KR20200140912A - Fuel injection valve - Google Patents

Abstract

A fuel injection valve for injecting fuel and water into a combustion chamber in a cylinder of a marine diesel engine from a powder hole, wherein a fuel flow path for circulating the fuel compressed from a fuel injection pump, and a communication between the fuel flow path and the powder hole can be opened A needle valve to block, a needle valve spring elastically supporting the needle valve toward the powder hole so as to block communication between the fuel flow path and the powder hole, and a main channel for injecting the water into a predetermined position of the fuel flow path; A water injection check valve is interposed between the needle valve and the needle valve spring and is provided with a water injection check valve configured to open a communication between the fuel passage and the main water passage. The main water passage includes a symmetric main water passage formed axially symmetrically with respect to a central axis in the operation direction of the main water check valve and having a discharge port facing the main water check valve.

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 considered 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 the water supply check valve from the water channel in the valve body is injected into the fuel pumped from the fuel injection pump into the fuel flow path, and the combustion chamber in the cylinder is A fuel injection valve has been proposed for injecting fuel and water in three stages in the order of fuel-water-fuel by injection.

In such a fuel injection valve, in general, the communication between the fuel flow path and the injection hole (injection port) is cut off so that it can be opened by a needle valve. Specifically, the needle valve is formed to be slid freely inside the fuel injection valve, and the colored portion (liquid reservoir) communicating with the fuel flow passage and the powder hole is closed so that it can be opened using the elastic force of the needle valve spring. do. In this color part, the fuel pressure-supplied from the fuel injection pump remains, and when the pressure of this fuel is less than or equal to the elastic force of the needle valve spring applied to the needle valve, the color part is closed by the needle valve. In this case, the communication between the fuel flow path and the powder hole is cut off. On the other hand, when the fuel pumped from the fuel injection pump is newly introduced into the color part through the fuel flow path, whereby the pressure of the fuel in the color part is increased and exceeds the elastic force of the needle valve spring, the needle valve has the elastic force of the needle valve spring. It slides against and thereby opens the color part. In this case, the communication between the fuel flow path and the powder hole is in an open state, and as described above, the fuel pumped from the fuel injection pump into the fuel flow path and the water injected into the fuel flow path through the water supply check valve from the water channel in the valve body It is injected into the combustion chamber from this powder hole.

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

However, in the prior art described above, since the fuel of a high pressure (for example, a pressure of 800 to 1000 bar) boosted by the fuel injection pump is introduced from one side into the color part through the fuel flow path, the needle valve in the color part has a high pressure. The pressure of the fuel is applied by removing the pressure, and due to this, the needle valve may slide in a tilted state. In this case, not only the sliding needle valve itself, but also the sliding surface rubbed by the sliding of the needle valve (for example, the inner wall surface of the receiving part accommodating the needle valve in the fuel injection valve) or the needle valve. There is a fear that the sliding parts (for example, parts that transmit the elastic force of the needle valve spring to the needle valve, etc.) are worn out and are liable to be damaged.

In addition, in the above-described conventional technique, since water that has passed through the water supply check valve from the water passage in the valve body is injected from one side into the fuel passage, it is often difficult to uniformly inject water into the fuel in the fuel passage. 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 a marine diesel engine, water is uniformly injected into the fuel in the fuel flow path, It is preferable to form a uniform main water layer (a layer of water injected into the fuel passage) in the fuel layer (layer of fuel formed in the fuel passage) during injection.

The present invention has been made in view of the above circumstances, and provides a fuel injection valve capable of uniformly injecting water into fuel in a fuel flow path while suppressing a situation in which sliding parts such as needle valves are inclined with respect to the sliding direction. It aims to provide.

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, and is pumped from the fuel injection pump. A fuel flow path for circulating the fuel, a needle valve for blocking communication between the fuel flow path and the powder hole, and elastically supporting the needle valve toward the powder hole so as to block communication between the fuel flow path and the powder hole. A needle valve spring, a main channel for injecting the water into a predetermined position of the fuel channel, and interposed between the needle valve and the needle valve spring, so that communication between the fuel channel and the main channel can be opened. And a symmetrical main water passage having a discharge port facing the main water check valve and formed axially symmetrically with respect to a central axis in the operation direction of the main water check valve. do.

Further, in the fuel injection valve according to the present invention, in the above invention, the water injection check valve includes a valve body in which a water pressure portion for receiving the pressure of the water from the symmetrical main channel is formed over an outer circumference. It features.

Further, in the fuel injection valve according to the present invention, in the above invention, the symmetrical main channel comprises a plurality of channels formed at equal angles around a central axis in the operation direction of the main water check valve.

