KR20100138095A - Needle nozzle type fuel injection valve - Google Patents

Abstract

PURPOSE: A fuel injection valve for a diesel engine is provided to prevent incomplete combustion carbide from being accumulated around a fuel injection port by preventing a fuel leak. CONSTITUTION: A fuel injection valve for a diesel engine comprises a valve body(10), a control bolt(11), a nozzle body(12), a first elastic member(13), a main needle(14), a second elastic member(15), and a sub needle(16). The valve body is connected to upper and lower hollows(101,102) through a hollow connection hole(100) and has a fuel inlet port(103). A fuel inlet(121c) of the nozzle body is connected to the fuel inlet port of the valve body. The first elastic member is supported by a first support sheet(130a). The main needle has multiple fuel feeding holes(142). The second elastic member is supported by a second support sheet. The sub needle supports the bottom surface of the first support sheet.

Description

Fuel nozzle for diesel engines {Needle nozzle type fuel injection valve}

The present invention relates to a sliding fuel injection valve for a diesel engine, and more particularly, it is possible to sequentially inject the fuel required for in-cylinder combustion of a diesel engine equipped with a direct injection fuel injector in multiple stages, and according to the fuel injection pressure. A sliding multistage fuel injection valve for a diesel engine which can adjust the fuel injection amount and prevent leakage of oil into the combustion chamber after the fuel injection is completed.

Hereinafter, a background art and a problem thereof will be described with reference to the accompanying drawings.

1 is a cross-sectional view for explaining a fuel injection valve for a general diesel engine.

Referring to FIG. 1, a conventional fuel injection valve 1 for a diesel engine includes a hollow portion 100 formed inside the valve body 10 to push the elastic member 13 to the hollow portion 100. A rod 12 is installed, and a nozzle body 15 is installed below the valve body 10.

A sliding hole 150 is formed at an inner central portion of the nozzle body 15, a high pressure chamber 151 is formed at a central portion of the sliding hole 150, and a seat surface 152 at a lower end of the sliding hole 150. ), An injection chamber 153 is formed at the lower end of the seat surface 152, and a plurality of injection holes 154 are formed from the injection chamber 153 to the outer circumferential surface of the nozzle body 15.

The needle valve 11 is slidably inserted into the sliding hole 150 of the nozzle body 15 configured as described above so that the upper end is supported by the lower end of the elastic member 13, and thus the lower surface of the needle valve 11 is provided. The injection chamber 153 can be opened and closed while being spaced or in contact with the seat surface 152.

In addition, the high pressure fuel supplied from the fuel pump (not shown) is supplied to the high pressure chamber 151 of the nozzle body 15 through the fuel injection hole 103 formed in the valve body 10, and the high pressure chamber ( When the pressure of the supplied fuel is greater than the force applied to the upper portion of the needle valve 11 by the elastic member 13 and the push rod 12, the lower surface of the needle valve 11 is separated from the seat surface 104. Then it is sprayed into the combustion chamber through the injection chamber 153 and the injection port 154. The upper side of the elastic member 13 is provided with a pressure adjusting screw 14 that can adjust the opening pressure by adjusting the elasticity of the elastic member.

Next, the operation of the conventional fuel injection valve for a conventional diesel engine configured as described above is as follows.

The fuel injection valve 1 for the conventional general diesel engine configured as described above includes a nozzle body in which the fuel supplied at high pressure by a fuel pump (not shown) is provided with the needle valve 11 through the fuel inlet 103. When supplied to the high pressure chamber 151 of 15), the needle valve 11 is driven by the fuel supplied at high pressure through the fuel inlet 103 due to the characteristic of the needle valve 11 is formed larger than the diameter of the lower end portion It is pushed in the direction of the push rod 12 to perform a sliding movement.

In addition, the push rod 12 is pushed by the needle valve 11 is raised in conjunction with the needle valve 11 to press the elastic member 13, thereby the elastic member 13 is in a compressed state Becomes

As described above, when the needle valve 11 is slid and moved up, the needle valve 11 is spaced apart from the sliding hole 150 seat surface 152 to provide fuel between the needle valve 11 and the seat surface 152. Is introduced, and the fuel introduced between the needle valve 11 and the seat surface 152 passes through the injection chamber 153 and is supplied into the combustion chamber through the injection hole 154.

