KR20210044297A - Water pump - Google Patents

Abstract

In one aspect of the present invention, a water injection pump includes a plurality of water discharge passages each communicating through a plurality of fuel injection valves formed in one cylinder and a pipe, and a plurality of water discharge passages respectively formed in the plurality of water discharge passages so as to be reciprocating. It has a water piston part and a hydraulic piston part. The hydraulic piston part moves the plurality of water piston parts to the discharge port side of the plurality of water discharge passages by using the pressure of the hydraulic oil. The plurality of water piston units pressurize water in the plurality of water discharge passages and discharge them to the plurality of fuel injection valves, respectively.

Description

Water pump

The present invention relates to a main water pump.

Conventionally, in a marine diesel engine mounted on a ship, a water technology has been proposed as one of the methods for reducing nitrogen oxides (NOx) in exhaust gas discharged from a combustion chamber in a cylinder. In this water technology, for example, by adding fuel and water to the combustion chamber from a fuel injection valve formed in the cylinder, the temperature increase of the flame when burning the fuel in the combustion chamber is suppressed, and as a result, NOx from the combustion chamber The emissions of are reduced. In such water technology, in order to inject water into the fuel existing in the fuel passage within the fuel injection valve, for a period other than the injection period in which fuel is injected into the combustion chamber (hereinafter referred to as the injection pause period), hydraulic pressure using hydraulic oil pressure A driven main water pump is used. As an example of this hydraulic driven water injection pump, Patent Document 1 discloses a water injection piston device. Hereinafter, the water injection pump means a hydraulically driven water injection pump exemplified in this water injection piston device.

In the diesel engine described in Patent Document 1, one fuel injection valve is formed in one cylinder, and fuel and water are injected into the combustion chamber in the cylinder from the one fuel injection valve. Thereafter, during the injection pause period, the fuel to be injected next time remains in the fuel passage in the fuel injection valve. The main water pump is generally configured to communicate with the fuel passage in the fuel injection valve through a pipe or the like. In the injection pause period, the water injection pump pressurizes water at a pressure greater than the pressure of the fuel remaining in the fuel passage (hereinafter, referred to as fuel residual pressure), thereby injecting water into the fuel in the fuel passage. The fuel and water in this fuel passage are injected into the combustion chamber from the fuel injection valve in the next injection period after the injection pause period.

Japanese Patent Publication No. 4550991

In recent years, in marine diesel engines, in order to uniformly inject fuel into the combustion chamber, there is a tendency that a plurality of (for example, 2 to 3) fuel injection valves are formed in one cylinder. In this case, in order to inject water to each of the plurality of fuel injection valves, in general, the injection pump is a plurality of fuel injection valves through a branching pipe (branch pipe) or the like as many as the number of fuel injection valves. It is configured to communicate with the inner fuel passage (hereinafter referred to as the first conventional configuration). Alternatively, as many injection pumps as the number of fuel injection valves are prepared, these injection pumps are configured to communicate with each other through fuel passages and pipes in the plurality of fuel injection valves (hereinafter referred to as a second conventional configuration).

However, between a plurality of fuel injection valves formed in one cylinder, there is a possibility that the fuel residual pressure is non-uniform. For this reason, in the first conventional configuration, water from the injection pump is easily injected into the fuel injection valve on the lower side of the fuel injection valve than the one with higher fuel residual pressure. Each injection quantity to the fuel injection valve becomes skewed. Further, in the second conventional configuration, not only the number of parts increases and the configuration becomes complicated, but also there is a concern that the bias of the respective injection amounts may increase due to manufacturing variations between the injection pumps. Furthermore, since it is difficult to predict the variation tendency of the fuel residual pressure, it is difficult to eliminate the bias in the injection amount between the plurality of fuel injection valves by driving control of the plurality of injection pumps.

In addition, the deviation (variation) of the injection quantity between the plurality of fuel injection valves causes the injection amount of fuel injected into the combustion chamber to be uneven among the plurality of fuel injection valves, and thus the flame at the time of fuel combustion in the combustion chamber It causes a variation in length or amount of heat generated. This deforms parts related to the combustion chamber such as cylinders or pistons, and not only causes variation in the amount of wear of the parts, but also leads to a decrease in combustion efficiency of the marine diesel engine (that is, deterioration in fuel economy).

The present invention has been made in view of the above circumstances, and is a water injection pump capable of suppressing variations in injection quantity between the plurality of fuel injection valves while watering a plurality of fuel injection valves formed in one cylinder. It aims to provide.

In order to solve the above-described problem and achieve the object, the water injection pump according to the present invention includes a plurality of water discharge passages each communicating through a plurality of fuel injection valves and pipes formed in one cylinder, and the plurality of water discharge passages. A plurality of water piston units each formed in the water discharge passage so as to be reciprocally reciprocally discharged to the plurality of fuel injection valves by pressurizing water in the plurality of water discharge passages, and the plurality of water using the pressure of the hydraulic oil. And a hydraulic piston part for moving the piston part toward the discharge port side of the plurality of water discharge passages.

