JP2008128136A - Fuel injection valve and its usage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve for preventing deterioration of combustion state of an internal combustion engine and its usage. <P>SOLUTION: The fuel injection valve is provided with a fuel passage 59 formed in a nozzle main body 33 in a vertical direction and a filling needle 35 provided in a manner movable for the fuel passage 59. After fuel injection, the filling needle 35 is disposed at the fuel passage 59. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel injection valve for a reciprocating internal combustion engine and a method of using the same.

  A first example of a conventional fuel injection valve will be described with reference to FIG. 6. In the first conventional fuel injection valve, a nozzle holder 2 in which a nozzle body 1 is disposed on a frame or the like (not shown). And a nozzle main portion 3 disposed at the lower end of the nozzle holder 2 and a rod-shaped nozzle end portion 4 disposed at the lower end of the nozzle main portion 3. A locking step 5 is provided and fixed by a first cap 6 screwed onto the lower outer periphery (not shown) of the nozzle holder 2, and the nozzle end 4 has a locking step 7 at the upper edge. The second cap 8 is fixed to the lower portion of the first cap 6.

  The nozzle holder 2 has a push rod 9 that is biased downward via a coil spring (not shown) inside, and a fuel passage 10 on the holder side that supplies fuel by extending obliquely up and down. Is forming.

  The nozzle main portion 3 includes a needle valve 11 that slides in the vertical direction by a push rod 9 inside, and is connected to the fuel passage 10 on the holder side of the nozzle main portion 3 and extends obliquely in the vertical direction. The oil chamber 13 is formed in the lower portion of the relay fuel passage 12 so that the lower portion of the needle valve 11 is located, and the lower portion of the oil chamber 13 is directed downward in the vertical direction. The fuel passage 14 is formed. Here, a valve seat 15 with which the tip end portion 11 a of the needle valve 11 abuts is disposed below the oil chamber 13 so that the fuel passage 14 can be opened and closed by the needle valve 11.

  The nozzle end 4 is internally connected to the fuel passage of the nozzle main portion 3 to form a fuel passage 16 extending in the vertical direction, and an injection hole 17 formed at the lower end of the fuel passage 16 toward the side. It has.

  When fuel is injected from the fuel injection valve, the fuel is sent to the oil chamber 13 through the fuel passage 10 on the holder side and the fuel passage 12 for relay, and the fuel pressure in the oil chamber 13 becomes equal to or higher than a predetermined pressure. Then, the needle valve 11 is pushed upward, and fuel is injected from the injection hole 17 to the side through the lower fuel passage 14 and the fuel passage 16 of the nozzle end 4.

  A second example of a conventional fuel injection valve will be described with reference to FIG. 7. A second example of a conventional fuel injection valve is a nozzle holder (not shown) in which a nozzle body 18 is disposed on a frame or the like (not shown). (Not shown), a nozzle main portion 19 disposed at the lower end of the nozzle holder, and a nozzle end portion 20 extending downward from the inside of the nozzle main portion 19. 19 includes a locking step portion 21 and is fixed by a cap (not shown) screwed to the lower outer periphery of the nozzle body 1, and the nozzle end portion 20 includes a locking step portion 22 and the nozzle main portion 19. The inner locking portion 23 is fixed.

  The nozzle holder (not shown) has a push rod (not shown) urged downward via a coil spring (not shown) inside and a fuel passage (not shown) for supplying fuel. ) And a cooling water passage (not shown) for supplying cooling water.

  The nozzle main portion 19 includes a needle valve 25 that slides in a vertical direction via a coil spring (not shown) by a push rod in a cylindrical guide bush 24 provided in an inner shaft portion. Around the periphery, a fuel passage 26 connected to a fuel passage (not shown) of the nozzle holder and a cooling water passage 27 connected to a cooling water passage (not shown) of the nozzle holder are formed, and a cooling water passage is further formed. An annular cooling chamber 28 that surrounds the periphery of the nozzle end 20 is connected to 27.