In addition, due to the nature of the fuel pump (not shown), since the pressure of the supplied fuel is momentarily interrupted, the original restoring force of the compressed elastic member 13 is greater than the pressure of the fuel formed in the high pressure chamber 151, so that the push rod 12 Will descend. The needle valve 11 is also pushed down by the push rod 12 that is lowered as described above, so that the lower end of the needle valve 11 comes into close contact with the seat surface 152 so that the fuel is no longer injected. It will not be supplied into the combustion chamber through.

However, the fuel injection valve 1 for the conventional general diesel engine as described above has the needle valve 11 descending due to the original restoring force of the elastic member 13 when the supply of fuel is interrupted, and thus the lower end of the needle valve 11. Has a structure in which the needle valve 11 is in close contact with the seat surface 152 of the nozzle body 15, so that a very large impact occurs when the needle valve 11 is in close contact with the seat surface 152, thereby causing the needle valve 11 to become premature. There is a problem that wear occurs, so the life of the needle valve 11 is very short, so that the normal injection of the fuel is not achieved, so that if the needle valve 11 is not replaced with a new product, soot generation and fuel consumption may occur. There was a problem that significantly increased.

In addition, the fuel injection valve 1 for the conventional general diesel engine as described above is injected when the needle valve 11 is raised and a plurality of injection ports 154 are opened at a time to lower the fuel injection pressure during low load operation. Since the open area of the chamber 153 is larger than necessary, there is a problem in that the spraying state is poor, leading to generation of soot and fuel consumption.

In addition, the fuel injection valve 1 for the conventional general diesel engine as described above has an injection chamber even after the needle valve 11 is lowered after fuel injection and the lower end of the needle valve 11 is in close contact with the seat surface 104. The phenomenon of leaking into the combustion chamber through the fuel hole injection hole 154 filled with 153 is caused, and further increases in the generation of smoke and fuel consumption, and excessive smoke by the accumulation of unburned carbide around the injection hole 154. There was a problem that occurred.

The object of the present invention is to significantly improve the life of the main needle and prevent the leakage of fuel remaining in the injection chamber through the fuel injection port after completion of the fuel injection, thereby fundamentally preventing the accumulation of incomplete combustion carbide around the fuel injection port. It is to provide a sliding fuel injection valve for a diesel engine that can reduce the generation of harmful gases such as smoke, nitrogen oxides and fuel consumption.

Another object of the present invention is to be able to adjust the opening and closing amount of the fuel inlet in accordance with the fuel injection pressure to reduce the fuel consumption at low load, as well as to allow the fuel injection amount to be gradually increased to be injected at high load It is to provide a sliding fuel injection valve for a diesel engine that can prevent a rise in combustion temperature and pressure.

It is still another object of the present invention to provide a sliding fuel injection valve for a diesel engine, in which fuel is not leaked into the combustion chamber through the fuel injection port other than the fuel injection period, and the gas in the combustion chamber is not flowed back into the fuel injection valve.

The present invention for achieving the above object, the inner central portion is penetrated by the hollow connecting hole to the upper hollow portion and the lower hollow portion is formed, the valve body portion through which the fuel inlet is formed from one side of the lower peripheral surface through the outer peripheral surface; The inner central portion is formed so that the elastic member installation hole and the main needle sliding hole in which the nozzle chamber is formed in the center communicate with each other in order from the upper surface to the lower surface, and the valve body portion from one side of the upper surface to one side of the nozzle chamber. A nozzle body portion through which a fuel injection passage formed in communication with the fuel injection hole is formed; The upper end is supported by an adjustment bolt screwed to the upper end of the upper hollow portion, and the lower end is supported by the upper surface of the one-stage elastic member support sheet installed in the upper hollow portion so as to be positioned at the lower end of the upper hollow portion. A one-stage elastic member inserted into the upper hollow portion; Sliding is fastened to the elastic member installation hole and the main needle sliding hole so that the upper end is inserted into the lower hollow portion, a fuel chamber is formed in the inner center portion, a plurality of fuel injection holes formed from the lower end of the fuel chamber to the outer peripheral surface through A main needle through which a plurality of fuel supply holes are formed from the center of the outer circumferential surface of the nozzle chamber to the fuel chamber; A two-stage elastic member inserted into the elastic member mounting hole and having a lower end supported by a lower surface of the elastic member mounting hole and an upper end supported by a two-stage elastic member supporting sheet slidingly fastened to the upper end of the elastic member mounting hole; And a sub-needle portion slidingly coupled to the hollow portion connecting hole so that the lower portion is slidably fastened to the upper end of the fuel chamber, and the upper portion passes through the hollow portion connecting hole to support the lower surface of the one-stage elastic member support sheet. It is to provide a sliding fuel injection valve for a diesel engine, characterized in that configured.