In addition, in the water injection pump according to the present invention, in the above-described invention, the plurality of water piston parts and the hydraulic piston part are connected to each other, and the plurality of water piston parts move integrally with the hydraulic piston part. Characterized in that.

Further, in the injection pump according to the present invention, in the above-described invention, the plurality of water discharge passages communicate with the same fuel passage position between the plurality of fuel injection valves.

In addition, in the water injection pump according to the present invention, in the above-described invention, the plurality of water piston portions are pistons having the same diameter as each other.

Advantageous Effects of Invention According to the present invention, while watering a plurality of fuel injection valves formed in one cylinder is performed, it is possible to suppress variations in the amount of injection water between the plurality of fuel injection valves.

1 is a schematic diagram showing a configuration example of a fuel injection system of a marine diesel engine according to an embodiment of the present invention.
2 is a schematic side cross-sectional view showing a configuration example of a water injection pump according to an embodiment of the present invention.
3 is a schematic cross-sectional view taken along line AA of the water injection pump shown in FIG. 2.
4 is a diagram for explaining the operation of the water injection pump according to the embodiment of the present invention.

Hereinafter, preferred embodiments of the injection pump 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, etc. may differ from that of the actual one. In the drawings, there are cases in which parts having different dimension relationships and ratios are included. In addition, the same reference numerals are attached to the same constituent parts in each drawing.

(Configuration of fuel injection system)

First, a configuration of a fuel injection system of a marine diesel engine to which a water injection pump according to an embodiment of the present invention is applied will be described. 1 is a schematic diagram showing a configuration example of a fuel injection system of a marine diesel engine according to an embodiment of the present invention. As shown in Fig. 1, the fuel injection system 100 includes a plurality of (three in this embodiment) fuel injection valves 20A, 20B, 20C, a fuel pressure delivery system 30, and a downstream water injection system. It includes (40) and the upstream side water supply system (50). In addition, the fuel injection system 100 includes a water supply pump 61, a water supply pipe 62, a check valve 63a, 63b, an accumulating portion 71, a high pressure pump 72, and a detection portion 81. ) And a control unit 82. In addition, in Fig. 1, solid arrows indicate the flow of fluids such as fuel and water, and broken arrows indicate electric signal lines.

The fuel injection valves 20A, 20B, and 20C are examples of a plurality of fuel injection valves for injecting fuel and water into a combustion chamber (all not shown) in a cylinder of a marine diesel engine. Although not shown in Fig. 1, the fuel injection valves 20A, 20B, and 20C are formed in one cylinder. For example, the fuel injection valves 20A, 20B, and 20C are disposed at predetermined intervals along the circumferential direction of this cylinder.

As shown in FIG. 1, the fuel injection valve 20A includes an injection port 21, a fuel passage 22 through the injection port 21, and an internal passage 23 through the fuel passage 22, It has non-return valves 24a and 24b. The fuel passage 22 has one end connected to the injection port 21 and the other end connected to the fuel injection pipe 32 (for example, its branch pipe 32a). In addition, at the upstream side of the fuel passage 22 (the second injection position P2), the piping of the upstream side water supply system 50 via the check valve 24a (for example, the upstream side water supply pipe (52a)) is connected. The internal passage 23 is connected at one end to a water injection position (first water injection position P1) on the downstream side of the fuel passage 22, and the other end is a pipe of the downstream water supply system 40 (for example, It is connected to the downstream main water supply pipe (42a). The check valve 24a enables water to flow from the upstream side water injection system 50 to the fuel passage 22 of the fuel injection valve 20A, and prevents the reverse flow. The check valve 24b is formed in the middle part of the internal passage 23. The check valve 24b enables water to flow from the downstream water injection system 40 to the fuel passage 22 through the internal passage 23 and prevents the reverse flow.

The fuel injection valve 20A having the configuration as described above includes the fuel pumped by the fuel pressure delivery system 30, the water injected by the downstream water injection system 40, and the upstream water injection system 50. The water injected by the injection port 21 is injected in a layered manner into the combustion chamber in the cylinder. In addition, the fuel injection valves 20B and 20C have the same configuration as the fuel injection valve 20A described above.

The fuel pressure feeding system 30 is a facility for pressure feeding fuel to the fuel injection valves 20A, 20B, and 20C. As shown in FIG. 1, the fuel pressure delivery system 30 includes a fuel injection pump 31, a fuel injection pipe 32, and a control valve 35.

The fuel injection pump 31 is a hydraulically driven pump driven by using the pressure of hydraulic oil, and pumps fuel to the fuel injection valves 20A, 20B, and 20C through the fuel injection pipe 32, respectively. Further, the pressure feeding action of the fuel injection pump 31 causes the fuel injection valves 20A, 20B, and 20C to perform layered injection of fuel and water from the injection port 21 to the combustion chamber in the cylinder.

