JP2007127005A - Internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine in which the in-cylinder injection of a fuel gas is stably performed without increasing the size of the structure. <P>SOLUTION: Compression cylinders 3, 4 compressing and outputting a hydrogen gas and combustion cylinders 1, 2, 5, 6 burning the hydrogen gas are formed in a common cylinder 10. The hydrogen gas supplied from a hydrogen supply source is supplied to an accumulator 60 after being compressed in two stages by the compression cylinders 3, 4 by utilizing a part of the power of a crankshaft 20. The hydrogen gas accumulated in the accumulator 60 is jetted from fuel injection valves 41, 42, 45, 46 into the combustion cylinders 1, 2, 5, 6, respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an internal combustion engine that generates power on a crankshaft by burning fuel gas in a cylinder.

  The related art of this type of internal combustion engine is disclosed in Patent Document 1 below. An internal combustion engine according to Patent Document 1 is a system for supplying hydrogen gas (fuel gas) from a hydrogen tank (fuel tank), a direct injection path for direct injection into a cylinder, a premixing path for intake from an intake valve together with intake air, This is a hydrogen engine equipped with two systems. In addition, using only the premixing path during start-up and idling, using two systems, the premixing path and the direct injection path at low loads, and using only the direct injection path at high loads, improves driving performance in each operating region. I am trying.

  As another related technique, a hydrogen engine according to the following Non-Patent Document 1 is disclosed.

JP-A 63-246460 Akagawa et al., “Development of Hydrogen Injection Clean Engine”, 15th World Hydrogen Energy Conference, July 2004, lecture number 28J-05

  In Patent Document 1, when the direct injection path is used, the injection pressure of the fuel gas (hydrogen gas) into the cylinder depends on the pressure of the fuel tank (hydrogen tank). For this reason, when the pressure of the fuel tank is low, it is difficult to appropriately perform in-cylinder injection of fuel gas. For example, in order to achieve a thermal efficiency of about 50% in a hydrogen engine, sonic injection from the vicinity of the compression top dead center at a high compression ratio (for example, a compression ratio of 18 or more) is necessary, and a hydrogen injection pressure of about 30 MPa is required. What is required is shown in Non-Patent Document 1. In order to perform such in-cylinder injection at high pressure stably without depending on the pressure of the fuel tank (hydrogen tank), a compressor for compressing the fuel gas (hydrogen gas) is required. However, in that case, the construction of the entire engine is increased by providing a compressor.

  An object of the present invention is to provide an internal combustion engine that can stably perform in-cylinder injection of fuel gas without increasing the size of the configuration.

  The internal combustion engine according to the present invention employs the following means in order to achieve the above-described object.

  An internal combustion engine according to the present invention is an internal combustion engine that generates power in a crankshaft by burning fuel gas in a cylinder, and a compression cylinder that compresses and outputs fuel gas by a part of the power of the crankshaft. The fuel gas compressed in the compression cylinder is injected, and the combustion cylinder that generates power in the crankshaft by burning the injected fuel gas is provided in a common cylinder. .

  According to the present invention, a compressor (compression cylinder) that compresses fuel gas is incorporated in an internal combustion engine (cylinder), and the internal combustion engine and the compressor are integrated, so that the configuration of the fuel gas can be reduced without increasing the size of the configuration. In-cylinder injection can be performed stably.

  In one aspect of the present invention, it is preferable that the compression cylinder and the combustion cylinder are provided in a common cylinder so that the inertia force generated in each of the compression cylinder and the combustion cylinder is substantially balanced across the entire compression cylinder and the combustion cylinder. It is. If it carries out like this, the vibration and noise which generate | occur | produce in an internal combustion engine by an inertial force can be reduced.

  In one aspect of the present invention, the pressure ratio of the compression cylinder is set so that the maximum force acting on the crankshaft by the pressure of the compression cylinder is substantially equal to the maximum force acting on the crankshaft by the pressure of the combustion cylinder. Is preferred. If it carries out like this, the vibration and noise which generate | occur | produce in an internal combustion engine by cylinder pressure can be reduced.

  In one aspect of the present invention, the combustion cylinder and the plurality of compression cylinders are provided in a common cylinder, and it is preferable that the fuel gas is compressed in a plurality of stages by the plurality of compression cylinders. In this way, the in-cylinder injection pressure of the fuel gas can be further increased. In this aspect, it is preferable that the pressure ratio of each compression cylinder is set so that the maximum forces acting on the crankshaft are substantially equal to each other due to the pressure of each compression cylinder. If it carries out like this, the vibration and noise which generate | occur | produce in an internal combustion engine by cylinder pressure can be reduced.