As described above, in the sliding fuel injection valve for the diesel engine according to the present invention, the sub-needle and the main needle are lowered or raised along the sliding hole so that the fuel injection hole formed in the main needle is exposed to the outside of the sliding hole, and is opened or inside the sliding hole. Since the main needle is not impacted by being introduced into and closed, the life of the needle is significantly increased, so that a good fuel spray state can be maintained for a long time, thereby maintaining the performance of the diesel engine in a good state for a long time.

In addition, in the sliding fuel injection valve for a diesel engine according to the present invention, the fuel injection port is primarily closed by the main needle sliding hole, and the main needle sliding hole is secondly closed by the poppet-shaped support sheet to complete the fuel injection. Afterwards, the fuel injection port prevents leakage of fuel remaining in the fuel chamber and prevents the supply pressure loss of the fuel from occurring, thereby preventing the accumulation of incomplete combustion carbide around the fuel injection port. It is possible to reduce the generation of harmful gases and fuel consumption, and to prevent the phenomenon that the combustion gas in the combustion chamber flows back into the sliding fuel injection valve for the diesel engine according to the present invention.

In addition, in the sliding fuel injection valve for a diesel engine according to the present invention, the opening and closing amount of the fuel injection port formed in multiple stages is adjusted according to the moving distance of the sub-needle nozzle which is slidably moved up and down by the injection pressure of the fuel so that the fuel is sequentially in the combustion chamber. It is possible to prevent sudden pressure rise and combustion noise in the combustion chamber due to the combustion delay caused by instantaneous excessive injection of fuel into the combustion chamber, and to increase the durability of the combustion chamber components. CO2 and smog can be greatly reduced, and at high loads, fuel injection holes formed in multiple stages are opened sequentially to inject fuel into the combustion chamber to prevent rapid combustion temperature and pressure rise, thereby generating soot and nitrogen oxides. Can be suppressed There is an effect.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view illustrating a sliding fuel injection valve for a diesel engine according to the present invention.

2, the sliding fuel injection valve for a diesel engine according to the present invention, the valve body portion 10, the adjustment bolt 11, the nozzle body portion 12, the first stage elastic member 13, the main needle ( 14), the two-stage elastic member 15, the sub-needle portion 16 is configured to include.

The valve body portion 10 of the sliding fuel injection valve for a diesel engine according to the present invention configured as described above, the inner central portion by the hollow connection hole 100, the upper hollow portion 101 and the lower hollow portion 102 Is penetrated so as to communicate with each other, and the fuel injection hole 103 is formed to penetrate from one lower side of the outer circumferential surface to one side of the lower surface. Is formed.

In addition, the adjustment bolt 11 is inserted into the upper hollow portion 101 of the valve body portion 10 is screwed to move up and down along the upper hollow portion 101.

The nozzle body part 12 is formed in the inner central portion so that the elastic member installation hole and the main needle sliding hole in which the nozzle chamber is formed in the central portion are sequentially communicated from the upper surface to the lower surface. A fuel injection passage formed in communication with the fuel injection hole of the valve body portion is formed through one side of the nozzle chamber, and a drain hole is formed in communication with the drain hole of the valve body portion from the other side of the upper surface to the center portion.

In more detail, the nozzle body 12 includes a nozzle nut 120, a nozzle body 121, a lower connection block 122, and an upper connection block 123. The nozzle nut 120 of the nozzle body part 12 configured as described above is screwed to the lower end of the valve body part 10, and the support jaw 120a protrudes from the lower surface. In addition, the nozzle body 121 has a lower end portion protruding outward from the lower surface of the nozzle nut 120 and is provided inside the nozzle nut 120 so as to be supported by the support jaw 120a of the nozzle nut 120. The main needle sliding hole 121a having the nozzle chamber 121b formed therein is inserted into and fastened to the inner central portion and the main needle 14 is slidingly fastened, and the fuel is provided from one side to the upper surface of the nozzle chamber 121b. Injection passage 121c is formed through. In addition, the lower connection block 122 is inserted into the nozzle nut 120 so as to be positioned above the nozzle body 121, and the elastic member installation hole into which the two-stage elastic member 15 is inserted in the inner central portion. A through hole 122a is formed therein, and a locking jaw 122b is formed at an upper surface thereof, and a fuel injection passage 122c is configured to communicate with the fuel injection passage 121c of the nozzle body 121 from one side of the lower surface to one side of the upper surface. Is formed through. In addition, the upper connection block 123 is inserted into the nozzle nut 120 so as to be interposed between an upper portion of the lower connection block 122 and a lower portion of the valve body portion 10, and a hollow portion 123a at a central portion thereof. Is formed, the upper jaw is formed with a locking jaw (123b), from one side of the lower surface to one side of the upper surface of the fuel injection passage 122c of the lower connection block 122 and the fuel injection hole 103 of the valve body portion (10) The fuel injection passage 123c is formed to be in communication with each other. In addition, a drain hole 123d communicating with the drain hole 104 of the valve body part 10 is formed through from the other side of the lower surface of the lower connection block 122 to the other side of the upper surface of the upper connection block 123. . In addition, a fuel circulation hole 123e may be formed through the lower hollow portion 102 of the valve body 10 to the drain hole 123d of the upper connection block 123.

Here, the lower surface is supported by the upper end of the two-stage elastic member 15 at the upper end of the elastic member installation hole 122a, the upper end protrudes into the hollow portion 123a of the upper connection block 123, The two-stage elastic member support sheet 124, which protrudes from the stop jaw 124a, which is selectively constrained by the locking tuck 122b of the lower connection block 122, is further slidingly coupled to the lower surface, and the two-stage elastic member is fastened. The support sheet 124 is fixed to the outer circumferential surface of the main needle 14 so as to slide in association with the main needle 14.

That is, the inner circumferential surface of the two-stage elastic member support sheet 124 is formed to gradually decrease in diameter from the upper end to the lower end, and the auxiliary locking ring fixing groove 125a is formed on the outer circumferential surface of the main needle 14. Auxiliary locking ring 125 is fixedly installed in the auxiliary locking ring fixing groove 125a, and the auxiliary locking ring 125 is formed by raising the two-stage elastic member supporting sheet 124 on the main needle 14 and raising the auxiliary locking ring 125. The two-stage elastic member support sheet 124 is sandwiched between the inner circumferential surface of the main needle 14 and the outer circumferential surface of the main needle 14 to fix the two-stage elastic member support sheet 124 to the outer circumferential surface of the main needle 14.

In addition, the lower surface is supported by the upper surface of the two-stage elastic member support sheet 124 on the hollow portion 123a of the upper connection block 123, and the upper surface is a locking step of the upper connection block 123 ( The main needle stopper 126 is slidably fastened to be selectively supported by the 123b, and the main needle stopper 126 is fixed to the outer circumferential surface of the main needle 14 so as to slide in association with the main needle 14.

That is, the inner circumferential surface of the main needle stopper 126 is formed so that the diameter gradually decreases from the upper end to the lower end direction, and the locking ring fixing groove 126a is formed on the outer circumferential surface of the main needle 14 to fix the locking ring. As the locking ring 126b is fixedly installed in the groove 126a and the main needle stopper 126 is built up on the main needle 14 to rise, the locking ring 126b is formed on the outer circumferential surface of the main needle 14 and the main. The main needle stopper 126 is fixed to the outer circumferential surface of the main needle 14 by being pinched between the inner circumferential surfaces of the needle stopper 126.

The first end of the elastic member 13, the upper end is supported by the adjustment bolt 11 is screwed to the upper end of the upper hollow portion 101, the lower end is located on the lower end of the upper hollow portion 101 It is inserted into the upper hollow portion 101 so that the lower surface is supported by the upper surface of the one-stage elastic member support sheet 130a inserted into the hollow portion 101.

The main needle 14 is slidably fastened to the elastic member installation hole 122a and the main needle sliding hole 121a of the nozzle body 12 so that the upper end is inserted into the lower hollow portion 102. A fuel chamber 140 is formed, and a plurality of fuel injection holes 141 are formed through the lower end of the fuel chamber 140 to the outer circumferential surface, and a plurality of fuel injection holes 141 are formed from the central portion of the outer circumferential surface of the nozzle chamber 121b to the fuel chamber 140. Fuel supply holes 142 are formed through.

Here, the fuel injection hole 141 of the main needle 14 is preferably formed so as to penetrate downward from the fuel chamber 140 toward the outer surface of the main needle 14, the fuel injection hole 141 as described above Is preferably formed in multiple stages in the vertical direction of the main needle (14).

In addition, the fuel supply hole 142 is preferably formed to be inclined downward from the outer circumferential surface of the main needle 14 in the direction of the fuel chamber 140, the fuel supply hole 142 as described above is the main needle 14 It is preferable that it is formed in multiple stages in the up-down direction.

In addition, a support sheet 143 having a poppet valve shape may further protrude from a lower end of the main needle 14.

In addition, the first stage injection spacer 144 may be further installed at the upper end of the outer circumferential surface of the main needle 14.

The two-stage elastic member 15, the lower end is supported by the lower surface of the elastic member installation hole 122a and the upper end is supported by the two-stage elastic member support sheet 124 slidingly fastened to the upper end of the elastic member installation hole. It is inserted into the elastic member installation hole 122a.

Here, the elastic force adjusting washer 150 may be further interposed between the two-stage elastic member 15 and the lower surface of the elastic member installation hole 122a.

The sub-needle portion 16, the lower end is slidingly fastened to the upper end of the fuel chamber 140, the upper end passes through the hollow connection hole 100 to the lower surface of the elastic member support sheet 130a for one-stage. Sliding is fastened to the hollow connection hole 100 to support.

Referring to the configuration of the sub-needle portion 16 as described above in more detail, the sub-needle portion 16 is composed of a sub-needle housing 160 and a sub-needle 161. The sub-needle housing 160 of the sub-needle portion 16 configured as described above, the lower end is slidingly fastened to the upper end of the fuel chamber 140, the valve body portion (such that it is supported by the upper surface of the main needle 14) 10 is inserted into the lower hollow portion 102 of the lower portion, the connecting hole 160a is formed from the lower surface to the center portion, and the sub-hole communicating with the connecting hole 160a from the upper end to the upper surface of the connecting hole 160a The needle sliding hole 160b is formed. In addition, the sub-needle 161, the lower end is slidingly fastened to the sub-needle sliding hole 160b of the sub-needle housing 160, the upper end penetrates the hollow connection hole 100 to support the elastic member for one-stage Sliding is fastened to the hollow connection hole 100 to support the lower surface of (130a).

Here, a sub-needle insertion groove 130a 'is formed at the center of the lower surface of the one-stage elastic member supporting sheet 130a so that the upper end of the sub-needle 161 is detachable from the sub-needle insertion groove 130a'. It is to be able to support the one-stage elastic member support sheet 130a in the inserted state.

In addition, the sub-needle sliding hole 160b of the sub-needle housing 160 and the sub-needle 161 slidingly fastened to the sub-needle sliding hole 160b are tapered so that the diameter gradually increases by a predetermined distance from the lower surface. It is preferable to be formed.

Herein, the diameter of the subneedle sliding hole 160b may be larger than the diameter of the upper end of the fuel chamber 140 of the main needle 14 to which the lower end of the sub needle 161 is slidingly fastened.

Again, with reference to Figure 2 will be described the operation and effect of the sliding fuel injection valve for a diesel engine according to the present invention.

When the fuel is supplied at high pressure by a fuel pump (not shown) as shown in FIG. 2, the fuel is injected into the fuel inlet 103 and the upper connection block 123 formed in the valve body 10. The fuel injection path 122c of the furnace 123c and the lower connection block 122c and the fuel injection path 121c of the nozzle body 121 are sequentially passed through the nozzle chamber 121b of the nozzle body 121. The fuel introduced into the nozzle chamber 121b is supplied into the fuel chamber 140 through a plurality of fuel supply holes 142 formed in the main needle 14.

As described above, the fuel supplied to the fuel chamber 140 of the main needle 14 at a high pressure passes through the fuel connecting hole 160a formed in the center of the subneedle housing 160, and the lower portion of the subneedle 161. Press the inclined surface.

At this time, not only the support sheet 143 of the main needle 14 is pressed by the pressure in the combustion chamber, but also the main needle 14 is raised by the elastic force of the two-stage elastic member 15. The first fuel inlet 141a and the second fuel inlet 141b of the needle 14 remain closed. In addition, the support sheet 143 of the main needle 14 is in close contact with the lower surface of the nozzle body 121 to maintain the main needle sliding hole 121a of the nozzle body 121 also in a closed state.

