WO2005083263A1

WO2005083263A1 - Internal combustion engine having fuel injection valve with mechanism for regulating needle valve spring force, and method of regulating fuel injection valve

Info

Publication number: WO2005083263A1
Application number: PCT/JP2005/003661
Authority: WO
Inventors: Norikatu Hakamata
Original assignee: Mitsubishi Heavy Industries, Ltd.
Priority date: 2004-02-27
Filing date: 2005-02-25
Publication date: 2005-09-09
Also published as: EP1726822A1; JP2005240779A; CN1950599A

Abstract

An internal combustion engine having a fuel injection valve, where, in the fuel injection valve, needle valves are pushed up and opened against force of needle valve springs by pressure of a fuel sent under pressure from a fuel injection pump, thereby injecting the fuel from an injection hole formed in a nozzle tip head section. The fuel injection valve has two of the needle valve springs, and a screw-type regulator for regulating a spring force is attached to each of the needle valve springs, and spring force of the two needle valve springs are independently regulatable by the corresponding two regulators. In assembly and regulation of the fuel injection valve, a valve opening pressure can be easily and highly accurately regulated in two stages without removing the fuel injection valve from a cylinder head and with the valve assembled in the cylinder head.

Description

TECHNICAL FIELD The present invention relates to an internal combustion engine having a fuel injection valve with a needle valve spring force adjustment mechanism and a method of adjusting the fuel injection valve.

INDUSTRIAL APPLICABILITY The present invention is applied to an internal combustion engine having a fuel injection valve such as a diesel engine or a gas engine, and pushes up a needle valve against the spring force of a needle valve spring by the pressure of fuel pumped from a fuel injection pump. A needle valve spring force adjusting mechanism configured to open a needle valve, inject the fuel into a combustion chamber from an injection hole formed at a tip end portion of a nozzle tip, and adjust a spring force of the needle valve. The present invention relates to an internal combustion engine provided with a fuel injection valve provided with the fuel injection valve, and a method for adjusting the fuel injection valve. Background art

In a diesel engine, the needle valve is opened by pushing up the needle valve against the spring force of the needle valve spring by the pressure of the fuel fed from the fuel injection pump, and the fuel is formed at the tip of the nozzle tip. By setting the valve opening pressure of the fuel injection valve, which is configured to inject into the combustion chamber from the injected holes, at two stages, low pressure and high pressure, and performing low-pressure and high-pressure two-stage injection, the combustion is improved and the exhaust gas condition is improved. Various technologies have been provided to achieve improvements.

One of such techniques is a technique provided in Japanese Patent Application Laid-Open No. 2-81948. In this technique, low-pressure and high-pressure springs 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. The low-pressure spring presses the needle valve in the valve closing direction, and the high-pressure spring is disposed in a lower spring receiver of the low-pressure spring. When the low-pressure injection is performed, the low-pressure spring is operated to inject the fuel at a low injection pressure. During high-pressure injection, the needle valve is pressed in the valve closing direction by both the high-pressure spring and the low-pressure spring to obtain a high valve-opening pressure, thereby enabling injection at such a high injection pressure.

In the technology of Patent Document 1, when adjusting the valve opening pressure on the low pressure side or the high pressure side, a shim is inserted into a low pressure or high pressure spring receiving portion, and the fuel The injection valve has been disassembled and replaced with a shim with the target thickness.

In such prior art, a valve-opening pressure adjusting shim is inserted into a low-pressure or high-pressure spring receiving portion. When adjusting the valve-opening pressure on the low-pressure side or the high-pressure side, fuel is used. The required low pressure side valve opening pressure or high pressure side valve opening pressure is set by disassembling the injection valve and replacing it with a shim with the target thickness.

