the injection is improved.

Therefore, the injection rate mode is as shown in FIG.

Note that the above two points can also be applied to a hall type fuel injection valve.

The above case has the following effects.

(1) It is possible to reduce fuel consumption during the ignition delay period, and combustion noise can be reduced.

(2) It is possible to prevent low-pressure, low-injection-rate injection from continuing sluggishly, and it is possible to reduce exhaustion, fuel consumption, etc.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a conventional fuel injection valve, and Figure 2 is a cross-sectional view of a conventional fuel injection valve.
FIG. 3 is a diagram showing the fuel injection rate of the fuel injection valve shown in the figure. FIG. 3 shows J#: f-'lf! of one embodiment according to the present invention.
+: A cross-sectional view showing the injection valve. FIG. 4 is a diagram showing the injection rate of 1 injection 9 of 1 injection in FIG. 3. 3... Main needle valve, 8 - Nozzle, 10... Main side valve oil control. 10: Check valve, 12: Throttle, 13: Sub-91 valve, 16: Sub-needle valve oil reservoir. Figure 1 Kurasiwa A, (deg) S'2 & Seki 3M Climber/River -, (deg) Figure 74 Procedural Amendment (Voluntary) January 29, 1981 Kazuo Wakasugi, Commissioner of the Patent Office, 1, of the case Display Patent Application No. 1 (1983) (I 6054 No. 2 Name of the invention Relationship with the 11 persons who operate the fuel injection valve 3 tilt it) Patent applicant 11 Location 1-5-1 Marunouchi Knee, Iyota-ku, Tokyo Name (620) Mitsubishi Heavy Industries, Ltd. 4 Sub-Agent JP 5 Subject of Supplementary IE, 71 Bill H1 6, Contents of Amendment (1) The scope of the claims is amended as shown in the attached sheet. (2) Specification No. From page 5, line 5 to line 6, delete the text ``,] - The recorder needle valve opens at ...''. (3) From page 5, line 8 to line 9, delete the text. (4) From page 8, line 7 of the same page, delete the line ``with 1 of ``The valve closes with ``2...''.'' (4) From page 8, line 7 of
Check valve 10...absorbed. ” to be deleted. (5) Delete ``Shu Liuben oil reservoir...'' from lines 14 to 15 on page 9. 2. Scope of Claims 1. The oil reservoir of the main side valve into which fuel is introduced from the fuel injection pump 0, the jet "J" that communicates the oil reservoir with the combustion chamber of the 7th ring, and the valve 1 installed inside the nozzle. In a fuel injection valve for an internal combustion engine having a main 91 valve that opens and closes both nozzles by attaching and detaching the valve, the valve is slidably housed in the space around the main side valve and is provided with an oil reservoir at one end (ill) and a spring at the other end. An oil passage branching from the fuel 41/A inlet to the oil sump of the main valve and leading to the oil sump of the secondary valve, provided in the same oil passage. A check valve that forces the sub ↑ 1 valve in the direction of increasing the volume of the oil reservoir of the plan 1 valve, and is installed in parallel with the reverse up valve and -1 - sub side after the said reverse up valve is closed. A fuel injection valve with a fliti function that gradually reduces the pressure of the oil sump in the valve release valve. !I11.

Claims (1)

[Claims] 1. A nozzle that communicates the oil reservoir of the main needle valve into which fuel from the fuel injection pump is introduced, the four oil reservoirs and the combustion chamber of the cylinder, and the valve 1 (no.4) provided inside the nozzle. In a fuel injection valve for an internal combustion engine, which has a main needle valve that opens and closes the nozzle opening by attaching and detaching, the secondary valve is slidably accommodated in the space around the upper needle valve and has an oil reservoir on one end and a spring on the other end. A side valve, an oil path branching from the fuel introduction path to the oil M1 of the main needle valve and leading to the oil M1 of the auxiliary needle valve, and an oil path provided in the same oil path to open the main needle valve. The secondary needle valve is opened at approximately the same pressure as the pressure, and the secondary needle valve is urged in a direction to increase the volume of the oil reservoir in the secondary needle valve.
A check piece that closes at a pressure lower than the closing pressure of the main needle valve, and a throttle that is installed in parallel with the four-way city valve and gradually reduces the pressure in the oil sump of the auxiliary needle valve after the check valve closes. A fuel injection valve characterized by comprising: