JP7030553B2 - Hydraulic drive - Google Patents

Description

The present invention relates to a hydraulic drive device for a marine diesel engine mounted on a ship.

Conventionally, in the field of marine diesel engines, hydraulic drive technology has been proposed in which a fuel injection pump for injecting fuel and a valve operating device for opening and closing an exhaust valve are operated by using the pressure of hydraulic oil (for example, a patent). See Documents 1 and 2). Generally, the hydraulic oil is discharged from the high pressure pump to the accumulator chamber through a pipe. The pressure of this hydraulic oil is adjusted by the amount of hydraulic oil discharged from the high-pressure pump to the accumulator chamber. The pressure of the hydraulic oil accumulated in the accumulator chamber in this way is transmitted to the fuel injection pump and the valve operating device through the supply of the hydraulic oil from the accumulator chamber. The fuel injection pump can inject fuel into the combustion chamber of the cylinder by driving the piston using the transmitted pressure of the hydraulic oil. The valve operating device is a hydraulic device having a driving oil for driving the opening and closing of the exhaust valve, and the exhaust valve can be driven to open and close by the pressure of the transmitted hydraulic oil.

Further, the fuel injection pump and the valve operating device are each provided with a control valve on the hydraulic oil supply path. Each operation timing of the hydraulic oil to the fuel injection pump and the valve drive device, that is, each operation timing of the fuel injection pump and the valve drive device using the pressure of the hydraulic oil is controlled by each control valve at a desired timing. ..

The fuel injection pump increases or decreases the injection pressure (hereinafter, appropriately referred to as fuel injection pressure) when injecting fuel into the combustion chamber as the pressure of the hydraulic oil increases or decreases. From the viewpoint of improving the fuel efficiency of the marine diesel engine, such fuel injection pressure is preferably increased as the load of the marine diesel engine (hereinafter, appropriately referred to as engine load) increases. That is, when the pressure of the hydraulic oil in the accumulator chamber described above is used for operating the fuel injection pump, it is preferable that the pressure increases or decreases according to the engine load. Hereinafter, the fuel efficiency means the fuel efficiency of a marine diesel engine unless otherwise specified.

On the other hand, the valve operating device increases or decreases the opening driving force of the exhaust valve when opening the exhaust port of the cylinder as the pressure of the hydraulic oil increases or decreases. The open driving force of the exhaust valve is the driving force required for the open drive of the exhaust valve. The valve operating device can open the exhaust valve if the open driving force of the exhaust valve is larger than the pressure in the cylinder (hereinafter, appropriately referred to as the in-cylinder pressure) that opposes the open drive of the exhaust valve. Therefore, from the viewpoint of improving the driving efficiency of the exhaust valve, the open driving force of the exhaust valve is preferably as small as possible within the range in which the exhaust valve can be driven without any trouble against the pressure inside the cylinder. That is, when the pressure of the hydraulic oil in the pressure accumulator chamber described above is used for operating the valve operating device, it is preferable that the pressure increases or decreases according to the in-cylinder pressure.

Japanese Patent No. 4176742 Japanese Patent No. 4250463

However, in the above-mentioned prior art, when the pressure of the hydraulic oil in the accumulator chamber is increased in accordance with the increase in the engine load in order to increase the fuel injection pressure by the fuel injection pump, the pressure after the increase of the hydraulic oil is increased. It may be excessively high for the operation of the valve operating device. That is, the open driving force of the exhaust valve may become excessively strong. This phenomenon can occur because the in-cylinder pressure does not always increase in proportion to the increase in engine load. If the open driving force of the exhaust valve is excessively strong, the exhaust valve collides strongly with the valve operating device, resulting in an unstable state such as vibration of the exhaust valve, and excessively vibrating the driving oil piping of the valve operating device. There is a risk of causing it. Furthermore, the energy consumed to drive the exhaust valve open is proportional to the product of the hydraulic oil pressure and the consumption amount, so if the pressure of the drive oil of the valve engine is excessively high, the drive efficiency of the exhaust valve will increase. There is a risk of deterioration.

When the pressure of the hydraulic oil in the accumulator chamber is increased or decreased according to the in-cylinder pressure in order to adjust the opening driving force of the exhaust valve by the valve operating device, the pressure after the increase or decrease of the hydraulic oil is the pressure of the fuel injection pump. It may be inadequate for operation. That is, it may be difficult to sufficiently increase the fuel injection pressure according to the engine load. Due to this, fuel efficiency may be deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydraulic drive device capable of achieving both improvement in fuel efficiency of a marine diesel engine and improvement in drive efficiency of an exhaust valve. ..

In order to solve the above-mentioned problems and achieve the object, the hydraulic drive device according to the present invention has a fuel injection valve that injects fuel into the combustion chamber of the cylinder of a marine diesel engine, and a first method that accumulates the pressure of hydraulic oil. The first hydraulic oil discharge pump that adjusts the pressure of the hydraulic oil in the first pressure accumulator by discharging the hydraulic oil to the first accumulator through the pressure accumulator and the first accumulator, and the first accumulator. A fuel injection pump that pumps the fuel to the fuel injection valve by using the pressure of the hydraulic oil accumulated in the unit, an exhaust valve that opens and closes the exhaust port of the cylinder, and the first pressure storage unit. The pressure of the hydraulic oil in the second accumulator is adjusted by discharging the hydraulic oil to the second accumulator through the pipe and the second accumulator that accumulates the pressure of the hydraulic oil independently of the above. It is characterized by comprising a second hydraulic oil discharge pump and a valve operating device for opening and closing the exhaust valve by utilizing the pressure of the hydraulic oil stored in the second pressure accumulating portion.

Further, in the above invention, the hydraulic drive device according to the present invention includes the piping of the first hydraulic oil discharge pump leading to the first accumulator and the second hydraulic oil leading to the second accumulator. The communication pipe that connects the piping of the discharge pump so as to be communicable, the on-off valve provided in the communication pipe, and the hydraulic oil discharged by the first hydraulic oil discharge pump are referred to the first hydraulic oil discharge pump. The on-off valve is controlled to be open for a predetermined period so that it can be circulated from the pipe to the pipe of the second hydraulic oil discharge pump through the communication pipe, and the communication is performed from the pipe of the first hydraulic oil discharge pump. It is provided with a control unit for controlling the on-off valve to a closed state for a period other than the predetermined period so as to stop the flow of the hydraulic oil to the piping of the second hydraulic oil discharge pump through the pipe. It is a feature.

Further, in the above invention, the hydraulic drive system according to the present invention includes a water injection pump that injects water into the fuel flow path by utilizing the pressure of the hydraulic oil accumulated in the first pressure accumulator. The fuel injection valve is characterized in that the pumped fuel and the injected water are injected into the combustion chamber of the cylinder.

Further, in the hydraulic drive device according to the present invention, in the above invention, the first hydraulic oil discharge pump is an electric pump, and the second hydraulic oil discharge pump is interlocked with the output shaft of the marine diesel engine. It is characterized by being an engine-driven pump that is driven by the engine.

According to the present invention, it is possible to achieve both an improvement in fuel efficiency of a marine diesel engine and an improvement in drive efficiency of an exhaust valve.

FIG. 1 is a schematic diagram showing a configuration example of a hydraulic drive system according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a configuration example of a marine diesel engine to which the hydraulic drive device according to the embodiment of the present invention is applied.

Hereinafter, preferred embodiments of the hydraulic drive system according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the present embodiment. In addition, it should be noted that the drawings are schematic, and the relationship between the dimensions of each element, the ratio of each element, etc. may differ from the actual ones. Even between the drawings, there may be parts where the relationship and ratio of the dimensions are different from each other. Further, in each drawing, the same components are designated by the same reference numerals.

FIG. 1 is a schematic diagram showing a configuration example of a hydraulic drive system according to an embodiment of the present invention. The hydraulic drive system 100 according to the present embodiment is for injecting fuel or the like and opening / closing the exhaust valve by using the pressure of the hydraulic oil, and as shown in FIG. 1, the fuel injection system 1 and the exhaust gas. A valve drive system 11 is provided. Further, the hydraulic drive device 100 includes equipment for supplying hydraulic oil and controlling pressure, for example, a filter 23, an injection valve side high pressure pump 24, an exhaust valve side high pressure pump 25, an on-off valve 26, and a check valve. 27, a control unit 28, a feeding pipe 111 to 114, and a communication pipe 115 are provided. Further, the hydraulic drive device 100 includes equipment for collecting and storing hydraulic oil, for example, a sump tank 21, a storage tank 22, recovery pipes 103 to 105, and a return pipe 110. In FIG. 1, the solid line arrow indicates the flow of a fluid such as hydraulic oil, and the alternate long and short dash line arrow indicates an electric signal line.

The fuel injection system 1 is a facility for injecting fuel or the like. As shown in FIG. 1, the fuel injection system 1 includes a fuel injection valve 2, a fuel injection pump 3, a fuel injection side control valve 4, a water injection pump 5, a water injection side control valve 6, and an injection valve side. A pressure accumulator 7 and a relief valve 8 are provided. Further, the fuel injection system 1 includes a fuel injection pipe 101, a water injection pipe 102, water injection valves 9a and 9b, and water injection check valves 10a and 10b.

The fuel injection valve 2 is configured to be able to inject fuel into the combustion chamber 204 of the cylinder 203 of the marine diesel engine. As shown in FIG. 1, the fuel injection valve 2 is communicatively connected to the fuel injection pump 3 via the fuel injection pipe 101. The fuel injection valve 2 receives the fuel pumped by the fuel injection pump 3 from the fuel injection pipe 101 and injects it into the combustion chamber 204. Further, in the present embodiment, water such as distilled water is injected by the water injection pump 5 into the fuel flow path from the discharge port of the fuel injection pump 3 to the injection port of the fuel injection valve 2. The fuel flow path is composed of, for example, a fuel injection pipe 101 and a flow path formed inside the fuel injection valve 2. The fuel injection valve 2 alternately injects (that is, injects into layers) the fuel pumped by the fuel injection pump 3 and the water injected by the water injection pump 5 into the combustion chamber 204 by the pressure feeding action of the fuel injection pump 3. ..

In FIG. 1, the fuel injection valve 2 is shown separately from the cylinder 203 in order to facilitate the explanation of the configuration of the hydraulic drive device 100, but the fuel injection valve 2 has its injection port in the combustion chamber 204. It is provided on the cylinder 203 in a oriented manner.

The fuel injection pump 3 is a hydraulically driven pump that pumps fuel by using the pressure of hydraulic oil. As shown in FIG. 1, the fuel injection pump 3 has a piston 3a, a discharge chamber 3b, and a hydraulic oil chamber 3c. The piston 3a is provided in the internal space of the fuel injection pump 3 so that it can be reciprocated along its longitudinal direction. For example, the piston 3a is formed in a rod shape so that the piston diameter on the fuel discharge side is smaller than the piston diameter on the hydraulic oil receiving side. The discharge chamber 3b is a space for temporarily storing the fuel discharged from the fuel injection pump 3. As shown in FIG. 1, the discharge chamber 3b is configured to be a space facing the end of the piston 3a on the fuel discharge side in the internal space of the fuel injection pump 3. The hydraulic oil chamber 3c is a space for receiving the hydraulic oil that operates the fuel injection pump 3. As shown in FIG. 1, the hydraulic oil chamber 3c is configured to be a space facing the end of the piston 3a on the hydraulic oil receiving side in the internal space of the fuel injection pump 3.

Further, the fuel injection pump 3 has an injection port 3d and a discharge port 3e for filling the discharge chamber 3b with fuel. The inlet 3d and the outlet 3e are provided in the main body of the fuel injection pump 3 so as to communicate with the discharge chamber 3b. Fuel is supplied to the discharge chamber 3b from the injection port 3d through a pipe or the like of a fuel tank (not shown). Further, the fuel stored in the discharge chamber 3b is returned to the fuel tank from the discharge port 3e through a pipe or the like. By circulating the fuel between the discharge chamber 3b and the fuel tank in this way, the discharge chamber 3b is filled with the fuel while the gas (air bubbles) is removed from the discharge chamber 3b.

Further, as shown in FIG. 1, a fuel injection pipe 101 is connected to the fuel injection pump 3. Specifically, one end of the fuel injection pipe 101 is connected to the discharge port of the discharge chamber 3b of the fuel injection pump 3, and the other end is connected to the fuel injection valve 2. The fuel injection pipe 101 communicates the discharge chamber 3b of the fuel injection pump 3 with the flow path and the injection port in the fuel injection valve 2.

The fuel injection pump 3 having such a configuration uses the pressure of the hydraulic oil accumulated in the pressure accumulator portion 7 on the injection valve side to pump fuel to the fuel injection valve 2. At this time, when the control valve 4 is driven so that the injection valve side accumulator 7 and the hydraulic oil chamber 3c communicate with each other, the fuel injection pump 3 is driven from the injection valve side accumulator 7 via the control valve 4. Accept the hydraulic oil in 3c. The fuel injection pump 3 uses the pressure of the received hydraulic oil to operate the piston 3a so as to compress the discharge chamber 3b. As a result, the fuel injection pump 3 pressurizes the fuel in the discharge chamber 3b while blocking the communication between the discharge chamber 3b and the injection port 3d and the discharge port 3e by the piston 3a. The pressurized fuel is pressure-fed from the discharge chamber 3b to the fuel injection valve 2 through the fuel injection pipe 101. After that, the control valve 4 is driven so as to cut off the communication between the injection valve side accumulator 7 and the hydraulic oil chamber 3c, whereby the hydraulic oil is supplied from the injection valve side accumulator 7 to the hydraulic oil chamber 3c. It will be stopped. In this case, the control valve 4 is in a state where the hydraulic oil chamber 3c and the recovery pipe 103 are communicated with each other. The piston 3a presses the hydraulic oil in the hydraulic oil chamber 3c toward the control valve 4 by the repulsive force of an urging portion (not shown) such as a spring provided in the internal space of the fuel injection pump 3. The pressed hydraulic oil is sent from the hydraulic oil chamber 3c to the sump tank 21 through the control valve 4 and the recovery pipe 103. As a result, the piston 3a is returned to the position before the fuel pumping. The fuel injection pump 3 releases the compression (pressurization of fuel) of the discharge chamber 3b by the piston 3a.

The control valve 4 is a valve for controlling the supply of hydraulic oil from the pressure accumulator portion 7 on the injection valve side to the fuel injection pump 3. Specifically, the control valve 4 is composed of an electric on-off valve such as a solenoid valve, and as shown in FIG. 1, the fuel injection pump 3 (specifically, the hydraulic oil chamber 3c) and the injection valve side pressure accumulator portion 7 It is provided so that it can communicate with. The control valve 4 is opened at the fuel injection timing, and supplies the hydraulic oil in the pressure accumulator portion 7 on the injection valve side to the hydraulic oil chamber 3c of the fuel injection pump 3. In this open state, the control valve 4 opens the communication path between the injection valve side accumulator portion 7 and the hydraulic oil chamber 3c, and closes the communication path between the hydraulic oil chamber 3c and the recovery pipe 103. On the other hand, the control valve 4 is closed for a period other than the fuel injection timing, and the supply of hydraulic oil from the injection valve side accumulator 7 to the hydraulic oil chamber 3c of the fuel injection pump 3 is stopped. In this closed state, the control valve 4 closes the communication path between the injection valve side accumulator 7 and the hydraulic oil chamber 3c, and opens the communication path between the hydraulic oil chamber 3c and the recovery pipe 103. The timing of opening / closing drive of the control valve 4 is controlled by the control unit 28. Further, as shown in FIG. 1, the control valve 4 is connected to the sump tank 21 via a recovery pipe 103 so as to be able to communicate with each other. The control valve 4 receives the hydraulic oil used for operating the fuel injection pump 3 from the hydraulic oil chamber 3c, and sends the received used hydraulic oil to the sump tank 21 through the recovery pipe 103.

The water injection pump 5 is a hydraulically driven pump that injects water by using the pressure of the hydraulic oil. As shown in FIG. 1, the water injection pump 5 has a piston 5a, a discharge chamber 5b, and a hydraulic oil chamber 5c. The piston 5a is provided in the internal space of the water injection pump 5 so that it can be reciprocated along its longitudinal direction. For example, the piston 5a is formed in a rod shape so that the piston diameter on the water discharge side is smaller than the piston diameter on the hydraulic oil receiving side. The discharge chamber 5b is a space for temporarily storing the fuel discharged from the water injection pump 5. As shown in FIG. 1, the discharge chamber 5b is configured to be a space facing the end of the piston 5a on the water discharge side in the internal space of the water injection pump 5. The hydraulic oil chamber 5c is a space for receiving the hydraulic oil for operating the water injection pump 5. As shown in FIG. 1, the hydraulic oil chamber 5c is configured to be a space facing the end portion of the piston 5a on the hydraulic oil receiving side in the internal space of the water injection pump 5.

Further, the water injection pump 5 has an injection port 5d for filling the discharge chamber 5b with water. The injection port 5d is provided in the main body of the water injection pump 5 so as to communicate with the discharge chamber 5b. The water to be injected is supplied from the injection port 5d to the discharge chamber 5b through a pipe or the like of a water tank (not shown). Water is supplied (replenished) to the discharge chamber 5b through the injection port 5d each time water is injected by the water injection pump 5.

Further, as shown in FIG. 1, a water injection pipe 102 is connected to the water injection pump 5. Specifically, the water injection pipe 102 is branched into a plurality of branch pipes (two water injection branch pipes 102a and 102b in the present embodiment) from one end to the other end. One end of the water injection pipe 102 is connected to the discharge port of the discharge chamber 5b of the water injection pump 5. The other end of the water injection pipe 102, specifically, each outlet end of the water injection branch pipes 102a and 102b, is connected to the fuel injection valve 2 and the fuel injection pipe 101, respectively. A water injection valve 9a and a water injection check valve 10a are provided in the middle of the water injection branch pipe 102a. The water injection valve 9a is opened to enable water injection from the water injection branch pipe 102a to the fuel injection valve 2, and is closed to prevent water injection from the water injection branch pipe 102a to the fuel injection valve 2. do. The water injection check valve 10a prevents backflow of water in the water injection branch pipe 102a. A water injection valve 9b and a water injection check valve 10b are provided in the middle of the other water injection branch pipe 102b. The water injection valve 9b is opened to enable water injection from the water injection branch pipe 102b to the fuel injection pipe 101, and is closed to prevent water injection from the water injection branch pipe 102b to the fuel injection pipe 101. do. The water injection check valve 10b prevents backflow of water in the water injection branch pipe 102b. The timing of opening / closing drive of the water injection valves 9a and 9b may be controlled by the control unit 28 or may be controlled by another control unit (not shown).

The water injection pump 5 having such a configuration utilizes the pressure of the hydraulic oil accumulated in the pressure accumulator portion 7 on the injection valve side to inject water into the above-mentioned fuel flow path. At this time, when the control valve 6 is driven so that the injection valve side accumulator 7 and the hydraulic oil chamber 5c communicate with each other, the water injection pump 5 is driven from the injection valve side accumulator 7 via the control valve 6 to the hydraulic oil chamber 5c. Accept hydraulic oil. The water injection pump 5 uses the pressure of the received hydraulic oil to operate the piston 5a so as to compress the discharge chamber 5b. As a result, the water injection pump 5 pressurizes the water in the discharge chamber 5b while blocking the communication between the discharge chamber 5b and the injection port 5d by the piston 5a. The pressurized water is injected from the discharge chamber 5b into the fuel flow path (specifically, in the fuel satisfying the flow path) through the water injection pipe 102. Specifically, when the water injection valve 9a is in the open state, the pressurized water is injected from the discharge chamber 5b into the flow path in the fuel injection valve 2 (in the fuel filling the flow path) through the water injection branch pipe 102a. To. When the water injection valve 9b is in the open state, the pressurized water is injected from the discharge chamber 5b into the fuel injection pipe 101 (in the fuel filling the fuel injection pipe 101) through the water injection branch pipe 102b. As a result, columnar fuel and columnar water are alternately present along the distribution channel. After that, the control valve 6 is driven so as to cut off the communication between the injection valve side accumulator 7 and the hydraulic oil chamber 5c, whereby the hydraulic oil is supplied from the injection valve side accumulator 7 to the hydraulic oil chamber 5c. It will be stopped. In this case, the control valve 6 is in a state where the hydraulic oil chamber 5c and the recovery pipe 104 are communicated with each other. The piston 5a presses the hydraulic oil in the hydraulic oil chamber 5c toward the control valve 6 by the repulsive force of an urging portion (not shown) such as a spring provided in the internal space of the water injection pump 5. The pressed hydraulic oil is sent from the hydraulic oil chamber 5c to the sump tank 21 through the control valve 6 and the recovery pipe 104. As a result, the piston 5a is returned to the position before water injection. The water injection pump 5 releases the compression (pressurization of water) of the discharge chamber 5b by the piston 5a.

The control valve 6 is a valve for controlling the supply of hydraulic oil from the pressure accumulator portion 7 on the injection valve side to the water injection pump 5. Specifically, the control valve 6 is composed of an electric on-off valve such as a solenoid valve, and as shown in FIG. 1, the water injection pump 5 (specifically, the hydraulic oil chamber 5c) and the injection valve side pressure accumulator portion 7. It is provided so that it can communicate. The control valve 6 is opened at the timing of injecting water, and the hydraulic oil in the pressure accumulator portion 7 on the injection valve side is supplied to the hydraulic oil chamber 5c of the water injection pump 5. In this open state, the control valve 6 opens the communication path between the injection valve side accumulator 7 and the hydraulic oil chamber 5c, and closes the communication path between the hydraulic oil chamber 5c and the recovery pipe 104. On the other hand, the control valve 6 is closed for a period other than the water injection timing, and the supply of hydraulic oil from the injection valve side accumulator 7 to the hydraulic oil chamber 5c of the water injection pump 5 is stopped. In this closed state, the control valve 6 closes the communication path between the injection valve side accumulator 7 and the hydraulic oil chamber 5c, and opens the communication path between the hydraulic oil chamber 5c and the recovery pipe 104. The timing of opening / closing drive of such a control valve 6 is controlled by the control unit 28. Further, as shown in FIG. 1, the control valve 6 is communicatively connected to the sump tank 21 via a recovery pipe 104. The control valve 6 receives the hydraulic oil used for operating the water injection pump 5 from the hydraulic oil chamber 5c, and sends the received used hydraulic oil to the sump tank 21 through the recovery pipe 104.

The pressure accumulator portion 7 on the injection valve side is a unit (first accumulator unit) that stores the pressure of the hydraulic oil used in the fuel injection system 1. The pressure accumulator portion 7 on the injection valve side is a hollow structure that forms a pressure accumulator chamber capable of storing hydraulic oil inside, and as shown in FIG. 1, communicates with the high pressure pump 24 on the injection valve side via the feed pipe 113. Can be connected. The pressure accumulator unit 7 on the injection valve side stores the hydraulic oil discharged (pressurized) from the high pressure pump 24 on the injection valve side through the supply pipe 113 in the internal pressure accumulator chamber, thereby accumulating the pressure of the hydraulic oil. The pressure of the hydraulic oil accumulated in the pressure accumulator portion 7 on the injection valve side is adjusted by the amount of hydraulic oil discharged from the high pressure pump 24 on the injection valve side to the pressure accumulator portion 7 on the injection valve side. The pressure of the hydraulic oil accumulated in the pressure accumulator portion 7 on the injection valve side is shared between the operation of the fuel injection pump 3 and the operation of the water injection pump 5 described above.

The relief valve 8 is a valve for releasing the excess pressure of the hydraulic oil from the pressure accumulating portion 7 on the injection valve side. As shown in FIG. 1, the relief valve 8 is provided in the pressure accumulator portion 7 on the injection valve side. When the pressure of the hydraulic oil exceeds the pressure required for each operation of the fuel injection pump 3 and the water injection pump 5 and is excessively accumulated in the pressure accumulator 7 on the injection valve side, the relief valve 8 is opened and this excess. The hydraulic oil is discharged from the pressure accumulator 7 on the injection valve side by a large amount of pressure. As a result, it is possible to avoid a situation in which the pressure of the hydraulic oil in the pressure accumulator portion 7 on the injection valve side exceeds the design upper limit pressure of the pressure accumulator portion 7 on the injection valve side.

The exhaust valve drive system 11 is a facility for opening and closing a valve for opening and closing the exhaust port 205 of the cylinder 203 of a marine diesel engine. As shown in FIG. 1, the exhaust valve drive system 11 includes an exhaust valve 12, an upper valve valve device 13, a lower valve valve device 14, a hydraulic pipe 15, a control valve 16, and an exhaust valve side pressure accumulator portion 17. , The relief valve 18 is provided.

The exhaust valve 12 is a valve that opens and closes the exhaust port 205 of the cylinder 203 of a marine diesel engine so as to be openable and closable. As shown in FIG. 1, the exhaust valve 12 is configured in a rod shape so as to have a valve portion 12a for opening and closing the exhaust port 205 at one end and a piston portion 12b for receiving hydraulic pressure during driving at the other end. Will be done. Further, the exhaust valve 12 is supported by the upper valve valve device 13 so that it can be reciprocated along its longitudinal direction (see the arrows on both sides of the thick line in FIG. 1). The exhaust valve 12 descends from the position where the exhaust port 205 is closed to open the exhaust port 205, and rises from the position where the exhaust port 205 is opened to close the exhaust port 205 by the action of the valve operating device described later.

The valve operating device opens and closes the exhaust valve 12 by utilizing the pressure of the hydraulic oil accumulated in the pressure accumulating portion 17 on the exhaust valve side. In the present embodiment, the valve operating device is composed of the upper valve operating device 13 and the lower valve operating device 14 shown in FIG. As shown in FIG. 1, the upper valve operating device 13 and the lower valve operating device 14 are connected by a hydraulic pipe 15 through which driving oil for opening and closing the exhaust valve 12 is circulated.

As shown in FIG. 1, the upper valve operating device 13 has a driving oil chamber 13a and an urging chamber 13b, and is configured to support the exhaust valve 12 so as to be openable and closable. The driving oil chamber 13a is a space for storing driving oil for opening and closing the exhaust valve 12 by using hydraulic pressure. As shown in FIG. 1, the drive oil chamber 13a and the piston portion 12b of the exhaust valve 12 in the internal space of the upper valve drive device 13 (a space for reciprocating in the longitudinal direction while supporting the exhaust valve 12). It is configured to be a facing space. The urging chamber 13b is a space for forming an urging portion (not shown) such as an air spring that urges the exhaust valve 12 in a direction in which the exhaust port 205 is closed by the valve portion 12a. As shown in FIG. 1, the urging chamber 13b is configured to slidably accommodate a protrusion (a portion that receives the urging force of the urging portion) formed in the middle portion of the exhaust valve 12.

As shown in FIG. 1, the lower valve valve device 14 has a piston 14a, a driving oil chamber 14b, and a hydraulic oil chamber 14c. The piston 14a is provided in the internal space of the lower valve valve device 14 so that it can be reciprocated along its longitudinal direction. For example, the piston 14a is formed so that the diameter of the piston on the driving oil receiving side and the diameter of the piston on the hydraulic oil receiving side are different from each other. The driving oil chamber 14b is a space for storing driving oil. As shown in FIG. 1, the drive oil chamber 14b is configured to be a space facing the end portion of the piston 14a on the drive oil receiving side in the internal space of the lower valve valve device 14. The hydraulic oil chamber 14c is a space for receiving the hydraulic oil for operating the valve operating device (specifically, the upper valve operating device 13 and the lower valve operating device 14). As shown in FIG. 1, the hydraulic oil chamber 14c is configured to be a space facing the end portion of the piston 14a on the hydraulic oil receiving side in the internal space of the lower valve valve device 14.

Further, as shown in FIG. 1, the lower valve operating device 14 is provided with a check valve 14d at the driving oil supply port of the driving oil chamber 14b. When the pressure of the driving oil in the driving oil chamber 14b becomes less than the predetermined reference pressure, the check valve 14d is opened against the pressure of the driving oil, and the check valve 14d moves to the driving oil chamber 14b. Enables the supply of driving oil. On the other hand, when the pressure of the driving oil in the driving oil chamber 14b is equal to or higher than a predetermined reference pressure, the check valve 14d is pressed by the driving oil having a pressure equal to or higher than the reference pressure to be closed, and the check valve 14d is checked from the driving oil chamber 14b. The flow of driving oil (backflow) toward the outside of the valve 14d is prevented, and the supply of the driving oil is disabled.

The hydraulic pipe 15 is a pipe for transmitting and receiving driving oil between the upper valve valve device 13 and the lower valve valve device 14. As shown in FIG. 1, one end of the hydraulic pipe 15 is connected to the upper valve operating device 13 so as to communicate the driving oil chamber 13a of the upper valve operating device 13 and the driving oil chamber 14b of the lower valve operating device 14. And the other end is connected to the lower valve valve device 14. The driving oil is supplied to the driving oil chamber 13a of the upper valve operating device 13 via the check valve 14d, and is delivered to the driving oil chamber 14b of the lower valve operating device 14 through the hydraulic pipe 15. In this way, the entire area from the driving oil chamber 13a of the upper valve operating device 13 to the driving oil chamber 14b of the lower valve operating device 14 through the hydraulic pipe 15 is filled with the driving oil. The drive oil chamber 13a of the upper valve valve device 13 is provided with a small-diameter discharge port (not shown) such as an orifice. The driving oil flows by the supply from the check valve 14d and the discharge from the discharge port. As a result, gas (air bubbles) is removed from the insides of the driving oil chambers 13a and 14b and the hydraulic pipe 15. Further, the hydraulic pipe 15 circulates the driving oil between the driving oil chambers 13a and 14b in response to the pressurization of the driving oil by the piston portion 12b or the piston 14a of the exhaust valve 12.

In the valve operating device having such a configuration, when the control valve 16 is driven so as to communicate the exhaust valve side pressure accumulating portion 17 and the hydraulic oil chamber 14c, the lower valve operating device 14 is driven from the exhaust valve side accumulating portion 17 The hydraulic oil is received in the hydraulic oil chamber 14c via the control valve 16. The lower valve valve device 14 uses the pressure of the received hydraulic oil to operate the piston 14a so as to compress the driving oil chamber 14b. As a result, the lower valve operating device 14 pressurizes the driving oil in the driving oil chamber 14b with the piston 14a, and transmits the pressure of the hydraulic oil from the exhaust valve side accumulator 17 to the driving oil. The driving oil to which the pressure of the hydraulic oil is transmitted is pressure-fed from the driving oil chamber 14b to the driving oil chamber 13a of the upper valve operating device 13 through the hydraulic pipe 15 and presses the piston portion 12b of the exhaust valve 12. The upper valve operating device 13 utilizes the pressure of the driving oil in the driving oil chamber 13a (that is, the pressure of the hydraulic oil transmitted to the driving oil) to resist the pressure in the cylinder 203 of the exhaust valve 12. And lower. As a result, the exhaust valve 12 is driven open to open the exhaust port 205. When the exhaust valve 12 is driven to open, the urging force of the urging chamber 13b acts as a drag force on the exhaust valve 12, but in the present embodiment, this urging force is included in the in-cylinder pressure. The exhaust valve 12 maintains the exhaust port 205 open for a period in which the hydraulic oil from the pressure accumulator portion 17 on the exhaust valve side is supplied to the hydraulic oil chamber 14c of the lower valve valve device 14 via the control valve 16.

On the other hand, in the lower valve operating device 14, the control valve 16 is driven so as to cut off the communication between the exhaust valve side accumulator 17 and the hydraulic oil chamber 14c, and the hydraulic oil from the exhaust valve side accumulator 17 to the hydraulic oil chamber 14c. When the supply of the driving oil is stopped, the pressurization of the driving oil by the piston 14a is stopped. In this case, the control valve 16 is in a state where the hydraulic oil chamber 14c and the recovery pipe 105 are communicated with each other. The upper valve operating device 13 raises the exhaust valve 12 by the urging force of the urging chamber 13b. As a result, the exhaust valve 12 is driven to close and the exhaust port 205 is closed by the valve portion 12a. Along with this, the piston portion 12b of the exhaust valve 12 presses the driving oil in the driving oil chamber 13a. The pressed driving oil is pushed back from the driving oil chamber 13a to the driving oil chamber 14b of the lower valve operating device 14 through the hydraulic pipe 15, and presses the piston 14a of the lower valve operating device 14. As a result, the piston 14a releases the pressurization of the driving oil in the driving oil chamber 14b and presses the hydraulic oil in the hydraulic oil chamber 14c toward the control valve 16. The pressed hydraulic oil is sent from the hydraulic oil chamber 14c to the sump tank 21 through the control valve 16 and the recovery pipe 105. As a result, the piston 14a is returned to its original position before the drive oil chamber 14b is compressed.