Here, when the pressure applied to the lower inclined surface of the sub-needle 161 is greater than the elastic force of the one-stage elastic member 13, from this point the sub-needle 161 is raised and at the same time the sub-needle 161 The one-stage elastic member support sheet 130a is pushed upward in the upward direction, so that the one-stage elastic member support sheet 130a also rises in conjunction with the sub-needle 161, and thus the one-stage elastic member 13 Is pressed by the one-stage elastic member support sheet 130a is in a compressed state.

When the sub-needle 161 is slid and moved as described above, the sub-needle 161 is spaced apart from the lower surface of the sub-needle sliding hole 160b so that the sub-needle 161 and the sub-needle of the sub-needle housing 160 are raised. When fuel flows between the sliding holes 160b and fuel flows between the sub-needle sliding holes 160b and the sub-needle 161 as described above, a fuel supply pressure is applied to the sub-needle sliding holes 110b.

That is, when the sub needle 161 is raised by a predetermined height, the sub needle 161 is supported by the upper surface of the lower hollow portion 102 to maintain the fixed state of the sub needle sliding hole as described above. When fuel flows between the 160b and the subneedle 161, a fuel supply pressure is applied to the subneedle sliding hole 110b.

Here, the diameter of the sub-needle sliding hole 160b is larger than the diameter of the upper end of the fuel chamber 140 in which the sub-needle housing 17 is slidingly fastened, so that the cross-sectional area of the sliding hole 160b is fuel chamber 140. Since the cross-sectional area of the upper end of the () is larger than, the upward force for pressing the main needle 14, the support sheet 143 in the upper direction due to the pressure in the combustion chamber and the sub-needle sliding hole than the elastic force of the two-stage elastic member 15 Is applied to the fuel supply pressure to lower the sub-needle housing 160 is greater.

Therefore, the subneedle housing 160 is lowered to press the upper surface of the main needle 14, thereby interlocking with the subneedle housing 160, and the main needle 14 is also slid along the main needle sliding hole 121a and lowered. Done.

As the main needle 14 is lowered, the first fuel injection hole 141a formed at the lowermost end of the main needle 14 is exposed to the outside of the nozzle body 1211 to be opened so that fuel is injected into the combustion chamber. As described above, the fuel injection timing may be controlled by the adjustment bolt 11 depending on the elastic force of the first stage elastic member 130a irrespective of factors such as combustion chamber pressure.

When the amount of fuel supplied increases as the engine load increases, a sufficiently high pressure is applied to the main needle sliding hole 121a of the subneedle housing 160 to be interlocked with the subneedle housing 160 to connect the main needle. 14 is further lowered, so that the second fuel injection hole 141b formed on the upper portion of the first fuel injection hole 141a of the main needle 14 is also exposed to the outside of the nozzle body 121 so as to be exposed to the first fuel injection hole. Along with 141a, fuel is injected into the combustion chamber. Therefore, the first fuel injection port 141a and the second fuel injection port 142b are sequentially opened to inject fuel into the combustion chamber.

When the main needle stopper 126 is lowered in conjunction with the lowered main needle 14 as described above, the main needle stopper 126 is caught by the engaging jaw 122b of the lower connection block 122 and the main needle ( The movement of 12) is limited.

In addition, when the fuel supply pressure for pressing and lowering the sub-needle sliding hole 160b is lower than the pressure inside the combustion chamber and the original restoring force of the two-stage elastic member 15, the pressure inside the combustion chamber and the two-stage elastic member 15 are reduced. The main needle 14 slides along the main needle sliding hole 121a by the original restoring force of) so that the second fuel inlet 141b and the first fuel inlet 141a of the main needle 14 are sequentially formed. Into the inside of the nozzle body 121 is closed, and at the same time the one-stage elastic member support sheet 130a is pressed down by the original restoring force of the one-stage elastic member 13, the one-stage elastic member support sheet ( The sub-needle 161 is also lowered along the hollow connection hole 100 in cooperation with 130a, such that the lower inclined surface of the sub-needle 161 is in close contact with the lower surface of the sub-needle sliding hole 161b, and thus the sub-needle sliding hole 161b. ) In As to prevent the fuel from entering.