  The nozzle end portion 20 extends from above to the middle position so that the lower portion of the needle valve 25 can be disposed, and forms an oil chamber 29 connected to the fuel passage 26 of the nozzle main portion 19. The small-diameter fuel passage 30 is formed in the vertical direction. Further, the lower end of the small-diameter fuel passage is provided with an injection hole 31 formed sideways. Here, a valve seat 32 with which the tip end portion 25 a of the needle valve 25 abuts is disposed below the oil chamber 29 so that the fuel passage 30 can be opened and closed by the needle valve 25.

  When fuel is injected from the fuel injection valve, the fuel is sent from the fuel passage 26 of the nozzle main portion 19 to the oil chamber 29. When the fuel pressure in the oil chamber 29 becomes a predetermined pressure or higher, the needle valve 25 is turned off. The fuel is pushed upward and fuel is injected from the injection hole 31 toward the side through the fuel passage 30 of the nozzle end 20.

Here, as prior art document information indicating a fuel injection valve, there are the following Patent Documents 1 and 2.
Japanese Patent Laid-Open No. 9-126084 JP-A-8-4630

  However, in the fuel injection valve, since the fuel passages 16 and 30 of the nozzle end portions 4 and 20 are arranged below the valve seats 15 and 32, the fuel passages 16 and 30 are closed by the needle valves 11 and 25 after fuel injection. Even so, there is a problem that fuel remains in the fuel passages 16 and 30 of the nozzle end portion 20 and the remaining fuel leaks into the cylinders of the internal combustion engine from the fuel passages 16 and 30 to deteriorate the combustion state of the internal combustion engine. . In addition, when the fuel injection amount is small, the flow rate of the injected fuel is reduced, so that the shape of the fuel spray is deteriorated and the combustion state of the internal combustion engine is deteriorated.

  An object of the present invention is to provide a fuel injection valve that prevents deterioration of the combustion state of an internal combustion engine and a method for using the same.

  The present invention includes a fuel passage formed in a vertical direction in a nozzle body, and a filling needle disposed so as to be movable with respect to the fuel passage, and the filling needle is disposed in the fuel passage after fuel injection. The present invention relates to a fuel injection valve characterized by that.

  Further, the present invention includes a filling needle spring on the side opposite to the fuel passage of the filling needle. When the fuel is injected, the filling needle is pushed up from the fuel passage by the fuel pressure. After the fuel injection, the filling needle is biased by the bias of the filling needle spring. Is preferably arranged in the fuel passage.

  Furthermore, the present invention preferably includes a needle valve that opens and closes the fuel passage, and is configured so that the filling needle penetrates the axis of the needle valve.

  Furthermore, the present invention preferably includes adjusting means so as to fix the movement of the filling needle at a midway position.

  In the present invention, it is preferable that a piston is provided on the anti-filling needle side of the filling needle spring.

  Furthermore, according to the present invention, when the fuel injection amount is small, the filling needle is arranged in the middle of the fuel passage to reduce the passage space of the fuel passage and increase the flow rate of the injected fuel. Is preferred.

  The present invention includes a fuel passage formed vertically in a nozzle body and a filling needle disposed so as to be movable relative to the fuel passage. When the fuel injection amount is small, the filling needle is disposed in the fuel passage. The present invention relates to a method for using a fuel injection valve, characterized in that it is disposed at a midway position to reduce the flow space of the fuel passage and to increase the flow rate of fuel to be injected.

  Thus, according to the present invention, since the filling needle is disposed in the fuel passage after fuel injection, the entire space of the fuel passage is reduced to reduce the fuel remaining in the fuel passage, and the fuel passage after the fuel injection is Inflow of fuel to the engine can be suppressed, and deterioration of the combustion state of the internal combustion engine can be prevented.

