JP7031457B2 - Variable compressor and engine system - Google Patents

Description

The present invention relates to a variable compression device 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 liquid fuel such as heavy oil and 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 support both the compression ratio suitable for operation with liquid fuel and the compression ratio suitable for operation with gaseous fuel. An adjustment mechanism (variable compression device) is provided in the crosshead portion.

Japanese Unexamined Patent Publication No. 2014-20375

The variable compression device having such a configuration has a regulating member that regulates the movement of the piston rod in the direction of increasing the compression ratio. By the way, when the combustion pressure is not applied, such as when the engine is started or when the engine is suddenly stopped, the force that pushes the piston downward due to the pressure inside the cylinder is smaller than the upward inertial force due to the reciprocation of the piston rod, and the piston rod becomes It rises by its own inertial force regardless of the hydraulic pressure of the lower oil chamber. As a result, when the piston rod is moved by the inertial force in the direction closer to the regulating member (the direction in which the compression ratio is increased), the regulating member and the piston rod collide with each other.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent a collision between a regulating member and a piston rod in a variable compression device.

In the present invention, as a first means for solving the above-mentioned problems, a fluid chamber in which the piston rod is moved in a direction of increasing the compression ratio by supplying a pressurized working fluid, and the compression ratio of the piston rod. A variable compression device having a restricting member that regulates movement in a direction that increases the amount of fluid, a fluid chamber on the regulating member side that is provided between the piston rod and the restricting member and that stores a working fluid, and the restricting member. A supply flow path for guiding the working fluid supplied to the side fluid chamber, a discharge flow path for guiding the working fluid discharged from the regulating member side fluid chamber, and the piston rod provided in the discharge flow path are provided. A configuration is adopted in which the flow control unit that regulates the flow of the working fluid is provided when approaching the regulation member.

As a second means, in the first means, the flow rate regulating unit has a weight member that can be moved together with the piston rod, and a valve body that is moved in the valve closing direction by the movement of the weight member. , Is adopted.

As a third means, in the second means, the flow rate regulating unit adopts a configuration in which the weight member has an urging member for urging the weight member in the valve opening direction.

As a fourth means, in the second or third means, the detecting means has a magnetic member provided on the rod, and the regulating member side fluid chamber has the working fluid supplied to the fluid chamber. The configuration is adopted in which a part of is supplied.

As a fifth means, the engine system adopts a configuration including the variable compression device according to the first to fourth means.

According to the present invention, when the piston rod is moved in the direction approaching the regulating member, the flow regulating unit closes the discharge flow path and can maintain the state in which the hydraulic oil is stored in the fluid chamber on the regulating member side. .. By acting as a damper in the working fluid in the fluid chamber on the regulating member side, it is possible to prevent the piston rod from colliding with the regulating member with a large force.

It is sectional drawing of the engine system in one Embodiment of this invention. It is a schematic sectional drawing which shows a part of the engine system in one Embodiment of this invention. It is sectional drawing which shows the modification of the flow rate regulation part provided with the engine system in one Embodiment of this invention.

Hereinafter, an embodiment of the engine system according to the present invention will be described with reference to the drawings. In the following drawings, 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 has an engine 1, a supercharger 200, and a control unit 300 as shown in FIG. In the present embodiment, the turbocharger 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 turbocharger 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, an air cooler 14, and an upper hydraulic chamber hydraulic mechanism 15. 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 pressure section 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 portion 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 has an exhaust port H formed in the central portion in a plan view and is connected to the exhaust reservoir 13. 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 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 has 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 the 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 (regulatory member). The cross head pin 7a is a columnar member that movably connects the piston rod 6 and the connecting rod 9, and supplies and discharges hydraulic oil (working fluid) to the insertion space into which the end of the piston rod 6 is inserted. The hydraulic chamber R3 (fluid chamber) to be performed is formed. The crosshead pin 7a is formed with an outlet hole O that penetrates along the axial direction of the crosshead 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. Further, the crosshead 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. ..

