JP6954090B2 - Compressed end pressure controller and engine system - Google Patents

Description

The present invention relates to a compression end pressure controller and an engine system.

For example, Patent Document 1 discloses a large reciprocating piston combustion engine having a crosshead. The large reciprocating piston combustion engine of Patent Document 1 is a dual fuel engine capable of operating on both a liquid fuel such as heavy oil and a gaseous fuel such as natural gas. The large reciprocating piston combustion engine of Patent Document 1 changes the compression ratio by moving the piston rod by hydraulic pressure in order to correspond to both the compression ratio suitable for operation with liquid fuel and the compression ratio suitable for operation with gaseous fuel. An adjustment mechanism is provided in the cross head portion.

Japanese Unexamined Patent Publication No. 2014-20375

By the way, in a multi-cylinder engine, the compression end pressure is adjusted by changing the valve closing timing of the exhaust valve in order to suppress the variation in the compression end pressure (combustion chamber pressure at top dead center) of each cylinder. Is being done. Even in an engine system equipped with a variable compression device, the compression end pressure between cylinders is adjusted by changing the closing timing of the exhaust valve. However, if the closing timing of the exhaust valve is delayed in order to reduce the compression end pressure, a large amount of air is discharged from the combustion chamber, so that the amount of air filled in the combustion chamber decreases and the relative gas in the combustion chamber is relative. Fuel gas concentration increases. As a result, abnormal combustion may occur in the combustion chamber.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent abnormal combustion when controlling the compression end pressure.

According to the present invention, as a first means for solving the above problems, the compression end pressure control device is a variable compression device for increasing the compression ratio of the combustion chamber by supplying a pressurized working fluid to the fluid chamber. A compression end pressure control device that controls the supply amount of working fluid, and when the compression end pressure in the combustion chamber is higher than a predetermined reference range, the variable compression device is controlled to control the compression ratio of the combustion chamber. The configuration is adopted to include a compression ratio setting means for reducing the pressure ratio and a variable compression device adjusting means for controlling the supply amount of the working fluid based on the compression ratio determined by the compression ratio setting means.

As a second means, in the first means, when the compression end pressure is lower than the reference range, the exhaust valve device that opens and closes the exhaust port in the combustion chamber is closed earlier than the current closing timing. A configuration having a valve adjusting means is adopted.

As a third means, in the first or second means, when the compression end pressure in the combustion chamber is higher than a predetermined reference range, the compression is based on the composition of the fuel supplied to the combustion chamber. It has an abnormal combustion estimating means for estimating whether or not abnormal combustion occurs at the end pressure, and the compression ratio setting means has a compression ratio by the variable compression device adjusting means based on the estimation result of the abnormal combustion estimating means. Is adopted.

As a fourth means, the engine system has a plurality of cylinders having a combustion chamber and a fluid chamber in which the piston rod is moved in a direction of increasing the compression ratio of the combustion chamber by supplying a boosted working fluid. A configuration is adopted in which a variable compression device and the compression end pressure control device according to any one of the first to third means are provided. The configuration is adopted.

According to the present invention, when the compression end pressure is higher than a predetermined reference range, the compression end pressure is lowered by lowering the compression ratio of the combustion chamber. Therefore, since the amount of gas discharged from the combustion chamber does not change, the pressure at the compressed end can be reduced without reducing the amount of filled air in the combustion chamber. Therefore, abnormal combustion can be prevented without increasing the concentration of gaseous fuel in the combustion chamber.

It is sectional drawing of the engine system in one Embodiment of this invention. It is a perspective view which shows a part of the engine system in one Embodiment of this invention. It is a block diagram of the control part of the engine system in one Embodiment of this invention. It is a flowchart of the compression end pressure control of the control part in one Embodiment of this invention. It is a flowchart of compression ratio change control of the control part in one Embodiment of this invention.

Hereinafter, an embodiment of the engine system 100 according to the present invention will be described with reference to the drawings. In the drawings below, the scale of each member is appropriately changed in order to make each member recognizable.