  Further, according to the present invention, when the fuel injection amount is small, the filling needle is arranged in the middle of the fuel passage to reduce the passage space of the fuel passage, so that the flow rate of the injected fuel is increased. The shape of the fuel spray can be maintained, and deterioration of the combustion state of the internal combustion engine can be prevented.

  According to the fuel injection valve and the method of using the same according to the present invention described above, the filling needle is disposed in the fuel passage, so that the fuel remaining in the fuel passage can be reduced and the deterioration of the combustion state of the internal combustion engine can be prevented. An excellent effect of being able to do so can be achieved.

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

  1 to 4 show a first example of an embodiment for carrying out the present invention.

  The fuel injection valve of the first example of the embodiment of the present invention is configured by including a needle valve 34 and a filling needle 35 in a nozzle body 33, and the nozzle body 33 is disposed in a frame or the like (not shown). A nozzle holder 36, a nozzle main portion 37 disposed at the lower end of the nozzle holder 36, and a rod-shaped nozzle end portion 38 disposed at the lower end of the nozzle main portion 37. The portion 37 has a locking step 39 on the outer periphery and is fixed by a first cap 41 screwed to the lower outer periphery 40 of the nozzle holder 36, and the nozzle end 38 has a locking step 42 on the upper edge. The second cap 43 is fixed to the lower portion of the first cap 41.

  The nozzle holder 36 forms an upper space 44 in the inner axis, and forms a large-diameter lower space 46 via a small-diameter communication space 45 below the upper space 44. A coil spring filling needle spring 49 is disposed between the lower pressure adjustment screw 47 and the lower surface tappet 48. In the lower space 46, the coil spring is interposed between the upper surface pressure adjustment shim 50 and the lower spring receiver 51. The needle valve spring 52 is arranged. Further, the tappet 48 of the filling needle spring 49 supports the end side of the filling needle 35, and the filling needle 35 passes from the tappet 48 through the inner center of the needle valve spring 52 of the coil spring to the communication space 45. And the nozzle main portion 37 and the nozzle end portion 38 through the lower space 46. The spring receiver 51 of the needle valve spring 52 is supported by the upper end surface 37 a of the nozzle main portion 37.

  Further, in the nozzle holder 36, the high-pressure fuel is extended in the vertical direction (vertical direction) so as to be located on the respective sides of the upper space 44, the communication space 45, and the lower space 46, and the high-pressure fuel is supplied to the nozzle main portion 37 side. A fuel passage 53 to be supplied to is formed.

  The nozzle main portion 37 is provided with a needle valve 34 which is urged by the needle valve spring 52 and slides in the vertical direction via the spring receiver 51 and is connected to the fuel passage 53 of the nozzle holder 36 in the vertical direction. An extending relay fuel passage 54 is formed, and an oil chamber 55 is formed in the lower portion of the relay fuel passage 54 so that the lower portion of the needle valve 34 is located. A lower fuel passage 56 directed in the vertical direction (up and down direction) is formed. Here, a valve seat 57 with which the tip end portion 34 a of the needle valve 34 abuts is disposed below the oil chamber 55, and when the needle valve 34 abuts on the valve seat 57 with the needle valve spring 52, the fuel passageway is provided. 56 is closed, and when the needle valve 34 is separated from the valve seat 57 by the fuel pressure, the fuel passage 56 is opened.

  In addition, the axial center of the needle valve 34 of the nozzle main portion 37 is provided with a through hole 58 coaxial with the lower fuel passage 56, and the filling needle 35 passes through the through hole 58 and the lower fuel passage 56. I have to.

  The nozzle end portion 38 is internally connected to the fuel passage 56 of the nozzle main portion 37 to form a fuel passage 59 extending in the vertical direction (vertical direction), and is formed at the lower end of the fuel passage 59 toward the side. The injection hole 60 is provided. Further, the fuel passage 59 is configured such that the lower portion 35a of the filling needle 35 can be arranged from the midway position to the lower end.

