KR20210002562A - Fuel injection valve - Google Patents

Abstract

In a fuel injection valve that injects fuel and water into a combustion chamber in a cylinder of a marine diesel engine from a powder hole, based on a needle valve spring that elastically supports the needle valve toward the powder hole so as to open and close the fuel flow path and the tip flow path through the powder hole. Thus, the first injection check valve for opening and closing the first main channel is disposed on the side of the spray hole, and the second injection check valve for opening and closing the second main channel is disposed on the side opposite to the powder hole. Water in the first main water channel is injected into the fuel passage from the position where the first main water check valve is disposed, and water in the second main water passage is injected into the fuel passage from the position where the second main water check valve is disposed.

Description

Fuel injection valve

The present invention relates to a fuel injection valve applied to fuel injection of a marine diesel engine mounted on a ship.

Conventionally, in the field of ships, it is effective to inject fuel and water into the combustion chamber in the cylinder from the same fuel injection valve as a method of reducing nitrogen oxides (NOx) generated during combustion in the engine of a marine diesel engine. . For example, in Patent Document 1, high-pressure water that has passed through a water supply check valve from a water channel in a valve body is injected into the fuel in a fuel flow path, and injection into the combustion chamber in the cylinder for one cycle. Thus, a fuel injection valve has been proposed for injecting fuel and water in three stages in the order of fuel-water-fuel.

Japanese Laid-Open Patent Publication No. Hei 6-66217

However, as described above, in the water injection technology in which fuel and water are alternately injected into the combustion chamber in the cylinder, from the viewpoint of improving the fuel efficiency performance and NOx reduction performance of the marine diesel engine, one cycle of fuel and water to the combustion chamber It is preferable to perform the injection of four or more stages in which a plurality of fuel layers and main water layers are alternately arranged. Further, the fuel layer is a layer of fuel formed in the fuel flow path during one cycle of injection. The main water layer is a layer of water injected into the fuel layer in this fuel flow path.

In addition, in the injection of four or more stages of the fuel layer and the main water layer, the amount of fuel in the fuel layer sandwiched between the main water layers in the fuel passage (hereinafter referred to as the amount of fuel between the main water layers) is the stable performance of the marine diesel engine It is a very important factor in terms of securing That is, by one cycle of injection into the combustion chamber, the first layer of fuel layer (first fuel layer), the first layer of main water layer (first main water layer), and second layer of water is counted from the pores of the fuel injection valve. When the fuel layer (the second fuel layer), the second layer of the main water layer (the second main water layer), and the third layer of the fuel layer (the third fuel layer) are injected in this order, the first and second main water layers It is preferable that the fuel amount of the second fuel layer sandwiched between the water layers (the amount of fuel between the main water layers) is a predetermined ratio with respect to the injection amount of fuel per cycle (hereinafter referred to as fuel injection amount) to the combustion chamber. In order to satisfy this condition, in general, a main water check valve of a channel for injecting water serving as the first main water layer into the fuel flow path and a main water check valve for a channel for injecting water serving as the second main water layer. They are arranged by spaced apart from each other so that the amount of fuel between the water layers is appropriate.

However, in the conventional fuel injection valve exemplified in Patent Literature 1, when the injection check valves are spaced apart from each other so that the amount of fuel between the injection water layers satisfies the above condition and attempts to be incorporated into the fuel injection valve, in most cases, It becomes larger (longer) in the longitudinal direction.

In addition, in order to secure the separation distance between the respective water injection and check valves, a water injection check valve corresponding to the first water supply layer is incorporated in the fuel injection valve, and a water injection check valve corresponding to the second water supply layer is connected to the fuel injection valve, etc. It is also possible to think of a method of exteriorizing through the. However, in this method, there is a concern that the bonding strength (mechanical reliability) between the fuel injection valve and the external water injection check valve may decrease due to vibrations of the cylinder and the fuel injection valve accompanying the operation of the marine diesel engine. Therefore, in the fuel injection valve, it is preferable to have a structure in which each of the above water injection check valves is incorporated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fuel injection valve capable of securing a desirable separation distance between each of the built-in injection water check valves and suppressing an enlargement of the structure.

In order to solve the above-described problems and achieve the object, the fuel injection valve according to the present invention is a fuel injection valve that injects fuel and water from a powder hole into a combustion chamber in a cylinder of a marine diesel engine. A fuel flow path through which the fuel is circulated, a tip flow path having one end passing through the fuel flow path and the other end passing through the powder hole, a needle valve opening and closing the tip flow path, and the needle so as to close the tip flow path A needle valve spring elastically supporting the valve toward the powder hole side, a first main channel for injecting water into a predetermined position of the fuel channel, and an upstream side of the fuel channel in the pressure feeding direction of the fuel than the first main channel of the fuel channel A second main water channel for injecting water into a position, a first main water check valve disposed on the hole side than the needle valve spring, and closing the first main water passage so as to be openable, and the needle valve spring A second main water supply check valve disposed on the opposite side of the water hole and closing the second main water passage so as to open and close the second main water passage, and the water in the first main water passage is the fuel flow path from the arrangement position of the first water supply check valve. It is injected into the inside, and the water in the second main water channel is injected into the fuel passage from a position where the second main water check valve is disposed.

Further, in the fuel injection valve according to the present invention, in the above invention, the first injection check valve and the second injection check valve are disposed on the same axis in the direction of the longitudinal central axis of the fuel injection valve. To do.

Further, in the fuel injection valve according to the present invention, in the above invention, the first main water passage has an annular main water passage formed in an annular shape surrounding the first water injection check valve.

Further, in the fuel injection valve according to the present invention, in the above invention, the fuel flow path is arranged so as to pass through the longitudinal central axis of the fuel injection valve.

In the fuel injection valve according to the present invention, in the above invention, the fuel flow path is disposed at a position separated from the longitudinal central axis of the fuel injection valve in the radial direction.

Advantageous Effects of Invention According to the present invention, it is possible to realize a fuel injection valve capable of securing a desirable separation distance between each of the built-in injection water check valves and suppressing an increase in the size of the structure.

1 is a schematic cross-sectional view showing a configuration example of a fuel injection valve according to Embodiment 1 of the present invention.
2 is a schematic cross-sectional view taken along line AA of the fuel injection valve shown in FIG. 1.
3 is a schematic cross-sectional view taken along line BB of the fuel injection valve shown in FIG. 1.
4 is a schematic cross-sectional view showing a configuration example of a fuel injection valve according to Embodiment 2 of the present invention.
5 is a schematic cross-sectional view showing a configuration example of a fuel injection valve according to Embodiment 2 of the present invention as viewed from a different viewpoint.
6 is a schematic cross-sectional view taken along line CC of the fuel injection valve shown in FIG. 4.

Hereinafter, preferred embodiments of the fuel injection valve according to the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment. In addition, the drawings are schematic, and it is necessary to note that the relationship between the dimensions of each element, the ratio of each element, and the like may be different from those in reality. In the drawings, there are cases in which parts having different dimension relationships and ratios are included. In addition, in each figure, the same code|symbol is attached|subjected to the same structural part.

(Embodiment 1)

First, a configuration of a fuel injection valve according to Embodiment 1 of the present invention will be described. 1 is a schematic cross-sectional view showing a configuration example of a fuel injection valve according to Embodiment 1 of the present invention. Fig. 2 is a schematic cross-sectional view taken along line A-A of the fuel injection valve shown in Fig. 1. 3 is a schematic cross-sectional view taken along line B-B of the fuel injection valve shown in FIG. 1. In FIG. 1, the axial direction F1 is the direction of the longitudinal central axis of the fuel injection valve 100. In the first embodiment, in order to facilitate the description of the configuration of the fuel injection valve 100, the positive side of the axial direction F1 is the front end side of the fuel injection valve 100, and the axial direction F1 is The negative side is taken as the rear end side of the fuel injection valve 100. The radial direction F2 is the radial direction of the fuel injection valve 100 and is a direction perpendicular to the longitudinal central axis of the fuel injection valve 100.