The guide shoe 7b is a member that rotatably supports the crosshead pin 7a, and moves along the stroke direction of the piston 4 on a guide rail (not shown) along with the crosshead pin 7a. By moving the guide shoe 7b along the guide rail, the cross head pin 7a is restricted from rotating motion 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 part of the crosshead pin 7a and into which the end portion of the piston rod 6 is inserted. Further, the lid member 7c is provided with a seal ring on the sliding surface with the piston rod 6. As a result, the upper hydraulic chamber R6 (regulatory member side fluid chamber) is formed between the lid member 7c and the large diameter portion of the piston rod 6. Further, the lid member 7c includes a part of the supply flow path R7 for guiding the hydraulic oil supplied to the upper hydraulic chamber R6 and one of the discharge flow paths R8 for guiding the hydraulic oil discharged from the upper hydraulic chamber R6. The part is formed. 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, the upper hydraulic chamber hydraulic mechanism 15, 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 generator 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 connecting 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 the crosshead 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, boosts the hydraulic oil, and supplies the hydraulic oil 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 thereof, 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 to the cylinder 8c2. is 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 drive portion 8f2. The main body 8f1 is a valve connected to the hydraulic chamber R3 and the 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 connected to the crosshead pin 7a and connected to the crank shaft 11. A crosshead pin 7a is rotatably connected to one end of the connecting rod 9, and the linear motion of the piston 4 transmitted to the crosshead pin 7a is converted 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 turbocharger 200. The gas discharged from the exhaust port H is temporarily stored in the exhaust reservoir 13 and is supplied to the turbocharger 200 in a state where pulsation is suppressed. The air cooler 14 is a device for cooling the air inside the scavenging reservoir 12.

The upper hydraulic chamber hydraulic mechanism 15 includes a check valve 15a and a throttle valve device 15b (fluid control unit). The check valve 15a is provided in the supply flow path R7 and is a valve that prevents the hydraulic oil in the upper hydraulic chamber R6 from flowing back to the supply pump 8a side. The throttle valve device 15b includes a flow path member 15c, a weight member 15d, an urging spring 15e (an urging member), and a support member 15f.

The flow path member 15c is a columnar member rotatably fixed to the lid member 7c by a bearing member (not shown) or the like. The flow path member 15c is a member that regulates the flow of the discharge flow path R8 by forming a part of the discharge flow path R8 in the valve open state and rotating the flow path member 15c. The weight member 15d is a member that is supported from below by the support member 15f fixed to the lid member 7c and is suspended by the urging spring 15e fixed to the piston rod 6.

The weight member 15d is connected to the flow path member 15c and is moved in the vertical direction by inertial force. That is, when the lid member 7c is moved upward in the vertical direction along with the crosshead pin 7a, the weight member 15d exerts an inertial force toward the upper side in the vertical direction, and the weight member 15d is directed toward the upper side in the vertical direction. Will be moved. The urging spring 15e is a member in which one end on the upper side in the vertical direction is fixed to the support member 15f and the weight member 15d is suspended. The support member 15f is a member that is fixed to the lid member 7c and moves up and down together with the lid member 7c, and supports the weight member 15d and the urging spring 15e.

The turbocharger 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 based on the operation and the like by the operator of the ship. The control unit 300 includes a receiving unit that receives the wireless communication of the communication unit 430 described later in the position detection unit 400. Further, the control unit 300 changes the compression ratio in the combustion chamber R1 by controlling the hydraulic pressure unit 8. Specifically, the control unit 300 acquires the position information of the piston rod 6 based on the signal from the position detection unit 400, controls the plunger pump 8c, the supply pump 8a, and the relief valve 8f, and operates in the hydraulic chamber R3. By adjusting the amount of oil, the position of the piston rod 6 is changed to change the compression ratio.