The control valve 16 is a valve for controlling the supply of hydraulic oil from the exhaust valve side accumulator portion 17 to the valve operating device (specifically, the lower valve operating device 14). The control valve 16 is composed of an electric on-off valve such as a solenoid valve, and as shown in FIG. 1, can communicate with the lower valve valve device 14 (specifically, the hydraulic oil chamber 14c) and the exhaust valve side pressure accumulator portion 17. It will be provided. The control valve 16 is opened at the timing when the exhaust port 205 is opened (the timing when the exhaust valve 12 is driven to open), and the hydraulic oil in the pressure accumulator portion 17 on the exhaust valve side is discharged into the hydraulic oil chamber 14c of the lower valve valve device 14. Supply to. In this open state, the control valve 16 opens the communication path between the exhaust valve side accumulator portion 17 and the hydraulic oil chamber 14c, and closes the communication path between the hydraulic oil chamber 14c and the recovery pipe 105. On the other hand, the control valve 16 is closed for a period other than the timing when the exhaust port 205 is opened, and the supply of hydraulic oil from the exhaust valve side accumulator 17 to the hydraulic oil chamber 14c of the lower valve operating device 14 is stopped. .. In this closed state, the control valve 16 closes the communication path between the exhaust valve side accumulator portion 17 and the hydraulic oil chamber 14c, and opens the communication path between the hydraulic oil chamber 14c and the recovery pipe 105. The timing of opening / closing drive of such a control valve 16 is controlled by the control unit 28. Further, as shown in FIG. 1, the control valve 16 is communicatively connected to the sump tank 21 via a recovery pipe 105. The control valve 16 receives the hydraulic oil used for operating the lower valve operating device 14 from the hydraulic oil chamber 14c, and sends the received used hydraulic oil to the sump tank 21 through the recovery pipe 105.

The exhaust valve side accumulator 17 stores the pressure of the hydraulic oil used in the valve operating device of the exhaust valve drive system 11 independently of the injection valve side accumulator 7 described above (second accumulator). Is. The exhaust valve side accumulator portion 17 is a hollow structure that forms an accumulator chamber capable of storing hydraulic oil inside, and communicates with the exhaust valve side high pressure pump 25 via a feed pipe 114 as shown in FIG. Can be connected. The exhaust valve side pressure accumulator 17 stores the hydraulic oil discharged (pressurized) from the exhaust valve side high pressure pump 25 through the feed pipe 114 in the internal pressure accumulator chamber, thereby accumulating the pressure of the hydraulic oil. The pressure of the hydraulic oil accumulated in the exhaust valve side accumulator 17 is adjusted by the amount of the hydraulic oil discharged from the exhaust valve side high pressure pump 25 to the exhaust valve side accumulator 17. That is, the pressure of the hydraulic oil in the pressure accumulator portion 17 on the exhaust valve side is independent of the pressure of the hydraulic oil in the pressure accumulator portion 7 on the injection valve side due to the discharge amount of the hydraulic oil from the high pressure pump 24 on the injection valve side as described above. And is adjustable.

On the other hand, when the feed pipe 113 and the feed pipe 114 are in a state of communicating with each other via the communication pipe 115 (that is, when the on-off valve 26 of the communication pipe 115 is in the open state), the exhaust valve side pressure accumulator portion 17 The hydraulic oil pumped from the high pressure pump 24 on the injection valve side is stored through the communication pipe 115 or the like, thereby accumulating the pressure of the hydraulic oil. In this case, the pressure of the hydraulic oil accumulated in the exhaust valve side accumulator 17 is adjusted by the discharge amount of the hydraulic oil from the injection valve side high pressure pump 24, similarly to the injection valve side accumulator 7.

The relief valve 18 is a valve for releasing the excess pressure of the hydraulic oil from the pressure accumulating portion 17 on the exhaust valve side. As shown in FIG. 1, the relief valve 18 is provided in the exhaust valve side accumulator portion 17. The relief valve 18 is opened when the pressure of the hydraulic oil exceeds the pressure required for operating the valve operating device (driving the opening and closing of the exhaust valve 12) and is excessively accumulated in the pressure accumulating portion 17 on the exhaust valve side. The hydraulic oil is discharged from the pressure accumulator 17 on the exhaust valve side by this excess pressure. As a result, it is possible to avoid a situation in which the pressure of the hydraulic oil in the exhaust valve side accumulator 17 exceeds the design upper limit pressure of the exhaust valve side accumulator 17.

The sump tank 21 is a tank for collecting used hydraulic oil. As shown in FIG. 1, the sump tank 21 is communicatively connected to the control valve 4 via the recovery pipe 103, communicatively connected to the control valve 6 via the recovery pipe 104, and is communicatively connected to the control valve 6 via the recovery pipe 105. It is connected to the control valve 16 so as to communicate with each other. The sump tank 21 collects the hydraulic oil used for operating the fuel injection pump 3 from the control valve 4 through the recovery pipe 103, and collects the hydraulic oil used for operating the water injection pump 5 from the control valve 6 through the recovery pipe 104. Collect from. Further, the sump tank 21 collects the hydraulic oil used for operating the valve operating device (specifically, operating the upper valve operating device 13 and the lower valve operating device 14) from the control valve 16 through the recovery pipe 105. On the other hand, the sump tank 21 is communicatively connected to the storage tank 22 via the return pipe 110. The used hydraulic oil collected in the sump tank 21 is sent (returned) from the sump tank 21 to the storage tank 22 through the return pipe 110.

The storage tank 22 is a tank for storing oil used in a ship. Examples of the oil stored in the storage tank (hereinafter referred to as storage oil) include used hydraulic oil, driving oil for opening and closing the exhaust valve 12, lubricating oil for a marine diesel engine, and the like. As shown in FIG. 1, the storage tank 22 is communicatively connected to the filter 23 via a feed pipe 111. For example, of the stored oil in the storage tank 22, the stored oil used as the hydraulic oil is sent to the filter 23 through the feed pipe 111. The stored oil used as the driving oil is supplied to the driving oil chamber 14b of the lower valve valve device 14 through another pipe or the like (not shown).

The filter 23 is for purifying the stored oil delivered from the storage tank 22 to the extent that it can be used as hydraulic oil. As shown in FIG. 1, the inlet side of the filter 23 is configured to be able to communicate with the storage tank 22 via the feed pipe 111. The outlet side of the filter 23 is configured to be able to communicate with the injection valve side high pressure pump 24 and the exhaust valve side high pressure pump 25 via the supply pipe 112. In the present embodiment, the filter 23 filters the stored oil fed from the storage tank 22 through the feed pipe 111 to remove foreign substances in the stored oil. As a result, the filter 23 keeps the stored oil in a clean state so that it does not interfere with the device even if it flows into the device such as the control valves 4, 6, 16. The hydraulic oil thus obtained by the filter 23 is sent from the filter 23 to the injection valve side high pressure pump 24 and the exhaust valve side high pressure pump 25 through the feed pipe 112.

As shown in FIG. 1, the feeding pipe 112 is a pipe that branches into two branch pipes 112a and 112b from one end to the other. One end of the feed pipe 112 is connected to the filter 23. The other end of the feed pipe 112, that is, the outlet end of the branch pipe 112a is connected to the injection valve side high pressure pump 24, and the outlet end of the branch pipe 112b is connected to the exhaust valve side high pressure pump 25. ..

The injection valve side high pressure pump 24 is a pump (first hydraulic oil discharge pump) for adjusting the pressure of the hydraulic oil accumulated in the injection valve side pressure accumulator portion 7. In the present embodiment, the injection valve side high pressure pump 24 is an electric pump, and more specifically, an electric piston pump (for example, an axial piston pump) provided with a swash plate, a piston, and the like. The high-pressure pump 24 on the injection valve side uses the electric power supplied from the generator in the ship as a power source to relatively rotate the swash plate and the piston at a predetermined rotation speed, thereby discharging hydraulic oil. The amount of hydraulic oil discharged by the high-pressure pump 24 on the injection valve side can be controlled by changing the inclination angle of the swash plate. The inclination angle (that is, the discharge amount of hydraulic oil) of the swash plate of the high-pressure pump 24 on the injection valve side is controlled by the control unit 28. Further, as shown in FIG. 1, the pipe of the injection valve side high pressure pump 24 leading to the injection valve side accumulator portion 7, that is, the feed pipe 113, has an inlet end connected to the injection valve side high pressure pump 24 and an outlet end. The portion is connected to the pressure accumulator portion 7 on the injection valve side. The high-pressure pump 24 on the injection valve side discharges (pressure feeds) hydraulic oil to the pressure accumulator portion 7 on the injection valve side through the supply pipe 113, whereby the pressure of the hydraulic oil in the pressure accumulator portion 7 on the injection valve side is adjusted.

The exhaust valve side high pressure pump 25 is a pump (second hydraulic oil discharge pump) for adjusting the pressure of the hydraulic oil accumulated in the exhaust valve side accumulator unit 17. In the present embodiment, the exhaust valve side high pressure pump 25 is a mechanical pump that is driven in conjunction with an output shaft (not shown) of a marine diesel engine, that is, an engine drive pump. Specifically, the exhaust valve side high pressure pump 25 is a piston pump type engine drive pump such as an axial piston pump. Although not particularly shown, the exhaust valve side high-pressure pump 25 is connected to an interlocking mechanism such as a gear interlocking with an output shaft (for example, a crank shaft) of a marine diesel engine. The high-pressure pump 25 on the exhaust valve side rotates the swash plate and the piston relatively in conjunction with the output shaft, thereby discharging hydraulic oil. The amount of hydraulic oil discharged by the high-pressure pump 25 on the exhaust valve side depends on the rotation speed of the output shaft (hereinafter, appropriately referred to as engine rotation speed) and the tilt angle of the swash plate, and by changing the tilt angle of the swash plate. It is controllable. The inclination angle of the swash plate of the exhaust valve side high pressure pump 25 is controlled by the control unit 28. Further, as shown in FIG. 1, the pipe of the exhaust valve side high pressure pump 25 leading to the exhaust valve side accumulator portion 17, that is, the feed pipe 114, has an inlet end connected to the exhaust valve side high pressure pump 25 and an outlet end. The section is connected to the pressure accumulator section 17 on the exhaust valve side. The exhaust valve side high pressure pump 25 discharges (pressure feeds) hydraulic oil to the exhaust valve side accumulator 17 through the feed pipe 114, thereby adjusting the pressure of the hydraulic oil in the exhaust valve side accumulator 17.