The engine system 100 of the present embodiment is mounted on a ship such as a large tanker, and as shown in FIG. 1, an engine 1, a supercharger 200, a control unit 300 (compressed end pressure control device), and an in-cylinder pressure sensor. It has 400 and 500 gas chromatography. In the present embodiment, the supercharger 200 will be regarded as an auxiliary machine, and will be described as a separate body from the engine 1 (main engine). However, it is also possible to configure the supercharger 200 as a part of the engine 1.

The engine 1 is a multi-cylinder uniflow scavenging diesel engine, and has a gas operation mode in which a gaseous fuel such as natural gas is burned together with a liquid fuel such as heavy oil, and a diesel operation mode in which the liquid fuel such as heavy oil is burned. There is. In the gas operation mode, only the gas fuel may be burned. Such an engine 1 includes a frame 2, a cylinder portion 3, a piston 4, an exhaust valve unit 5, a piston rod 6, a crosshead 7, a hydraulic portion 8 (boosting mechanism), and a connecting rod 9. It has a crank angle sensor 10, a crank shaft 11, a scavenging reservoir 12, an exhaust reservoir 13, and an air cooler 14. Further, the cylinder is composed of the cylinder portion 3, the piston 4, the exhaust valve unit 5, and the piston rod 6.

The frame 2 is a strength member that supports the entire engine 1, and houses a crosshead 7, a hydraulic unit 8, and a connecting rod 9. Further, inside the frame 2, the crosshead pin 7a, which will be described later, of the crosshead 7 can reciprocate.

The cylinder portion 3 has a cylindrical cylinder liner 3a, a cylinder head 3b, and a cylinder jacket 3c. The cylinder liner 3a is a cylindrical member, and a sliding surface with the piston 4 is formed inside. The space surrounded by the inner peripheral surface of the cylinder liner 3a and the piston 4 is defined as the combustion chamber R1. Further, a plurality of scavenging ports S are formed in the lower part of the cylinder liner 3a. The scavenging port S is an opening arranged along the peripheral surface of the cylinder liner 3a, and communicates the scavenging chamber R2 inside the cylinder jacket 3c with the inside of the cylinder liner 3a. The cylinder head 3b is a lid member provided at the upper end of the cylinder liner 3a. The cylinder head 3b is connected to the exhaust reservoir 13 by forming an exhaust port H at the center in a plan view. Further, the cylinder head 3b is provided with a fuel injection valve (not shown). Further, an in-cylinder pressure sensor (not shown) is provided in the vicinity of the fuel injection valve of the cylinder head 3b. The in-cylinder pressure sensor detects the pressure in the combustion chamber R1 and transmits it to the control unit 300. The cylinder jacket 3c is a cylindrical member provided between the frame 2 and the cylinder liner 3a and into which the lower end of the cylinder liner 3a is inserted, and a scavenging chamber R2 is formed therein. Further, the scavenging chamber R2 of the cylinder jacket 3c is connected to the scavenging reservoir 12.

The piston 4 has a substantially cylindrical shape, is connected to a piston rod 6 described later, and is arranged inside the cylinder liner 3a. Further, a piston ring (not shown) is provided on the outer peripheral surface of the piston 4, and the gap between the piston 4 and the cylinder liner 3a is sealed by the piston ring. The piston 4 slides in the cylinder liner 3a together with the piston rod 6 due to the fluctuation of the pressure in the combustion chamber R1.

The exhaust valve unit 5 includes an exhaust valve 5a, an exhaust valve housing 5b, and an exhaust valve drive unit 5c. The exhaust valve 5a is provided inside the cylinder head 3b, and the exhaust valve driving portion 5c closes the exhaust port H in the cylinder portion 3. The exhaust valve housing 5b is a cylindrical housing that accommodates an end portion of the exhaust valve 5a. The exhaust valve drive unit 5c is an actuator that moves the exhaust valve 5a in the direction along the stroke direction of the piston 4.

The piston rod 6 is a long member having one end connected to the piston 4 and the other end connected to the crosshead pin 7a. The end of the piston rod 6 is inserted into the crosshead pin 7a and is connected so that the connecting rod 9 can rotate. Further, the piston rod 6 has a large diameter portion in which a part of the cross head pin 7a side end portion has a large diameter.