One end of the fuel injection pipe 32 is connected to the discharge port of the fuel injection pump 31. A branch portion 33 is formed in the middle portion of the fuel injection pipe 32. The fuel injection pipe 32 is branched into a plurality of branch pipes (three branch pipes 32a, 32b, 32c in this embodiment) from the branch portion 33 toward the other end. As shown in FIG. , Among the branch pipes 32a, 32b, 32c of the fuel injection pipe 32, the branch pipe 32a is connected to the fuel passage 22 of the fuel injection valve 20A. The fuel injection pipe 32 is a powder. The fuel injection valve 20A and the fuel injection pump 31 are communicated through the engine 32a. Likewise, the remaining branch pipes 32b and 32c are each of the fuel injection valves 20B and 20C. They are connected to passages 22, respectively.

The control valve 35 controls supply of hydraulic oil from the accumulating portion 71 to the fuel injection pump 31. The control valve 35 is opened during the injection period of fuel and water from the fuel injection valves 20A, 20B, and 20C to the combustion chamber, and supplies the hydraulic oil in the accumulating portion 71 to the fuel injection pump 31. On the other hand, the control valve 35 is in a closed state during the injection pause period of the fuel injection valves 20A, 20B, and 20C to stop supply of hydraulic oil from the accumulating portion 71 to the fuel injection pump 31. The timing of the opening/closing drive of the control valve 35 is controlled by the control unit 82.

The downstream water injection system 40 is a facility for injecting water into a water injection position on the downstream side of each fuel passage 22 of the fuel injection valves 20A, 20B, and 20C. As shown in FIG. 1, the downstream water supply system 40 includes a first water supply pump 41, a downstream water supply pipe 42a, 42b, 42c, a check valve 44a, 44b, 44c, and control A valve 45 is provided.

The first injection pump 41 is an example of the injection pump according to the present embodiment. The downstream water supply pipe 42a has one end connected to the first discharge port of the first water injection pump 41 and the other end connected to the internal passage 23 of the fuel injection valve 20A. The first injection pump 41 pressurizes water to the fuel passage 22 of the fuel injection valve 20A through the downstream injection pipe 42a or the like, and thereby, the water injection on the downstream side of the fuel passage 22 Water is injected into the position (that is, the first injection position P1). Further, the downstream side water supply pipe 42b has one end connected to the second discharge port of the first water injection pump 41 and the other end connected to the internal passage of the fuel injection valve 20B. As in the case of the fuel injection valve 20A, the first injection pump 41 passes through the downstream injection pipe 42b or the like, and the first injection position of the fuel passage 22 of the fuel injection valve 20B ( Inject water into P1). Further, the downstream side water supply pipe 42c has one end connected to the third discharge port of the first water injection pump 41 and the other end connected to the internal passage of the fuel injection valve 20C. As in the case of the fuel injection valve 20A, the first injection pump 41 passes through the downstream injection pipe 42c or the like, and the first injection position of the fuel passage 22 of the fuel injection valve 20C ( Inject water into P1).

Check valves (44a, 44b, 44c) are, for example, as shown in Fig. 1, each inlet end of the downstream side water supply pipes (42a, 42b, 42c) (the end of the first water supply pump 41 side), respectively Is formed. The check valve 44a enables water to flow from the first injection pump 41 side toward the fuel injection valve 20A side, and prevents the reverse flow. The check valve 44b enables water to flow from the first injection pump 41 side to the fuel injection valve 20B side, and prevents the reverse flow. The check valve 44c enables water to flow from the first injection pump 41 side to the fuel injection valve 20C side, and prevents the reverse flow.

The control valve 45 controls supply of hydraulic oil from the accumulating portion 71 to the first injection pump 41. The control valve 45 is opened in a period other than the injection period of fuel and water by the fuel injection valves 20A, 20B, and 20C (that is, the injection pause period), and the hydraulic oil in the accumulating portion 71 is first supplied. It is supplied to the main water pump (41). On the other hand, the control valve 45 is in a closed state during the injection period of the fuel and water and stops the supply of hydraulic oil from the accumulating portion 71 to the first injection pump 41. The timing of the opening/closing drive of the control valve 45 is controlled by the control unit 82.

The upstream water injection system 50 is a facility for injecting water into the upstream water injection position of each fuel passage 22 of the fuel injection valves 20A, 20B, and 20C. As shown in FIG. 1, the upstream side water supply system 50 includes a second water supply pump 51, an upstream side water supply pipe 52a, 52b, 52c, a check valve 54a, 54b, 54c, and control Equipped with a valve (55).