The fuel injection valve 100 according to the first embodiment is mounted on a cylinder (not shown) of a marine diesel engine, and pumps fuel from a fuel injection pump (not shown) and water pumped from a main water pump (not shown). It is for sequentially spraying (for example, spraying in a layered form) into the combustion chamber in the cylinder. As shown in FIG. 1, the fuel injection valve 100 includes a nozzle 1 positioned at the front end, an injection valve body 11 positioned at the rear end side of the nozzle 1, and the injection valve body 11 It is provided with an injection valve body 40 located at the rear end of the. The nozzle 1 and the injection valve body 11 are fastened from the outer periphery by a nut-shaped nozzle fastening material 10, and are fixed in a state connected in the axial direction F1. In addition, the injection valve body 11 and the injection valve body 40 on the rear end are fastened from the outer periphery by a nut-shaped valve body fastening member 30, thereby being fixed in a state connected in the axial direction F1. .

The nozzle 1 constitutes a tip portion of the fuel injection valve 100. As shown in FIG. 1, in the nozzle 1, the needle valve accommodating part 2 in the shape of a hole extending in the axial direction F1 is formed. In this needle valve receiving portion 2, a needle valve 6 that blocks communication between the fuel flow path of the fuel injection valve 100 and the powder hole 4 so as to be openable is accommodated so as to be able to slide freely. In the needle valve 6, a needle valve inner flow path 7 extending in the axial direction F1 is formed. A storage portion 3 is formed between the tip side of these needle valve accommodating portions 2 and the tip side of the needle valve 6. At the tip end of the needle valve 6, a communication hole 8 for communicating the flow path 7 in the needle valve and the reservoir 3 is formed. Further, a hole 4 and a tip flow path 5 are formed on the tip side of the nozzle 1. One end of the tip flow path 5 communicates with the fuel flow path of the fuel injection valve 100 (specifically, the flow path 7 in the needle valve that becomes a part of the fuel flow path of the fuel injection valve 100 ). The other end of the tip flow path 5 communicates with the blow hole 4.

The injection valve body 11 constitutes an intermediate portion between the nozzle 1 on the front end side and the injection valve body 40 on the rear end side. As shown in FIG. 1, in the injection valve main body 11, the check valve accommodating part 12 of the hole shape extending in the axial direction F1 is formed. In this check valve accommodating portion 12, a water injection check valve 20 corresponding to the first main channel of the fuel injection valve 100 is accommodated. In the first embodiment, the first water passage is a water passage for injecting water to a predetermined position in the fuel passage of the fuel injection valve 100 (the first injection position P1 shown in FIG. 1 ).

The water injection check valve 20 is a check valve (first injection check valve) that closes the first main water passage of the fuel injection valve 100 so as to be openable and closed. As shown in FIG. 1, the water injection non-return valve 20 is comprised by the valve body 21, the valve seat 24, the check valve spring 26, and the valve body accommodation part 27, mentioned later. It is arranged on the side of the hole 4 than the needle valve spring 50.

As shown in FIG. 1, the valve body 21 has a pressure receiving part 23 that receives the pressure of water from the first main channel, so that it can slide freely in the valve body accommodating part 27. Is accepted. As shown in FIGS. 1 and 2, the pressure receiving portion 23 is formed in an annular shape over the outer periphery of the valve body 21 in the vicinity of the tip portion. In addition, in the valve body 21, a flow path 22 in the valve body that becomes a part of the fuel flow path of the fuel injection valve 100 is formed. As shown in FIG. 1, the valve seat 24 is fixed to the distal end of the valve body accommodating portion 27 by fastening or the like. In the valve seat 24, a valve seat inner flow path 25 that becomes a part of the fuel flow path of the fuel injection valve 100 is formed. The check valve spring 26 is disposed between the rear end of the valve body 21 and the valve body accommodating portion 27 as shown in FIG. 1. The check valve spring 26 imparts an elastic force to the valve body 21 to elastically support the valve seat 24 side. The water injection check valve 20 presses the valve body 21 to the valve seat 24 by using the elastic force of the check valve spring 26, whereby the fuel flow path of the fuel injection valve 100 and the first Shut off the main channel communication so that it can be opened.

In addition, in the first embodiment, the water injection check valve 20 has a function as the check valve and a function as a pressing rod that transmits the elastic force of the needle valve spring 50 to the needle valve 6. Specifically, as shown in FIG. 1, the water injection check valve 20 is interposed between the needle valve 6 and the needle valve spring 50. For example, the water injection non-return valve 20 receives the needle valve spring 50 at the rear end of the valve body accommodating portion 27, and the front end of the valve seat 24 is the rear end of the needle valve 6 It is in a pressurized state. The water injection check valve 20 can slide freely in the axial direction F1 in the check valve accommodating portion 12, and by using the elastic force of the needle valve spring 50, the needle valve 6 is connected to the tip flow path ( 5) Pressurize. In addition, the water injection check valve 20 uses the pressure of the fuel in the reservoir 3 together with the needle valve 6 to slide in a direction away from the front flow path 5, and the elastic force of the needle valve spring 50 It slides in the direction (the direction which compresses the needle valve spring 50) to resist.

In addition, as shown in FIG. 1, in the injection valve main body 11, a columnar main channel 72, an annular main channel 73, 75, and a symmetrical main channel 74 are formed, and the main water supply and check valve 20 A symmetrical main channel 76 is formed in the valve body receiving portion 27. The columnar main water passage 72 is a columnar water passage, and a hole is formed in the rear end portion of the injection valve body 11. The annular main channel 73 is constituted by a gap between the inner wall surface of the valve body fastening member 30 and the outer wall surface of the injection valve body 11, for example, as shown in Figs. It is formed in an annular shape surrounding the valve 20 (valve body accommodating portion 27, etc.). The symmetric main channel 74 is a channel formed axially symmetric with respect to the central axis in the operation direction of the main water check valve 20. In the first embodiment, as shown in Figs. 1 and 2, the symmetrical main channel 74 is formed in the injection valve body 11 at equiangular intervals around the central axis in the operation direction of the main water check valve 20 (perforation It consists of a plurality of channels (for example, 4) that are formed). The annular main channel 75 is constituted by, for example, a groove formed in the inner peripheral surface of the injection valve body 11 (the inner wall surface of the check valve accommodating portion 12). As shown in Figs. 1 and 2, the annular main channel 75 is located between the outlet end of the symmetric main channel 74 and the inlet end of the symmetric main channel 76, and a main water check valve 20 (valve body accommodating part (27), etc.). The symmetrical main channel 76 is formed axially symmetric with respect to the central axis in the operation direction of the main water check valve 20, and the main water check valve 20 (specifically, the pressure receiving part 23 of the valve body 21) and It is a channel with opposite discharge ports. In the first embodiment, as shown in Figs. 1 and 2, the symmetric main channel 76 is formed in the valve body receiving portion 27 at equiangular intervals around the central axis in the operation direction of the main water check valve 20 ( It consists of a plurality of channels (for example, four) to be perforated.

In addition, the central axis in the operation direction of the water injection check valve 20 is a central axis in the sliding direction of the valve body 21. In the first embodiment, the central axis in the operation direction of the water injection check valve 20 coincides with the central axis in the longitudinal direction of the fuel injection valve 100 or is parallel to the central axis in the longitudinal direction.

The columnar main channels 72, the annular main channels 73 and 75, and the symmetric main channels 74 and 76 described above are channels that become part of the first main channel of the fuel injection valve 100, respectively. 1 and 2, the columnar main channel 72 passes through the annular main channel 73, the annular main channel 73 passes through the symmetric main channel 74, and the symmetric main channel 74 Is connected to the annular main channel 75, and the annular main channel 75 is connected to the symmetric main channel 76. Moreover, when the valve body 21 is separated from the valve seat 24, the symmetrical water supply passage 76 communicates with the first water injection position P1 in the fuel flow passage of the fuel injection valve 100. In addition, as shown in FIG. 1, on the outer wall surface of the injection valve main body 11, at a position between the annular main channel 73 and the distal end of the valve main body 30 from the annular main channel 73, etc. O-ring 91 for preventing water leakage is formed.

On the other hand, the injection valve body 40 constitutes a rear end portion of the fuel injection valve 100. As shown in FIG. 1, in the injection valve main body 40, a hole-shaped accommodation part 41 extending in the axial direction F1 is formed. In this accommodation part 41, a needle valve spring 50, a spring accommodation part 51, and a water injection check valve 60 corresponding to the second main channel of the fuel injection valve 100 are accommodated. In the first embodiment, the second main water passage is a position upstream in the pressure feeding direction of the fuel than the first main passage in the fuel passage of the fuel injection valve 100 (for example, the second water injection position shown in FIG. It is a channel to inject water into P2)).