For this reason, in such prior art, when assembling and adjusting the fuel injection valve, it is necessary to disassemble the fuel injection valve and adjust the thickness of the shim every time the low-pressure side or high-pressure side valve opening pressure is adjusted. The adjustment of the valve opening pressure is complicated, requiring a great deal of man-hours to assemble and adjust the fuel injection valve. Also, if it becomes necessary to adjust the valve opening pressure of the fuel injection valve of a certain cylinder during operation of the engine, the fuel injection valve is pulled out of the cylinder head and disassembled to adjust the shim thickness. Must be repeated, which greatly impairs engine operation and maintainability.

And the like. Disclosure of the invention

In view of the problems of the prior art, the present invention makes it possible to easily and accurately adjust the valve opening pressure in two stages with the cylinder head assembled without disassembling the fuel injection valve during assembly and adjustment of the fuel injection valve. The internal combustion engine and the fuel injection valve equipped with a needle valve spring force adjustment mechanism that can significantly reduce the assembly and adjustment man-hours of the fuel injection valve and improve engine operation and maintainability. The purpose is to provide a method for adjusting

The present invention achieves the above object, and opens the needle valve by pushing up the needle valve against the spring force of the needle valve spring by the pressure of the fuel pumped from the fuel injection pump to open the needle valve. In an internal combustion engine provided with a fuel injection valve that injects into a combustion chamber from an injection hole formed at a tip end, 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 attached to the spring, and the spring force of the corresponding two needle valve springs can be adjusted independently by the two adjusting tools. And

In the present invention, preferably, the two needle valve springs are one needle. First and second springs having different valve opening pressures with respect to the valve are connected to the adjusting tool corresponding to each of the first and second springs in the axial direction of the needle valve.

More specifically, the adjusting tool for adjusting the spring force of the first spring is connected to an upper spring receiver of the first spring, and the needle valve is closed by the adjusting tool and the first spring. And a second spring and an adjusting device for adjusting the spring force of the second spring are arranged above the adjusting device for the first spring, and the needle valve is operated by the second spring. It is preferable to be configured to be able to be pressed in the valve closing direction. In addition, as a method of adjusting the fuel injection valve for an internal combustion engine, a first spring is incorporated in a valve body in a form in which a head of a needle valve is pressed in a valve closing direction, and the first spring is mounted on a screw type low-pressure side adjusting tool. The valve opening pressure on the low pressure side is adjusted by changing the spring force of the first spring, and then the second spring is incorporated into the valve body in a form in which the end of the first spring opposite to the needle valve side is pressed, and the screw is screwed. An adjustment method is proposed in which the high-pressure side valve opening pressure is adjusted by changing the spring force of the second spring with a high-pressure side adjustment tool.

According to this invention, the valve opening pressure of the needle valve is connected to one needle valve in the axial direction of the needle valve and the spring force of the first and second springs having different valve opening pressures (mounting load). The first-stage valve opening pressure, that is, the valve opening pressure on the low pressure side, can be adjusted by changing the screw-in amount by a screw-type adjusting tool provided corresponding to the first spring. It is set by adjusting the spring force of the first spring.

The second-stage valve opening pressure, that is, the valve opening pressure on the high pressure side, is adjusted by a screw-type adjustment provided for the second spring in addition to the spring force adjustment value of the first spring on the low pressure side. The amount of screwing is changed by an adjuster to adjust the spring force of the second spring, and is set by the resultant force of the spring forces 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 adjusting tool, and The second-stage valve opening pressure, that is, the valve opening pressure on the high pressure side can be adjusted steplessly by changing the screwing amount of the second spring adjuster.

Therefore, according to this invention, when assembling and adjusting the fuel injection valve, the screwing amount of the first spring adjusting tool is changed without disassembling the fuel injection valve. Alternatively, the first-stage valve opening pressure, that is, the valve-opening pressure on the low-pressure side, can be increased independently by changing the screw-in amount of the second spring adjuster, or the first-stage valve opening pressure and the second-stage Both the valve opening pressure, that is, the valve opening pressure on the high pressure side, can be easily and steplessly adjusted as described above, and the valve opening pressure on the low pressure side or the high pressure side can be adjusted as in the prior art shown in Patent Document 1. It is not necessary to disassemble the fuel injection valve and adjust the thickness of the shim every time the adjustment is performed, and the man-hour for assembling and adjusting the fuel injection valve can be greatly reduced as compared with the related art.