The crosshead 7 has a crosshead pin 7a, a guide shoe 7b, and a lid member 7c. As shown in FIG. 2, the cross head pin 7a is a columnar member that movably connects the piston rod 6 and the connecting rod 9, and the hydraulic oil (hydraulic fluid) is inserted into the insertion space into which the end of the piston rod 6 is inserted. ) Is supplied and discharged, and a hydraulic chamber R3 (fluid chamber) is formed. The cross head pin 7a is formed with an outlet hole O that penetrates along the axial direction of the cross head pin 7a below the center. The outlet hole O is an opening through which cooling oil that has passed through a cooling flow path (not shown) of the piston rod 6 is discharged. Internally, the cross head pin 7a is provided with a supply flow path R4 for connecting the hydraulic chamber R3 and the plunger pump 8c described later, and a relief flow path R5 for connecting the hydraulic chamber R3 and the relief valve 8f described later. There is.

The guide shoe 7b is a member that rotatably supports the cross head pin 7a, and moves along the stroke direction of the piston 4 along the stroke direction of the piston 4 along with the cross head pin 7a on a guide rail (not shown). When the guide shoe 7b moves along the guide rail, the cross head pin 7a is restricted from rotating and moving in a direction other than the linear direction along the stroke direction of the piston 4. The lid member 7c is an annular member fixed to the upper portion of the cross head pin 7a and into which the end portion of the piston rod 6 is inserted. Such a crosshead 7 transmits the linear motion of the piston 4 to the connecting rod 9.

As shown in FIG. 2, the hydraulic unit 8 includes a supply pump 8a, a swing pipe 8b, a plunger pump 8c, a first check valve 8d and a second check valve 8e included in the plunger pump 8c, and a relief valve. It has 8f. Further, the piston rod 6, the crosshead 7, the hydraulic unit 8, and the control unit 300 function as the variable compression device in the present invention.

The supply pump 8a is a pump that boosts the hydraulic oil supplied from the hydraulic oil tank (not shown) and supplies it to the plunger pump 8c based on the instruction from the control unit 300. The supply pump 8a is driven by the electric power of the battery of the ship and can be operated before the liquid fuel is supplied to the combustion chamber R1. The swing pipe 8b is a pipe that connects the supply pump 8a and the plunger pump 8c of each cylinder, and swings between the plunger pump 8c that moves along with the crosshead pin 7a and the fixed supply pump 8a. It is possible.

The plunger pump 8c is fixed to a cross head pin 7a, and has a rod-shaped plunger 8c1, a cylindrical cylinder 8c2 that slidably accommodates the plunger 8c1, and a plunger drive unit 8c3. When the plunger 8c1 is connected to a drive unit (not shown), the plunger pump 8c slides in the cylinder 8c2 to boost the hydraulic oil and supply it to the hydraulic chamber R3. Further, the cylinder 8c2 is provided with a first check valve 8d at the opening on the discharge side of the hydraulic oil provided at the end, and a second check valve 8e is provided at the opening on the suction side provided on the side peripheral surface. It is provided. The plunger drive unit 8c3 is connected to the plunger 8c1 and reciprocates the plunger 8c1 based on an instruction from the control unit 300.

The first check valve 8d has a structure in which the valve body is urged toward the inside of the cylinder 8c2 to close the valve, and prevents the hydraulic oil supplied to the hydraulic chamber R3 from flowing back into the cylinder 8c2. doing. Further, in the first check valve 8d, the valve body is pushed by the hydraulic oil when the pressure of the hydraulic oil in the cylinder 8c2 becomes equal to or higher than the urging force (valve opening pressure) of the urging member of the first check valve 8d. To open the valve. The second check valve 8e is urged toward the outside of the cylinder 8c2 to prevent the hydraulic oil supplied to the cylinder 8c2 from flowing back to the supply pump 8a. Further, in the second check valve 8e, when the pressure of the hydraulic oil supplied from the supply pump 8a becomes equal to or higher than the urging force (valve opening pressure) of the urging member of the second check valve 8e, the valve body becomes the hydraulic oil. The valve is opened by being pushed. The first check valve 8d is supplied from the supply pump 8a during steady operation in which the valve opening pressure is higher than the valve opening pressure of the second check valve 8e and is operated at a preset compression ratio. The valve does not open due to the pressure of the hydraulic oil.