The needle valve spring 50 elastically supports the needle valve 6 toward the powder hole 4 so as to close the tip flow path 5. As shown in FIG. 1, the needle valve spring 50 is constituted by, for example, a coil spring, and is accommodated in the accommodation part 41 in a state attached to the spring accommodation part 51. The spring accommodating portion 51 is accommodated in the accommodating portion 41 while receiving the needle valve spring 50, and is formed at the rear end of the valve body accommodating portion 27 of the water injection check valve 20 described above. It is mounted to be able to slide freely in the insertion hole (29). The spring accommodating portion 51 receives one end of the needle valve spring 50 and presses the other end of the needle valve spring 50 to the rear end of the valve body accommodating portion 27, whereby the needle valve spring ( 50) to generate elastic force. Further, in the spring accommodating portion 51, a flow path 52 in the spring accommodating portion, which becomes a part of the fuel flow path of the fuel injection valve 100, is formed.

The water injection check valve 60 is a check valve (a second injection check valve) that closes the second main water passage of the fuel injection valve 100 so that it can be opened and closed. As shown in FIG. 1, the water injection non-return valve 60 is constituted by a valve body 61, a valve seat 64, a check valve spring 66, and a valve body accommodation part 67, and a needle The valve spring 50 is disposed on the opposite side from the hole 4 as a reference. In the first embodiment, the main water check valve 60 corresponding to the second main channel and the main water check valve 20 corresponding to the first main channel are axially arranged (F1) with the needle valve spring 50 interposed therebetween. ) Is placed on the opposite side. At this time, it is preferable that these two water injection check valves 20 and 60 are disposed on the same axis in the axial direction F1.

As shown in FIG. 1, the valve body 61 has a pressure receiving part 63 that receives pressure of water from the second main water channel, and is accommodated in the valve body accommodation part 67 so as to be able to slide freely. As shown in FIGS. 1 and 3, the pressure receiving portion 63 is formed in an annular shape over the outer periphery of the valve element 61 in the vicinity of the tip portion. Further, in the valve body 61, a flow path 62 in the valve body that becomes a part of the fuel flow path of the fuel injection valve 100 is formed. As shown in FIG. 1, the valve seat 64 is fixed to the distal end of the valve body housing 67 by fastening or the like. In the valve seat 64, a valve seat inner flow path 65 that becomes a part of the fuel flow path of the fuel injection valve 100 is formed. The check valve spring 66 is disposed between the rear end of the valve body 61 and the valve body housing 67 as shown in FIG. 1. The check valve spring 66 imparts an elastic force to the valve body 61 to elastically support the valve seat 64 side. The water injection check valve 60 presses the valve body 61 against the valve seat 64 by using the elastic force of the check valve spring 66, whereby the fuel flow path of the fuel injection valve 100 and the second Shut off the main channel communication so that it can be opened. The valve body housing portion 67 is configured so that it can be screwed into the housing portion 41 of the injection valve body 40. In this valve body accommodation part 67, a flow path 68 in the accommodation part that becomes a part of the fuel flow path of the fuel injection valve 100 is formed. Further, to the rear end of the valve body accommodating portion 67, as shown in Fig. 1, a fuel supply pipe 90 communicating with a flow path 68 inside the accommodating portion is connected. The fuel supply pipe 90 is a pipe for introducing the fuel pumped by a fuel injection pump (not shown) into the fuel flow path of the fuel injection valve 100.

In addition, in the first embodiment, the water injection check valve 60 functions as the check valve and functions as an adjustment screw for adjusting the elastic force of the needle valve spring 50 (that is, the valve opening pressure of the needle valve 6 ). Specifically, as shown in FIG. 1, the water injection check valve 60 is attached by screwing the valve body receiving portion 67 into the receiving portion 41 of the injection valve body 40. The water injection check valve 60 screwed into the receiving portion 41 is in a state in which the tip of the valve seat 64 abuts against the rear end of the spring receiving portion 51. The water injection check valve 60 is, The elastic force of the needle valve spring 50 is adjusted by adjusting the amount of twisting into the receiving portion 41. Specifically, the water injection check valve 60 increases the amount of twisting into the receiving portion 41. , By increasing the amount of press-fitting of the spring receiving portion 51 to the side of the powder hole 4, the amount of compression of the needle valve spring 50 is increased to adjust the elastic force strongly. On the other hand, the water injection check valve 60 has a receiving portion. (41) By reducing the amount of screwing into the inside and reducing the amount of press-fitting of the spring receiving portion 51 to the side of the hole 4, the amount of compression of the needle valve spring 50 is reduced, and the elastic force is weakly adjusted.

In addition, as shown in Figs. 1 and 3, columnar main water passages 71 and 81 are formed in the injection valve main body 40, and annular main water passages are formed in the valve body receiving portion 67 of the water injection and check valve 60. 82) and a symmetric main channel 84 are formed. The columnar main water passages 71 and 81 are water passages forming a columnar shape, and each of them is perforated at different positions in the injection valve body 40. The annular main channel 82 is constituted by, for example, a groove formed on the outer peripheral surface of the valve body accommodating portion 67. As shown in FIG. 3, the annular main channel 82 is located between the outlet end of the columnar main channel 81 and the inlet end of the symmetric main channel 84, and the main water check valve 60 (valve body 61) Etc.). The symmetrical main channel 84 is formed axially symmetrically with respect to the central axis in the operation direction of the main water check valve 60, and the main water check valve 60 (specifically, the pressure receiving part 63 of the valve body 61) and It is a channel with opposite discharge ports. In the first embodiment, as shown in Figs. 1 and 3, the symmetric main channel 84 is formed in the valve body receiving portion 67 at equiangular intervals around the central axis in the operation direction of the main water check valve 60 ( It consists of a plurality of channels (for example, four) to be perforated.

In addition, the central axis in the operation direction of the water injection check valve 60 is a central axis in the sliding direction of the valve body 61. In the first embodiment, the central axis in the operation direction of the water injection check valve 60 coincides with the central axis in the longitudinal direction of the fuel injection valve 100 or is parallel to the central axis in the longitudinal direction.

The columnar main channel 71 described above is a channel used as a part of the first main channel of the fuel injection valve 100. As shown in FIG. 1, the columnar main channel 71 is connected to the columnar main channel 72 in the injection valve body 11 described above. On the other hand, the columnar main channel 81, the annular main channel 82, and the symmetric main channel 84 described above are channels that become part of the second main channel of the fuel injection valve 100, respectively. 1 and 3, the columnar main channel 81 passes through the annular main channel 82, and the annular main channel 82 passes through the symmetrical main channel 84. Moreover, when the valve body 61 is separated from the valve seat 64, the symmetrical water supply passage 84 communicates with the second water injection position P2 in the fuel passage of the fuel injection valve 100. In addition, as shown in Fig. 1, on the outer circumferential surface of the valve body accommodating portion 67, an O-ring for preventing water leakage from the annular main channel 82 etc. at each position sandwiching the annular main channel 82 (92, 93) is formed.

Next, a fuel flow path of the fuel injection valve 100 according to the first embodiment will be described. The fuel flow path of the fuel injection valve 100 is a path (flow path) through which the fuel pumped from the fuel injection pump flows. In the first embodiment, the fuel flow path of the fuel injection valve 100 is the needle valve internal flow path 7 shown in FIG. 1, the valve body internal flow paths 22 and 62, and the valve seat internal flow paths 25 and 65. ), flow paths 28 and 68 in the receiving portion, and flow paths 52 in the spring receiving portion.

Specifically, as shown in FIG. 1, in the fuel flow path of the fuel injection valve 100, the flow path 7 in the needle valve communicates with the flow path 25 in the valve seat, and the flow path 25 in the valve seat is The valve body internal flow path 22 communicates with the valve body internal flow path 22 communicates with the housing part internal flow path 28. Moreover, the flow path 28 in the accommodation part communicates with the flow path 52 in the spring accommodation part, and the flow path 52 in the spring accommodation part communicates with the flow path 65 in the valve seat. In addition, the flow path 65 in the valve seat communicates with the flow path 62 in the valve body, and the flow path 62 in the valve body communicates with the flow path 68 in the accommodating portion. The fuel flow path of the fuel injection valve 100 constituted by these flow paths passes through the longitudinal central axis of the fuel injection valve 100 (refer to the dashed-dotted line in FIG. 1 ), for example, as shown in FIG. 1. It is placed. In addition, the front end side of the fuel flow path of the fuel injection valve 100 (pump hole 4 side) is the reservoir 3 through the communication hole 8 of the needle valve 6 from the flow path 7 in the needle valve. It is connected to. The rear end side (fuel injection pump side) of the fuel flow path of the fuel injection valve 100 communicates with the fuel supply pipe 90 via the flow path 68 in the accommodation part.