The second injection pump 51 is an example of the injection pump according to the present embodiment. The upstream side water supply pipe 52a has one end connected to the first discharge port of the second water injection pump 51 and the other end through the check valve 24a to the fuel passage 22 of the fuel injection valve 20A. It is connected. The second water injection pump 51 pressurizes water to the fuel passage 22 of the fuel injection valve 20A through the upstream water injection pipe 52a or the like, whereby water injection on the upstream side of the fuel passage 22 Water is injected into the position (i.e., the second injection position P2). In addition, the upstream side water supply pipe 52b has one end connected to the second discharge port of the second water injection pump 51, and the other end is the fuel passage of the fuel injection valve 20B via a check valve (not shown). 22). As in the case of the fuel injection valve 20A, the second injection pump 51 passes through the upstream injection pipe 52b or the like, and the second injection position of the fuel passage 22 of the fuel injection valve 20B ( Inject water into P2). Further, the upstream side water supply pipe 52c has one end connected to the third discharge port of the second water injection pump 51, and the other end is the fuel passage of the fuel injection valve 20C via a check valve (not shown). 22). As in the case of the fuel injection valve 20A, the second injection pump 51 passes through the upstream injection pipe 52c or the like, and the second injection position of the fuel passage 22 of the fuel injection valve 20C ( Inject water into P2).

Check valves 54a, 54b, 54c are, for example, as shown in Fig. 1, at each inlet end (end of the second main water pump 51 side) of the upstream side water supply pipes 52a, 52b, 52c, respectively. Is formed. The check valve 54a enables water to flow from the second injection pump 51 side toward the fuel injection valve 20A side, and prevents the reverse flow. The check valve 54b enables water to flow from the second injection pump 51 side toward the fuel injection valve 20B side, and prevents the reverse flow. The check valve 54c enables water to flow from the second injection pump 51 side toward the fuel injection valve 20C side, and prevents the reverse flow.

The control valve 55 controls the supply of hydraulic oil from the accumulating portion 71 to the second injection pump 51. The control valve 55 is opened during the injection stop period of the fuel injection valves 20A, 20B, and 20C to supply the hydraulic oil in the accumulating portion 71 to the second main water pump 51. On the other hand, the control valve 55 is in a closed state during the injection period of the fuel and water of the fuel injection valves 20A, 20B, and 20C to supply hydraulic oil from the accumulating unit 71 to the second main water pump 51. Stop. The timing of the opening/closing drive of the control valve 55 is controlled by the control unit 82.

The water supply pump 61 is a pump for supplying water to be discharged to the first injection pump 41 and the second injection pump 51. The water supply pipe 62 has one end connected to the water supply pump 61 and the other end is branched into branch pipes 62a and 62b. One branch pipe 62a of the water supply pipe 62 is connected to the first injection pump 41 via a check valve 63a. The other branch pipe 62b of the water supply pipe 62 is connected to the second injection pump 51 via a check valve 63b. The water supply pump 61 supplies water to be discharged to the first main water pump 41 through a branch pipe 62a or the like of the water supply pipe 62, and connects the branch pipe 62b of the water supply pipe 62 and the like. Through this, water to be discharged is supplied to the second main water pump 51. The check valve 63a enables water to flow from the water supply pump 61 side toward the first main water pump 41 side, and prevents the reverse flow. The check valve 63b enables water to flow from the water supply pump 61 side toward the second main water pump 51 side, and prevents the reverse flow.

The pressure accumulating unit 71 accumulates pressure of hydraulic oil for operating the fuel pumping system 30, the downstream side watering system 40, and the upstream side watering system 50, respectively. As shown in Fig. 1, the pressure storage unit 71 stores hydraulic oil discharged (pressurized) from the high pressure pump 72 through a pipe or the like in an internal pressure storage chamber, thereby accumulating the pressure of the hydraulic oil. In this way, the pressure of the hydraulic oil accumulated in the pressure storage unit 71 is adjusted by the amount of hydraulic oil discharged from the high pressure pump 72 to the pressure storage unit 71. The pressure of the hydraulic oil accumulated in the accumulating part 71 is shared with the operation of the fuel injection pump 31, the operation of the first injection pump 41, and the operation of the second injection pump 51.

The detection unit 81 detects a crank angle of a marine diesel engine (not shown). The detection unit 81 detects the crank angle as time passes, and transmits an electric signal indicating the detected crank angle to the control unit 82 each time.

The control unit 82 receives the electric signal from the detection unit 81 and opens the control valve of the fuel pressure delivery system 30 at a timing when the crank angle indicated by the received electric signal becomes a predetermined rotation angle. It controls the opening/closing operation of 35). The control unit 82 controls the operation timing of the fuel injection pump 31, that is, the injection of fuel and water into the combustion chamber from the fuel injection valves 20A, 20B and 20C through the control of the opening/closing drive of the control valve 35. Control the timing. At this injection timing, the fuel pumped from the fuel injection pump 31, the water discharged from the first injection pump 41, and the water discharged from the second injection pump 51 are It is injected in a layered manner from the fuel injection valves 20A, 20B, and 20C into the combustion chamber by the pressure feeding action. After that, each of the fuel passages 22 and the fuel injection pipe 32 of the fuel injection valves 20A, 20B, and 20C are filled with the remaining fuel without being injected.

