JP2005240779A - Internal combustion engine including fuel injection valve with needle valve spring force adjusting mechanism and adjusting method of fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine including a fuel injection valve with a needle valve spring force adjusting mechanism and an adjusting method of the fuel injection valve, remarkably decreasing the assembling and adjusting man-hour for the fuel injection valve and improving the operation of an engine and maintainability by easily adjusting the valve opening pressure in two stages with high accuracy without disassembling the fuel injection valve and with the fuel injection valve assembled to the cylinder head, not pulled out of the cylinder head in assembling and adjusting the fuel injection valve. <P>SOLUTION: This internal combustion engine includes a fuel injection valve adapted to push up a needle valve against the spring force of a needle valve spring by pressure of fuel force-fed from a fuel injection pump and inject the fuel through a jet orifice formed at the forward end of a nozzle tip into a combustion chamber, wherein the fuel injection valve includes two needle valve springs, the two needle valve springs are respectively provided with a screw type adjuster for adjusting the spring force, and the two adjusters can adjust the spring force of the corresponding needle valve springs independently. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is applied to an internal combustion engine equipped with a fuel injection valve such as a diesel engine or a gas engine, and pushes the needle valve up against the spring force of the needle valve spring by the pressure of fuel pumped from a fuel injection pump. The needle valve is opened, and the fuel is injected into the combustion chamber from the nozzle hole formed at the tip of the nozzle tip, and the needle valve spring force adjustment mechanism for adjusting the spring force of the needle valve is provided. The present invention relates to an internal combustion engine including a fuel injection valve and a method for adjusting the fuel injection valve.

In the diesel engine, the pressure of the fuel pumped from the fuel injection pump pushes up the needle valve against the spring force of the needle valve spring to open the needle valve, and the fuel is formed at the tip of the nozzle tip. By setting the opening pressure of the fuel injection valve configured to inject into the combustion chamber from the nozzle hole to two stages of low pressure and high pressure, and performing two-stage injection of low pressure and high pressure, combustion improvement and exhaust gas state Various techniques for realizing the improvement are provided.
One such technique is the technique provided in Patent Document 1 (Japanese Patent Laid-Open No. 2-81948).

In such a technique, a low-pressure and high-pressure spring having different valve opening pressures are connected to one needle valve in the axial direction of the needle valve, and the low-pressure spring is connected to the head of the needle valve to connect the low-pressure spring. The needle valve is pressed in the valve closing direction by a spring, and the high pressure spring is arranged in the lower spring receiver of the low pressure spring, and at the time of low pressure injection, the low pressure spring is operated to enable injection at a low injection pressure. During high-pressure injection, both the high-pressure spring and the low-pressure spring press the needle valve in the valve closing direction to obtain a high valve opening pressure, thereby enabling injection at such high injection pressure.
And in the technique of patent document 1, when adjusting the valve opening pressure of a low pressure side or a high pressure side, it comprises so that a shim may be inserted in a low pressure or a high pressure spring receiving part, and a fuel injection valve is disassembled. It is rearranged to the target thickness shim.

Japanese Patent Laid-Open No. 2-81948

  The prior art disclosed in Patent Document 1 has a structure in which a shim for adjusting the valve opening pressure is inserted into a low-pressure or high-pressure spring receiving portion, and when adjusting the valve-opening pressure on the low-pressure side or the high-pressure side. In this case, the fuel injection valve is disassembled and replaced with a shim having a target thickness, thereby setting the required low pressure side valve opening pressure or high pressure side valve opening pressure.

For this reason, in this prior art, when assembling and adjusting the fuel injection valve, it is necessary to disassemble the fuel injection valve and adjust the shim thickness each time the valve opening pressure on the low pressure side or the high pressure side is adjusted. Therefore, adjustment of the valve opening pressure is complicated, and a great amount of man-hour is required for assembly and adjustment of the fuel injection valve. Also, when it becomes necessary to adjust the opening pressure of the fuel injection valve of a cylinder during engine operation, the fuel injection valve is removed from the cylinder head and disassembled to adjust the shim thickness. Must be repeated, which greatly impedes engine operation and maintainability.
And so on.

  In view of the problems of the prior art, the present invention can easily and accurately increase the valve opening pressure in two stages without disassembling the fuel injection valve when assembling and adjusting the fuel injection valve. Adjustment of internal combustion engine and fuel injection valve with fuel injection valve with needle valve spring force adjustment mechanism that can greatly reduce the assembly and adjustment man-hours of fuel injection valve and improve engine operation and maintainability It aims to provide a method.

  The present invention achieves such an object. The pressure of the fuel pumped from the fuel injection pump pushes up the needle valve against the spring force of the needle valve spring to open the needle valve, and the fuel is supplied to the nozzle tip. In an internal combustion engine having a fuel injection valve that injects into a combustion chamber from an injection hole formed at a tip portion, the fuel injection valve includes two needle valve springs, and each of the two needle valve springs. A screw-type adjusting tool for adjusting the spring force is provided, and the spring force of the two needle valve springs corresponding to the two adjusting tools can be independently adjusted. .

In the invention, preferably, the two needle valve springs correspond to the first and second springs, respectively, having different valve opening pressures with respect to the one needle valve. Together with the adjustment tool, it is provided in the axial direction of the needle valve.
More specifically, the adjustment tool for adjusting the spring force of the first spring is connected to the upper spring receiver of the first spring, and the needle valve is closed by the adjustment tool and the first spring. And a second spring and an adjustment tool for adjusting the spring force of the second spring are arranged on the upper part of the adjustment tool for the first spring, and the needle valve is moved by the second spring. It is preferable to be able to press in the valve closing direction.

  Further, as a method for adjusting the fuel injection valve for the internal combustion engine, a first spring is incorporated in the valve body in a form in which the head of the needle valve is pressed in the valve closing direction, and the first low-pressure side adjustment tool of the screw type is used. The valve opening pressure on the low pressure side is adjusted by changing the spring force of the spring, and then the second spring is incorporated into the valve body in such a form that the end on the side opposite to the needle valve of the first spring is pressed. The adjustment method is characterized in that the valve opening pressure on the high pressure side is adjusted by changing the spring force of the second spring with the high pressure side adjustment tool.

According to this invention, the opening pressure of the needle valve is set such that the spring force (mounting load) of the first and second springs connected to one needle valve in the axial direction of the needle valve and having different valve opening pressures. ) Can be adjusted by changing the screwing amount of the first stage valve opening pressure, that is, the valve opening pressure on the low pressure side, by a screw-type adjusting tool provided corresponding to the first spring. , By adjusting the spring force of the first spring.
The valve opening pressure at the second stage, that is, the valve opening pressure on the high pressure side, is adjusted by a screw type provided corresponding to the second spring in addition to the spring force adjustment value of the first spring on the low pressure side. The spring amount of the second spring is adjusted by changing the screwing amount with the tool, and is set by the resultant force of the spring force of the first and second springs.

Therefore, according to this invention, the first stage valve opening pressure, that is, the valve opening pressure on the low pressure side can be adjusted steplessly by changing the screwing amount of the first spring adjustment tool, and the second spring By changing the screwing amount of the adjusting tool, the valve opening pressure at the second stage, that is, the valve opening pressure on the high pressure side can be adjusted steplessly.
Therefore, according to this invention, when the fuel injection valve is assembled and adjusted, the screwing amount of the first spring adjustment tool is changed without disassembling the fuel injection valve, or the second spring adjustment tool. By changing the screwing amount of the first stage, the first stage valve opening pressure, that is, the low side valve opening pressure alone, or the first stage valve opening pressure and the second stage valve opening pressure, ie, the high side valve opening pressure. Both pressures can be adjusted easily and steplessly as described above, and the fuel injection valve is disassembled each time the valve opening pressure on the low pressure side or high pressure side is adjusted as in the prior art disclosed in Patent Document 1. It is not necessary to adjust the thickness of the shim, and the fuel injection valve assembly and adjustment man-hours can be greatly reduced as compared with the prior art.

  Further, according to this invention, even when it becomes necessary to adjust the valve opening pressure of the fuel injection valve of a certain cylinder during operation of the engine, the valve opening pressure is reduced with the fuel injection valve assembled to the cylinder head. It is possible to adjust the first stage valve opening pressure or the second stage valve opening pressure by simply changing the screwing amount of the first spring adjustment tool or the second spring adjustment tool. Therefore, engine operation and maintainability are improved in each stage compared to the conventional technology.

In this invention, it is preferable that any one of the outer peripheral portion of the lower spring support and the counterpart member, and the upper and lower spring supports of the lower spring receiver. A gap for absorbing the falling of the first spring and the second spring is formed between the outer peripheral portion and the counterpart member.
If comprised in this way, even if the fall of the 1st spring or the 2nd spring provided in a row in the axial direction of the fuel injection valve occurs, the outer peripheral portion of any one of the upper and lower spring supports and the counterpart member The above-described tilting can be absorbed by the gap formed between them, and the occurrence of malfunction of the needle valve and the spring due to the tilting can be avoided.

In this invention, preferably, the lower spring receiver of the first spring is brought into contact with the head of the needle valve, and is connected to the lower spring receiver of the second spring via a push rod. An upper spring support of the first spring is connected to the second spring adjustment tool, the upper spring support of the second spring is brought into contact with the head of the second spring adjustment tool, and the push rod A spherical contact portion is formed at the contact portion between the first spring spring support and the contact portion between the upper spring support and the second spring adjustment tool.
If comprised in this way, the escape part by spherical contact will be formed in the contact part of a comparatively long push rod and the 1st spring spring holder, and the push rod will fall down and the push rod will be seized by this And occurrence of needle valve operation can be avoided. Further, by forming a spherical contact portion at the contact portion between the upper spring receiver and the adjustment tool of the second spring, it is possible to avoid seizure due to misalignment between the adjustment tool, the second spring and the upper spring support.

In this invention, preferably, the lower spring receiver of the first spring is brought into contact with the head of the needle valve, and is connected to the lower spring receiver of the second spring via a push rod. The rod and the lower spring support of the second spring are brought into contact with each other at the plane contact portion.
If comprised in this way, since a comparatively long push rod is cut off from the 2nd spring lower spring holder and abutted and assembled in a plane contact part, manufacture of a push rod becomes easy, and a fuel injection valve Can be easily assembled with misalignment.

  Further, according to the present invention, the pressure of the fuel pumped from the fuel injection pump pushes up the needle valve against the spring force of the needle valve spring to open the needle valve, and the fuel is formed at the tip of the nozzle tip. In a method of adjusting a fuel injection valve for an internal combustion engine that injects into a combustion chamber from an injection hole, the fuel injection valve is connected to a first valve and a second spring having different valve opening pressures relative to one needle valve. A screw-type adjustment tool that adjusts the spring force of the first spring is connected to the upper spring receiver of the first spring, and the needle is connected to the needle by the adjustment tool and the first spring. The second spring and a screw-type adjusting tool for adjusting the spring force of the second spring are arranged above the adjusting tool for adjusting the spring force of the first spring by pressing the valve in the valve closing direction. Then, the needle spring is pushed in the valve closing direction by the second spring. Capable constituted, from the fuel injection valve, remove the second spring and its associated member, characterized in that the spring force of the first spring is adjusted by the adjuster screw type.

According to this invention, the first and second springs and the screw type adjuster for adjusting these spring forces are incorporated in the fuel injection valve, and the first stage valve opening pressure adjustment on the low pressure side and the first pressure adjustment on the high pressure side. The valve opening pressure of the second stage can be adjusted, and if the second spring and its attached member are removed from the above-described form, the first stage on the low pressure side can be obtained by the first spring and its adjusting tool. The valve opening pressure can be easily adjusted.
Thereby, the single valve opening pressure adjustment test of the low pressure side and the two valve opening pressure adjustment tests of the low pressure side and the high pressure side can be performed with one fuel injection valve.

According to the present invention, when the fuel injection valve is assembled and adjusted, the screwing amount of the first spring adjusting tool is changed or the second spring adjusting tool is screwed without disassembling the fuel injection valve. By changing the amount, the valve opening pressure of the first stage (low pressure side) can be made easy, or both the valve opening pressure of the first stage and the valve opening pressure of the second stage (high pressure side) can be easily and It can be adjusted steplessly, and it is not necessary to disassemble the fuel injection valve and adjust the thickness of the shim every time the valve opening pressure on the low pressure side or high pressure side is adjusted as in the prior art. This greatly reduces the man-hours for assembly and adjustment of the fuel injection valve.
Further, according to the present invention, it is possible to adjust the valve opening pressure while the fuel injection valve is assembled to the cylinder head during operation of the engine, and the first spring adjusting tool or the second spring. The valve opening pressure of the first stage or the valve opening pressure of the second stage can be easily adjusted by simply changing the screwing amount of the adjustment tool for the engine. To improve.