Next, the first main channel and the second main channel of the fuel injection valve 100 according to the first embodiment will be described. In the first embodiment, in the first injection channel, water supplied by pressure from the injection pump is injected into the first injection position P1 of the fuel passage of the fuel injection valve 100 via the injection check valve 20. It is a passage (waterway) for. 1 and 2, as shown in Figs. 1 and 2, the columnar main channel 71, the columnar main channel 72, the annular main channel 73, the symmetrical main channel 74, and the annular main channel 75 ) And the symmetric main channel 76 in this order. Moreover, the 1st main water passage is connected from the columnar main water passage 71 through a water supply pipe (not shown) to a water injection pump. Further, the annular main water passage 73 forms an annular shape surrounding the water injection and check valve 20 so that the water circulation range is wider than that of the columnar main water passages 71 and 72. For this reason, in the annular main channel 73, even if the width of the channel in the radial direction F2 is smaller than that of the columnar main channels 71, 72, the volume of the channel per unit length in the axial direction F1 is changed to the columnar main channel ( 71, 72).

In addition, in the first embodiment, the water pumped from the injection pump is transferred to the second injection channel P2 of the fuel flow path of the fuel injection valve 100 via the injection check valve 60. It is a passage (channel) for injection. As shown in Figs. 1 and 3, the second main channel is configured by communicating the columnar main channel 81, the annular main channel 82, and the symmetric main channel 84 in this order. Moreover, the 2nd main water passage is connected from the columnar main water passage 81 through a water supply pipe (not shown) to a water injection pump. In addition, the main water pump for pumping water to the second main channel may be the same as or different from the main pump for pumping water to the first main channel described above.

Next, the operation of the fuel injection valve 100 according to the first embodiment will be described. The fuel injection valve 100 injects fuel and water in a layered form from the powder hole 4 by one cycle of injection into a combustion chamber in a cylinder of a marine diesel engine.

The period from the end of this one cycle injection until the next injection is performed (hereinafter referred to as a non-fuel injection period), from the fuel flow passage of the fuel injection valve 100 through the reservoir 3 through the front end flow path In the circulation path over (5) and in the fuel supply pipe 90, the fuel pumped from the fuel injection pump remains. In this step, the pressure of the fuel remaining in the reservoir 3 is lower than the valve opening pressure of the needle valve 6. Therefore, the needle valve 6 is in a state in which the tip flow path 5 is closed so as to be able to open and close. In addition, the valve opening pressure of the needle valve 6 is the pressure required to open the needle valve 6, and the needle valve spring 50 transmitted to the needle valve 6 via the water injection check valve 20 It is set by the elastic force.

In addition, in this non-fuel injection period, in each of the first main channel and the second main channel of the fuel injection valve 100, water pumped from the main water pump remains. In this step, the pressure of the water remaining in the first main water channel is lower than the valve opening pressure of the main water check valve 20. Accordingly, the water injection check valve 20 is in a state in which the communication between the fuel passage of the fuel injection valve 100 and the first main water passage can be opened. Similarly to this, since the pressure of the water remaining in the second main water channel is lower than the valve opening pressure of the main water check valve 60, the main water check valve 60 is the fuel flow path of the fuel injection valve 100 and the second It is in a state in which the communication of the main canal is opened so as to be open. In addition, the valve opening pressure of the water injection check valve 20 is a pressure required to open the water injection check valve 20, and the elastic force of the check valve spring 26 to press the valve body 21 to the valve seat 24 Is set by The valve opening pressure of the water injection check valve 60 is a pressure required to open the water injection check valve 60, and is due to the elastic force of the check valve spring 66 that presses the valve body 61 against the valve seat 64. Is set.

Here, in this non-fuel injection period, when water having a high pressure exceeding the valve opening pressure of the main water check valve 20 is pumped from the main water pump into the first main channel of the fuel injection valve 100, this high pressure water The insides of the columnar main channels 71 and 72, the annular main channels 73, the symmetric main channels 74, the annular main channels 75, and the symmetric main channels 76 shown in Figs. Distribute in order. And this high-pressure water flows so as to pressurize the valve body 21 from the axially symmetrical direction with respect to the central axis of the operation direction of the water injection check valve 20 through the discharge port of the symmetric main water channel 76. That is, the valve body 21 receives this high-pressure water pressure (water pressure) from the pressure receiving portion 23 in a axial symmetry. Since this water pressure is higher than the valve opening pressure of the main water check valve 20, the valve element 21 slides against the elastic force of the check valve spring 26 using this water pressure, and the valve seat 24 Separate from In this way, the water injection check valve 20 opens the communication between the fuel passage of the fuel injection valve 100 and the first main water passage.

In this step, the water in the first main water channel is injected into the fuel flow path of the fuel injection valve 100 from the arrangement position of the main water check valve 20. Specifically, the water in the first main channel is axially symmetric with respect to the central axis in the fuel flow direction of the fuel passage of the fuel injection valve 100 (for example, the longitudinal central axis of the fuel injection valve 100). , Is injected into the first injection position P1 in the fuel flow path. The injected water spreads axially symmetrically (evenly in the radial direction F2) in this fuel flow path, while pushing the residual fuel in this fuel flow path back to the rear end side (fuel injection pump side) in the axial direction F1. Serve. As a result, a first water main layer serving as the first water main layer is formed in this fuel passage. Further, on the downstream side of the first water injection layer (the side of the powder hole 4), a first fuel layer made of fuel remaining in the fuel passage on the side of the hole 4 from the first injection position P1 is formed.

On the other hand, in this non-fuel injection period, when high pressure water exceeding the valve opening pressure of the main water check valve 60 is pumped from the main water pump into the second main channel of the fuel injection valve 100, this high pressure water Silver flows through each interior of the columnar main channel 81, the annular main channel 82, and the symmetric main channel 84 shown in Figs. 1 and 3 in this order. Then, the high-pressure water flows through the discharge port of the symmetric main water channel 84 so as to pressurize the valve body 61 from a direction axially symmetric with respect to the central axis of the operation direction of the water injection check valve 60. That is, the valve body 61 receives the water pressure of this high-pressure water at the pressure receiving portion 63 in a axial symmetry. Since this water pressure is higher than the valve opening pressure of the main water check valve 60, the valve element 61 uses this water pressure to resist the elastic force of the check valve spring 66 and slides, and the valve seat 64 Separate from In this way, the water injection check valve 60 opens the communication between the fuel passage of the fuel injection valve 100 and the second main water passage.

In this step, water in the second main channel is injected into the fuel flow path of the fuel injection valve 100 from the arrangement position of the main water check valve 60. Specifically, water in the second main water passage is injected into the second water injection position P2 in the fuel passage from a direction axially symmetric with respect to the central axis in the fuel passage direction of the fuel injection valve 100. The injected water spreads axially symmetrically (evenly in the radial direction F2) in this fuel flow path, while pushing the residual fuel in this fuel flow path back to the rear end side (fuel injection pump side) in the axial direction F1. Serve. As a result, a second main water layer serving as the second water main layer is formed in this fuel passage. Further, a second fuel layer made of fuel remaining in the fuel flow path is formed between the second water main layer and the above-described first water main layer. Further, on the upstream side (fuel injection pump side) of the second water injection layer, a third fuel layer made of fuel remaining in the fuel passage on the fuel injection pump side than at the second injection position P2 is formed.

After the above-described non-fuel injection period, fuel is pumped from the fuel injection pump into the fuel passage of the fuel injection valve 100, and fuel and water are injected by one cycle to the combustion chamber in the cylinder of the marine diesel engine.

Specifically, during the period in which this injection is performed (hereinafter referred to as the fuel injection period), fuel of a high pressure exceeding the valve opening pressure of the needle valve 6 is injected from the fuel injection pump through the fuel supply pipe 90 It is pressurized into the fuel flow path of the valve 100. In this case, the pressure of the fuel pumped from the fuel injection pump passes through the fluid (remaining fuel and injected water) existing in the fuel flow path of the fuel injection valve 100, and the communication hole 8 of the needle valve 6 ) To the fuel in the reservoir (3). As a result, the pressure of the fuel in the reservoir 3 is raised to a higher pressure than the valve opening pressure of the needle valve 6. The needle valve 6 receives the pressure of the boosted fuel in the reservoir 3 at the tip end, and slides against the elastic force of the needle valve spring 50 by using the pressure of the fuel, and the tip flow path 5 ) From the opening (sheet part). At this time, the water injection check valve 20 slides together with the needle valve 6 in a direction that resists the elastic force of the needle valve spring 50 (the rear end side of the axial direction F1). In this way, the needle valve 6 opens the communication between the fuel flow path of the fuel injection valve 100 and the powder hole 4.