In addition, the control unit 82, in the injection pause period of the fuel injection valves 20A, 20B, and 20C, the injection position on the downstream side of each of the fuel passages 22 in a state filled with fuel (the first injection position ( P1)) and the operation timing of the second injection pump 51 and the first injection pump 41 are controlled so that water is injected into the injection position (second injection position P2) on the upstream side, respectively. In this injection pause period, the water discharged from the first injection pump 41 and the water discharged from the second injection pump 51 flow into each of the fuel passages 22 of the fuel injection valves 20A, 20B, and 20C. At a pressure higher than the pressure of the remaining fuel (fuel residual pressure), they are injected into the first injection position P1 and the second injection position P2 of each of these fuel passages 22, respectively.

(Composition of the main water pump)

Next, a configuration of a water injection pump according to an embodiment of the present invention will be described. 2 is a schematic side cross-sectional view showing a configuration example of a water injection pump according to an embodiment of the present invention. 3 is a schematic cross-sectional view taken along line A-A of the water injection pump shown in FIG. 2. Below, as an example of the injection pump according to the present embodiment, a first injection pump for injecting water into the first injection position P1 of each fuel passage 22 of the fuel injection valves 20A, 20B, 20C ( 41) (see Fig. 1) is illustrated. In addition, in the configuration of the second injection pump 51 described above, the injection position of the fuel injection valves 20A, 20B, and 20C with respect to the respective fuel passages 22 is different from the first injection pump 41 (i.e., It is the same as the first injection pump 41 except that it is the second injection position (P2).

The first water injection pump 41 is a hydraulically driven water injection pump that discharges water using the pressure of hydraulic oil. As shown in Figs. 2 and 3, the first injection pump 41 includes a water cylinder 1, a hydraulic cylinder 5, and a plurality of (three in this embodiment) water piston portions 6a, 6b, and 6c), a hydraulic piston part 7, a connecting part 8, and an elastic support part 9 are provided.

The water cylinder 1 is a hollow cylindrical member capable of receiving the water piston portions 6a, 6b, 6c in a reciprocating manner. Specifically, as shown in Figs. 2 and 3, the water cylinder 1 includes water discharge passages 2a, 2b, 2c, which are internal passages for discharging water, and these water discharge passages 2a, 2b, 2c. ) And continuous inner space (4).

The water discharge passages 2a, 2b, 2c are an example of a plurality of water discharge passages each communicating through a plurality of fuel injection valves formed in one cylinder and a pipe. As shown in Figs. 2 and 3, the water discharge passages 2a, 2b, and 2c have a shape in which the water piston portions 6a, 6b, 6c can slide in the reciprocating direction (e.g., cylindrical shape). Is formed by The water discharge passages 2a, 2b, 2c temporarily store water to be discharged, which is supplied through a passage (not shown) formed inside the water cylinder 1, respectively. In addition, although not shown in Figs. 2 and 3, the downstream side water supply pipe 42a shown in Fig. 1 is connected to the discharge port 3a (first discharge port) of the water discharge passage 2a. The water discharge passage 2a communicates with the fuel injection valve 20A through the downstream main water supply pipe 42a. To the discharge port 3b (the second discharge port) of the water discharge passage 2b, a downstream water supply pipe 42b shown in FIG. 1 is connected. The water discharge passage 2b communicates with the fuel injection valve 20B through this downstream water injection pipe 42b. To the discharge port 3c (third discharge port) of the water discharge passage 2c, a downstream water supply pipe 42c shown in FIG. 1 is connected. The water discharge passage 2c communicates with the fuel injection valve 20C through this downstream main water supply pipe 42c. These water discharge passages 2a, 2b, 2c communicate with the position of the same fuel passage between the fuel injection valves 20A, 20B, and 20C. For example, the water discharge passage 2a communicates with the first water injection position P1 of the fuel passage 22 of the fuel injection valve 20A. Similarly, the water discharge passage 2b communicates with the first water injection position P1 of the fuel passage 22 of the fuel injection valve 20B, and the water discharge passage 2c is of the fuel injection valve 20C. It communicates with the first water injection position P1 of the fuel passage 22.

The inner space 4 is a space for enabling reciprocating movement of a plurality of (three in this embodiment) water piston parts 6a, 6b, 6c accompanying the operation of one hydraulic piston part 7. As shown in FIG. 2, in the inner space 4, each lower part of the water piston part 6a, 6b, 6c, an upper part of the hydraulic piston part 7, and a connecting part 8 connecting these are provided. It is accommodated in a reciprocating manner.