  Hereinafter, the present invention will be described in detail using embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

  FIG. 1 is a sectional view taken along the axis of a fuel injection valve according to a first embodiment of the present invention. 2 is a diagram corresponding to FIG. 1 showing the second embodiment, FIG. 3 is a diagram corresponding to FIG. 1 showing the third embodiment, and FIG. 4 is a diagram corresponding to FIG.

In FIG. 1 showing the first embodiment of the present invention, 1 is a valve body, 2 is a body cover screwed into the upper part of the valve body 1, and 18 is screwed into the upper part of the body cover 2 to be described later. A second stage adjustment tool 19 for adjusting the spring force of the spring 14, 19 is a lock nut that is screwed into the upper part of the second stage adjustment tool 18 to lock the second stage adjustment tool 18, 18 a is a gasket for fluid sealing, Reference numeral 20 denotes a set screw screwed into the upper portion of the lock nut 19.
Reference numeral 3 denotes a nozzle tip fastened to the valve body 1 via a nozzle nut 5, and reference numeral 4 denotes a nozzle hole that is perforated at the tip of the nozzle tip 5. 8 is a fuel passage into which high-pressure fuel from a fuel injection pump (not shown) is introduced, and 7 is an oil sump that is open at the outlet end of the fuel passage 8 and communicates with the inlet passage of the nozzle hole 4. 1a is a fuel leak passage.

A needle valve 6 is fitted in the nozzle tip 3 so as to be slidable in a reciprocating manner. 25a is a spacer interposed between the nozzle tip 3 and the lower end surface of the valve body 1, and 24 is a gasket for fluid sealing between the nozzle nut 5 and a cylinder head (not shown).
Reference numeral 9 denotes a first-stage spring constituting a low-pressure side spring, and the first-stage spring 9 presses the head of the needle valve 6 via a first-stage lower spring receiver 10 abutted against the lower end surface of the first-stage spring 9. It is like that. Reference numeral 22 denotes a hollow first-stage upper spring support for supporting the upper end surface of the first-stage spring 9, which is slidably fitted into the valve body 1 and has an upper-end surface that will be described later. Is pressed against the lower end surface by the spring force of the first spring 9 and a second spring 14 described later. Reference numeral 21 denotes a lock nut for locking the first stage adjustment tool 16.
Reference numeral 25 denotes a positioning pin between the nozzle tip 3 and the spacer 25a, and 11 denotes a positioning pin between the valve body 1 and the spacer 25a.

Reference numeral 14 denotes a second-stage spring constituting a high-pressure side spring, and 16 denotes a hollow first-stage adjustment tool that is screwed into the upper inner periphery of the valve body 1 and in which the second-stage spring 14 is housed. Reference numeral 23 denotes a second-stage upper spring support that supports the upper-end surface of the second-stage spring 14, and the upper-end surface of the second-stage upper spring receiver 23 is connected to the lower-end surface of the second-stage adjustment tool 18. It is pressed by the spring force.
Reference numeral 13 denotes a second-stage lower spring receiver that supports the lower end surface of the second-stage spring 14, and 12 denotes a push rod that is slidably fitted to the inner periphery of the hollow first-stage upper spring receiver 22. .
The push rod 12 is formed in a rod shape, and the lower end surface is pressed against the upper end surface of the first step lower spring receiver 10 by the spring force of the second step spring 14, and the upper end surface is the second step lower spring. It is in pressure contact with the lower end surface of the receiver 13.
Also, the push rod 12 and the second stage lower spring receiver 13 can be manufactured integrally.

A flat contact portion 12 a is formed between the upper end surface of the push rod 12 and the lower end surface of the second lower spring receiver 13. By forming in this way, the relatively long push rod 12 is separated from the second stage lower spring receiver 13 and abutted and assembled at the flat contact portion 12a, so that the push rod 12 can be formed in a rod shape. This can be easily manufactured and can be easily assembled to the fuel injection valve by allowing misalignment.
Further, when the push rod 12 and the second stage lower spring support 13 are manufactured integrally, the number of parts can be reduced and the number of assembling steps can be reduced.