The relief valve 8f is provided on the cross head pin 7a and has a main body portion 8f1 and a relief valve driving portion 8f2. The main body 8f1 is a valve connected to the hydraulic chamber R3 and a hydraulic oil tank (not shown). The relief valve drive unit 8f2 is connected to the valve body of the main body 8f1 and opens and closes the main body 8f1 based on an instruction from the control unit 300. When the relief valve 8f is opened by the relief valve drive unit 8f2, the hydraulic oil stored in the hydraulic chamber R3 is returned to the hydraulic oil tank.

As shown in FIG. 1, the connecting rod 9 is a long member that is connected to the cross head pin 7a and also to the crank shaft 11. The connecting rod 9 converts the linear motion of the piston 4 transmitted to the crosshead pin 7a into a rotary motion. The crank angle sensor 10 is a sensor for measuring the crank angle of the crank shaft 11, and transmits a crank pulse signal for calculating the crank angle to the control unit 300.

The crank shaft 11 is a long member connected to a connecting rod 9 provided in the cylinder, and is rotated by a rotational motion transmitted by each connecting rod 9, thereby transmitting power to, for example, a screw or the like. The scavenging reservoir 12 is provided between the cylinder jacket 3c and the supercharger 200, and the air pressurized by the supercharger 200 flows into the scavenging reservoir 12. Further, the scavenging reservoir 12 is provided with an air cooler 14 inside. The exhaust reservoir 13 is a tubular member connected to the exhaust port H of each cylinder and connected to the supercharger 200. The gas discharged from the exhaust port H is temporarily stored in the exhaust reservoir 13 and is supplied to the supercharger 200 in a state where pulsation is suppressed. The air cooler 14 is a device that cools the air inside the scavenging reservoir 12.

The supercharger 200 is a device that pressurizes the air sucked from the intake port (not shown) by a turbine rotated by the gas discharged from the exhaust port H and supplies the air to the combustion chamber R1.

The control unit 300 is a computer that controls the fuel supply amount and the like of each cylinder based on the operation and the like by the operator of the ship. Further, the control unit 300 changes the compression ratio in the combustion chamber R1 by controlling the hydraulic unit 8.

Specifically, as shown in FIG. 3, the control unit 300 includes a compression end pressure determination unit 301, a self-ignition timing calculation unit 302, an abnormal combustion estimation unit 303 (abnormal combustion estimation means), and an exhaust valve adjustment unit. It has 304 (exhaust valve adjusting means), a compression ratio setting unit 305 (compression ratio setting means), and a hydraulic pressure adjusting unit 306 (variable compression device adjusting means). The compression end pressure determination unit 301 compares the compression end pressure acquired from the in-cylinder pressure sensor 400 with the reference range stored in advance. The reference range stored in advance is determined from, for example, a map based on the engine speed, engine load, and compression end pressure.

The self-ignition timing calculation unit 302 calculates the self-ignition timing (information on abnormal combustion) from the self-ignition timing map stored in advance based on the information including the composition of the gaseous fuel acquired from the gas chromatography 500. The self-ignition timing map stores the time from the start of fuel injection to self-ignition in a plurality of patterns of combinations of the content ratios of each component of the gaseous fuel. The self-ignition timing calculation unit 302 refers to the self-ignition timing map, and determines from the time from the start of fuel injection to self-ignition in the pattern of the combination of the detected fuel composition and the content ratio of each component of the gas fuel closest to the detected fuel composition. Calculate the self-ignition timing.

The abnormal combustion estimation unit 303 calculates the distribution of the combustion gas of the gaseous fuel in the combustion chamber R1 based on the injection amount of the gaseous fuel and the acquired compression end pressure, and the timing at which the combustion gas spreads to the combustion chamber R1 ( Combustion completion timing) is calculated. Then, the abnormal combustion estimation unit 303 compares the combustion completion timing with the self-ignition timing and determines whether the self-ignition timing is earlier, thereby determining whether or not the abnormal combustion occurs.