The hydraulic cylinder 5 is a hollow cylindrical member capable of receiving the hydraulic piston part 7 reciprocally. Specifically, as shown in FIG. 2, the hydraulic cylinder 5 has a hydraulic oil chamber 5a for receiving hydraulic oil for operating the hydraulic piston part 7. The hydraulic oil chamber 5a is formed so as to accommodate the hydraulic piston part 7 reciprocally. In addition, the hydraulic cylinder 5 is connected with the water cylinder 1 by the mounting bolt 10. Moreover, the lower end of the hydraulic cylinder 5 is attached to hydraulic oil supply facilities, such as the pressure accumulating part 71 and the control valve 45 shown in FIG.

The water piston parts 6a, 6b, 6c are examples of a plurality of water piston parts that pressurize and discharge water in a plurality of water discharge passages with respect to a plurality of fuel injection valves formed in one cylinder. In the present embodiment, the water piston portions 6a, 6b, 6c are, for example, pistons having the same diameter as each other, and as shown in Figs. 2 and 3, in the water discharge passages 2a, 2b, 2c Each is formed to be reciprocating. In addition, "the respective diameters of the water piston parts 6a, 6b, 6c are the same" means that each diameter of the water piston parts 6a, 6b, 6c is within the manufacturing tolerance. The water piston part 6a reciprocates in the piston shaft direction (the vertical direction of the paper in Fig. 2) while sliding in the water discharge passage 2a. At this time, the water piston part 6a moves in the direction of compressing the water discharge passage 2a and pressurizes it to discharge water in the water discharge passage 2a. The water piston part 6b reciprocates in the piston shaft direction while sliding in the water discharge passage 2b. At this time, the water piston part 6b moves in the direction of compressing the water discharge passage 2b and pressurizes it so as to discharge water in the water discharge passage 2b. The water piston part 6c reciprocates in the piston shaft direction while sliding in the water discharge passage 2c. At this time, the water piston part 6c moves in the direction of compressing the water discharge passage 2c and pressurizes it to discharge water in the water discharge passage 2c. The water piston portions 6a, 6b, 6c pressurize water in the water discharge passages 2a, 2b, 2c in this way, and discharge them to the fuel injection valves 20A, 20B, and 20C, respectively.

The hydraulic piston part 7 is a piston that operates using the pressure of hydraulic oil. As shown in FIG. 2, the hydraulic piston part 7 is accommodated in the hydraulic oil chamber 5a of the hydraulic cylinder 5 so that it can reciprocate in the piston axial direction. The hydraulic piston part 7 uses the pressure of the hydraulic oil supplied to the hydraulic oil chamber 5a to connect the water piston parts 6a, 6b, 6c to the discharge ports 3a, 3b of the water discharge passages 2a, 2b, 2c. And 3c), respectively. Moreover, the hydraulic piston part 7 moves (falls) in the piston axis direction while pushing the hydraulic oil out of the hydraulic oil chamber 5a, and returns to the original position before operation.

The connecting portion 8 is an example of a connecting portion connecting a plurality of water piston portions and one hydraulic piston portion. In detail, as shown in FIG. 2, the connection part 8 is fixed at one end of the lower end of the water piston parts 6a, 6b, 6c, and the upper end of the hydraulic piston part 7 is fixed to the other end. , With this structure, the water piston portions 6a, 6b, 6c and the hydraulic piston portion 7 are connected and integrated. Moreover, the connection part 8 is accommodated in the inner space 4 of the water cylinder 1 so that reciprocation is possible. The water piston portions 6a, 6b, and 6c fixed to the connecting portion 8 are integrated with the hydraulic piston portion 7 to be movable.

The elastic support part 9 elastically supports the hydraulic piston part 7 in a predetermined direction. For example, the elastic support part 9 is comprised by a compression spring, an air spring, etc., and is formed in the upper part of the hydraulic cylinder 5 as shown in FIG. The protrusion (not shown) of the hydraulic piston part 7 is arranged in the elastic support part 9. The elastic support portion 9 elastically supports the hydraulic piston portion 7 in a direction (a direction under the paper in Fig. 2) that pushes the hydraulic oil from the hydraulic oil chamber 5a by applying an elastic force to the protrusion.

(Operation of the injection pump)

Next, the operation of the water injection pump according to the embodiment of the present invention will be described. 4 is a diagram for explaining the operation of the water injection pump according to the embodiment of the present invention. Below, as an example of the operation|movement of the injection pump which concerns on this embodiment, the operation|movement of the 1st injection pump 41 mentioned above is demonstrated with reference to FIG.

As shown in Fig. 4, the first water injection pump 41 is in a state in which the hydraulic piston part 7 is positioned at a predetermined reference position (state S1) in a step before discharging water. At this time, water to be discharged is supplied to the water discharge passages 2a, 2b, 2c through a water supply pipe 62 or the like from a water supply pump 61 shown in FIG. 1. Thereby, the water discharge passages 2a, 2b, 2c are respectively filled with water to be discharged.