In this step, the fuel injection valve 100 injects fuel and water for one cycle into a combustion chamber in a cylinder of a marine diesel engine. For example, the fuel injection valve 100 includes the first fuel layer, the first main water layer, the second fuel layer, the second main water layer, and the third fuel layer in the fuel passage from the hole 4 in this order. It is injected in a layered form into the combustion chamber inside. After that, the pressure of the fuel in the storage portion 3 is reduced to less than or equal to the valve opening pressure of the needle valve 6. In this case, the needle valve 6 slides toward the hole 4 by using the elastic force of the needle valve spring 50, and again contacts the seat portion of the tip flow path 5 to open and close the tip flow path 5 Closed. In this way, the needle valve 6 cuts off the communication between the fuel flow path of the fuel injection valve 100 and the powder hole 4 so that it can be opened.

As described above, in the fuel injection valve 100 according to the first embodiment of the present invention, based on the needle valve spring 50 elastically supporting the needle valve 6 toward the hole 4, the first main The water supply check valve 20 of the water channel is disposed on the side of the spray hole 4, and the water supply check valve 60 of the second main channel is arranged on the side opposite to the spray hole 4, so that the water in the first main channel is It is injected from the check valve 20 to the first injection position P1 in the fuel flow path, and water in the second main channel is injected from the injection check valve 60 to the second injection position P2 in the fuel flow path.

For this reason, while the injection check valve 20 of the first main channel can be disposed in the vicinity of the needle valve 6, it is between the first injection position P1 and the second injection position P2 in the fuel flow path. The injection check valve 20 of the first main channel and the check valve of the second main channel so that the amount of fuel between the main water layers is a suitable ratio (for example, about 10 to 20%) with respect to the fuel injection amount per cycle. It is possible to arrange 60 apart, and furthermore, the area between these two water injection check valves 20 and 60 can be effectively utilized as an area in which the needle valve spring 50 is disposed. As a result, while ensuring a desirable separation distance between each of the injection water check valves 20 and 60 built in the fuel injection valve 100, the fuel injection valve 100 is enlarged (especially the lengthening of the structure in the longitudinal direction) Can be suppressed. By injecting fuel and water into the combustion chamber in the cylinder of the marine diesel engine using such a fuel injection valve 100, water can be injected into the combustion chamber from the initial stage of fuel injection, and as a result, the fuel in the combustion chamber It is possible to efficiently reduce the amount of NOx generated at the beginning of combustion.

In addition, in the fuel injection valve 100 according to Embodiment 1 of the present invention, the injection check valve 20 of the first main channel and the injection check valve 60 of the second main channel are provided in the fuel injection valve 100. It is arranged on the same axis in the direction of the longitudinal central axis. For this reason, the width (length of the radial direction F2 of the fuel injection valve 100) of the region occupied by the arrangement of these two water injection check valves 20 and 60 can be reduced. As a result, it is possible to suppress an increase in size (increase in width) in the radial direction F2 of the fuel injection valve 100.

Further, in the fuel injection valve 100 according to the first embodiment of the present invention, the first main channel is configured to have an annular main channel 73 formed in an annular shape surrounding the main water check valve 20. Here, since the annular main channel 73 can expand the circulation range of water into an annular shape, even if the channel width in the radial direction F2 is smaller than that of the columnar channel, the channel volume per unit length in the axial direction F1 is reduced. It can be done equal to the columnar channel. For this reason, the width of the channel in the region of the annular main channel 73 of the first main channel can be reduced without impeding the flow of water in the first main channel, and as a result, the fuel injection valve 100 It is possible to promote the miniaturization of the radial direction F2.

Further, in the fuel injection valve 100 according to the first embodiment of the present invention, a fuel flow path through which the fuel pressurized from the fuel injection pump is circulated is disposed so as to pass through the longitudinal central axis of the fuel injection valve 100. For this reason, a plurality of components constituting the fuel flow path (for example, the needle valve 6, the water injection check valve 20, 60, the spring receiving portion 51 of the needle valve spring 50, etc.) are used as a fuel injection valve. (100) It can be concentrated and arranged on the central axis in the longitudinal direction. As a result, since the width of the region occupied by the arrangement of the plurality of parts can be reduced, the miniaturization of the radial direction F2 of the fuel injection valve 100 can be promoted.

(Embodiment 2)

Next, Embodiment 2 of the present invention will be described. First, the configuration of the fuel injection valve according to the second embodiment of the present invention will be described. 4 is a schematic cross-sectional view showing a configuration example of a fuel injection valve according to Embodiment 2 of the present invention. 5 is a schematic cross-sectional view showing a configuration example of a fuel injection valve according to Embodiment 2 of the present invention as viewed from a different viewpoint. In FIG. 5, a schematic cross-sectional view of the fuel injection valve shown in FIG. 4 viewed from the direction D is shown. 6 is a schematic cross-sectional view taken along line C-C of the fuel injection valve shown in FIG. 4. In addition, the definition of the axial direction (F1) and the radial direction (F2) is the same as the fuel injection valve 100 according to the first embodiment described above replaced with the fuel injection valve 200 according to the second embodiment. .

The fuel injection valve 200 according to the second embodiment is mounted on a cylinder of a marine diesel engine, and sequentially injects fuel pumped from the fuel injection pump and water pumped from the main water pump into the combustion chamber in the cylinder (for example, a layered Is to be sprayed). As shown in Figs. 4 and 5, the fuel injection valve 200 includes a nozzle 101 located at the front end, an injection valve body 111 located at a rear end side of the nozzle 101, and these nozzles 101 And an intermediate prohibition 112 positioned between the injection valve body 111 and the injection valve body 111. The nozzle 101, the injection valve body 111, and the intermediate prohibition 112 are in a nut-shaped nozzle fastening prohibition 110 with the intermediate prohibition 112 interposed between the nozzle 101 and the injection valve body 111. ) Is fastened from the outer periphery, and is fixed in a state connected in the axial direction (F1).

The nozzle 101 constitutes a tip portion of the fuel injection valve 200. As shown in Figs. 4 and 5, in the nozzle 101, a hole-shaped needle valve accommodating portion 102 extending in the axial direction F1 is formed. In this needle valve receiving portion 102, a needle valve 106 that blocks communication between the fuel flow path of the fuel injection valve 200 and the powder hole 104 so as to be openable is accommodated so as to be able to slide freely. In the middle portion of the needle valve 106, a tapered portion 106a that widens from the front end side in the axial direction F1 toward the rear end side is formed. In addition, a storage portion 103 is formed in the middle portion of the needle valve accommodating portion 102. In the state where the needle valve 106 is accommodated in the needle valve accommodating portion 102, the tapered portion 106a is located in the storage portion 3.

Further, as shown in Figs. 4 and 5, a hole 104 and a tip flow path 105 are formed on the tip side of the nozzle 101. One end of the tip flow path 105 communicates with the fuel flow path of the fuel injection valve 200 via the needle valve accommodating portion 102. The other end of the tip flow path 105 communicates with the blow hole 104. In addition, as shown in FIG. 4, in the nozzle 101, a columnar fuel flow path 174 that becomes a part of the fuel flow path of the fuel injection valve 200 is formed. The columnar fuel flow passage 174 is a columnar flow path, from the central axis in the operation direction of the needle valve 106 to the width direction of the fuel injection valve 200 (left side of the radial direction F2 shown in FIG. 4 ). A perforation is formed in the spaced area. The columnar fuel flow path 174 extends so as to be inclined with respect to the axial direction F1, and communicates from the reservoir 103 to the tip flow path 105 via the needle valve accommodating portion 102. In addition, the central axis in the operation direction of the needle valve 106 is a central axis in the sliding direction of the needle valve 106.