  Here, when the fuel is not supplied, the filling needle 35 is urged by the filling needle spring 49 and is connected from the tappet 48 to the communication space 45, the lower space 46, the through hole 58 of the needle valve 34, the lower fuel passage 56, and the nozzle. When the predetermined fuel pressure is generated in the lower end space 61 below the lower end of the filling needle 35 through the fuel passage 59 of the end portion 38, it extends to the vicinity of the injection hole 60. The filling needle 35 is pushed up so as to compress the spring 49. Further, when the lower portion 35a of the filling needle 35 is positioned in the fuel passage 59 of the nozzle end portion 38, a flow passage space 59a through which fuel can flow is formed between the wall surface of the fuel passage 59 and the filling needle 35. It has become.

  The operation of the first example of the embodiment of the present invention will be described below.

  When fuel is injected from the fuel injection valve, the fuel is sent to the oil chamber 55 through the fuel passage 53 on the nozzle holder 36 side and the relay fuel passage 54 as shown in FIG. Next, as shown in FIG. 3, when the fuel pressure in the oil chamber 55 becomes equal to or higher than a predetermined pressure, the needle valve 34 is pushed upward to supply fuel to the lower fuel passage 56 to fill the nozzle end 38 and the filling. Fuel is poured into the flow path space 59 a between the needles 35.

  Subsequently, as shown in FIG. 4, when the fuel pressure becomes equal to or higher than a predetermined pressure, the filling needle 35 is pushed upward to maximize the volume of the fuel passage 59 at the nozzle end 38, and the fuel is optimized from the injection hole 60. Inject in a simple shape. Here, when the filling needle 35 is pushed up by the fuel pressure, the reaction force of the spring 49 for the filling needle is overcome, and in FIG. 4, the filling needle 35 is pushed up to the through hole 58 of the needle valve 34 by the fuel pressure. It has been.

  When stopping fuel injection from the fuel injection valve, first, as the fuel pressure decreases, the filling needle 35 is urged by the filling needle spring 49 to move downward, and a lower portion 35a of the filling needle 35 is moved. Is inserted into the fuel passage 59 at the nozzle end 38 to reduce the entire space of the fuel passage 59 at the nozzle end 38 to a minimum.

  Next, as the fuel pressure further decreases, the needle valve 34 is urged by the needle valve spring 52 and comes into contact with the valve seat 57, and the fuel passage 56 below the oil chamber 55 is closed to close the fuel. Supply is stopped, and fuel injection from the injection hole 60 is stopped.

  As described above, according to the first example of the embodiment of the present invention, since the lower portion 35a of the filling needle 35 is disposed in the fuel passage 59 of the nozzle end 38 after fuel injection, the fuel passage 59 of the nozzle end 38 is provided. This reduces the remaining space in the fuel passage 59 at the nozzle end 38, suppresses the inflow of fuel from the fuel passage 59 after fuel injection into the internal combustion engine, and prevents deterioration of the combustion state of the internal combustion engine. can do.

  A filling needle spring 49 is provided on the side opposite to the fuel passage of the filling needle 35, and when the fuel is injected, the lower portion 35a of the filling needle 35 is pushed up from the fuel passage 59 of the nozzle end 38 by the fuel pressure. If the lower portion 35a of the filling needle 35 is arranged in the fuel passage 59 of the nozzle end portion 38 by urging 49, the volume of the fuel passage 59 of the nozzle end portion 38 is changed by supplying and stopping the supply of fuel. The combustion state of the internal combustion engine can be maintained during fuel injection, and the deterioration of the combustion state of the internal combustion engine due to the inflow of fuel can be prevented after fuel injection.

  When the needle valve 34 that opens and closes the fuel passage 59 is provided and the filling needle 35 penetrates the axis of the needle valve 34, the space on the configuration is reduced, and the needle valve 34 and the filling needle 35 are suitable for the fuel pressure. Accordingly, the combustion state of the internal combustion engine can be maintained during fuel injection, and after the fuel injection, deterioration of the combustion state of the internal combustion engine due to the inflow of fuel can be prevented.