As described above, in the sliding fuel injection valve for a diesel engine according to the present invention, the fuel injection hole 141 is formed in multiple stages on the main needle 14 according to a moving distance in which the main needle 14 slides down by the injection pressure of the fuel. Is sequentially exposed to the outside of the nozzle body 121 to open the fuel sequentially into the combustion chamber through the fuel injection port 141 formed in multiple stages due to the combustion delay caused by instantaneous excessive fuel is injected into the combustion chamber It is possible to reduce the rapid pressure rise in the combustion chamber, thereby reducing the generation of NOx and combustion noise, and to increase the durability of the combustion chamber components.

In addition, the sliding degree of the main needle 14 is adjusted according to the injection pressure of the fuel, so that the opening and closing degree of the fuel injection hole 141 is adjusted, so that the fuel injection hole 141 formed in multiple stages in the vertical direction of the main needle 14 at a low load. ), Fuel consumption can be reduced by only allowing a portion of the fuel injection holes 141 located in the lower part thereof to inject fuel into the combustion chamber, thereby significantly reducing carbon dioxide and soot, and the fuel injection holes formed in multiple stages at high loads 141. ) To sequentially open from the bottom to the top to prevent the rapid rise of combustion temperature and pressure by injecting fuel into the combustion chamber to suppress the generation of nitrogen oxides.

In addition, the sliding fuel injection valve for a diesel engine according to the present invention, when the fuel injection is completed and the injection pressure of the fuel is removed, the original restoring force of the two-stage elastic member 15, the main needle 14 is compressed and the pressure of the combustion chamber The fuel injection hole 141 formed in multiple stages by sliding upward is inserted into the nozzle body 121 sequentially from the upper end to the lower end, and closed, and at the same time, the support sheet 143 formed at the lower end of the main needle 14 includes the nozzle body ( By closing the main needle sliding hole 121a of the nozzle body 121 by being in close contact with the lower surface of 121, the fuel remaining in the fuel chamber 140 after the fuel injection is completed does not leak into the combustion chamber through the fuel injection hole 141. As a result, the accumulation of incomplete combustion carbide around the fuel injection hole 141 may be prevented, thereby reducing the generation of fumes and harmful gases such as NOx and fuel consumption. The addition, the developer from flowing back into the interior of the sliding valve for a fuel injection diesel engine according to the invention the combustion chamber of the internal combustion gases present and to be prevented.

In addition, the sliding fuel injection valve for a diesel engine according to the present invention, unlike the conventional fuel injection valve that opens and closes the injection port while the needle valve is in close contact with the seat surface or the needle valve is spaced from the seat surface, the main needle 14 is the main needle The main needle 14 is lowered or raised along the needle sliding hole 121a to be exposed to the outside of the nozzle body 121 or closed by the nozzle body 121. Since the impact does not occur, the life of the main needle 14 is significantly increased, so that a good fuel spray state can be maintained for a long time, so that the performance of the diesel engine can be maintained in a good state for a long time.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

1 is a cross-sectional view for explaining a fuel injection valve for a general diesel engine.

2 is a cross-sectional view illustrating a sliding fuel injection valve for a diesel engine according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: valve body portion 11: adjusting bolt

(12): nozzle body portion (13): one-stage elastic member

14: main needle 15: two-stage elastic member

16: sub-needle part

Claims (11)