The intermediate prohibition 112 constitutes an intermediate portion between the nozzle 101 and the injection valve body 111. As shown in Figs. 4 and 5, in the intermediate prohibition 112, an insertion hole 113 extending in the axial direction F1 is formed. In this insertion hole 113, a pressing rod 155 for pressing the needle valve 106 toward the powder hole 104 is inserted so as to slide freely. In addition, as shown in Figs. 4 to 6, in the intermediate prohibition 112, the injection check valve 120 corresponding to the first main channel of the fuel injection valve 200 and the fuel flow path of the fuel injection valve 200 A columnar fuel passage 173 and a confluence passage 176 that become part of it are formed. In the second embodiment, the first water passage is a water passage for injecting water to a predetermined position in the fuel passage of the fuel injection valve 200 (first water injection position P1 shown in FIG. 4 ).

The water injection check valve 120 is a check valve (first water injection check valve) that closes the first main water passage of the fuel injection valve 200 so that it can be opened and closed. In the second embodiment, the water injection and check valve 120 is not particularly shown, but is constituted by a valve body, a valve seat, a check valve spring, etc., and is a columnar water supply channel 182 that is a part of the first main water channel. The communication between the and the confluence passage 176 is blocked openably. As shown in FIG. 5, the water injection non-return valve 120 is disposed on the side of the hole 104 from the needle valve spring 150 described later. Moreover, the water injection check valve 120 is located in a region separated from the central axis in the operation direction of the needle valve 106 in the width direction of the fuel injection valve 200.

The columnar fuel flow passage 173 is a columnar flow path, from the central axis in the operation direction of the needle valve 106 to the width direction of the fuel injection valve 200 (left side of the radial direction F2 shown in FIG. 4 ). A perforation is formed in the spaced area. The columnar fuel flow passage 174 extends in the axial direction F1 and communicates the columnar fuel flow passage 174 in the nozzle 101 and the columnar fuel flow passage 172 in the injection valve body 111. Further, the confluence passage 176 is a passage for joining the water flowing from the first main water passage through the main water check valve 120 and the fuel in the fuel passage of the fuel injection valve 200. For example, the confluence passage 176 is constituted by a groove or the like formed in the end face of the intermediate metal 112. As shown in FIGS. 4-6, the confluence passage 176 has one end through the injection check valve 120 and the other end through the columnar fuel flow passage 173.

The injection valve body 111 constitutes a portion extending from the middle portion to the rear end portion of the fuel injection valve 200. As shown in Figs. 4 and 5, in the injection valve main body 111, a hole-shaped receiving portion 141 extending in the axial direction F1 is formed. In this accommodation part 141, a needle valve spring 150, a spring accommodation part 151, a pressing rod 155, and an adjustment screw 156 are accommodated.

The needle valve spring 150 elastically supports the needle valve 106 toward the powder hole 104 so as to close the tip flow path 105. As shown in Figs. 4 and 5, the needle valve spring 150 is constituted by, for example, a coil spring, and is sandwiched between the spring accommodating portion 151 and the adjustment screw 156, in the accommodating portion 141 Is accepted. The spring accommodating portion 151 is a component receiving the needle valve spring 150 and is accommodated in the accommodating portion 141 while being fixed to the rear end of the pressing rod 155. The spring receiving portion 151 receives one end of the needle valve spring 150 and presses the other end of the needle valve spring 150 to the tip of the adjustment screw 156, thereby pressing the needle valve spring 150 It compresses and generates elastic force. The pressing bar 155 is disposed so as to be able to slide freely over the insertion hole 113 from the inside of the receiving portion 141. The distal end of the pressing rod 155 is in contact with the rear end of the needle valve 106. A spring accommodating portion 151 is in contact with the rear end of the pressing rod 155. The pressing rod 155 presses the needle valve 106 against the tip flow path 105 by using the elastic force of the needle valve spring 150 transmitted from the spring accommodating portion 151. In addition, the pressing rod 155 is applied to the elastic force of the needle valve spring 150 together with the needle valve 106 that slides in a direction separated from the tip flow path 105 by using the pressure of the fuel in the reservoir 103. It slides in a resisting direction (the direction in which the needle valve spring 150 is compressed).

The adjustment screw 156 is for adjusting the elastic force of the needle valve spring 150 (that is, the valve opening pressure of the needle valve 106). As shown in FIGS. 4 and 5, the adjustment screw 156 is attached by screwing into the receiving portion 141 of the injection valve body 111. The adjustment screw 156 screwed into the receiving portion 141 is in a state in which the tip thereof abuts against the rear end of the needle valve spring 150. The adjustment screw 156 adjusts the elastic force of the needle valve spring 150 by adjusting the amount of screwing into the receiving portion 141. Specifically, the adjustment screw 156 increases the amount of compression of the needle valve spring 150 by increasing the amount of screwing into the receiving portion 141 to strongly adjust the elastic force. On the other hand, the adjustment screw 156 reduces the amount of screwing into the receiving portion 141, thereby reducing the amount of compression of the needle valve spring 150 to weakly adjust the elastic force.

In addition, as shown in FIG. 4, in the injection valve main body 111, a columnar fuel flow path 172 that becomes a part of the fuel flow path of the fuel injection valve 200 is formed. The columnar fuel flow passage 172 is a columnar flow path, from the central axis in the operation direction of the needle valve 106 to the width direction of the fuel injection valve 200 (left side of the radial direction F2 shown in FIG. 4 ). A perforation is formed in the spaced area. The columnar fuel flow passage 172 extends so as to be inclined with respect to the axial direction F1 and communicates with the columnar fuel flow passage 173 in the intermediate metal 112. Moreover, the rear end of the columnar fuel flow path 172 communicates with the fuel accommodating part 171. The fuel container 171 receives the fuel pushed by the fuel injection pump. As shown in FIG. 4, one end of the fuel accommodation part 171 is attached to the rear end of the injection valve body 111. A fuel supply pipe 90 through which the fuel injection pump is connected is connected to the other end of the fuel container 171. The fuel accommodating portion 171 communicates the fuel supply pipe 90 and the columnar fuel flow passage 172.

In addition, as shown in FIG. 5, in the injection valve main body 111, a water injection check valve 160 corresponding to the second main channel of the fuel injection valve 200, a stopper 167, and a water receiving portion ( 181, 185, columnar main channels 182, 186, and a confluence passage 175 are formed. In the second embodiment, the second main water passage is a position upstream from the first main passage in the pressure feeding direction of the fuel in the fuel passage of the fuel injection valve 200 (for example, the second injection position shown in FIG. It is a channel to inject water into P2)).

The water injection check valve 160 is a check valve (second water injection check valve) that closes the second main water passage of the fuel injection valve 200 so that it can be opened and closed. In the second embodiment, the water injection and check valve 160 is not particularly shown, but is constituted by a valve body, a valve seat, a check valve spring, etc., and is a columnar water supply passage 186 that is a part of the second main water passage. The communication between the and the confluence passage 175 is blocked openably. As shown in FIG. 5, the water injection non-return valve 160 is disposed on the opposite side to the powder hole 104 based on the needle valve spring 150. Further, the water injection check valve 160 is located in a region separated from the central axis in the operation direction of the needle valve 106 in the width direction of the fuel injection valve 200. The stopper 167 receives one end (lower end in FIG. 5) of the water injection check valve 160 and limits the sliding range of the water injection check valve 160.

The columnar main channel 182 is a columnar channel that becomes a part of the first main channel of the fuel injection valve 200, and the width direction of the fuel injection valve 200 from the central axis in the operation direction of the needle valve 106 ( In Fig. 5, a perforation is formed in a region separated from the right side). The columnar main water passage 182 extends so as to be inclined with respect to the axial direction F1 and communicates with the main water check valve 120 in the intermediate prohibition 112. In addition, the rear end of the columnar main water passage 182 communicates with the water receiving portion 181. The water accommodating portion 181 receives the water pumped by the water injection pump, and is formed in the rear end of the injection valve body 111 as shown in FIG. 5. The water accommodating part 181 communicates the water supply pipe (not shown) through the main water pump and the columnar main water passage 182.

The columnar main channel 186 is a columnar channel that becomes a part of the second main channel of the fuel injection valve 200, and the width direction of the fuel injection valve 200 from the central axis in the operation direction of the needle valve 106 ( In Fig. 5, a perforation is formed in a region separated by the left). The columnar main water passage 186 extends in the axial direction F1, and makes the water accommodating part 185 and the water injection check valve 160 communicate with each other. The water accommodating portion 185 receives water pumped by the injection pump, and is formed in the rear end of the injection valve body 111 as shown in FIG. 5. The water accommodating portion 185 communicates the water supply pipe (not shown) through the water pump and the columnar water supply passage 186.