  Hereinafter, a second example of the embodiment for carrying out the present invention will be described. In the second example, the pressure adjusting screw 47 of the nozzle holder 36 is changed. In FIG. 5, the same reference numerals as those in FIGS. 1 to 4 denote the same components.

  As in the first example, the fuel injection valve of the second example of the embodiment of the present invention is configured by including the needle valve 34 and the filling needle 35 in the nozzle main body 62, and the nozzle main body 62 is configured with a frame or the like. A nozzle holder 63 (not shown), a nozzle main portion 37 substantially the same as the first example arranged at the lower end of the nozzle holder 63, and a first example arranged at the lower end of the nozzle main portion 37, A substantially rod-shaped nozzle end 38 is provided.

  The nozzle holder 63 forms an upper space 44 in the inner axial center, and forms a large-diameter lower space 46 via a small-diameter communication space 45 below the upper space 44. As in the example, a filling needle spring 49 and a tappet 48 are arranged, and an adjusting means 64 is arranged in the upper part of the upper space 44. In the lower space 46, as in the first example, a needle valve spring 52 and the like are arranged.

  The adjustment means 64 closes the upper end of the piston 65 disposed on the upper end (on the side opposite to the filling needle 35) of the spring 49 for the filling needle and the upper end of the upper space 44 to form a hydraulic chamber 66 between the piston 65. A portion 67, a first adjustment channel 68 formed penetrating the upper end closing portion 67, and a second adjustment channel 69 of a pipe connected to the first adjustment channel 68 of the upper end closing portion 67, The hydraulic chamber 66 is supplied with hydraulic oil from the outside via a first adjustment flow path 68 and a second adjustment flow path 69 by supply means (not shown) such as a pump. Here, the push-up amount (lift amount) of the filling needle 35 depends on the force of the filling needle spring 49 and the force obtained by multiplying the pressure receiving area of the piston 65 by the pressure in the hydraulic chamber 66.

  The operation of the second example of the embodiment of the present invention will be described below.

  When injecting fuel from the fuel injection valve, fuel is sent to the oil chamber 55 from the fuel passage 53 on the nozzle holder 63 side and the relay fuel passage 54 in substantially the same manner as in the first example. Next, when the fuel pressure in the oil chamber 55 becomes equal to or higher than a predetermined pressure, the needle valve 34 is pushed upward to supply fuel to the lower fuel passage 56 and flow between the nozzle end 38 and the filling needle 35. Fuel is poured into the road space 59a. Subsequently, when the fuel pressure becomes equal to or higher than a predetermined pressure, the filling needle 35 is pushed upward to maximize the volume of the fuel passage 59 at the nozzle end 38 and the fuel is injected from the injection hole 60 in an optimum shape.

  Here, when the fuel injection amount is small, the adjusting means 64 increases the pressure of the oil supplied to the hydraulic chamber 66 to increase the compression force of the filling needle spring 49, and the filling needle 35 moves upward from a predetermined position. The movement of the filling needle 35 is fixed at a midway position so that the lower portion 35a of the filling needle 35 is disposed in the middle position of the fuel passage 59 at the nozzle end portion 38, so that the flow path of the fuel passage 59 is larger than the maximum accumulation of the fuel passage. The space 59a is reduced and the flow rate of the injected fuel is increased.

  When stopping fuel injection from the fuel injection valve, first, as the fuel pressure decreases, the filling needle 35 is biased by the filling needle spring 49 and moves downward. The entire space of the fuel passage 59 at the nozzle end 38 is reduced to the minimum by being inserted into the fuel passage 59 at the nozzle end 38. Next, as the fuel pressure further decreases, the needle valve 34 is urged by the needle valve spring 52 and comes into contact with the valve seat 57, and the fuel passage 56 below the oil chamber 55 is closed to close the fuel. Supply is stopped and fuel injection from the fuel injection valve is stopped.