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 the piston 4 moves toward the top dead center to be compressed and the temperature rises, which is natural. 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, the supply pump 8a is driven by the control unit 300, and hydraulic oil is supplied to the plunger pump 8c. Then, 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. Due to the pressure of the hydraulic oil in the hydraulic chamber R3, the end portion of the piston rod 6 is lifted, and the top dead center position of the piston 4 is moved upward (exhaust port H side) accordingly.

When the compression ratio is reduced, the relief valve 8f is driven by the control unit 300, and the hydraulic chamber R3 and the hydraulic oil tank (not shown) are in a communicating state. 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, a part of the hydraulic oil flows from the supply pump 8a into the upper hydraulic chamber R6 via the supply flow path R7, and the upper hydraulic chamber R6 is filled with the hydraulic oil. When the force applied to the piston rod 6 is downward in the vertical direction, the throttle valve device 15b provided in the discharge flow path R8 is always in the valve open state, and the hydraulic oil overflowing from the upper hydraulic chamber R6 passes through the discharge flow path R8. Is discharged to the outside. The pressure of the hydraulic oil supplied from the supply pump 8a is lower than that of the hydraulic oil supplied via the plunger pump 8c. Therefore, the pressure of the hydraulic oil in the upper hydraulic chamber R6 is set to be smaller than the pressure of the hydraulic oil in the hydraulic chamber R3.

The crank shaft 11 is rotated via the connecting rod 9 as the cross head pin 7a moves up and down. With respect to the movement of the cross head pin 7a, the piston 4 and the piston rod 6 are not fixed to the cross head pin 7a in the vertical direction, so that an inertial force acts. At this time, when the engine 1 is suddenly stopped due to a crash astern or the like, or when the engine 1 is started, the combustion pressure is not applied to the piston 4, and the force for pushing the piston downward due to the pressure inside the cylinder becomes small, and the piston rod 6 On the other hand, when an upward inertial force in the vertical direction, which is larger than the force for pushing the piston downward due to the pressure inside the cylinder, is applied, the piston rod 6 is moved in the direction approaching the lid member 7c. At this time, the weight member 15d movably supported by the urging spring 15e is lifted upward in the vertical direction by the action of the inertial force applied vertically upward and the elastic force of the urging spring 15e, and the flow path member 15c is lifted. It is rotated. As a result, the discharge flow path R8 is closed, and the hydraulic oil in the upper hydraulic chamber R6 is not discharged from the upper hydraulic chamber R6. Therefore, even if the piston rod 6 is lifted vertically upward by the inertial force, the hydraulic oil in the upper hydraulic chamber R6 acts as a damper to prevent the piston rod 6 from colliding with the lid member 7c with a large force. can.
Then, when the piston rod 6 starts moving downward in the vertical direction (direction away from the lid member 7c) due to reaction or the like, the weight member 15d moves downward in the vertical direction due to its own weight, and the flow path member 15c is rotated and discharged. The flow path R8 is opened.

Further, even when the rotation speed of the engine 1 changes, an inertial force acts on the weight member 15d, and the weight member 15d is slightly lifted upward in the vertical direction. As a result, the flow path member 15c rotates slightly, and the inlet and outlet of the flow path member 15c are narrowed, so that the flow rate of the discharge flow path R8 can be reduced.

According to the present embodiment as described above, when the piston rod 6 is moved in the direction approaching the lid member 7c, the throttle valve device 15b is operated to maintain the state in which the upper hydraulic chamber R6 hydraulic oil is stored. The hydraulic oil in the upper hydraulic chamber R6 acts as a damper, so that the piston rod 6 can be prevented from colliding with the lid member 7c with a large force.

Further, according to the present embodiment, the throttle valve device 15b switches the opening and closing of the discharge flow path R8 by rotating the flow path member 15c by the weight member 15d that moves together with the piston rod 6. As a result, the throttle valve device 15b can be mechanically opened and closed, and the problem can be solved with a simple configuration without performing complicated sensing or the like.