The confluence passage 175 is a passage for joining the water flowing from the second main channel through the main water check valve 160 and the fuel in the fuel passage of the fuel injection valve 200. For example, the confluence passage 175 is constituted by a passage or the like formed in the injection valve body 111 in a columnar shape. As shown in FIGS. 4 and 5, the confluence passage 175 has one end through the injection check valve 160 and the other end through the columnar fuel flow passage 172.

Next, a fuel flow path of the fuel injection valve 200 according to the second embodiment will be described. The fuel flow path of the fuel injection valve 200 is a path (flow path) through which the fuel pumped from the fuel injection pump flows. The fuel passage of the fuel injection valve 200 is configured by connecting the columnar fuel passages 172, 173, 174 shown in FIG. 4. Such a fuel passage is disposed at a position separated from the longitudinal central axis of the fuel injection valve 200 in the radial direction F2 (left in FIG. 4 ).

In the fuel passage of the fuel injection valve 200, as shown in FIG. 4, the first injection position P1 into which water is injected from the first main passage is the columnar fuel passage 173 in the intermediate prohibition 112 and The confluence passage 176 becomes a confluence position. The second water injection position P2 where water is injected from the second main water passage is a position where the columnar fuel passage 172 and the confluence passage 175 in the injection valve body 111 merge.

Next, the first main channel and the second main channel of the fuel injection valve 200 according to the second embodiment will be described. In the second embodiment, the water supplied by pressure from the injection pump is injected into the first injection channel into the first injection position P1 of the fuel passage of the fuel injection valve 200 via the injection check valve 120 or the like. It is a passage (waterway) to do. As shown in FIG. 5, the 1st main water passage is comprised by making the columnar main water passage 182, the injection water check valve 120, and the confluence passage 176 communicate in this order.

In addition, in the second embodiment, the water pumped from the injection pump is supplied to the second injection path P2 of the fuel flow path of the fuel injection valve 200 via the injection check valve 160. It is a passage (channel) for injection. As shown in FIG. 5, the 2nd main water passage is comprised by making the columnar main water passage 186, the injection water check valve 160, and the confluence passage 175 communicate in this order. In addition, the main water pump for pumping water to the second main channel may be the same as or different from the main pump for pumping water to the first main channel described above.

Next, the operation of the fuel injection valve 200 according to the second embodiment will be described. The fuel injection valve 200 injects fuel and water in a layered form from the blow hole 104 by one cycle of injection into a combustion chamber in a cylinder of a marine diesel engine.

The non-fuel injection period from the end of this one cycle injection until the next injection is performed, from the fuel flow path of the fuel injection valve 200 to the tip flow path 105 via the needle valve receiving portion 102 Fuel pumped from the fuel injection pump remains in the circulation path, in the fuel accommodation part 171 and in the fuel supply pipe 90. In this step, the pressure of the fuel remaining in the reservoir 103 is lower than the valve opening pressure of the needle valve 106. Therefore, the needle valve 106 is in a state in which the tip flow path 105 is closed so as to be able to open and close. In addition, the valve opening pressure of the needle valve 106 is set by the elastic force of the needle valve spring 150 transmitted to the needle valve 106 via the spring receiving portion 151 and the pressing rod 155.

In addition, in this non-fuel injection period, in each of the first main channel and the second main channel of the fuel injection valve 200, water pumped from the main water pump remains. In this step, the pressure of the water remaining in the first main water channel is lower than the valve opening pressure of the main water check valve 120. Therefore, the water injection check valve 120 is in a state in which the communication between the fuel passage of the fuel injection valve 200 and the first main water passage can be opened. Like this, since the pressure of the water remaining in the second main water channel is lower than the valve opening pressure of the main water check valve 160, the main water check valve 160 is provided with the fuel flow path of the fuel injection valve 200 and the second It is in a state in which the communication of the main canal is opened so as to be open.

Here, in this non-fuel injection period, when high pressure water exceeding the valve opening pressure of the main water check valve 120 is pumped from the main water pump into the first main channel of the fuel injection valve 200, this high pressure water Silver flows through each interior of the water accommodating part 181 and the columnar main water passage 182 shown in FIG. 5 in this order. And this high-pressure water flows into the main water check valve 120 from the columnar main water passage 182. Since this water pressure is higher than the valve opening pressure of the water injection check valve 120, the water injection check valve 120 opens the valve using this water pressure, and the fuel flow path of the fuel injection valve 200 and the first main water passage Open the communication. Specifically, the injection check valve 120 communicates the columnar main channel 182 and the confluence passage 176, and the columnar main channel 182 and the columnar fuel passage through the confluence passage 176 (173) communicate.

In this step, the water in the first main water channel is injected into the fuel passage of the fuel injection valve 200 from the arrangement position of the main water check valve 120. Specifically, water in the first main channel is injected from the main water check valve 120 through the confluence passage 176 to the first injection position P1 in this fuel passage. This injected water pushes the residual fuel in this fuel flow path back to the rear end side (fuel injection pump side) in the axial direction F1. As a result, a first water main layer serving as the first water main layer is formed in this fuel passage. Further, on the downstream side of the first water injection layer (the side of the hole 104), a first fuel layer made of fuel remaining in the fuel passage on the side of the hole 104 from the first injection position P1 is formed.

On the other hand, in this non-fuel injection period, when water having a high pressure exceeding the valve opening pressure of the main water check valve 160 is pumped from the main water pump into the second main channel of the fuel injection valve 200, this high pressure water Silver flows through each interior of the water receiving portion 185 and the columnar main water passage 186 shown in FIG. 5 in this order. And this high-pressure water flows into the main water check valve 160 from the columnar main water passage 186. Since this water pressure is higher than the valve opening pressure of the water injection check valve 160, the water injection check valve 160 opens the valve using this water pressure, and the fuel flow path of the fuel injection valve 200 and the second main water passage are Open the communication. Specifically, the injection check valve 160 communicates the columnar main channel 186 and the confluence passage 175, and the columnar main channel 186 and the columnar fuel passage through the confluence passage 175 (172) communicate.

In this step, the water in the second main channel is injected into the fuel flow path of the fuel injection valve 200 from the arrangement position of the main water check valve 160. Specifically, the water in the second main channel is injected from the main water check valve 160 through the confluence passage 175 to the second injection position P2 in this fuel passage. This injected water pushes the residual fuel in this fuel flow path back to the rear end side (fuel injection pump side) in the axial direction F1. As a result, a second main water layer serving as the second water main layer is formed in this fuel passage. Further, a second fuel layer made of fuel remaining in the fuel flow path is formed between the second water main layer and the above-described first water main layer. Further, on the upstream side (fuel injection pump side) of the second water injection layer, a third fuel layer made of fuel remaining in the fuel passage on the fuel injection pump side than at the second injection position P2 is formed.

After the above-described non-fuel injection period, fuel is pumped from the fuel injection pump into the fuel passage of the fuel injection valve 200, and fuel and water are injected in one cycle to the combustion chamber in the cylinder of the marine diesel engine.

Specifically, during this fuel injection period, the high-pressure fuel exceeding the valve opening pressure of the needle valve 106 is pumped from the fuel injection pump into the fuel flow path of the fuel injection valve 200 via the fuel supply pipe 90. In this case, the pressure of the fuel pumped from the fuel injection pump is transmitted to the fuel in the reservoir 103 through the fluid (remaining fuel and injected water) existing in the fuel flow path of the fuel injection valve 200 . As a result, the pressure of the fuel in the reservoir 103 is raised to a higher pressure than the valve opening pressure of the needle valve 106. The needle valve 106 receives the pressure of the boosted fuel in the reservoir 103 from the tapered portion 106a, and slides against the elastic force of the needle valve spring 150 using the pressure of this fuel, It is separated from the opening part (sheet part) of the tip flow path 105. In this way, the needle valve 106 opens the communication between the fuel flow path of the fuel injection valve 200 and the powder hole 104.

In this step, the fuel injection valve 200 injects fuel and water for one cycle into a combustion chamber in a cylinder of a marine diesel engine. For example, the fuel injection valve 200 includes the first fuel layer, the first main water layer, the second fuel layer, the second main water layer, and the third fuel layer in the fuel passage from the hole 104 in this order. It is injected in a layered form into the combustion chamber inside. After that, the pressure of the fuel in the reservoir 103 is reduced to a valve opening pressure or less of the needle valve 106. In this case, the needle valve 106 slides toward the hole 104 by using the elastic force of the needle valve spring 150, and again contacts the seat portion of the tip flow path 105 to open and close the tip flow path 105. Closed. In this way, the needle valve 106 cuts off the communication between the fuel flow path of the fuel injection valve 200 and the powder hole 104 so that it can be opened.