Further, as shown in FIG. 1, a feed pipe 113 communicating from the injection valve side high pressure pump 24 to the injection valve side accumulator 7 and a supply pipe 114 communicating from the exhaust valve side high pressure pump 25 to the exhaust valve side accumulator 17. A communication pipe 115 is provided between them. The communication pipe 115 is a pipe that connects the feed pipe 113 and the feed pipe 114 so as to be able to communicate with each other. Specifically, in the communication pipe 115, the inlet end portion is connected to the middle portion of the feed pipe 113 and the outlet end portion is connected to the feed pipe 114. Further, an on-off valve 26 and a check valve 27 are provided in the middle of the communication pipe 115. The on-off valve 26 drives an on-off drive to open or close the communication pipe 115. The opening / closing drive of the on-off valve 26 is controlled by the control unit 28. The check valve 27 sets the flow direction of the hydraulic oil in the communication pipe 115 from the pipe (feed pipe 113) side of the injection valve side high pressure pump 24 to the pipe (feed pipe 114) side of the exhaust valve side high pressure pump 25. Regulate in one direction towards.

The control unit 28 controls the operation of the fuel injection system 1, the operation of the exhaust valve drive system 11, and the opening / closing drive of the on-off valve 26 of the communication pipe 115. Specifically, the control unit 28 is composed of a CPU, a memory, a sequencer, and the like for executing various programs. The control unit 28 controls the pressure of the hydraulic oil that operates the fuel injection pump 3 and the water injection pump 5 and the operation timing of each of the fuel injection pump 3 and the water injection pump 5 for the fuel injection system 1. Further, the control unit 28 operates the pressure of the hydraulic oil for operating the valve valve device (in this embodiment, the upper valve valve device 13 and the lower valve valve device 14) for opening and closing the exhaust valve 12 in the exhaust valve drive system 11. And the operation timing of this valve operating device are controlled. Further, the control unit 28 controls each timing of the open state and the closed state of the communication pipe 115, that is, the open drive timing and the closed drive timing of the on-off valve 26 according to the operating condition of the marine diesel engine.

Specifically, the on-off valve 26 is closed during the period during which the marine diesel engine is in fuel operation (hereinafter, appropriately referred to as the fuel operation period), and the communication pipe 115 is closed by the on-off valve 26. That is, the communication pipe 115 communicates the feed pipe 113 that leads from the injection valve side high pressure pump 24 to the injection valve side accumulator 7 and the feed pipe 114 that leads from the exhaust valve side high pressure pump 25 to the exhaust valve side accumulator 17. It is in a state of not letting it. In the fuel operation of a marine diesel engine, the fuel injected into the combustion chamber 204 of the cylinder 203 is burned together with the combustion gas, so that the output shaft is rotationally moved along with the reciprocating motion of the piston to output the propulsive force of the ship. It is driving (self-sustaining driving).

During the fuel operation period, the control unit 28 controls the discharge amount of the hydraulic oil by the high pressure pump 24 on the injection valve side, and controls the pressure of the hydraulic oil in the pressure accumulator unit 7 on the injection valve side through the control of this discharge amount. At this time, the control unit 28 acquires the engine load required for the marine diesel engine from the operation unit or the like (not shown) according to the navigation status of the ship, or the engine speed is based on the acquired engine load. Derive the number. Further, a first data table showing the correlation between the engine load or the engine speed and the pressure of the hydraulic oil suitable for fuel injection is input to the control unit 28, and the engine load or the engine speed is set. Appropriate hydraulic oil pressure is preset accordingly. The above-mentioned "pressure of hydraulic oil suitable for fuel injection" is, for example, the fuel injection pump 3 for injecting a required amount of fuel from the fuel injection valve 2 according to the engine load or the engine rotation speed. It is the pressure of the hydraulic oil required for. The control unit 28 derives the pressure of the hydraulic oil suitable for fuel injection according to the engine load or the engine speed. The control unit 28 controls the inclination angle of the swash plate of the injection valve side high pressure pump 24 so that the pressure of the derived hydraulic oil is accumulated in the injection valve side pressure storage unit 7, and through this control, the injection valve side high pressure pump 24 Controls the amount of hydraulic oil discharged from the pressure accumulator 7 on the injection valve side. In the present embodiment, the high-pressure pump 24 on the injection valve side is started at a predetermined rotation speed by using electric power after being started based on an instruction from the control unit 28. The control unit 28 controls the amount of hydraulic oil discharged from the injection valve side high pressure pump 24 to the injection valve side pressure accumulator 7 by changing the inclination angle of the swash plate of the injection valve side high pressure pump 24. do.

The control unit 28 operates by using the pressure of the hydraulic oil by controlling the pressure of the hydraulic oil in the pressure accumulating unit 7 on the injection valve side through the control of the discharge amount of the hydraulic oil by the high pressure pump 24 on the injection valve side in this way. The fuel injection pressure from the fuel injection pump 3 can be increased to a pressure suitable for improving fuel efficiency as the engine load increases. In addition to this, the control unit 28 independently controls the pressure of the hydraulic oil when the fuel injection pressure is increased in this way without being restricted by the upper limit due to the pressure of the hydraulic oil of the exhaust valve drive system 11. be able to. In the present embodiment, the pressure of the hydraulic oil in the pressure accumulating portion 7 on the injection valve side controlled as described above is used for the operation of the fuel injection pump 3 and the operation of the water injection pump 5.

Further, during the fuel operation period, the control unit 28 controls the discharge amount of the hydraulic oil by the exhaust valve side high pressure pump 25, and controls the pressure of the hydraulic oil in the exhaust valve side pressure accumulator unit 17 through the control of this discharge amount. At this time, the control unit 28 acquires the engine load as described above, or derives the engine speed based on the acquired engine load. Further, a second data table showing the correlation between the engine load or the engine speed and the pressure of the hydraulic oil suitable for opening the exhaust valve 12 is input to the control unit 28, and the engine load or the engine is input. The appropriate hydraulic oil pressure is preset according to the number of revolutions. The above-mentioned "pressure of hydraulic oil suitable for open driving of the exhaust valve 12" means, for example, in order to cause the exhaust valve 12 to open drive the driving force required according to the engine load or the engine speed. It is the pressure of the hydraulic oil required for the valve train. The control unit 28 derives the pressure of the hydraulic oil suitable for opening the exhaust valve 12 according to the engine load or the engine speed. The control unit 28 controls the inclination angle of the swash plate of the exhaust valve side high pressure pump 25 so that the pressure of the derived hydraulic oil is accumulated in the exhaust valve side pressure storage unit 17, and through this control, the exhaust valve side high pressure pump 25 Controls the amount of hydraulic oil discharged from the exhaust valve side pressure accumulator portion 17. In the present embodiment, the exhaust valve side high pressure pump 25 is driven in conjunction with the output shaft of the marine diesel engine. Such an exhaust valve side high pressure pump 25 increases or decreases the amount of hydraulic oil discharged as the engine speed increases or decreases. When the pressure of the hydraulic oil in the exhaust valve side accumulator 17 is insufficient for the operation of the valve operating device in the discharge amount of the hydraulic oil according to the engine rotation speed, the control unit 28 compensates for the shortage of the pressure. The inclination angle of the slant plate of the exhaust valve side high pressure pump 25 is changed so as to control the amount of hydraulic oil discharged from the exhaust valve side high pressure pump 25 to the exhaust valve side pressure accumulator portion 17.

The control unit 28 operates by using the pressure of the hydraulic oil by controlling the pressure of the hydraulic oil in the pressure accumulator unit 17 on the exhaust valve side through the control of the discharge amount of the hydraulic oil by the high pressure pump 25 on the exhaust valve side in this way. The opening driving force of the exhaust valve 12 by the upper valve operating device 13 and the lower valve operating device 14 can be minimized within the range in which the exhaust valve 12 can be opened and driven without any trouble against the in-cylinder pressure. In addition to this, the control unit 28 makes the pressure of the hydraulic oil when the open driving force of the exhaust valve 12 is minimized in this way independent without being affected by the pressure increase of the hydraulic oil of the fuel injection system 1. Can be controlled.

On the other hand, in a period other than the fuel operation period, the marine diesel engine operates in a state where the engine speed is lower than that during the fuel operation, such as at the time of starting. In this situation, since the exhaust valve side high pressure pump 25 is an engine drive pump as described above, in many cases, it becomes difficult to sufficiently supply hydraulic oil to the exhaust valve side accumulator unit 17. Therefore, the control unit 28 opens and closes the on-off valve 26 of the communication pipe 115 so that the hydraulic oil discharged by the high-pressure pump 24 on the injection valve side is supplied to the pressure accumulator unit 7 on the injection valve side and the pressure accumulator unit 17 on the exhaust valve side. Control the drive. The control unit 28 controls the discharge amount of the hydraulic oil by the high pressure pump 24 on the injection valve side, and through the control of this discharge amount, the pressure of the hydraulic oil in the pressure accumulator unit 7 on the injection valve side and the operation in the pressure accumulator unit 17 on the exhaust valve side. Control the pressure of the oil.

Specifically, the control unit 28 determines whether or not the marine diesel engine has started fuel operation based on the fuel injection amount (fuel input amount) by the fuel injection system 1 into the combustion chamber 204 and the engine rotation speed. to decide. When the fuel injection amount is less than the predetermined reference injection amount and the engine rotation speed is less than the predetermined reference rotation speed, the control unit 28 determines that the marine diesel engine has not started the fuel operation. During the period when the marine diesel engine has not started fuel operation, that is, during a predetermined period from the time before the start of the marine diesel engine (including the start time) to the start time of fuel operation, the control unit 28 has a high pressure on the injection valve side. The hydraulic oil discharged by the pump 24 can be circulated from the pipe (feed pipe 113) of the injection valve side high pressure pump 24 to the pipe (feed pipe 114) of the exhaust valve side high pressure pump 25 through the communication pipe 115. The on-off valve 26 is controlled to be in the open state.

By the open drive control of the on-off valve 26 by the control unit 28, the communication pipe 115 is opened by the on-off valve 26 so that the feed pipe 113 and the feed pipe 114 are communicated with each other. That is, the hydraulic oil discharged by the high-pressure pump 24 on the injection valve side is supplied to the pressure accumulator portion 7 on the injection valve side through the feed pipe 113, and is supplied to the pressure accumulator portion 17 on the exhaust valve side through the communication pipe 115, the feed pipe 114, and the like. Be supplied. The control unit 28 controls the amount of hydraulic oil discharged from the injection valve side high-pressure pump 24 to the injection valve side pressure accumulator 7, and controls the pressure of the hydraulic oil in the injection valve side pressure accumulator 7 through the control of this discharge amount. .. In parallel with this, the control unit 28 controls the amount of hydraulic oil discharged from the injection valve side high pressure pump 24 to the exhaust valve side pressure accumulator unit 17, and through the control of this discharge amount, the operation in the exhaust valve side pressure accumulator unit 17 is performed. Control the pressure of the oil. In this way, the control unit 28 controls the pressure of the hydraulic oil in the pressure accumulator unit 7 on the injection valve side and the pressure of the hydraulic oil in the pressure accumulator unit 17 on the exhaust valve side to substantially the same pressure.