  In one embodiment of the present invention, a pressure accumulator that accumulates fuel gas compressed in the compression cylinder is provided, and it is preferable that the fuel gas accumulated in the pressure accumulator is injected into the combustion cylinder. In this way, the in-cylinder injection of the fuel gas can be stably performed even if the injection amount of the fuel gas varies.

  In one aspect of the present invention, it is preferable that a pressure regulator for adjusting the pressure of the fuel gas injected into the combustion cylinder is provided. In this way, the injection pressure of the combustion gas to the combustion cylinder can be adjusted.

  In one aspect of the present invention, it is preferable that a supply amount adjuster for adjusting the supply amount of fuel gas to the compression cylinder is provided. In this way, the injection pressure of the combustion gas to the combustion cylinder can be adjusted.

  In one aspect of the present invention, it is preferable that a cooler for cooling the fuel gas compressed in the compression cylinder is provided. If it carries out like this, compression of fuel gas can be performed efficiently.

  In one embodiment of the present invention, the fuel gas is preferably hydrogen gas.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 is a diagram schematically showing an outline of an internal configuration of an internal combustion engine according to an embodiment of the present invention. The internal combustion engine according to the present embodiment is a reciprocating internal combustion engine (reciprocating engine) using a piston-crank mechanism, and a plurality of combustion cylinders 1 that generate power in the crankshaft 20 by burning hydrogen gas as a fuel gas. , 2, 5, 6 in the cylinder 10.

  In the combustion cylinders 1, 2, 5, and 6, the combustion cylinder pistons 11, 12, 15, and 16 connected to the crankshaft 20 reciprocate. The combustion cylinder pistons 11, 12, 15, and 16 are connected to the small ends of the combustion cylinder connecting rods 21, 22, 25, and 26 via piston pins, respectively, and the combustion cylinder connecting rods 21, 22, and 25 are connected to each other. , 26 are connected to combustion cylinder crank pins 31, 32, 35, 36 disposed on the crankshaft 20, respectively. The combustion cylinders 1, 2, 5, and 6 are provided with fuel injection valves 41, 42, 45, and 46, respectively, for directly injecting fuel gas (hydrogen gas) into the cylinder.

  In each of the combustion cylinders 1, 2, 5, and 6, the intake gas is sucked into the cylinder in the intake stroke, and the intake gas in the cylinder is compressed by the combustion cylinder pistons 11, 12, 15, and 16 in the compression stroke, respectively. Is done. And, for example, when the combustion cylinder pistons 11, 12, 15, 16 are positioned near the compression top dead center, the in-cylinder injection of hydrogen gas is performed by the fuel injection valves 41, 42, 45, 46, respectively. Hydrogen gas burns in the cylinder (diesel combustion by self-ignition) and power is generated in the crankshaft 20. The in-cylinder gas after combustion is discharged as exhaust gas in the exhaust stroke.

  In order to improve the thermal efficiency of the engine (combustion cylinders 1, 2, 5, 6), it is necessary to increase the pressure of hydrogen gas injected into the cylinder from the fuel injection valves 41, 42, 45, 46. For example, in order to achieve a thermal efficiency of about 50%, sonic injection from the vicinity of the compression top dead center at a high compression ratio (for example, a compression ratio of 18 or more) is necessary, and a hydrogen injection pressure of about 30 MPa is required. (For example, refer nonpatent literature 1). In order to realize such high-pressure injection stably, a compressor for compressing hydrogen gas is required.

  In the present embodiment, a compressor for compressing hydrogen gas is incorporated in the hydrogen engine, and the hydrogen engine and the compressor are integrated. Therefore, compression cylinders 3 and 4 that compress and output hydrogen gas and combustion cylinders 1, 2, 5, and 6 that combust hydrogen gas are provided in a common cylinder 10. More specifically, the cylinder block and the cylinder head used for the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4 are all made common. Hereinafter, the detailed structure of the compression cylinders 3 and 4 will be described.

  In the compression cylinders 3 and 4, the compression cylinder pistons 13 and 14 connected to the crankshaft 20 reciprocate using a part of the power of the crankshaft 20 to compress and output hydrogen gas. . That is, in each of the compression cylinders 3 and 4, a reciprocating compressor using a piston-crank mechanism is configured. The compression cylinder pistons 13 and 14 are respectively connected to the small end portions of the compression cylinder connecting rods 23 and 24 via piston pins, and the large end portions of the compression cylinder connecting rods 23 and 24 are arranged on the crankshaft 20. These are connected to the provided compression cylinder crank pins 33 and 34, respectively.

  The suction port 3 a of the compression cylinder 3 is connected to a hydrogen supply source (fuel supply source) (not shown) via a hydrogen flow path 51. The hydrogen supply source here can be constituted by, for example, a hydrogen tank that stores hydrogen gas. However, in addition to the hydrogen tank, a hydrogen storage alloy, a hydrogen generator using a hydrogen compound, or the like can be used as the hydrogen supply source. The discharge port 3 b of the compression cylinder 3 is connected to the suction port 4 a of the compression cylinder 4 via the hydrogen flow path 52, and the discharge port 4 b of the compression cylinder 4 is connected to the accumulator 60 via the hydrogen flow path 53. ing.