Further, according to the invention, even if it becomes necessary to adjust the valve opening pressure of a fuel injection valve of a certain cylinder during operation of the engine, the valve is opened with the fuel injection valve assembled to the cylinder head. The pressure can be adjusted, and the first stage valve opening pressure or the second stage valve opening pressure can be adjusted only by changing the screwing amount of the first spring adjusting device or the second spring adjusting device. Since the engine can be easily adjusted, the operation and maintainability of the engine are greatly improved compared to the conventional technology.

Further, in this invention, preferably, any one of the upper and lower spring receivers between the outer peripheral portion of any one of the upper and lower spring receivers and the mating member, and the upper and lower spring receivers of the second spring. A gap is formed between the outer periphery and the mating member to absorb the fall of the first spring and the second spring.

According to this structure, even if the first spring or the second spring connected in the axial direction of the fuel injection valve falls down, the outer peripheral portion of either one of the upper and lower spring supports is opposed to the outer periphery. The fall can be absorbed by the gap formed between the member and the member, and the malfunction of the needle valve and the spring due to the fall 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 the lower spring receiver is connected to the lower spring receiver of the second spring via a push rod. The upper spring receiver of the first spring is connected to the second spring adjuster, the upper spring receiver of the second spring is brought into contact with the head of the second spring adjuster, and A spherical contact portion is formed at a contact portion between the rod and the first spring support and a contact portion between the upper spring support and the second spring adjuster.

According to this structure, a relief portion formed by spherical contact is formed at a contact portion between the relatively long push rod and the first spring spring support, so that the push rod Of the push rod and seizure of the push rod and operation of the needle valve can be avoided. Further, by forming a spherical contact portion at a contact portion between the upper spring receiver of the second spring and the adjusting tool, seizure due to misalignment of the adjusting tool with the second spring and the upper spring receiver is avoided. it can.

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 push rod and the lower spring receiver of the second spring abut on a flat contact portion.

With this configuration, the relatively long push rod is separated from the lower spring receiver for the second spring and is assembled by abutting at the flat contact portion, so that the push rod can be easily manufactured and the fuel injection can be performed. Assembly to the valve can be facilitated by allowing misalignment.

Further, according to the present invention, the needle valve is opened by pushing up the needle valve by staking the spring force of the needle valve spring by the pressure of the fuel pumped from the fuel injection pump, and the fuel is formed at the tip of the nozzle tip. The method for adjusting a fuel injection valve for an internal combustion engine that injects fuel into an internal combustion chamber from an injection hole, wherein the fuel injection valve is provided with first and second springs having different valve opening pressures relative to one needle valve. A screw-type adjuster for adjusting the spring force of the first spring is connected to an upper spring bearing of the first spring, and the adjuster and the first spring are connected to each other in the axial spring direction. A spring presses the needle valve in the valve closing direction, and a screw for adjusting the spring force of the second spring and the second spring is provided above the adjusting tool for adjusting the spring force of the first spring. The needle valve is closed in the valve closing direction by the second spring The second spring and its attached member are removed from the fuel injection valve, and the spring force of the first spring is adjusted by the screw-type adjuster. ,

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 second-stage adjustment on the high-pressure side are performed. The second-stage valve opening pressure adjustment can be performed, and if the second spring and its attached members are removed from the above-described configuration, the first spring and the adjustment tool for the first spring can adjust the first-stage low pressure side. Can easily be adjusted. This allows one fuel injection valve to perform a one-stage low-pressure side valve opening pressure adjustment test and a two-stage low-pressure and high-pressure side valve opening pressure adjustment test. Brief Description of Drawings

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

FIG. 3 is a diagram corresponding to FIG. 1 showing a third embodiment.