Further, according to the present embodiment, the weight member 15d is urged upward (valve opening direction) in the vertical direction by the urging spring 15e. As a result, after the throttle valve device 15b is closed once, the flow path member 15c can be smoothly rotated and opened as the piston rod 6 moves.

Further, according to the present embodiment, a part of the hydraulic oil supplied to the hydraulic chamber R3 is supplied to the upper hydraulic chamber R6 via the supply flow path R7. As a result, it is not necessary to provide a new hydraulic system when providing the upper hydraulic chamber R6, and the configuration can be simplified.

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.

In the above embodiment, the throttle valve device 15b is used as the flow rate control unit, but the present invention is not limited thereto. For example, the throttle valve 16 shown in FIG. 3 may be used as the flow rate regulating unit. The throttle valve 16 has a flow path member 16a, a valve body 16b internally installed in the flow path member 16a, and an urging spring 16c that urges the valve body 16b in the valve opening direction. The flow path member 16a is fixed to the lid member 7c and forms a part of the discharge flow path R8. The valve body 16b is provided inside the flow path member 16a so as to be movable in the vertical direction, and is moved in the valve closing direction when the piston rod 6 is moved in the direction approaching the lid member 7c due to inertial force. Even if such a throttle valve 16 is used, as in the above embodiment, when the piston rod 6 is moved in the direction approaching the lid member 7c, the flow path member 16a is closed to enter the upper hydraulic chamber R6. The hydraulic oil can be held and the collision between the piston rod 6 and the lid member 7c can be prevented.

Further, in the above embodiment, the throttle valve device 15b is used, but the position of the piston rod 6 is provided by providing a position detection sensor for detecting the position of the piston rod 6 and providing a solenoid valve in the discharge flow path R8. The solenoid valve may be switched between opening and closing by electronic control based on the above.

A part of the hydraulic oil supplied to the hydraulic chamber R3 is to be supplied to the upper hydraulic chamber R6, but the present invention is not limited to this, and the hydraulic oil is supplied to the upper hydraulic chamber R6 by another system. May be.

1 Engine 2 Frame 3 Cylinder 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 reservoir 13 Exhaust reservoir 14 Air cooler 15 Upper hydraulic chamber hydraulic mechanism 15a Check valve 15b Valve device 15c Flow path member 15d Weight member 15e Bounce spring 16 Valve 16a Flow path member 16b Valve body 16c Bounce spring 100 Engine system 200 Supercharger 300 Control unit 400 Position detection unit 430 Communication unit H Exhaust port O Outlet hole R1 Combustion chamber R2 Scavenging chamber R3 Hydraulic chamber R4 Supply flow path R5 Relief flow path R6 Upper hydraulic chamber R7 Supply flow path R8 Discharge Flow path S Sweep port

Claims (4)

A variable compression device having a fluid chamber in which the piston rod is moved in a direction of increasing the compression ratio by supplying a boosted working fluid, and a regulating member for restricting the movement of the piston rod in a direction of increasing the compression ratio. And,
A fluid chamber on the regulatory member side, which is provided between the piston rod and the regulatory member and in which the working fluid is stored,
A supply flow path that guides the working fluid supplied to the regulation member side fluid chamber, and
A discharge flow path that guides the working fluid discharged from the regulation member side fluid chamber, and
It is provided in the discharge flow path and has a flow rate regulating unit that regulates the flow of the working fluid when the piston rod approaches the regulating member.
The flow rate regulating unit is a variable compression device including a weight member that can be moved together with the piston rod and a valve body that is moved in the valve closing direction by the movement of the weight member . The variable compression device according to claim 1 , wherein the flow rate regulating unit includes an urging member that urges the weight member in the valve opening direction . The variable compression device according to claim 1 or 2, wherein a part of the working fluid supplied to the fluid chamber is supplied to the regulation member side fluid chamber . An engine system comprising the variable compression device according to any one of claims 1 to 3.

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