Since the engine load is low during the above predetermined period, the fuel injection pressure by the fuel injection pump 3 is allowed to be low according to the engine load. Therefore, since the pressure of the hydraulic oil required for the injection valve side accumulator 7 becomes low, the pressure of the hydraulic oil in the exhaust valve side accumulator 17 can be set to the same pressure as the injection valve side accumulator 7 as described above. The open driving force of the exhaust valve 12 is unlikely to be excessively large compared to the in-cylinder pressure.

On the other hand, when the fuel injection amount is equal to or higher than the predetermined reference injection amount and the engine rotation speed is equal to or higher than the predetermined reference rotation speed, the control unit 28 determines that the marine diesel engine has started fuel operation. The period after the marine diesel engine starts fuel operation, that is, the fuel operation period of the marine diesel engine (a period other than the above-mentioned predetermined period), the control unit 28 is the pipe (feed pipe 113) of the injection valve side high pressure pump 24. ) To the pipe (feed pipe 114) of the high pressure pump 25 on the exhaust valve side through the communication pipe 115, the on-off valve 26 is controlled to be closed.

Due to the closing drive control of the on-off valve 26 by the control unit 28, the communication pipe 115 is closed by the on-off valve 26 so that the feed pipe 113 and the feed pipe 114 are not communicated with each other. That is, the hydraulic oil discharged by the injection valve side high pressure pump 24 does not flow from the communication pipe 115 to the exhaust valve side pressure accumulator portion 17, but is supplied to the injection valve side pressure accumulator portion 7 through the feed pipe 113. In parallel with this, the hydraulic oil discharged by the exhaust valve side high pressure pump 25 is supplied to the exhaust valve side accumulator portion 17 through the supply pipe 114. In this state, the control unit 28 controls the discharge amount of the hydraulic oil by the injection valve side high pressure pump 24 and the control of the hydraulic oil discharge amount by the exhaust valve side high pressure pump 25, as in the case of the fuel operation period described above. And do. As a result, the control unit 28 independently controls the pressure of the hydraulic oil in the pressure accumulator unit 7 on the injection valve side and the pressure of the hydraulic oil in the pressure accumulator unit 17 on the exhaust valve side.

On the other hand, during the period from the start to the stop of the marine diesel engine (including the fuel operation period), the control unit 28 controls the operation timings of the fuel injection pump 3 and the water injection pump 5 and the operation of the lower valve valve device 14. The timing (that is, the opening / closing drive timing of the exhaust valve 12 by the upper valve operating device 13) is controlled.

The control unit 28 controls the opening / closing drive of the control valve 6, and controls the operation timing of the water injection pump 5 through the control of the opening / closing drive. Specifically, in the period before the fuel is injected from the fuel injection valve 2, the control unit 28 supplies the hydraulic oil for operating the water injection pump 5 from the pressure accumulating unit 7 on the injection valve side to the hydraulic oil chamber 5c of the water injection pump 5. The control valve 6 is driven to open so as to be operated. As a result, the water injection pump 5 starts operation using the pressure of the hydraulic oil, and injects water into the fuel flow path (that is, in the fuel satisfying the flow path) through the water injection pipe 102 as described above. After that, the control unit 28 closes and drives the control valve 6, thereby stopping the supply of hydraulic oil from the pressure accumulator unit 7 on the injection valve side to the hydraulic oil chamber 5c of the water injection pump 5.

The water injection pump 5 continuously injects water into the fuel distribution path during the period from the opening drive to the closed drive of the control valve 6. Thereby, this water injection amount is adjusted to the water injection amount required to reduce the emission amount of nitrogen oxides (NOx) due to the combustion of the fuel. The control unit 28 sets such a water injection amount in advance according to the engine load, and controls the opening / closing drive of the control valve 6 so that the set water injection amount of water is injected into the fuel distribution path. .. At this time, the control unit 28 determines the open drive timing and the closed drive timing of the control valve 6 based on, for example, the crank angle of the marine diesel engine (the rotation angle of the crank with respect to a predetermined reference axis).

Further, the control unit 28 controls the opening / closing drive of the control valve 4, and controls the operation timing of the fuel injection pump 3 through the control of the opening / closing drive. Specifically, during the fuel injection period, the control unit 28 controls the control valve 4 so that the hydraulic oil for operating the fuel injection pump 3 is supplied from the pressure accumulator 7 on the injection valve side to the hydraulic oil chamber 3c of the fuel injection pump 3. Is driven to open. As a result, the fuel injection pump 3 starts operation using the pressure of the hydraulic oil, and as described above, the fuel is pressure-fed to the fuel injection valve 2 through the fuel injection pipe 101 to inject it. At this time, if water has been injected in advance into the fuel flow path, the fuel and water are injected in layers from the fuel injection valve 2. After that, the control unit 28 closes and drives the control valve 4, thereby stopping the supply of hydraulic oil from the pressure accumulator unit 7 on the injection valve side to the hydraulic oil chamber 3c of the fuel injection pump 3.

The fuel injection pump 3 continuously pumps the fuel injected from the fuel injection valve 2 during the period from the opening drive to the closed drive of the control valve 4. The control unit 28 determines, for example, the open drive timing and the closed drive timing of the control valve 4 based on the crank angle of the marine diesel engine. That is, the rotation period of the crank from the crank angle corresponding to the open drive timing of the control valve 4 to the crank angle corresponding to the closed drive timing corresponds to the fuel injection period in the present embodiment. The fuel injection amount from the fuel injection valve 2 is determined by the length of the fuel injection period and the fuel injection pressure. As described above, the control unit 28 controls the pressure of the hydraulic oil so that the fuel injection pressure increases according to the increase in the engine load, and through this control, the fuel injection amount increases according to the engine load. Control. As a result, the fuel injection amount is adjusted to an amount suitable for improving fuel efficiency. The control unit 28 controls the opening / closing drive of the control valve 4 so that the fuel of such a fuel injection amount is injected from the fuel injection valve 2.

Further, the control unit 28 controls the opening / closing drive of the control valve 16, and drives the exhaust valve 12 with the operation timing of the lower valve valve device 14, that is, the operation of the lower valve valve device 14 through the control of the opening / closing drive. The opening / closing drive timing of the exhaust valve 12 is controlled by the upper valve operating device 13 to be operated. Specifically, during the scavenging period of the cylinder 203, the control unit 28 causes the hydraulic oil for operating the lower valve valve device 14 to be supplied from the exhaust valve side pressure accumulator unit 17 to the hydraulic oil chamber 14c of the lower valve valve device 14. , The control valve 16 is driven to open. As a result, the lower valve operating device 14 starts operation using the pressure of the hydraulic oil, and as described above, the driving oil (driving oil to which the pressure of the hydraulic oil is transmitted) is transferred to the upper valve operating device through the hydraulic pipe 15. It is pumped to the driving oil chamber 13a of 13. The upper valve operating device 13 utilizes the pressure of the driven oil that has been pumped (that is, the pressure of the hydraulic oil that has been transmitted) to cause the exhaust valve 12 to perform an open drive for opening the exhaust port 205. After that, the control unit 28 closes and drives the control valve 16, thereby stopping the supply of hydraulic oil from the exhaust valve side accumulator unit 17 to the hydraulic oil chamber 14c of the lower valve valve device 14.

The lower valve valve device 14 continuously pumps the driving oil to the upper valve valve device 13 during the period from the opening drive to the closed drive of the control valve 16. Along with this, the upper valve operating device 13 continues to press the exhaust valve 12 by utilizing the pressure of the pressure-fed driving oil, and keeps the exhaust valve 12 in an open state (a state in which the exhaust port 205 is open). The control unit 28 determines, for example, the open drive timing and the closed drive timing of the control valve 16 based on the crank angle of the marine diesel engine. That is, the rotation period of the crank from the crank angle corresponding to the open drive timing of the control valve 16 to the crank angle corresponding to the closed drive timing corresponds to the scavenging period of the cylinder 203 in the present embodiment. The scavenging period is a period during which the piston (not shown) reciprocates once in the cylinder 203, and the scavenging is performed in the cylinder 203. The control unit 28 opens the control valve 16 at the timing when the scavenging period starts and closes the control valve 16 at the timing when the scavenging period ends each time the piston reciprocates in the cylinder 203. In this way, the control unit 28 drives the control valve 16 to open / close so that the exhaust valve 12 opens the exhaust port 205 during the scavenging period and the exhaust valve 12 closes the exhaust port 205 during the period other than the scavenging period. Control.

FIG. 2 is a schematic diagram showing a configuration example of a marine diesel engine to which the hydraulic drive device according to the embodiment of the present invention is applied. FIG. 2 shows the fuel injection valve 2, the fuel injection pump 3, the water injection pump 5, the injection valve side pressure accumulator 7, the upper valve drive device 13, and the lower drive of the hydraulic drive device 100 (see FIG. 1) in the marine diesel engine 200. The arrangement of the valve device 14, the exhaust valve side accumulator portion 17, the injection valve side high pressure pump 24, and the exhaust valve side high pressure pump 25 is shown.

The marine diesel engine 200 is a propulsion engine (main engine) for a ship, and specifically, is a two-stroke diesel engine such as a uniflow sweep-exhaust type crosshead diesel engine. As shown in FIG. 2, the marine diesel engine 200 includes a base plate 201 located on the lower side in the height direction, a frame 202 provided on the upper part of the base plate 201, and a plurality of frames provided on the upper part of the frame 202 (this implementation). In the form, the cylinder 203 and the exhaust manifold 211 of 6) are provided. The base plate 201, the frame 202, and the plurality of cylinders 203 are integrally fastened and fixed by connecting members such as a plurality of tie bolts (not shown) and nuts (not shown) extending in the height direction. Has been done.

In the present embodiment, the portion where the base plate 201 is provided is the lower stage of the marine diesel engine 200. The part where the frame 202 is provided is the middle stage of the marine diesel engine 200. The portion where the plurality of cylinders 203 and the exhaust manifold 211 are provided is the upper stage of the marine diesel engine 200.

The base plate 201 constitutes a crankcase. As shown in FIG. 2, the base plate 201 is provided with an output shaft 210 for driving and rotating a propeller for propulsion of a ship. For example, the output shaft 210 is composed of a propeller shaft, a crank shaft, or the like. The crank shaft is rotatably supported by bearings. A lower end of a connecting rod (not shown) is rotatably connected to the crank shaft via a crank.