The exhaust valve adjusting unit 304 opens and closes the exhaust valve 5a by controlling the exhaust valve driving unit 5c. Further, the exhaust valve adjusting unit 304 advances (accelerates) the closing timing of the exhaust valve 5a when the compression end pressure is lower than the reference range based on the determination result of the compression end pressure determination unit 301. Control.

The compression ratio setting unit 305 calculates the optimum compression ratio according to the type of fuel based on the input from the outside. Further, the compression ratio setting unit 305 refers to the compression ratio setting map stored in advance based on the self-ignition timing calculated by the self-ignition timing calculation unit 302, and in the range where the gaseous fuel self-ignites at the compression end. , Determine the compression ratio to be the best. The compression ratio setting map stores the correlation between the self-ignition timing and the compression ratio.

The oil pressure adjusting unit 306 adjusts the amount of hydraulic oil supplied to the hydraulic chamber R3 by controlling the plunger pump 8c and the relief valve 8f of the oil pressure unit 8 based on the compression ratio acquired from the compression ratio setting unit 305. do.

The in-cylinder pressure sensor 400 is a sensor that measures the pressure in the combustion chamber R1 and is provided on the inner wall of the combustion chamber R1. When the gas fuel is supplied, the gas chromatography 500 acquires the supplied gas fuel and detects the distribution of each composition of the gas fuel. The gas chromatography 500 detects the composition distribution of the gaseous fuel, for example, once a day or once an hour.

Such an engine system 100 is a device that ignites and explodes the fuel injected into the combustion chamber R1 from a fuel injection valve (not shown) to slide the piston 4 in the cylinder liner 3a and rotate the crank shaft 11. be. More specifically, the fuel supplied to the combustion chamber R1 is mixed with the air flowing in from the scavenging port S, and then compressed by the piston 4 moving toward the top dead center, and the temperature rises naturally. Ignite. Further, in the case of liquid fuel, the temperature rises in the combustion chamber R1 to vaporize and spontaneously ignite.

Then, the fuel in the combustion chamber R1 spontaneously ignites and rapidly expands, and pressure is applied to the piston 4 toward the bottom dead center. As a result, the piston 4 moves toward the bottom dead center, the piston rod 6 is moved along with the piston 4, and the crank shaft 11 is rotated via the connecting rod 9. Further, when the piston 4 is moved to the bottom dead center, pressurized air flows into the combustion chamber R1 from the scavenging port S. When the exhaust valve unit 5 is driven, the exhaust port H is opened, and the exhaust gas in the combustion chamber R1 is pushed out to the exhaust reservoir 13 by the pressurized air.

When the compression ratio is increased to use gaseous fuel, the optimum compression ratio is calculated by the compression ratio setting unit 305 of the control unit 300, the supply pump 8a is driven by the oil pressure adjusting unit 306, and the plunger pump 8c operates. Oil is supplied. Then, the hydraulic pressure adjusting unit 306 of the control unit 300 drives the plunger pump 8c to pressurize the hydraulic oil until the pressure is such that the piston rod 6 can be lifted, and supplies the hydraulic oil to the hydraulic chamber R3. The pressure of the hydraulic oil in the hydraulic chamber R3 lifts the end of the piston rod 6, and the top dead center position of the piston 4 is moved upward (exhaust port H side) accordingly.

When the compression ratio is reduced due to the use of liquid fuel, the optimum compression ratio is calculated by the compression ratio setting unit 305 of the control unit 300, the relief valve 8f is driven by the oil pressure adjusting unit 306, and the system is not compatible with the hydraulic chamber R3. The hydraulic oil tank shown in the figure is in communication with the tank. Then, the load of the piston rod 6 is applied to the hydraulic oil in the hydraulic chamber R3, and the hydraulic oil in the hydraulic chamber R3 is pushed out to the hydraulic oil tank via the relief valve 8f. As a result, the hydraulic oil in the hydraulic chamber R3 is reduced, the piston rod 6 is moved downward (crank shaft 11 side), and the top dead center position of the piston 4 is moved downward accordingly.