FIG. 4 is a diagram corresponding to FIG. 1 showing the fourth embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just

FIG. 1 is a sectional view taken along an axis of a fuel injection valve according to a first embodiment of the present invention. FIG. 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. 1 showing the fourth embodiment.

In FIG. 1 showing a first embodiment of the present invention, 1 is a valve body, 2 is a body cover screwed into an upper portion of the valve body 1, and 18 is screwed into an upper portion of the body cover 2 to be described later. A second-stage adjuster for adjusting the spring force of the second-stage spring 14, a lock nut 19 screwed into the upper portion of the second-stage adjuster 18 to lock the second-stage adjuster 18 Reference numeral 18a denotes a gasket for a fluid seal, and reference numeral 20 denotes a set screw screwed into an upper portion of the lock nut 19.

Reference numeral 3 denotes a nozzle tip which is fastened to the valve body 1 via a nozzle nut 5, and reference numeral 4 denotes a plurality of injection holes formed at the tip of the nozzle tip 5. Reference numeral 8 denotes a fuel passage through which high-pressure fuel from a fuel injection pump (not shown) is introduced, and reference numeral 7 denotes an oil reservoir having an opening at the outlet end of the fuel passage 8 and communicating with the inlet passage of the injection hole 4. 1a is a fuel leak passage.

Reference numeral 6 denotes a needle valve fitted in the nozzle tip 3 so as to be slidable back and forth. 2 5a is A spacer interposed between the nozzle tip 3 and the lower end surface of the valve body 1 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. The first-stage spring 9 presses the head of the needle valve 6 through a first-stage lower spring receiver 10 abutting on a lower end surface of the first-stage spring 9. I'm going to do it. 22 is a hollow first-stage upper spring support that supports the upper end surface of the first-stage spring 9 and is slidably fitted in the valve body 1, the upper end surface of which is a first-stage adjusting tool described later. 16 is pressed against the lower end surface by the spring force of the first-stage spring 9 and a second-stage spring 14 described later. Reference numeral 21 denotes a lock nut for locking the first-stage adjuster 16.

Reference numeral 25 denotes a positioning pin between the nozzle tip 3 and the spacer 25a, and reference numeral 11 denotes a positioning pin between the valve body 1 and the spacer 25a. .

Numeral 14 denotes a second-stage spring constituting a high-pressure side spring, and numeral 16 denotes a hollow first-stage adjuster which is screwed into the upper inner periphery of the valve body 1 and houses the second-stage spring 14 therein. It is. Reference numeral 23 denotes a second-stage upper spring support for supporting the upper end surface of the second-stage spring 14. The upper end surface of the second-stage upper spring support 23 is attached to the lower end surface of the second-stage adjuster 18. The two-stage spring 14 is pressed by the spring force.

13 is a second-stage lower spring support for supporting the lower end surface of the second-stage spring 14, and 12 is slidably fitted to the inner periphery of the hollow first-stage upper spring support 22. It is a push mouth pad.

The push rod 12 is formed in a rod shape, and the lower end face is pressed against the upper end face of the first lower spring receiver 10 by the spring force of the second-stage spring 14, and the upper end face is It is pressed against the lower end surface of the second-stage lower spring receiver 13.

Also, the push rod 12 and the second-stage lower spring support 13 can be manufactured integrally.

A flat surface contact portion 12a is formed between the upper end surface of the push rod 12 and the lower end surface of the second-stage lower spring receiver 13. By forming in this manner, the relatively long push rod 12 is cut off from the second-stage lower spring support 13 and abutted at the flat contact portion 12 a so that the push rod 12 is assembled. It can be formed into a rod shape As well as being easy to manufacture, assembly to the fuel injector can be facilitated by allowing for misalignment.