The frame 202 is provided with the above-mentioned connecting rod, a piston rod (not shown), and a crosshead (not shown) that rotatably connects the piston rod and the connecting rod. Specifically, the lower end of the piston rod and the upper end of the connecting rod are connected to the crosshead. The crosshead is arranged between a pair of guide plates (not shown) fixed to the frame 202, and is slidably supported along the pair of guide plates.

Each of the plurality of cylinders 203 is composed of a cylinder jacket, a cylinder liner, a cylinder cover, and the like. Although not particularly shown, the cylinder liner is provided so as to extend from the inside to the upper part of the cylinder jacket. A cylinder cover is provided at the upper end of the cylinder liner. Inside each of these plurality of cylinders 203, the combustion chamber 204 and the exhaust port 205 shown in FIG. 1 are configured, and a piston (not shown) is provided reciprocally along the inner wall of the cylinder. There is. The upper end of the piston rod described above is attached to the lower end of the piston.

As shown in FIG. 2, the exhaust manifold 211 is provided in the vicinity of the plurality of cylinders 203, and each combustion chamber 204 (see FIG. 1) is provided via each exhaust port 205 (see FIG. 1), piping, or the like of the plurality of cylinders 203. It is connected so that it can be communicated with. The exhaust manifold 211 receives the exhaust gas generated by the combustion of the fuel from each combustion chamber 204 of the plurality of cylinders 203 and temporarily stores the exhaust gas, whereby the dynamic pressure of the exhaust gas is changed to the static pressure.

Further, as shown in FIG. 2, in the upper stage of the marine diesel engine 200, a fuel injection valve 2, a fuel injection pump 3, a water injection pump 5, and an upper valve valve device 13 are each in the same number as a plurality of cylinders 203 (this implementation). In the form, 6 each) are provided. Further, in the upper stage of the marine diesel engine 200, an injection valve side accumulator 7 shared by a plurality of fuel injection pumps 3 and a water injection pump 5, and an injection valve side for supplying hydraulic oil to the injection valve side accumulator 7. A high pressure pump 24 is provided.

The plurality of fuel injection valves 2 are arranged in each of the plurality of cylinders 203 in such a manner that the injection port is directed to the combustion chamber 204 shown in FIG. The plurality of fuel injection pumps 3 and the water injection pump 5 are arranged on the pressure accumulator 7 on the injection valve side so that the set of the fuel injection pump 3 and the water injection pump 5 paired with each cylinder 203 is arranged in the longitudinal direction of the output shaft 210. Has been done. The pressure accumulator portion 7 on the injection valve side and the high pressure pump 24 on the injection valve side are arranged in the vicinity of the plurality of cylinders 203 as shown in FIG. The plurality of upper valve actuating devices 13 are respectively arranged on the upper portions of the plurality of cylinders 203 in such a manner that the exhaust valve 12 shown in FIG. 1 closes and closes the exhaust port 205 so as to be openable and closable. In this way, while supporting the fuel injection system 1 (see FIG. 1) related to the injection of fuel and water to the cylinder 203, the high pressure pump 24 on the injection valve side, and the exhaust valve 12 among the valve operation devices of the exhaust valve 12. The upper valve valve device 13 for opening / closing drive is centrally arranged at a position near the cylinder 203, that is, at the upper stage of the marine diesel engine 200.

Further, although not shown in FIG. 2, the plurality of fuel injection valves 2 are connected to the plurality of fuel injection pumps 3 via the fuel injection pipe 101 (see FIG. 1) so as to communicate with each other, and the water injection pipe 102 (FIG. 1). (See), each of which is communicatively connected to a plurality of water injection pumps 5. Each of the plurality of fuel injection pumps 3 is connected to the injection valve side pressure accumulator 7 via a control valve 4 (see FIG. 1) so as to communicate with each other. Each of the plurality of water injection pumps 5 is connected to the injection valve side accumulator 7 via a control valve 6 (see FIG. 1) so as to communicate with each other. The pressure accumulator portion 7 on the injection valve side is connected to the high pressure pump 24 on the injection valve side so as to be able to communicate with each other via the supply pipe 113 (see FIG. 1).

On the other hand, as shown in FIG. 2, a plurality of (six in this embodiment) lower valve valves 14 are provided in the middle stage of the marine diesel engine 200 in the same number corresponding to the plurality of cylinders 203 described above. There is. Further, in the middle stage of the marine diesel engine 200, an exhaust valve side pressure accumulator portion 17 shared by a plurality of lower valve valves 14 is provided. Further, an exhaust valve side high pressure pump 25 for supplying hydraulic oil to the exhaust valve side pressure accumulator portion 17 is provided in a portion extending from the middle stage to the lower stage of the marine diesel engine 200.

The plurality of lower valve actuating devices 14 are arranged on the exhaust valve side pressure accumulating portion 17 so as to correspond to the plurality of cylinders 203 and be arranged in the longitudinal direction of the output shaft 210. Since the exhaust valve side high-pressure pump 25 is an engine-linked pump that is driven in conjunction with the output shaft 210 of the marine diesel engine 200, it outputs so that it can be easily connected to the output shaft 210 via an interlocking mechanism such as a gear. It is arranged in the vicinity of the shaft 210 (preferably between the output shaft 210 and the exhaust valve side accumulator 17). The exhaust valve side accumulator portion 17 is arranged in the vicinity of the exhaust valve side high pressure pump 25. In this way, the exhaust valve side high pressure pump 25 interlocked with the output shaft 210 of the marine diesel engine 200, the plurality of lower valve operating devices 14 receiving the hydraulic oil from the exhaust valve side high pressure pump 25, and the exhaust valve side pressure accumulator. The 17 is centrally arranged at a position not excessively separated from both the output shaft 210 and the cylinder 203, that is, in the middle stage of the marine diesel engine 200 or in the vicinity thereof.

Further, although not shown in FIG. 2, the plurality of lower valve valves 14 are connected to the plurality of upper valve devices 13 via hydraulic pipes 15 (see FIG. 1) so as to be able to communicate with each other. The exhaust valve side accumulator portion 17 is connected to each of the plurality of lower valve actuating devices 14 so as to be able to communicate with each other via the control valve 16 (see FIG. 1). The exhaust valve side high pressure pump 25 is connected to the exhaust valve side pressure accumulator portion 17 so as to be able to communicate with each other via a feed pipe 114 (see FIG. 1). Further, in the portion extending from the upper stage to the middle stage of the marine diesel engine 200, the pipe (feed pipe 113) of the injection valve side high pressure pump 24 and the pipe (feed pipe 114) of the exhaust valve side high pressure pump 25 are opened and closed. A communication pipe 115 and an on-off valve 26 (both of which see FIG. 1) are arranged for possible communication.

As described above, in the hydraulic drive device 100 according to the embodiment of the present invention, the pressure accumulator 7 on the injection valve side for accumulating the pressure of the hydraulic oil in the fuel injection system 1 and the pressure accumulator 7 on the injection valve side are operated through the pipes. The pressure of the hydraulic oil in the exhaust valve drive system 11 independently of the injection valve side high pressure pump 24 that adjusts the pressure of the hydraulic oil in the injection valve side accumulator 7 by discharging the oil and the injection valve side accumulator 7. The exhaust valve side pressure accumulator 17 for accumulating fuel, and the exhaust valve side high pressure pump 25 for adjusting the pressure of the hydraulic oil in the exhaust valve side accumulator 17 by discharging the hydraulic oil to the exhaust valve side accumulator 17 through a pipe. In the fuel injection system 1, the fuel injection pump 3 pumps fuel to the fuel injection valve 2 using the pressure of the hydraulic oil accumulated in the pressure accumulator portion 7 on the injection valve side, and the fuel injection valve 2 is used. The pumped fuel is injected into the combustion chamber 204 of the cylinder 203 of the marine diesel engine, and in the exhaust valve drive system 11, the valve operating device (upper valve operating device 13 and lower valve operating device 14) exhausts the cylinder 203. The exhaust valve 12 that closes and closes the port 205 so as to be openable and closable is driven to open and close by utilizing the pressure of the hydraulic oil accumulated in the pressure accumulator portion 17 on the exhaust valve side.

With the above configuration, the pressure of the hydraulic oil in the pressure accumulator portion 7 on the injection valve side and the pressure of the hydraulic oil in the pressure accumulator portion 17 on the exhaust valve side can be independently adjusted without being affected by each other. That is, the pressure of the hydraulic oil in the pressure accumulator portion 7 on the injection valve side is adjusted so that the fuel injection pressure increases or decreases according to the engine load. The pressure of the hydraulic oil in the pressure accumulator portion 17 on the exhaust valve side is adjusted so that the opening driving force of the exhaust valve 12 increases or decreases according to the pressure inside the cylinder. The in-cylinder pressure does not always increase with an increase in the engine load (increase in the engine speed), and may reach the maximum pressure when the engine load is less than 100%. According to the hydraulic drive device 100 having the above configuration, the pressure of the hydraulic oil in the pressure accumulator portion 7 on the injection valve side can be adjusted to the pressure of the hydraulic oil in the pressure accumulator portion 17 on the exhaust valve side, which is restricted by the in-cylinder pressure. It can be increased or decreased according to the engine load without being affected. As a result, the fuel injection pump 3 can be operated so that the fuel injection pressure increases to a desired pressure as the engine load increases. As a result, the combustion efficiency of the fuel is improved as the fuel injection pressure is increased, so that the fuel efficiency of the marine diesel engine can be improved.

In addition to this, the pressure of the hydraulic oil in the exhaust valve side accumulator 17 is not affected by the pressure adjustment (particularly pressure increase) of the hydraulic oil in the injection valve side accumulator 7 according to the engine load. It can be increased or decreased according to the pressure. As a result, the valve operating device can be operated so that the opening driving force of the exhaust valve 12 is minimized in a range exceeding the in-cylinder pressure. As a result, problems caused by the unstable open drive of the exhaust valve 12 described above (for example, vibration of the exhaust valve 12 and the hydraulic pipe 15 due to excessive collision between the exhaust valve 12 and the upper valve drive device 13, and the lower valve drive device 14). A marine diesel engine used in the hydraulic drive device 100 (particularly the high pressure pump 25 on the exhaust valve side) to prevent malfunction of the check valve 14d) and to generate the pressure of the hydraulic oil required for the valve drive device. It is possible to improve the driving efficiency of the exhaust valve 12 by reducing the power (power generated by the rotational movement of the output shaft 210) or the power supplied from the in-ship equipment such as the power generation equipment.