  Thus, according to the second example of the embodiment of the present invention, when the fuel injection amount is small at the time of fuel injection, the lower portion 35a of the filling needle 35 is placed in the middle position of the fuel passage 59 of the nozzle end portion 38. Since the flow path space 59a of the fuel passage 59 is made smaller, the flow rate of the fuel to be injected can be increased to maintain the shape of the fuel spray, and the deterioration of the combustion state of the internal combustion engine can be prevented.

  In addition, when the adjusting means 64 is provided so as to fix the movement of the filling needle 35 at a midway position, the filling needle 35 is moved halfway through the fuel passage 59 without completely pushing up the filling needle 35 from the fuel passage 59 at the nozzle end 38. Since the flow path space 59a of the fuel passage 59 is reduced by appropriately arranging the fuel passage 59, the flow rate of the injected fuel can be increased to maintain the shape of the fuel spray, and the combustion state of the internal combustion engine can be prevented from deteriorating. .

  When the piston 65 is provided on the anti-filling needle 35 side of the filling needle spring 49, the fixing pressure is quickly transmitted to the filling needle 35 via the filling needle spring 49, and the filling needle 35 is placed in the middle of the fuel passage. Since the flow path space 59a of the fuel passage 59 is made small by appropriately arranging it, the flow rate of the injected fuel can be increased to maintain the shape of the fuel spray, and the deterioration of the combustion state of the internal combustion engine can be prevented.

  Further, according to the second example, it is possible to obtain substantially the same effect as the first example.

  Note that the fuel injection valve and the method of using the same according to the present invention are not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

It is sectional drawing which shows the 1st example of embodiment of this invention. It is sectional drawing which shows the state which supplied the fuel to the oil chamber of the fuel injection valve of this invention. It is sectional drawing which shows the state into which the fuel flowed into the flow-path space of the fuel injection valve of this invention. It is sectional drawing which shows the state which injects a fuel from the injection port of the fuel injection valve of this invention. It is an expanded sectional view showing a part of the second example of an embodiment of the invention. It is sectional drawing which shows the 1st example of the conventional fuel injection valve. It is sectional drawing which shows the 2nd example of the conventional fuel injection valve.

Explanation of symbols

33 Nozzle body 34 Needle valve 35 Filling needle 49 Filling needle spring 59 Fuel passage 59a Flow passage space 62 Nozzle body 64 Adjustment means 65 Piston

Claims (7)

  A fuel passage formed vertically in the nozzle body and a filling needle disposed so as to be movable with respect to the fuel passage are provided, and the filling needle is disposed in the fuel passage after fuel injection. Fuel injection valve.   A filling needle spring is provided on the anti-fuel passage side of the filling needle, and when the fuel is injected, the filling needle is pushed up from the fuel passage by the fuel pressure, and after the fuel injection, the filling needle is arranged in the fuel passage by urging the filling needle spring. 2. The fuel injection valve according to claim 1, wherein the fuel injection valve is configured as described above.   3. The fuel injection valve according to claim 1, further comprising a needle valve that opens and closes the fuel passage, and the filling needle penetrates the axis of the needle valve.   The fuel injection valve according to any one of claims 1 to 3, further comprising an adjusting means for fixing the movement of the filling needle at a midway position.   The fuel injection valve according to claim 4, wherein a piston is provided on the anti-filling needle side of the filling needle spring.   2. The fuel injection system according to claim 1, wherein when the fuel injection amount is small, the filling needle is arranged in the middle of the fuel passage to reduce the passage space of the fuel passage and increase the flow rate of the injected fuel. The fuel injection valve according to 4 or 5.   A fuel passage formed vertically in the nozzle body and a filling needle disposed so as to be movable with respect to the fuel passage. When the fuel injection amount is small, the filling needle is positioned in the middle of the fuel passage. A method for using a fuel injection valve, characterized in that the fuel injection valve is arranged to reduce a flow passage space of a fuel passage and increase a flow rate of fuel to be injected.

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