Also, 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 assembly 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 an oil reservoir 7 through a fuel passage 8, and the pressure of the high-pressure fuel increases. When the needle valve 6 overcomes the spring force of the first-stage spring 9, the needle valve 6 is pushed up by the spring force of the first-stage spring 9 and lifted to open the valve. Thus, the first-stage low-pressure injection is performed.

When the pressure of the high-pressure fuel further rises and the combined force of the spring forces of the first-stage spring 9 and the second-stage spring 14 is overcome, the needle valve 6 is further lifted, and the needle valve 6 is lifted through the injection hole 4. The second stage high pressure injection is performed.

In adjusting the valve opening pressure of the needle valve 6 in such a fuel injection valve, a first-stage spring 9 is incorporated in the valve body 1 in such a manner that the head of the needle valve 6 is pressed in the valve closing direction. The first-stage adjustment tool 16 on the low-pressure side is changed in the amount of screwing in the first-stage adjustment screw portion 15 to change the spring force of the first-stage spring, and the required valve-opening pressure, that is, low-pressure opening When the valve pressure is reached, the lock nut 21 is tightened to fix the first-stage adjusting tool 16.

Next, the second-stage spring 14 is assembled into the first-stage adjustment tool 16 in a state in which the push rod 12 is pressed, and the second-stage adjustment tool 18 is attached to the second-stage adjustment screw 17. When the required valve opening pressure, that is, a high valve opening pressure, is reached, the lock nut 19 is tightened to adjust the second stage adjustment. Fix tool 1 8.

By the above operation, the low 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 springs 14 and the first stage spring 9 are increased. Set to an appropriate value.

According to such an embodiment, as described above, the valve opening pressure of the needle valve 6 is changed in the first stage of the needle valve 6 which is connected in the axial direction of the needle valve 6 and has a different valve opening pressure. It can be adjusted by changing the spring force (mounting load) of the spring 9 and the second stage spring 14, The first-stage valve opening pressure, that is, the valve-opening pressure on the low-pressure side, is changed by the screw type first-stage adjuster 16 provided corresponding to the first-stage spring 9, and the first-stage spring 9 is changed in the first-stage spring 9. Spring 9 Set by adjusting the spring force.

The second-stage valve opening pressure, that is, the valve-opening pressure on the high-pressure side, is changed by the screw-type second-stage adjuster 18 provided corresponding to the second-stage spring 14, and the screw-in amount is changed. The spring force of the second-stage springs 14 is adjusted to be set by the resultant force of the first-stage and second-stage springs 9 and 14.

Therefore, according to this embodiment, the first-stage valve opening pressure, that is, the valve-opening pressure on the low-pressure side is steplessly changed by changing the screwing amount of the first-stage adjusting tool 16 for the first-stage spring 9. By adjusting the screwing amount of the second-stage adjusting tool for the second-stage springs 14, the second-stage valve opening pressure, that is, the valve-opening pressure on the high-pressure side can be continuously adjusted.

That is, when assembling and adjusting the fuel injection valve, the screwing amount of the first-stage adjusting tool 16 for the first-stage spring 9 is changed without disassembling the fuel injection valve, or the second-stage spring 14 is not disassembled. By changing the amount of screwing of the first-stage adjusting tool 16 of the first stage, the first-stage valve opening pressure, that is, the valve-opening pressure on the low-pressure side, alone or the first-stage valve opening pressure and the second-stage opening Both the valve pressure, ie, the valve opening pressure on the high pressure side, can be adjusted easily and steplessly as described above.

Therefore, it is not necessary to disassemble the fuel injection valve and adjust the thickness of the shim every time the low-pressure side or high-pressure side valve opening pressure is adjusted unlike the conventional one, and assembling and adjusting the fuel injection valve Man-hours can be significantly reduced.