Further, according to the hydraulic drive device 100 having the above configuration, the injection valve side accumulator unit 7 and the exhaust valve side accumulator unit 17 can be configured as separate bodies from each other. Therefore, the injection valve side accumulator portion 7 and the exhaust valve side accumulator portion 17 can be arranged at suitable portions of the marine diesel engine, respectively. For example, the exhaust valve side accumulator portion 17 can be arranged in the vicinity of the exhaust valve side high pressure pump 25, whereby the pipe (feed pipe 114) leading from the exhaust valve side high pressure pump 25 to the exhaust valve side accumulator portion 17 can be provided. It can be easily configured short. Similarly, the injection valve side pressure accumulator 7 can be arranged in the vicinity of the injection valve side high pressure pump 24, whereby the pipe (feed pipe) leading from the injection valve side high pressure pump 24 to the injection valve side pressure accumulator 7. 113) can be easily configured to be short. Further, the pressure accumulator portion 7 on the injection valve side and the fuel injection pump 3 that receives hydraulic oil from the pressure accumulator portion 7 on the injection valve side can be centrally arranged in the vicinity of the cylinder 203 in which the fuel injection valve 2 is provided. Therefore, the pipe (fuel injection pipe 101) leading from the fuel injection pump 3 to the fuel injection valve 2 can be easily configured to be short. As a result, it is possible to reduce the pressure loss (loss of fuel injection pressure) when the fuel pumped from the fuel injection pump 3 flows through the fuel injection pipe 101.

Further, in the hydraulic drive device 100 according to the embodiment of the present invention, the pipe (feed pipe 113) of the injection valve side high pressure pump 24 leading to the injection valve side accumulator 7 and the exhaust valve side communicating with the exhaust valve side accumulator 17 An operation pipe 115 for connecting the pipe (feed pipe 114) of the high-pressure pump 25 so as to be communicable, and an on-off valve 26 for opening or closing the communication pipe 115 are provided, and the operation is discharged by the high-pressure pump 24 on the injection valve side. The on-off valve 26 is provided by the control unit 28 for a predetermined period so that oil can be circulated from the feed pipe 113 on the injection valve side high pressure pump 24 side to the feed pipe 114 on the exhaust valve side high pressure pump 25 side through the communication pipe 115. Is controlled to be in the open state, and the hydraulic oil flows from the feed pipe 113 on the injection valve side high pressure pump 24 side to the feed pipe 114 on the exhaust valve side high pressure pump 25 side through the communication pipe 115 for a period other than this predetermined period. The on-off valve 26 is controlled to be in the closed state by the control unit 28 so as to stop the operation.

Therefore, the valve operating device needs to discharge the hydraulic oil from the high-pressure pump 25 on the exhaust valve side during a period when the engine speed is lower than that during fuel operation, such as before the marine diesel engine is started or before fuel operation is started. When the pressure of the hydraulic oil is insufficient to be accumulated in the pressure accumulator portion 17 on the exhaust valve side, the shortage of the discharge amount of the hydraulic oil can be compensated by the hydraulic oil from the high pressure pump 24 on the injection valve side. As a result, even during the period when the marine diesel engine is starting or preparing for fuel operation, the pressure of the hydraulic oil sufficient to open and close the exhaust valve 12 can be applied to the valve drive device, and as a result, from the cylinder 203. Since the exhaust gas can be ensured, the marine diesel engine can be operated safely. Further, since the injection valve side high-pressure pump 24 can bear the compensation for the shortage of the hydraulic oil, which has been conventionally performed by the auxiliary pump (electric pump), it is not necessary to provide the conventional auxiliary pump. As a result, the device configuration of the marine diesel engine hydraulic drive system can be simplified, and the manufacturing cost of the marine diesel engine can be reduced.

Further, in the hydraulic drive device 100 according to the embodiment of the present invention, a water injection pump 5 for injecting water into the fuel flow path by utilizing the pressure of the hydraulic oil accumulated in the pressure accumulator portion 7 on the injection valve side is provided. The fuel injection valve 2 injects the fuel pumped by the fuel injection pump 3 and the water injected by the water injection pump 5 into the combustion chamber 204 of the cylinder 203. Therefore, when the pressure of the hydraulic oil of the fuel injection pump 3 is increased to increase the fuel injection pressure, the NOx content (NOx emission amount), which is conventionally increased in the exhaust gas from the cylinder 203, is set as the fuel. It is possible to reduce the decrease in combustion efficiency while suppressing the decrease in combustion efficiency. As a result, it is possible to achieve both improvement in fuel efficiency of a marine diesel engine and reduction in NOx emissions.

Further, since the injection valve side accumulator 7 and the exhaust valve side accumulator 17 are separated as described above, the lower valve valve device 14 that receives hydraulic oil from the exhaust valve side accumulator 17 and the injection valve side accumulator The fuel injection pump 3 and the water injection pump 5 that receive the hydraulic oil from 7 can be separately arranged in the marine diesel engine. As a result, a space for arranging the fuel injection pump 3 and the water injection pump 5 can be secured in the vicinity of the cylinder 203, and the fuel injection pump 3 and the water injection pump 5 can be centrally arranged for each cylinder 203.

Further, in the hydraulic drive device 100 according to the embodiment of the present invention, the injection valve side high pressure pump 24 is used as an electric pump, and the exhaust valve side high pressure pump 25 is driven in conjunction with the output shaft 210 of the marine diesel engine. It is supposed to be. With this configuration, it is possible to ensure the operation of the exhaust valve drive system 11 by continuing the discharge of the hydraulic oil by the exhaust valve side high pressure pump 25 while the marine diesel engine is rotating the output shaft 210. Therefore, even if the high-pressure pump 24 on the injection valve side loses the power source (power) and the fuel injection system 1 becomes inoperable, at least after the marine diesel engine stops fuel operation, the output shaft 210 The operation of the exhaust valve drive system 11 can be continued while the fuel is rotating due to inertia. As a result, the exhaust valve 12 can be driven to open and close, so that a situation in which the in-cylinder pressure increases excessively can be avoided, and the marine diesel engine can be made safer.

In the above-described embodiment, the injection valve side pressure accumulator 7 shared by the fuel injection pump 3 and the water injection pump 5 is exemplified, but the present invention is not limited thereto. For example, the pressure accumulator portion 7 on the injection valve side may be divided into a pressure accumulator unit for accumulating the pressure of the hydraulic oil of the fuel injection pump 3 and a pressure accumulator unit for accumulating the pressure of the hydraulic oil of the water injection pump 5. Further, water injection equipment such as a water injection pump 5 and a water injection pipe 102 for injecting water into the fuel distribution path may be provided according to the reduction of NOx emissions required for a marine diesel engine, and is not always required. The hydraulic drive device 100 may not be provided.

Further, in the above-described embodiment, the injection valve side high pressure pump 24 is an electric pump and the exhaust valve side high pressure pump 25 is an engine drive pump, but the present invention is not limited thereto. For example, the injection valve side high pressure pump 24 may be an engine drive pump, the exhaust valve side high pressure pump 25 may be an electric pump, and both the injection valve side high pressure pump 24 and the exhaust valve side high pressure pump 25 may be electric pumps or engine drive pumps. May be.

Further, in the above-described embodiment, the case where the hydraulic drive device 100 is applied to the marine diesel engine 200 provided with the six cylinders 203 has been exemplified, but the present invention is not limited thereto. For example, the marine diesel engine to which the hydraulic drive device 100 is applied may be provided with a desired number (one or more) of cylinders. Similarly, the number of arrangements of the fuel injection pump 3, the water injection pump 5, and the valve valve device of the hydraulic drive device 100 is not limited to the six illustrated in FIG. 2, but is the required number for each cylinder of the marine diesel engine. There may be.

Further, the present invention is not limited to the above-described embodiment, and the present invention also includes a configuration in which the above-mentioned components are appropriately combined. In addition, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

1 Fuel injection system 2 Fuel injection valve 3 Fuel injection pump 3a Piston 3b Discharge chamber 3c Hydraulic oil chamber 3d Injection port 3e Discharge port 4, 6 Control valve 5 Water injection pump 5a Piston 5b Discharge chamber 5c Hydraulic oil chamber 5d Injection inlet 7 Injection valve Side pressure accumulator 8 Relief valve 9a, 9b Water injection valve 10a, 10b Water injection check valve 11 Exhaust valve drive system 12 Exhaust valve 12a Valve part 12b Piston part 13 Upper valve operation device 13a Drive oil chamber 13b Basis chamber 14 Lower valve operation 14a Piston 14b Drive oil chamber 14c Hydraulic oil chamber 14d Check valve 15 Hydraulic pipe 16 Control valve 17 Exhaust valve side pressure accumulator 18 Relief valve 21 Samp tank 22 Storage tank 23 Filter 24 Injection valve side high pressure pump 25 Exhaust valve side high pressure pump 26 On-off valve 27 Check valve 28 Control unit 100 Hydraulic drive device 101 Fuel injection pipe 102 Water injection pipe 102a, 102b Water injection branch pipe 103, 104, 105 Recovery pipe 110 Return pipe 111, 112, 113, 114 Feed pipe 112a, 112b Branch Pipe 115 Communication pipe 200 Marine diesel engine 201 Base plate 202 Frame 203 Cylinder 204 Combustion chamber 205 Exhaust port 210 Output shaft 211 Exhaust manifold

Claims (3)

A fuel injection valve that injects fuel into the combustion chamber of the cylinder of a marine diesel engine,
The first pressure accumulator that stores the pressure of the hydraulic oil,
A first hydraulic oil discharge pump that adjusts the pressure of the hydraulic oil in the first accumulator by discharging the hydraulic oil to the first accumulator through a pipe.
A fuel injection pump that pumps the fuel to the fuel injection valve by using the pressure of the hydraulic oil accumulated in the first pressure accumulator.
An exhaust valve that opens and closes the exhaust port of the cylinder,
A second accumulator that accumulates the pressure of hydraulic oil independently of the first accumulator,
A second hydraulic oil discharge pump that adjusts the pressure of the hydraulic oil in the second pressure accumulator by discharging the hydraulic oil to the second pressure accumulator through a pipe.
A valve operating device that opens and closes the exhaust valve by using the pressure of the hydraulic oil accumulated in the second pressure accumulator.
A communication pipe that connects the pipe of the first hydraulic oil discharge pump leading to the first accumulator and the pipe of the second hydraulic oil discharge pump leading to the second accumulator so as to be communicable.
An on-off valve provided in the communication pipe and
Predetermined so that the hydraulic oil discharged by the first hydraulic oil discharge pump can be circulated from the piping of the first hydraulic oil discharge pump to the piping of the second hydraulic oil discharge pump through the communication pipe. During the period, the on-off valve is controlled to be in an open state, and the flow of the hydraulic oil from the pipe of the first hydraulic oil discharge pump to the pipe of the second hydraulic oil discharge pump through the communication pipe is stopped. A control unit that controls the on-off valve to a closed state for a period other than the predetermined period,
A hydraulic drive device characterized by being provided with. A water injection pump for injecting water into the fuel flow path by utilizing the pressure of the hydraulic oil accumulated in the first pressure accumulator is provided.
The hydraulic drive device according to claim 1, wherein the fuel injection valve injects the pumped fuel and the injected water into the combustion chamber of the cylinder. The first hydraulic oil discharge pump is an electric pump.
The hydraulic drive device according to claim 1 or 2 , wherein the second hydraulic oil discharge pump is an engine drive pump that is driven in conjunction with the output shaft of the marine diesel engine.

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