Subsequently, when the first injection pump 41 discharges water, the hydraulic oil is supplied from the pressure storage unit 71 shown in Fig. 1 to the hydraulic oil chamber 5a through the control valve 45 or the like. Is supplied. As in the state S2 shown in FIG. 4, the hydraulic piston part 7 receives the pressure of the hydraulic oil in the hydraulic oil chamber 5a, and uses the pressure of the hydraulic oil to discharge the water discharge passages 2a, 2b, 2c ( 3a, 3b, 3c) move (ascend) to the side. At this time, while the hydraulic piston part 7 moves against the elastic force of the elastic support part 9, the water piston part 6a, 6b, 6c together with the connection part 8 is connected to the discharge ports 3a, 3b, 3c. Move to the side. Thereby, the hydraulic piston part 7 has the same lift amount (preferably equal to each other) in the direction of compressing these water piston parts 6a, 6b, 6c, the water discharge passages 2a, 2b, 2c, respectively. By volume).

The water piston parts 6a, 6b, 6c, by the action of the hydraulic piston part 7, make the movement amount (lift amount) equal to each other, and slide in the water discharge passages 2a, 2b, 2c, respectively, while water Water (water to be discharged) in the discharge passages 2a, 2b, 2c is pressurized, respectively. Water in the water discharge passage 2a is pressurized by the water piston part 6a to push and open the check valve 44a shown in Fig. 1 from the discharge port 3a, and flows into the downstream main water pipe 42a, It is injected into the first injection position P1 of the fuel passage 22 of the fuel injection valve 20A through this downstream injection pipe 42a. The water in the water discharge passage 2b is pressurized by the water piston part 6b to push and open the check valve 44b shown in FIG. 1 from the discharge port 3b to flow into the downstream main water pipe 42b, It is injected into the first injection position P1 of the fuel passage 22 of the fuel injection valve 20B through this downstream injection pipe 42b. Water in the water discharge passage 2c is pressurized by the water piston part 6c to push and open the check valve 44c shown in FIG. 1 from the discharge port 3c, and flow into the downstream main water pipe 42c, It is injected into the first injection position P1 of the fuel passage 22 of the fuel injection valve 20C through this downstream injection pipe 42c.

In the discharge of water by the first injection pump 41 as described above, the hydraulic piston part 7 is discharged at the discharge ports 3a, 3b, 3c using the pressure of the hydraulic oil during the period in which the hydraulic oil is supplied to the hydraulic oil chamber 5a. During the period moving toward the) side, it continues. Here, by the action of one hydraulic piston part 7 common to the water piston parts 6a, 6b, 6c, each lift amount (preferably moving volume) of the water piston parts 6a, 6b, 6c is , Forcibly becomes the same between the water discharge passages 2a, 2b, 2c. As a result, the amount of water discharged from the water discharge passages 2a, 2b, 2c is suppressed from variation (biased) between the water discharge passages 2a, 2b, and 2c, and it is possible to set the amount equal to each other. That is, from the water discharge passages 2a, 2b, 2c to the first injection position P1 of each fuel passage 22 of the fuel injection valves 20A, 20B, 20C, the fuel injection valves 20A, 20B, 20C Regardless of the variation in fuel residual pressure (difference in height) between, the variation in the amount of water to be poured is suppressed so that the same amount of water can be injected with each other. As a result, it becomes possible to inject the same amount of fuel and water into the combustion chamber in one cylinder from the fuel injection valves 20A, 20B, and 20C in a layered manner between the fuel injection valves 20A, 20B, and 20C.

Thereafter, when the supply of the hydraulic oil to the hydraulic oil chamber 5a is stopped, the discharge of water for one batch by the first main water pump 41 is ended. At this time, the hydraulic piston part 7 transfers the hydraulic oil (the hydraulic oil used for discharging the water described above) in the hydraulic oil chamber 5a by the elastic force of the elastic support part 9 from the hydraulic cylinder 5a. 5) It moves from the current lift position to the original reference position while pushing it to the outside. As the hydraulic piston part 7 moves, the water piston parts 6a, 6b, 6c are connected to the connection part 8 in the direction of releasing the compression (pressurization of water) of the water discharge passages 2a, 2b, 2c. It moves together with, and returns to the position before the discharge of water was performed like state S1 shown in FIG. Water to be discharged is supplied from the water supply pump 61 to the water discharge passages 2a, 2b, 2c through the water supply pipe 62, etc., whereby the water discharge passages 2a, 2b, 2c are Return to the state filled with water.

As described above, in the injection pump according to the embodiment of the present invention, a plurality of water discharge passages each communicating through a plurality of fuel injection valves and pipes formed in one cylinder are formed, and the plurality of water discharge passages A plurality of water piston units are formed in each of the plurality of water piston units to be reciprocated, and the plurality of water piston units are moved to the discharge port side of the plurality of water discharge passages by a hydraulic piston unit operating using the pressure of hydraulic oil, and the action of the hydraulic piston unit Thereby, the plurality of water piston units pressurize water in the plurality of water discharge passages to discharge each of the plurality of fuel injection valves. In particular, in this embodiment, the plurality of water piston parts and the hydraulic piston parts are connected by a connecting part, whereby the plurality of water piston parts move integrally with the hydraulic piston part.