Further, according to this embodiment, even when the opening pressure of the fuel injection valve of a certain cylinder needs to be adjusted during operation of the engine, the fuel injection valve is mounted on the cylinder head. By changing the screw-in amount of the first-stage adjusting member 16, the low-pressure valve opening pressure on the first-stage spring 9 side is changed, and the screw-in amount of the second-stage adjusting member 18 is changed. The two-stage spring 14 can easily adjust the high-pressure valve opening pressure on each side, improving engine operation and maintainability in each stage.

In the second embodiment shown in FIG. 2, a dimension S ₂ is defined between the outer periphery of the first-stage lower spring support 10 for the first-stage spring 9 and the inner periphery of the spacer 25 a. Gap 3 And forming a gap 30—of a dimension S i between the outer periphery of the second-stage upper spring support 23 for the second-stage spring 14 and the inner periphery of the first-stage adjuster 16. Has formed.

According to the second embodiment, even if the first-stage spring 9 or the second-stage spring 14 constructed in the axial direction of the fuel injection valve falls down, the first-stage lower spring on the first-stage spring 9 side The gap 31 formed between the outer circumference of the support 10 and the inner circumference of the spacer 25a, the outer circumference of the second-stage upper spring support 23, and the inner circumference of the first-stage adjuster 16 The gap can be absorbed by the gap 30 formed between the needle valves, and the malfunction of the needle valve 6 ゃ springs 9, 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 second-stage adjustment tool 18 for the second-stage spring 14 are provided. The lower surface 36 of the push rod 12 and the lower surface 38 of the first-stage lower spring receiver 10 are formed into spherical surfaces. Therefore, the two are in contact 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 seizure of the push rods 1 and 2 and the operation of the needle valve 6 can be avoided. Also, by making the second-stage upper spring support 23 and the second-stage adjustment tool 18 into spherical contact, the second-stage adjustment tool 18 and the second-stage spring 14 and the second-stage upper spring support 2 are provided. Seizure due to misalignment with 3 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, a second-stage spring 14 for setting the valve-opening pressure on the high-pressure side and a second-stage upper spring support 2 are different from the first embodiment shown in FIG. 3, and the second-stage lower spring support 13 are removed (the second-stage adjustment device 18 may also be removed), and the first-stage spring 9 and the first-stage adjustment device 16 on the low-pressure side Valve opening pressure is set. That is, according to the fourth embodiment, as in the first embodiment, the first and second springs 9 and 14 and the screw-type first and second springs for adjusting the spring force thereof are provided. The adjusters 16 and 18 are incorporated into the fuel injection valve to perform both the first-stage opening pressure adjustment on the low-pressure side and the second-stage opening pressure adjustment on the high-pressure side. By removing the second-stage spring 14 and its attached members from the form of the first embodiment and changing to the form of FIG. 4, the first-stage spring 9 and its adjusting tool 16 open one stage on the low-pressure side. The valve pressure can be easily adjusted.

This allows one fuel injection valve to perform a one-stage low-pressure side valve opening pressure adjustment test and a two-stage low-pressure and high-pressure side valve opening pressure adjustment test.

According to the present invention, when assembling and adjusting the fuel injection valve, the screwing amount of the first spring adjusting tool is changed without disassembling the fuel injection valve, or the second spring adjusting tool is screwed in. By changing the amount, the valve opening pressure of the first stage (low pressure side) alone 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 does not require disassembly of the fuel injection valve and adjustment of the shim thickness every time the low-pressure side or high-pressure side valve opening pressure is adjusted as in the conventional technology. As a result, the man-hours for assembling and adjusting the fuel injection valve can be significantly reduced.