As described above, in the fuel injection valve 200 according to the second embodiment of the present invention, based on the needle valve spring 150 elastically supporting the needle valve 106 toward the hole 104, the first main The water supply check valve 120 of the water channel is disposed on the side of the water hole 104, and the water supply check valve 160 of the second main water channel is disposed on the side opposite to the water hole 104, so that the water in the first main channel It is injected from the check valve 120 to the first injection position P1 in the fuel passage through the confluence passage 175, and the water in the second main water passage is fed through the confluence passage 176 from the injection check valve 160 It is made to be injected into the inner second injection position P2.

For this reason, while the injection check valve 120 of the first main channel can be disposed in the vicinity of the needle valve 106, between the first injection position P1 and the second injection position P2 in the fuel passage The injection check valve 120 of the first main channel and the check valve of the second main channel so that the amount of fuel between the main water layers is a suitable ratio (for example, about 10 to 20%) with respect to the fuel injection amount per cycle. 160 can be spaced apart, and further, the area between these two water injection check valves 120 and 160 can be effectively utilized as an area in which the needle valve spring 150 is disposed. As a result, while ensuring a desirable separation distance between each of the main water check valves 120 and 160 incorporated in the fuel injection valve 200, the fuel injection valve 200 is enlarged (especially the lengthening of the structure in the longitudinal direction) Can be suppressed. By injecting fuel and water into the combustion chamber in the cylinder of a marine diesel engine using such a fuel injection valve 200, water can be injected into the combustion chamber from the initial stage of fuel injection, and as a result, the fuel in the combustion chamber It is possible to efficiently reduce the amount of NOx generated at the beginning of combustion.

Further, in the fuel injection valve 200 according to the second embodiment of the present invention, a fuel flow path through which the fuel pumped from the fuel injection pump is circulated is a position separated from the longitudinal central axis of the fuel injection valve 200 in the radial direction. Posted in. For this reason, the needle valve 106, the needle valve spring 150, the spring receiving portion 151, the pressing rod 155, the adjustment screw 156, etc. that are arranged in the vicinity of the longitudinal central axis of the fuel injection valve 200 The fuel flow path can be formed by avoiding the parts of This eliminates the need to form a fuel flow path by connecting passages in a plurality of components arranged in the vicinity of the longitudinal central axis of the fuel injection valve 200, thereby reducing the number of components constituting the fuel flow path, It is possible to reduce the number of connection points between passages.

In addition, in the above-described embodiment 1, as an example of a symmetric main channel for discharging water to the valve body of the main water check valve, a symmetrical structure consisting of four channels formed at equiangular intervals around the central axis in the operation direction of the main water check valve Although the main channel was illustrated, the present invention is not limited to this. In the present invention, the symmetrical main channel may be composed of two or more (plural) channels formed at equiangular intervals around the central axis in the operation direction of the main water check valve, and around the central axis in the operation direction of the main water check valve It may consist of a single annular channel having continuous annular discharge ports.

In addition, in the above-described Embodiment 1, as an example of the first main channel and the second main channel, having an annular main channel is illustrated, but the present invention is not limited thereto. For example, even if the first main channel and the second main channel are directly connected to the valve body of the main water check valve, the symmetric main channel facing the discharge port and the columnar main channel for receiving the water pumped from the main water pump. do.

Moreover, in the above-described embodiment 1, as an example of the valve body of the water injection check valve, a valve body provided with a pressure receiving part on the outer periphery that receives the pressure of water discharged from the discharge port of the symmetric main water channel was illustrated, but the present invention is limited to this. It does not become. For example, the valve body of the water injection check valve may be one that receives pressure of water at the outer circumferential portion or the tip portion, not in the water pressure portion formed thereon.

In addition, in the first embodiment described above, as an example of the first main channel and the second main channel, water is supplied in a axially symmetrical direction with respect to the valve body of the main water check valve. Although discharge was illustrated, the present invention is not limited to this. For example, the first main channel and the second main channel may discharge water in an asymmetrical direction (single direction, etc.) with respect to the valve body of the injection check valve.

In addition, in the above-described Embodiments 1 and 2, the fuel injection valve provided with two main water check valves was illustrated, but the present invention is not limited to this. For example, the number of injection check valves formed in the fuel injection valve may be three or more. In this case, three or more injection check valves may be formed at the rear end of the injection valve body of the fuel injection valve, or may be formed at a confluence of the pipe from the fuel injection pump and the pipe from the injection pump.

In addition, the present invention is not limited by the above-described Embodiments 1 and 2, and the present invention includes a configuration formed by appropriately combining the above-described components. In addition, other embodiments, examples, and operation techniques made by those skilled in the art based on the first and second embodiments described above are all included in the scope of the present invention.

Industrial availability

As described above, the fuel injection valve according to the present invention is suitable for a fuel injection valve capable of securing a desirable separation distance between each of the built-in injection water check valves and suppressing an enlargement of the structure.

1: nozzle
2: Needle valve receiving part
3: reservoir
4: Mining
5: tip euro
6: needle valve
7: flow path in needle valve
8: communication hole
10: No nozzle fastening
11: injection valve body
12: check valve receiving part
20: main water check valve
21: valve body
22: flow path in the valve body
23: water pressure part
24: valve seat
25: flow path in the valve seat
26: check valve spring
27: valve body receiving part
28: Euro in the receiving part
29: insertion hole
30: Do not tighten the valve body
40: injection valve body
41: receiving part
50: needle valve spring
51: spring receiving part
52: flow path in the spring receiving part
60: main water check valve
61: valve body
62: flow path in the valve body
63: water pressure part
64: valve seat
65: flow path in the valve seat
66: check valve spring
67: valve body receiving part
68: Euro in the receiving part
71, 72, 81: columnar main channel
73, 75, 82: annular main channel
74, 76, 84: symmetric main channel
90: fuel supply pipe
91, 92, 93: O-ring
100, 200: fuel injection valve
101: nozzle
102: needle valve receiving portion
103: reservoir
104: division
105: end flow path
106: needle valve
106a: tapered portion
110: No nozzle fastening
111: injection valve body
112: medium prohibition
113: insertion through hole
120: main water check valve
141: receiving part
150: needle valve spring
151: spring receiving part
155: push rod
156: adjustment screw
160: main water check valve
167: stopper
171: fuel receiving part
172, 173, 174: columnar fuel flow path
175, 176: confluence passage
181, 185: water receiving part
182, 186: columnar main channel
F1: axial direction
F2: radial direction
P1: 1st injection position
P2: 2nd main water position

Claims (5)

A fuel injection valve for injecting fuel and water from a powder hole into a combustion chamber in a cylinder of a marine diesel engine,
A fuel flow path for circulating the fuel pumped from the fuel injection pump;
A tip flow path through which one end passes through the fuel flow passage and the other end through the powder hole,
A needle valve that closes the front end flow path so that it can be opened and closed,
A needle valve spring elastically supporting the needle valve toward the powder hole so as to close the tip flow path;
A first main channel for injecting water into a predetermined position of the fuel channel,
A second main channel for injecting water into a position upstream of the fuel flow path in a pressure feeding direction of the fuel than the first main channel,
A first water injection check valve disposed on the side of the injection hole than the needle valve spring and closing the first main water passage so as to be openable,
A second main water check valve disposed on the opposite side of the needle valve spring and closing the second main water passage so as to be able to open and close it,
Water in the first main water channel is injected into the fuel passage from the position where the first main water check valve is placed, and water in the second main water passage is injected into the fuel passage from the position where the second main water check valve is disposed. Fuel injection valve, characterized in that. The method of claim 1,
The fuel injection valve, wherein the first and second injection and check valves are disposed on the same axis in a direction of a longitudinal central axis of the fuel injection valve. The method according to claim 1 or 2,
The fuel injection valve, wherein the first main water passage has an annular main water passage formed in an annular shape surrounding the first water injection check valve. The method according to any one of claims 1 to 3,
The fuel injection valve, wherein the fuel passage is disposed so as to pass through a longitudinal central axis of the fuel injection valve. The method of claim 1,
The fuel injection valve, wherein the fuel passage is disposed at a position separated from the longitudinal central axis of the fuel injection valve in a radial direction.

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