The inner center portion is penetrated so that the upper hollow portion and the lower hollow portion communicate with each other by the hollow portion connecting hole, and a valve body portion through which the fuel inlet is formed from one side of the outer circumferential surface to one side of the lower surface; The inner central portion is formed so that the elastic member installation hole and the main needle sliding hole in which the nozzle chamber is formed in the center communicate with each other in order from the upper surface to the lower surface, and the valve body portion from one side of the upper surface to one side of the nozzle chamber. A nozzle body portion through which a fuel injection passage formed in communication with the fuel injection hole is formed; The upper end is supported by an adjustment bolt screwed to the upper end of the upper hollow portion, and the lower end is supported by the upper surface of the one-stage elastic member support sheet installed in the upper hollow portion so as to be positioned at the lower end of the upper hollow portion. A one-stage elastic member inserted into the upper hollow portion; Sliding is fastened to the elastic member installation hole and the main needle sliding hole so that the upper end is inserted into the lower hollow portion, a fuel chamber is formed in the inner center portion, a plurality of fuel injection holes formed from the lower end of the fuel chamber to the outer peripheral surface through A main needle through which a plurality of fuel supply holes are formed from the center of the outer circumferential surface of the nozzle chamber to the fuel chamber; A two-stage elastic member inserted into the elastic member mounting hole and having a lower end supported by a lower surface of the elastic member mounting hole and an upper end supported by a two-stage elastic member supporting sheet slidingly fastened to the upper end of the elastic member mounting hole; And And a sub-needle portion slidingly coupled to the hollow portion connecting hole to support a lower end portion of the fuel chamber in a lower end portion, the upper portion passing through the hollow portion connecting hole to support the lower surface of the one-stage elastic member support sheet. Sliding fuel injection valve for a diesel engine, characterized in that. The method of claim 1, The fuel injection port of the main needle is a sliding fuel injection valve for a diesel engine, characterized in that formed through the inclined downward from the fuel chamber toward the outer surface of the main needle. The method of claim 2, The fuel injection port is a sliding fuel injection valve for a diesel engine, characterized in that formed in multiple stages in the vertical direction of the main needle. The method of claim 1, The fuel supply hole is a sliding fuel injection valve for a diesel engine, characterized in that the inclined downward from the outer peripheral surface of the main needle toward the fuel chamber. The method of claim 4, wherein The fuel supply hole is a sliding fuel injection valve for a diesel engine, characterized in that formed in multiple stages in the vertical direction of the main needle. The method of claim 1, The nozzle body portion, A nozzle nut screwed to a lower end of the valve body, and a support nut protruding from a lower surface of the valve body; A lower end portion protrudes outward from the lower surface of the nozzle nut, and is inserted into the nozzle nut so as to be supported by the support jaw of the nozzle nut. A nozzle body formed therethrough and having a fuel injection passage therethrough from one side of the nozzle chamber to an upper surface thereof; Inserted and fastened into the nozzle nut so as to be positioned above the nozzle body, the inner center portion is formed through the elastic member installation hole through which the two-stage elastic member is inserted, the upper surface is formed with a locking jaw, the upper surface from one side of the lower surface A lower connection block through which a fuel injection passage is formed so as to communicate with the fuel injection passage of the nozzle body; It is inserted into the nozzle nut so as to be interposed between the upper portion of the lower connection block and the lower portion of the valve body portion, a hollow portion is formed in the center portion, a locking jaw is formed on the upper surface, the lower connection block from one side of the lower surface to one side of the upper surface And an upper connection block through which the fuel injection passage is formed so as to communicate with the fuel injection passage and the fuel injection hole of the valve body part. The method of claim 6, A lower surface is supported by an upper end of a two-stage elastic member at an upper end of the elastic member installation hole, and an upper end is protruded into the hollow part of the upper connection block, and the lower surface is selectively restrained by a locking jaw of the lower connection block. The two-stage elastic member supporting sheet, which stops protruding from the protrusion, is slidingly fastened, The two-stage elastic member support sheet is sliding fuel injection valve for a diesel engine, characterized in that fixed to the outer peripheral surface of the main needle so as to slide in conjunction with the main needle. The method of claim 7, wherein The lower surface is supported by the upper surface of the two-stage elastic member support sheet on the hollow portion of the upper connection block, and the upper surface of the main needle stopper is slidably fastened to be selectively supported by the locking jaw of the upper connection block. The main needle stopper is a sliding fuel injection valve for a diesel engine, characterized in that fixed to the outer circumferential surface of the main needle to slide in conjunction with the main needle. The method of claim 1, The sub needle portion, The lower end is slidably fastened to the upper end of the fuel chamber, and is inserted into the lower hollow part of the valve body so as to be supported by the upper surface of the main needle, and a connecting hole is formed from the lower side to the center portion, and from the upper end to the upper side of the connecting hole. A sub-needle housing in which a sub-needle sliding hole in communication with the connecting hole is formed; And A lower needle slidingly coupled to a sub-needle sliding hole of the sub-needle housing, and an upper end slidingly fastened to the hollow connection hole so as to support a lower surface of the one-stage elastic member support sheet through the hollow connection hole; Sliding fuel injection valve for a diesel engine, characterized in that configured. The method of claim 9, The diameter of the sub-needle sliding hole is larger than the diameter of the upper end of the main needle fuel chamber to which the lower end of the sliding needle sliding fast injection valve for a diesel engine. The method according to any one of claims 1 to 10, Sliding fuel injection valve for a diesel engine, characterized in that the lower end of the main needle is a poppet valve-shaped support sheet is further protruded.

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