During operation of an engine equipped with such a fuel injection valve, high-pressure fuel pumped from a fuel injection pump (not shown) through a high-pressure injection pipe reaches the oil sump 7 through the fuel passage 8, and the pressure of the high-pressure fuel When the spring force of the first stage spring 9 is overcome, the needle valve 6 is lifted against the spring force of the first stage spring 9 and lifted to open, and the needle valve 6 is opened via the nozzle hole 4. First-stage low-pressure injection is performed.
When the pressure of the high pressure fuel further rises and overcomes the resultant force of the first stage spring 9 and the second stage spring 14, the needle valve 6 is further lifted, and the second stage through the nozzle hole 4. High-pressure injection of the eyes is made.

In the fuel injection valve, when adjusting the valve opening pressure of the needle valve 6, the first stage spring 9 is incorporated in the valve body 1 in such a form that the head of the needle valve 6 is pressed in the valve closing direction, When the first stage adjustment tool 16 on the side is screwed in by the first stage adjustment screw portion 15 to change the spring force of the first stage spring, the valve opening pressure becomes a required valve opening pressure, that is, a low valve opening pressure. The lock nut 21 is tightened to fix the first stage adjuster 16.
Next, the second-stage spring 14 is assembled in the first-stage adjustment tool 16 in a form in which the push rod 12 is pressed, and the screwing amount of the second-stage adjustment tool 18 is changed by the second-stage adjustment screw portion 17. Then, the spring force of the second stage spring 14 is changed, and when the required valve opening pressure, that is, a high valve opening pressure is reached, the lock nut 19 is tightened to fix the second stage adjustment tool 18.
By the above operation, the low pressure valve opening pressure for performing the low pressure injection by the first stage spring 9 and the high valve opening pressure for performing the high pressure injection by the second stage spring 14 and the first stage spring 9 are appropriate. Set to a value.

According to this embodiment, as described above, the opening pressure of the needle valve 6 is connected to the single needle valve 6 in the axial direction of the needle valve 6 and the first stage springs having different valve opening pressures. 9 and the second stage spring 14 can be adjusted by changing the spring force (mounting load), and the first stage valve opening pressure, that is, the low-side valve opening pressure is provided corresponding to the first stage spring 9. The amount of screwing is changed by the screw-type first stage adjusting tool 16 and the first stage spring 9 is adjusted by adjusting the spring force,
Further, the second stage valve opening pressure, that is, the valve opening pressure on the high pressure side is changed by a screw type second stage adjustment tool 18 provided corresponding to the second stage spring 14 to change the screwing amount. The spring force of the stage spring 14 is adjusted and set by the resultant force of the first stage and second stage springs 9 and 14.

Therefore, according to this embodiment, by changing the screwing amount of the first stage adjustment tool 16 for the first stage spring 9, the first stage valve opening pressure, that is, the low side valve opening pressure can be adjusted steplessly. At the same time, by changing the screwing amount of the second stage adjusting tool for the second stage spring 14, the valve opening pressure of the second stage, that is, the valve opening pressure on the high pressure side can be adjusted steplessly.
That is, when the fuel injection valve is assembled and adjusted, the screwing amount of the first stage adjustment tool 16 for the first stage spring 9 is changed without disassembling the fuel injection valve, or the second stage spring 14 is adjusted. By changing the screwing amount of the first-stage adjusting tool 16, the first-stage valve opening pressure, that is, the low-pressure side valve-opening pressure alone, or the first-stage valve opening pressure and the second-stage valve opening pressure, that is, Both of the valve opening pressures on the high pressure side can be easily and continuously adjusted as described above.
Therefore, it is not necessary to disassemble the fuel injection valve and adjust the thickness of the shim every time the valve opening pressure on the low pressure side or the high pressure side is adjusted, unlike the conventional ones. Can be greatly reduced.

  Further, according to such an embodiment, even when the opening pressure of the fuel injection valve of a certain cylinder needs to be adjusted during the operation of the engine, the fuel injection valve is attached to the cylinder head, By changing the screwing amount of the first stage adjuster 16, the low-pressure valve opening pressure on the first stage spring 9 side is changed, and by changing the screwing amount of the second stage adjuster 18, the second stage spring 14 side is changed. Since the high-pressure valve opening pressure can be adjusted easily, engine operation and maintainability are improved in each stage.