Further, the adjustment of the compression end pressure will be described with reference to FIGS. 4 and 5.
After the operation of changing the compression ratio depending on the type of fuel (liquid fuel or gaseous fuel) is completed, the control unit 300 acquires the compression end pressure by the compression end pressure determination unit 301 (step S1), and obtains the compression end pressure. Comparison with the reference range is performed (step S2). When the acquired compression end pressure is lower than the reference range, the exhaust valve adjusting unit 304 controls the exhaust valve driving unit 5c to advance the valve closing timing of the exhaust valve 5a (step S3). If the acquired compression end pressure is within the reference range, the flow is terminated. If the acquired compression end pressure is higher than the reference range, the compression ratio of the variable compression device is changed (step S4). By such control, the compression end pressure of all cylinders is kept within the reference range, and the variation of the compression end pressure in each cylinder is prevented.

The operation of step S4 will be described in detail with reference to FIG.
First, when the gaseous fuel is supplied, the control unit 300 acquires the composition of the supplied gaseous fuel from the gas chromatography 500 by the self-ignition timing calculation unit 302 (step S11), and obtains the composition of the supplied gaseous fuel from the self-ignition timing map. The self-ignition timing is calculated (step S12).

Then, the control unit 300 calculates the combustion completion timing based on the injection amount and the combustion speed of the gaseous fuel by the abnormal combustion estimation unit 303 (step S13). Next, the control unit 300 determines whether or not the self-ignition timing is earlier than the calculated combustion completion timing under the acquired compression end pressure by the abnormal combustion estimation unit 303 (step S14).

When the determination in step S14 is YES, that is, when the self-ignition timing is earlier than the combustion completion timing, the air-fuel mixture self-ignites earlier than the combustion gas spreads to the combustion chamber R1, and abnormal combustion occurs. Probability is high. Therefore, the control unit 300 determines the compression ratio from the compression ratio setting map by the compression ratio setting unit 305 so as to lower the compression ratio from the current compression ratio of the combustion chamber R1 (step S15). Then, in order to lower the compression ratio, the control unit 300 reduces the supply amount of hydraulic oil in the hydraulic chamber R3 by the hydraulic pressure adjusting unit 306 (step S16).

Further, when the determination in step S14 is NO, that is, when the self-ignition timing is later than the combustion completion timing, or at the same time, the flow is terminated.

The amount of movement of the piston rod 6 when the compression ratio is changed depending on the type of fuel is much larger than the amount of movement of the piston rod 6 when the compression ratio is changed by adjusting the compression end pressure. Therefore, by adjusting the compression end pressure after changing the compression ratio according to the type of fuel, the optimum compression ratio can be obtained for each fuel.

According to this embodiment, when the compression end pressure is higher than a predetermined reference range, the compression end pressure is lowered by lowering the compression ratio of the combustion chamber R1. Therefore, since the amount of gas discharged from the combustion chamber R1 does not change, the pressure at the compressed end can be reduced without reducing the amount of filled air in the combustion chamber R1. Therefore, abnormal combustion can be prevented without increasing the concentration of gaseous fuel in the combustion chamber R1.

Further, according to the present embodiment, when the compression end pressure is lower than a predetermined reference range, the compression end pressure is increased by advancing the valve closing timing of the exhaust valve 5a. Therefore, the compression end pressure can be increased without reducing the amount of filled air in the combustion chamber R1. Therefore, abnormal combustion can be prevented without increasing the concentration of gaseous fuel in the combustion chamber R1.

Further, according to the present embodiment, the self-ignition timing calculation unit 302 calculates the self-ignition timing based on the fuel composition, and the compression ratio setting unit 305 sets the compression ratio so that abnormal combustion does not occur based on the self-ignition timing. The compression ratio of the combustion chamber R1 can be determined so as to be. Therefore, the compression ratio can be determined based on the ease of abnormal combustion, which differs depending on the composition of the gaseous fuel, and abnormal combustion can be prevented.

Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The various shapes and combinations of the constituent members shown in the above-described embodiment are examples, and can be variously changed based on design requirements and the like without departing from the spirit of the present invention.

Further, in the above embodiment, the engine system 100 has a configuration having gas chromatography 500, but the present invention is not limited to this. If the composition of the gaseous fuel is known in advance, it is not necessary to have the gas chromatography 500. Further, the composition acquisition device may have a configuration other than the gas chromatography 500.