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

Advantageous Effects of Invention According to the present invention, it is possible to uniformly inject water into the fuel in the fuel flow path while suppressing the situation in which sliding parts such as needle valves are inclined with respect to the sliding direction.

1 is a schematic cross-sectional view showing a configuration example of a fuel injection valve according to an embodiment 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.

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, the present 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 component part.

(Configuration of fuel injection valve)

First, a configuration of a fuel injection valve according to an embodiment 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 an embodiment 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 this 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 negative side of the axial direction F1 (負側) is set to the rear end side of the fuel injection valve 100. The radial direction F2 is a 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 present embodiment is mounted on a cylinder (not shown) of a marine diesel engine, and receives fuel pumped from a fuel injection pump (not shown) and water pumped from a main water pump (not shown). It is intended for sequential injection (eg, layered injection) 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 hardware 10, and are fixed in a state connected to 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 hardware 30 to be fixed in a state connected to 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 the communication between the fuel flow path of the fuel injection valve 100 and the powder hole 4 so as to be opened is accommodated so as 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, on the front end side of the nozzle 1, a powder hole 4 and a tip flow path 5 are formed. One end of the tip flow path 5 is through 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 passes through the 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 present embodiment, the first injection channel is a channel for injecting water to a predetermined position (first injection position P1 shown in FIG. 1) in the fuel flow path of the fuel injection valve 100.

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 to open and close. 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 which receives the pressure of water from a 1st main channel, and is accommodated in the valve body accommodating part 27 so that it can slide freely. 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 near the tip end. 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 so that it can be opened.

In addition, in this embodiment, the water injection non-return valve 20 has a function as the above-described non-return valve and a function as a pressure bar 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 accommodates 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 after the needle valve 6 It is in a state of being pressed against the end. 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 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 separated 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 hardware 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 this 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 is formed ) Consisting of multiple (for example, 4) channels. 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 symmetrically 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 this embodiment, as shown in Figs. 1 and 2, the symmetrical 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 (perforation It consists of a plurality of channels (for example, 4) that are formed).

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 this 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 serving as a 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 tip end of the valve main body fastening hardware 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 present embodiment, the second main channel is a position of the fuel passage of the fuel injection valve 100 on the upstream side of the fuel pressure feeding direction than the first main channel (for example, the second injection position P2 shown in FIG. 1 ). It is a channel to inject water into )).

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 in a state where the needle valve spring 50 is accommodated, 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 so that it can slide freely in the inserted hole 29. The spring receiving portion 51 accommodates 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 receiving portion 27, whereby the needle valve spring (50) is compressed 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 as to open and close. 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 present 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 directed to each other with the needle valve spring 50 interposed therebetween (F1). It is placed on the opposite side of. 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 circumference of the valve body 61 near the tip end 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 so that it can be opened. The valve body housing portion 67 is configured to be helically inserted 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 fed by a fuel injection pump (not shown) into the fuel flow path of the fuel injection valve 100.

In addition, in this embodiment, the water injection non-return valve 60 serves as an adjustment screw for adjusting the function as the above non-return valve and the elastic force of the needle valve spring 50 (that is, the valve opening pressure of the needle valve 6). It has a function. Specifically, as shown in FIG. 1, the water injection check valve 60 is attached by inserting the valve body housing 67 into the housing 41 of the injection valve body 40 by spirally inserting. The water injection check valve 60 helically inserted into the receiving portion 41 is brought into 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 adjusts the elastic force of the needle valve spring 50 by adjusting the amount of twisting into the receiving portion 41. Specifically, the injection check valve 60 increases the amount of screwing into the accommodation part 41, and increases the amount of press-fitting of the spring accommodation part 51 toward the hole 4, so that the needle valve spring 50 The elastic force is strongly adjusted by increasing the amount of compression. On the other hand, the water injection check valve 60 reduces the amount of screwing into the accommodation part 41 and reduces the amount of press-fitting of the spring accommodation part 51 to the hole 4 side, thereby compressing the needle valve spring 50 Reduce the amount to weaken the elastic force.

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 symmetric 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 this embodiment, as shown in Figs. 1 and 3, the symmetrical 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 (perforation It consists of a plurality of channels (for example, 4) that are formed).

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 this 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.

(Fuel Euro)

Next, a fuel flow path of the fuel injection valve 100 according to the present 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 this 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, 62, and the valve seat internal flow paths 25, 65. And, 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 communicated with the flow path 22 in the valve body, and the flow path 22 in the valve body communicates with the flow path 28 in the receiving portion. 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 from the flow path 7 in the needle valve to the reservoir 3 through the communication hole 8 of the needle valve 6. It works. 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 through the flow path 68 in the accommodation part.