In the second embodiment shown in FIG. 2, to form a dimension S ₂ become the gap 31 between the outer periphery and the inner periphery of the spacer 25a of the first stage lower spring receiver 10 for the first stage spring 9 A gap 30 having a dimension S ₁ is formed between the outer periphery of the second step upper spring receiver 23 for the second step spring 14 and the inner periphery of the first step adjustment tool 16.
According to the second embodiment, even if the first-stage spring 9 or the second-stage spring 14 connected in the axial direction of the fuel injection valve falls down, the first-stage lower spring support on the first-stage spring 9 side. 10 by the gap 31 formed between the outer periphery of the spacer 10 and the inner periphery of the spacer 25a and the gap 30 formed between the outer periphery of the second-stage upper spring receiver 23 and the inner periphery of the first-stage adjustment tool 16. The fall can be absorbed and the occurrence of malfunction of the needle valve 6 and the springs 9 and 14 due to the fall can be avoided.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

In the third embodiment shown in FIG. 3, the upper surface 35 of the second-stage upper spring receiver 23 of the second-stage spring 14 and the lower surface 36 of the second-stage adjustment tool 18 for the second-stage spring 14 are spherical. Both are formed and brought into contact with each other by spherical contact, and the lower surface 38 of the push rod 12 and the upper surface 37 of the first stage lower spring receiver 10 are formed into spherical surfaces, and both are brought into contact with each other by spherical contact.
According to this embodiment, by forming a relief portion by spherical contact between the relatively long push rod 12 and the first stage lower spring receiver 10, the push rod 12 falls down and the push rod 12 is caused thereby. It is possible to avoid the occurrence of seizure and the operation of the needle valve 6. Further, by making the second stage upper spring receiver 23 and the second stage adjustment tool 18 into spherical contact, due to the misalignment between the second stage adjustment tool 18, the second stage spring 14 and the second stage upper spring receiver 23. Burn-in can be avoided.
Other configurations are the same as those in the first embodiment, and the same members are denoted by the same reference numerals.

In the fourth embodiment shown in FIG. 4, the second stage spring 14, the second stage upper spring receiver 23, and the second stage spring 14 for setting the valve opening pressure on the high pressure side are compared with the first embodiment shown in FIG. 1. The second stage lower spring receiver 13 is removed (the second stage adjustment tool 18 may also be removed), and the valve opening pressure on the low pressure side is set by the first stage spring 9 and the first stage adjustment tool 16 on the low pressure side. Yes.
That is, according to the fourth embodiment, the first-stage and second-stage springs 9 and 14 and the screw type first-stage and second-stage adjustments for adjusting the spring force as in the first embodiment. The tools 16 and 18 are incorporated in the fuel injection valve, and both the first-stage valve opening pressure adjustment on the low-pressure side and the second-stage valve opening pressure adjustment on the high-pressure side can be performed. If the second-stage spring 14 and its associated members are removed from the form of FIG. 4 to obtain the form of FIG. 4, the first-stage spring 9 and its adjustment tool 16 can easily adjust the opening pressure of the first stage on the low pressure side. It can be carried out.
Thereby, the single valve opening pressure adjustment test of the low pressure side and the two valve opening pressure adjustment tests of the low pressure side and the high pressure side can be performed with one fuel injection valve.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

  According to the present invention, at the time of assembly and adjustment of the fuel injection valve, the valve opening pressure can be easily adjusted with high accuracy in two stages without disassembling the fuel injection valve and assembled to the cylinder head. It is possible to provide an internal combustion engine having a fuel injection valve with a needle valve spring force adjustment mechanism that can greatly reduce the assembly and adjustment man-hours of the fuel injection valve and can improve the operation and maintainability of the engine.

It is sectional drawing which follows the axis line of the fuel injection valve which concerns on 1st Example of this invention. It is a figure corresponding to FIG. 1 which shows 2nd Example. It is a figure corresponding to FIG. 1 which shows 3rd Example. It is a figure corresponding to FIG. 1 which shows 4th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve body 2 Body cover 3 Nozzle tip 4 Injection hole 5 Nozzle nut 6 Needle valve 7 Oil reservoir 8 Fuel passage 9 First stage spring 10 First stage lower spring holder 12 Push rod 12a Plane contact part 13 Second stage lower spring holder 14 Second stage spring 16 First stage adjustment tool 18 Second stage adjustment tool 19 Lock nut 22 First stage upper spring receiver 23 Second stage upper spring receiver 30, 31 Gap

Claims (8)