In the above embodiment, abnormal combustion is determined based on the input from the in-cylinder pressure sensor 400, but the present invention is not limited to this. For example, a vibration sensor may be provided in the combustion chamber R1 and abnormal combustion may be determined based on the input from the vibration sensor.

Further, in the above embodiment, when the compression end pressure is increased, the adjustment is performed by the exhaust valve adjusting unit 304, but the present invention is not limited to this. Even when the compression end pressure is increased, it can be adjusted by increasing the compression ratio by the hydraulic pressure adjusting unit 306.

1 Engine 2 Frame 3 Cylinder part 3a Cylinder liner 3b Cylinder head 3c Cylinder jacket 4 Piston 5 Exhaust valve unit 5a Exhaust valve 5b Exhaust valve housing 5c Exhaust valve drive part 6 Piston rod 7 Cross head 7a Cross head pin 7b Guide shoe 7c Lid member 8 Hydraulic part 8a Supply pump 8b Swing pipe 8c Plunger pump 8c1 Plunger 8c2 Cylinder 8c3 Plunger drive part 8d 1st check valve 8e 2nd check valve 8f Relief valve 8f1 Main body part 8f2 Relief valve drive part 9 Connecting rod 10 Crank angle sensor 11 Cylinder shaft 12 Scavenging air reservoir 13 Exhaust reservoir 14 Air cooler 100 Engine system 200 Supercharger 300 Control unit 301 Compressed end pressure determination unit 302 Self-ignition timing calculation unit 303 Abnormal combustion estimation unit 304 Exhaust valve adjustment unit 305 Compression ratio setting unit 306 Hydraulic adjustment unit 400 Cylinder pressure sensor 500 Gas chromatography H Exhaust port O Outlet hole R1 Combustion chamber R2 Sweeper chamber R3 Hydraulic chamber R4 Supply flow path R5 Relief flow path S Sweep port

Claims (4)

A compression end pressure control device that controls the supply amount of the working fluid of a variable compression device that increases the compression ratio of the combustion chamber by supplying the boosted working fluid to the fluid chamber.
A compression ratio setting means for controlling the variable compression device to reduce the compression ratio of the combustion chamber when the compression end pressure in the combustion chamber is higher than a predetermined reference range.
A variable compression device adjusting means that controls the supply amount of the working fluid based on the compression ratio determined by the compression ratio setting means , and
Abnormal combustion estimation that estimates whether or not abnormal combustion occurs at the compressed end pressure based on the composition of the fuel supplied to the combustion chamber when the compressed end pressure in the combustion chamber is higher than the reference range. Have means and
The compression ratio setting means is a compression end pressure control device, characterized in that the compression ratio by the variable compression device adjusting means is determined based on the estimation result of the abnormal combustion estimation means. Claim 1 is characterized by having an exhaust valve adjusting means for advancing the valve closing timing of the exhaust valve device that opens and closes the exhaust port in the combustion chamber when the compression end pressure is lower than the reference range than the current valve closing timing. The compressed end pressure control device according to the description. With multiple cylinders with combustion chambers,
With a variable compression device having a fluid chamber in which the piston rod is moved in a direction of increasing the compression ratio of the combustion chamber by supplying the boosted working fluid.
With the compression end pressure control device according to claim 1 or 2.
An engine system characterized by having. With multiple cylinders with combustion chambers,
A variable compression device having a fluid chamber in which the piston rod is moved in a direction of increasing the compression ratio of the combustion chamber by supplying a pressurized working fluid.
Wherein possess the compression end pressure controller for controlling the supply amount of hydraulic fluid in the variable compression device to increase the compression ratio of the combustion chamber by boosted the working fluid is supplied to the fluid chamber,
The compression end pressure control device includes a compression ratio setting means for controlling the variable compression device to reduce the compression ratio of the combustion chamber when the compression end pressure in the combustion chamber is higher than a predetermined reference range.
A variable compression device adjusting means that controls the supply amount of the working fluid based on the compression ratio determined by the compression ratio setting means.
Engine system, characterized in that the have a.

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