For this reason, by the operation of one hydraulic piston part, the plurality of water piston parts can be reciprocated in a state in which the lift amounts are the same. Accordingly, the plurality of water piston units may be moved by the same volume in a direction in which the plurality of water discharge passages are respectively compressed. As a result, since it is possible to suppress variations in the amount of water discharged between the plurality of water discharge passages, watering for a plurality of fuel injection valves formed in one cylinder can be performed with a simple watering mechanism. Together, it is possible to suppress variations in the amount of water injected between the plurality of fuel injection valves.

Furthermore, it is possible to suppress variations between the plurality of fuel injection valves in the injection amount of fuel injected into the combustion chamber from a plurality of fuel injection valves per cycle of the marine diesel engine. As a result, it is possible to suppress variations in the length of the flame or the amount of heat generated during fuel combustion in the combustion chamber, thereby suppressing variations in the amount of wear of parts related to the combustion chamber such as cylinders or pistons, and combustion of marine diesel engines. It is possible to suppress a decrease in efficiency.

In addition, in the water injection pump according to the embodiment of the present invention, since the plurality of water piston parts are reciprocated by the operation of one hydraulic piston part, the lift amount of these plurality of water piston parts is controlled by controlling the lift amount of the hydraulic piston part. It can be controlled collectively. For this reason, control for making the lift amount of these plural water piston parts equal to each other can be performed with a simple structure.

In addition, in the above-described embodiment, the injection pump for injecting water into each fuel passage of the three fuel injection valves 20A, 20B, 20C formed in one cylinder was illustrated, but the present invention is not limited thereto. . For example, the injection pump according to the present invention may inject water into each of the fuel passages of two or more (plural) fuel injection valves formed in one cylinder.

In addition, in the above-described embodiment, the injection pump for operating the three water piston parts 6a, 6b, 6c by the action of one hydraulic piston part 7 was illustrated, but the present invention is not limited thereto. . For example, the water injection pump according to the present invention may operate two or more (plural) water piston units by the action of one hydraulic piston unit. That is, in the present invention, each number of the water piston portion and the water discharge passage may be set according to the number of fuel injection valves to be injected into one cylinder.

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 constituent elements. In addition, other embodiments, examples, and operation techniques performed by a person skilled in the art or the like based on the above-described embodiments are all included in the scope of the present invention.

Industrial applicability

As described above, the injection pump according to the present invention is useful for injection of a fuel injection valve, and in particular, while performing injection of a plurality of fuel injection valves formed in one cylinder, between the plurality of fuel injection valves It is suitable for the injection pump that can suppress the deviation of the injection quantity.

1: water cylinder
2a, 2b, 2c: water discharge passage
3a, 3b, 3c: discharge port
4: inner space
5: hydraulic cylinder
5a: operating loss
6a, 6b, 6c: water piston part
7: hydraulic piston part
8: connection
9: elastic support
10: mounting bolt
20A, 20B, 20C: fuel injection valve
21: nozzle
22: fuel passage
23: inner passage
24a, 24b: non-return valve
30: fuel pressure delivery system
31: fuel injection pump
32: fuel injection pipe
32a, 32b, 32c: branch pipe
33: branch
35: control valve
40: downstream side water supply system
41: first main water pump
42a, 42b, 42c: downstream main water pipe
44a, 44b, 44c: non-return valve
45: control valve
50: upstream side water supply system
51: second main water pump
52a, 52b, 52c: upstream main water pipe
54a, 54b, 54c: non-return valve
55: control valve
61: water supply pump
62: water supply pipe
62a, 62b: branch tube
63a, 63b: non-return valve
71: accumulator
72: high pressure pump
81: detection unit
82: control unit
100: fuel injection system
P1: 1st main water position
P2: 2nd main water position

Claims (4)

A plurality of water discharge passages each communicating through a plurality of fuel injection valves and pipes formed in one cylinder,
A plurality of water piston units respectively formed in the plurality of water discharge passages so as to be reciprocally reciprocated, and pressurizing water in the plurality of water discharge passages to discharge each of the plurality of fuel injection valves;
And a hydraulic piston unit for moving the plurality of water piston units to a discharge port side of the plurality of water discharge passages using pressure of hydraulic oil. The method of claim 1,
And a connection part connecting the plurality of water piston parts and the hydraulic piston part,
The water injection pump, characterized in that the plurality of water piston parts move integrally with the hydraulic piston part. The method according to claim 1 or 2,
The plurality of water discharge passages communicate with a position of the same fuel passage between the plurality of fuel injection valves. The method according to any one of claims 1 to 3,
The plurality of water piston parts, water injection pump, characterized in that the pistons having the same diameter.

Images