  The pressure of the fuel pumped from the fuel injection pump pushes up the needle valve against the spring force of the needle valve spring to open the needle valve, and the fuel is discharged from the nozzle hole formed at the tip of the nozzle tip into the combustion chamber. In the internal combustion engine having a fuel injection valve for injecting into the fuel, the fuel injection valve has two needle valve springs and a screw type adjustment for adjusting a spring force to each of the two needle valve springs A fuel injection valve with a needle valve spring force adjusting mechanism is provided, wherein a spring is provided to adjust the spring force of the two needle valve springs corresponding to the two adjusting tools. An internal combustion engine provided.   The two needle valve springs include first and second springs having different valve opening pressures with respect to the one needle valve, together with the adjustment tool corresponding to each of the first and second springs. 2. An internal combustion engine comprising a fuel injection valve with a needle valve spring force adjustment mechanism according to claim 1, wherein the fuel injection valve is provided continuously in the axial direction.   The adjustment tool for adjusting the spring force of the first spring is connected to the upper spring receiver of the first spring to press the needle valve in the valve closing direction with the adjustment tool and the first spring, and The second spring and the adjusting tool for adjusting the spring force of the second spring are arranged on the upper part of the adjusting tool for the first spring, and the needle valve is closed by the second spring. 3. An internal combustion engine provided with a fuel injection valve with a needle valve spring force adjusting mechanism according to claim 2, wherein the fuel injection valve is configured to be able to be pressed to the inside.   Between the outer periphery of any one of the lower spring supports and the mating member on the first spring and between the outer periphery of any one of the lower spring supports and the mating member of the second spring. 3. An internal combustion engine comprising a fuel injection valve with a needle valve spring force adjusting mechanism according to claim 2, wherein a gap for absorbing the tilting of the first spring and the second spring is formed.   The lower spring support of the first spring is brought into contact with the head of the needle valve and is connected to the lower spring support of the second spring via a push rod, and the upper spring support of the first spring is The second spring adjustment tool is connected, the upper spring holder of the second spring is brought into contact with the second spring adjustment tool, and the push rod and the first spring spring holder are in contact with each other. 4. A fuel injection valve with a needle valve spring force adjustment mechanism according to claim 3, wherein a spherical contact portion is formed at a contact portion between the first spring support portion and the second spring adjustment tool. Internal combustion engine.   The lower spring support of the first spring is brought into contact with the head of the needle valve and connected to the lower spring support of the second spring via a push rod, and the lower part of the push rod and the second spring is connected. 4. An internal combustion engine having a fuel injection valve with a needle valve spring force adjusting mechanism according to claim 3, wherein the spring bearing is brought into contact with a flat contact portion.   The pressure of the fuel pumped from the fuel injection pump pushes up the needle valve against the spring force of the needle valve spring to open the needle valve, and the fuel is discharged from the nozzle hole formed at the tip of the nozzle tip into the combustion chamber. In a method for adjusting a fuel injection valve for an internal combustion engine that injects into the valve body, a first spring is incorporated in the valve body in a form in which the head of the needle valve is pressed in the valve closing direction, and the first spring is incorporated with a screw-type low pressure side adjuster. Adjusting the valve opening pressure on the low pressure side by changing the spring force of the first spring, and then incorporating the second spring into the valve body in a form in which the anti-needle valve side end of the first spring is pressed, A method for adjusting a fuel injection valve for an internal combustion engine, wherein the valve opening pressure on the high pressure side is adjusted by changing the spring force of the second spring with a screw-type high pressure side adjusting tool.   The pressure of the fuel pumped from the fuel injection pump pushes up the needle valve against the spring force of the needle valve spring to open the needle valve, and the fuel is discharged from the nozzle hole formed at the tip of the nozzle tip into the combustion chamber. In the method for adjusting a fuel injection valve for an internal combustion engine that injects into a single valve, the fuel injection valve is provided with first and second springs having different valve opening pressures relative to one needle valve in the axial direction of the needle valve. Then, a screw-type adjusting tool for adjusting the spring force of the first spring is connected to the upper spring receiver of the first spring, and the needle valve is closed by the adjusting tool and the first spring. The second spring and a screw-type adjusting tool for adjusting the spring force of the second spring are arranged above the adjusting tool for adjusting the spring force of the first spring. The needle valve can be pressed in the valve closing direction with a spring of A method for adjusting a fuel injection valve for an internal combustion engine, comprising: removing the second spring and its attached member from the fuel injection valve; and adjusting a spring force of the first spring with the screw-type adjusting tool. .

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