(1st main channel and 2nd main channel)

Next, the first main channel and the second main channel of the fuel injection valve 100 according to the present embodiment will be described. In the present embodiment, the first pouring passage is for injecting the water pumped from the injection pump into the first pouring position P1 of the fuel flow path of the fuel injection valve 100 via the pouring check valve 20. It is a passage (channel). 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 to the main water pump through a water supply pipe (not shown) from the columnar main water passage 71. 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, the annular main channel 73, even if the channel width in the radial direction F2 is smaller than that of the columnar main channels 71, 72, the channel volume per unit length in the axial direction F1 is set as the columnar main channel It is maintained equal to (71, 72).

In addition, in this embodiment, in the second pouring channel, the water pumped from the main water pump is injected into the second pouring position P2 of the fuel passage of the fuel injection valve 100 via the pouring check valve 60. It is a passage (waterway) to do. 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 to the main water pump through a water supply pipe (not shown) from the columnar main water passage 81. 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.

(Fuel injection valve action)

Next, the operation of the fuel injection valve 100 according to the present embodiment will be described. The fuel injection valve 100 injects fuel and water in a layered form from the blow hole 4 in 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 made (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 closed state so that the tip flow path 5 can be opened and closed. 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. Likewise, 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 a fuel flow path of the fuel injection valve 100 and a second main water channel. It is in a state of being blocked so that the communication of the device can be opened. 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 pressing 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 water passage of the fuel injection valve 100, this high pressure Water flows inside each 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. It is distributed in this order. Then, this high-pressure water flows through the discharge port of the symmetrical main channel 76 so as to pressurize the valve body 21 from the axially symmetrical direction with respect to the central axis in the operation direction of the main water check valve 20. . 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 Is separated 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, water in the first main water channel is injected into the fuel passage 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 diffuses axially symmetrically (uniformly in the radial direction F2) in this fuel flow path, and 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 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 water passage 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, this high-pressure water flows through the discharge port of the symmetrical main channel 84 so as to pressurize the valve body 61 from the direction of axial symmetry with respect to the central axis of the operation direction of the main water 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 Is separated 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 water channel is injected into the fuel passage of the fuel injection valve 100 from the arrangement position of the main water check valve 60. Specifically, water in the second main channel is injected from a direction axially symmetric with respect to the central axis in the fuel flow direction of the fuel injection valve 100 to the second injection position P2 in this fuel channel. The injected water diffuses axially symmetrically (uniformly in the radial direction F2) in this fuel flow path, and 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 flow path of the fuel injection valve 100, and fuel and water are injected in one cycle to the combustion chamber in the cylinder of the marine diesel engine.

Specifically, during this injection period (hereinafter referred to as a fuel injection period), a high-pressure fuel exceeding the valve opening pressure of the needle valve 6 is transferred from the fuel injection pump through the fuel supply pipe 90 through the fuel injection valve ( 100) is pumped into the fuel flow path. In this case, the pressure of the fuel pumped from the fuel injection pump is 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 ) Is separated from the opening (sheet portion). 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 layers 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 powder 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 Close it so that you can. In this way, the needle valve 6 blocks 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 embodiment of the present invention, a needle valve that cuts off the communication between the fuel flow path through which the fuel pressurized from the fuel injection pump flows and the powder hole 4 can be opened. 6) Wow, a needle valve spring 50 elastically supporting the needle valve 6 toward the hole 4, a first main channel for injecting water into the first injection position P1 of the fuel flow path, and the fuel It is provided with a water injection check valve 20 which cuts off communication of the flow path so as to be able to open, and the injection check valve 20 is arranged so as to be interposed between the needle valve 6 and the needle valve spring 50. In addition, the first main channel is configured to include a symmetric main channel 76 having a discharge port formed axially symmetric with respect to the central axis in the operation direction of the main water check valve 20, and the symmetric main channel 76, The discharge port and the water injection check valve 20 are arranged to face each other.