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 adjuster can be used. The valve opening pressure of the first stage or the valve opening pressure of the second stage can be easily adjusted only by changing the amount of screwing of the spring adjustment tool of (2). It improves in each step compared with. Industrial applicability

According to the present invention, when assembling and adjusting the fuel injection valve, the valve opening pressure can be easily and precisely adjusted in two stages without disassembling the fuel injection valve and in a state where the fuel injection valve is assembled to the cylinder head. The fuel with a needle valve spring force adjustment mechanism that can significantly reduce the assembly and adjustment man-hours of the fuel injection valve and improve engine operation and maintainability It is possible to provide an internal combustion engine equipped with an injection valve ₍

Claims

1. Due to the pressure of the fuel pumped from the fuel injection pump, the needle valve spring is pushed up by the spring force of the needle valve spring, the needle valve is pushed up, the needle valve is opened, and the fuel is injected into the nozzle tip at the nozzle tip. An internal combustion engine provided with a fuel injection valve that injects fuel into the combustion chamber from above, the fuel injection valve includes two needle valve springs, and adjusts a spring force of each of the two needle valve springs. A needle valve spring force adjusting mechanism, wherein a screw-type adjusting device is attached so that the two adjusting devices can independently adjust the spring forces of the corresponding two needle valve springs. Internal combustion engine equipped with a fuel injection valve.

2. The two needle valve springs are arranged so that the first and second springs having different valve-opening pressures with respect to one needle valve are the adjusting devices respectively corresponding to the first and second springs. 2. The internal combustion engine equipped with a fuel injection valve with a spring force adjusting mechanism according to claim 1, wherein the fuel injection valve and the needle valve are provided continuously in the axial direction of the needle valve.

3. The adjuster 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 pressed in the valve closing direction by the adjuster and the first spring. The second spring and the adjusting device for adjusting the spring force of the second spring are arranged above the adjusting device for the first spring, and the needle valve is closed by the second spring. 3. The internal combustion engine equipped 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 in a valve direction.

4. Above the first spring, between any one outer peripheral part of the lower spring receiver and the mating member, and, above the second spring, one outer peripheral part of the lower spring receiver and the other member 3.A fuel injection valve with a needle valve spring force adjusting mechanism according to claim 2, wherein a gap is formed between said first spring and said second spring to absorb a fall of said first spring and said second spring. Internal combustion engine.

5. 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. Connecting an upper spring support to the second spring adjuster, and bringing an upper spring support of the second spring into contact with the second spring adjuster; Further, a spherical contact portion is formed at a contact portion between the push port and the first spring support and a contact portion between the upper spring support and the second spring adjuster. 4. An internal combustion engine comprising the fuel injection valve with the needle valve spring force adjusting mechanism according to claim 3.

6. 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. 4. The internal combustion engine having a fuel injection valve with a needle valve spring force adjusting mechanism according to claim 3, wherein the lower spring receiver of the second spring is in contact with a flat contact portion.

7. Due to the pressure of the fuel pumped from the fuel injection pump, the needle valve spring is pushed up by the spring force of the needle valve spring, the needle valve is pushed up, the needle valve is opened, and the fuel is injected into the nozzle tip formed at the tip of the nozzle tip. Adjusting the fuel injection valve for an internal combustion engine that injects fuel into the combustion chamber from the valve by incorporating a first spring into the valve body in a form in which the head of the needle valve is pressed in the valve closing direction, and adjusting the screw type low pressure side. The spring force of the first spring is changed by a tool to adjust the valve opening pressure on the low pressure side, and then the second spring is pressed in such a manner that the end of the first spring on the anti-needle valve side 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 incorporated in a valve body. .

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 sprays the fuel at the tip of the nozzle tip. The method for adjusting a fuel injection valve for an internal combustion engine, which injects fuel into the combustion chamber from the fuel injection valve, comprises: And a screw-type adjuster for adjusting the spring force of the first spring is connected to an upper spring receiver of the first spring, and the needle valve is adjusted by the adjuster and the first spring. Is pressed in the valve closing direction, and the second spring and a screw-type adjusting device for adjusting the spring force of the second spring are arranged above the adjusting device for adjusting the spring force of the first spring. Then, the needle valve can be pressed in the valve closing direction by the second spring. Removing the second spring and its associated members from the fuel injection valve, and adjusting the spring force of the first spring with the screw-type adjuster. How to adjust the valve.