For this reason, by pressing the water injection check valve 20 to the needle valve 6 by the elastic force of the needle valve spring 50, these water injection check valves 20 and the needle valve 6 are integrally connected. can do. Thereby, the inclination (deformation) of the needle valve 6 with respect to the sliding direction can be suppressed by the pressing action of the injection check valve 20 which presses the needle valve 6 using the elastic force of the needle valve spring 50. I can. Furthermore, when the water injection check valve 20 is opened, the pressure of water from the first main water channel can be axially applied to the water supply check valve 20, whereby the operation of the water injection check valve 20 The inclination of the water injection check valve 20 with respect to the directional central axis can be suppressed. The inclination of the needle valve 6 in the state integrally connected with the water injection check valve 20 with respect to the sliding direction can be suppressed through suppression of the inclination of the water injection check valve 20. As a result, it is possible to suppress a situation in which sliding parts such as the needle valve 6 and the water injection check valve 20 that slide integrally with the needle valve 6 inclined with respect to the sliding direction can be suppressed. Breakage can be suppressed.

In addition, while suppressing the slope of the sliding part as described above, water is axially symmetrically injected into the first injection position P1 in the fuel flow path through the injection check valve 20 from the discharge port of the first main channel. can do. Thereby, water can be uniformly injected into the fuel in the fuel flow path, and a uniform main water layer can be formed in the fuel. As a result, since a uniform fuel layer and a main water layer can be sequentially injected into the combustion chamber in the cylinder by injection of fuel and water in one cycle, it can contribute to the improvement of fuel efficiency performance and NOx reduction performance of a marine diesel engine.

In addition, in the fuel injection valve 100 according to the embodiment of the present invention, a pressure receiving portion for receiving pressure of water from a symmetrical main channel is formed in the valve body of the main water check valve over the outer periphery. For this reason, the valve element of the main water check valve can efficiently receive the pressure of water from the symmetric main water channel in an axisymmetric manner by the pressure receiving unit. As a result, it is possible to efficiently slide the valve body while suppressing the inclination of the valve body in the sliding direction.

In addition, in the fuel injection valve 100 according to the embodiment of the present invention, the first main channel is configured to have the same annular main channel 73 formed in an annular shape surrounding the main water check valve 20. Here, the annular main channel 73 can expand the circulation range of water to an annular shape, so 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 Can be made 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.

In addition, in the above-described embodiment, as an example of a symmetric main channel for discharging water to the valve body of the injection check valve, a symmetric main channel consisting of four channels formed at equiangular intervals around the central axis in the operation direction of the injection check valve Although the waterway 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 of 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, 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, the first main channel and the second main channel may be in direct communication with the symmetric main channel facing the discharge port by the valve body of the main water check valve, and the columnar main channel for receiving the water pumped from the main water pump. .

In addition, in the above-described embodiment, 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 circumference that receives the pressure of water discharged from the discharge port of the symmetric main water channel was illustrated, It does not become. For example, the valve body of the water injection check valve may not be provided with a water pressure portion, but may be subjected to water pressure on the outer peripheral portion or the tip portion.

In addition, in the above-described embodiment, the fuel injection valve provided with two water injection check valves was illustrated, but the present invention is not limited to this. In the present invention, the number of injection check valves provided in the fuel injection valve may be one or three or more. For example, the third or more injection check valves may be provided at the rear end of the injection valve body of the fuel injection valve, or may be provided 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 embodiment, and the present invention includes a configuration formed by appropriately combining each of the above-described components. In addition, other embodiments, examples, operation techniques, etc. made by a person skilled in the art based on the above-described embodiments 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 a fuel injection valve capable of uniformly injecting water into the fuel in the fuel flow path while suppressing the situation in which sliding parts such as needle valves are inclined with respect to the sliding direction. Suitable.

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: nozzle fastening hardware
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: valve body fastening hardware
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: fuel injection valve
F1: axial direction
F2: radial direction
P1: 1st injection position
P2: 2nd main water position

Claims (4)

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 needle valve that blocks the communication between the fuel passage and the powder hole so as to be opened,
A needle valve spring elastically supporting the needle valve toward the powder hole so as to block communication between the fuel flow path and the powder hole;
A main channel for injecting the water into a predetermined position of the fuel channel,
A water injection check valve interposed between the needle valve and the needle valve spring and blocking the communication between the fuel passage and the main water passage so as to be opened,
The fuel injection valve, wherein the main water passage is formed axially symmetrically with respect to a central axis in the operation direction of the main water check valve, and includes a symmetric main water passage having a discharge port facing the main water check valve. The method of claim 1,
The fuel injection valve, wherein the injection water check valve includes a valve body having a water pressure portion formed thereon over an outer periphery to receive the pressure of the water from the symmetrical main channel. The method according to claim 1 or 2,
The symmetrical pouring channel is a fuel injection valve comprising a plurality of channels formed at equal angles around a central axis in an operation direction of the injection check valve. The method according to any one of claims 1 to 3,
The fuel injection valve, wherein the main water passage has an annular main water passage formed in an annular shape surrounding the main water check valve.

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