  The hydrogen gas supplied from the hydrogen supply source is compressed by the first-stage compression cylinder 3 and then further compressed by the second-stage compression cylinder 4. As described above, the hydrogen gas supplied from the hydrogen supply source is compressed into a plurality of stages (two stages) by the compression cylinders 3 and 4 and then supplied to the accumulator 60. That is, in the compression cylinders 3 and 4, a multistage (two-stage) reciprocating compressor is configured. Here, an example of the history of the hydrogen gas pressure in the compression cylinders 3 and 4 with respect to the crank angle is shown in FIG. In FIG. 2, the first stage shows the compression cylinder 3, and the second stage shows the compression cylinder 4. An accumulator 60 provided between the compression cylinder 4 and the combustion cylinders 1, 2, 5, 6 (fuel injection valves 41, 42, 45, 46) accumulates hydrogen gas compressed in the compression cylinders 3, 4. . Hydrogen gas accumulated in the accumulator 60 is injected from the fuel injection valves 41, 42, 45, 46 into the combustion cylinders 1, 2, 5, 6 respectively.

  A hydrogen supply amount control valve 54 is provided in the hydrogen flow path 51 that connects the hydrogen supply source and the suction port 3 a of the compression cylinder 3. The hydrogen supply amount control valve 54 adjusts the supply amount of hydrogen gas from the hydrogen supply source to the compression cylinder 3. By adjusting the supply amount of hydrogen gas by the hydrogen supply amount control valve 54, the pressure of the hydrogen gas accumulated in the accumulator 60, that is, the pressure of the hydrogen gas injected into the combustion cylinders 1, 2, 5, 6 can be adjusted. it can. A check valve 55 is provided in the hydrogen flow path 52 that connects the discharge port 3 b of the compression cylinder 3 and the suction port 4 a of the compression cylinder 4. The check valve 55 allows the flow of hydrogen gas in the direction from the discharge port 3b of the compression cylinder 3 to the suction port 4a of the compression cylinder 4, and from the suction port 4a of the compression cylinder 4 to the discharge port 3b of the compression cylinder 3. Shut off the flow of hydrogen gas in the direction to go. The check valve 55 prevents the backflow of hydrogen gas from the compression cylinder 4 to the compression cylinder 3. A check valve 56 is provided in the hydrogen flow path 53 that connects the discharge port 4 b of the compression cylinder 4 and the accumulator 60. The check valve 56 allows the flow of hydrogen gas in the direction from the discharge port 4 b of the compression cylinder 4 to the accumulator 60 and blocks the flow of hydrogen gas in the direction from the accumulator 60 to the discharge port 4 b of the compression cylinder 4. . The check valve 56 prevents the backflow of hydrogen gas from the accumulator 60 to the compression cylinder 4. A pressure control valve 58 is provided in the hydrogen flow path 57 that connects the accumulator 60 and the hydrogen flow path 51 (hydrogen supply source). The pressure control valve 58 adjusts the pressure of the hydrogen gas accumulated in the accumulator 60, that is, the pressure of the hydrogen gas injected into the combustion cylinders 1, 2, 5, 6. For example, when the pressure of the hydrogen gas in the hydrogen supply source (hydrogen tank) is higher than the pressure of the hydrogen gas in the accumulator 60, the hydrogen gas can be supplied from the hydrogen supply source to the accumulator 60 by opening the pressure control valve 58. .

  In each of the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4, cooling with a coolant is performed. A cooler 61 is provided around the hydrogen flow path 52 that connects the discharge port 3 b of the compression cylinder 3 and the suction port 4 a of the compression cylinder 4. The cooler 61 cools the hydrogen gas compressed in the compression cylinder 3 with a coolant. A cooler 62 is provided around the hydrogen flow path 53 that connects the discharge port 4 b of the compression cylinder 4 and the accumulator 60. The cooler 62 cools the hydrogen gas compressed in the compression cylinder 4 with a coolant.

  In the configuration example shown in FIG. 1, the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4 are in the combustion cylinder 1, the combustion cylinder 2, the axial direction of the crankshaft 20 (the direction parallel to the rotation center axis). The compression cylinder 3, the compression cylinder 4, the combustion cylinder 5, and the combustion cylinder 6 are arranged in series at equal intervals. That is, the combustion cylinders 1, 2, 5, and 6 and the compression cylinders 3 and 4 as a whole constitute a so-called in-line 6 cylinder. In the crankshaft 20, as shown in FIG. 3, the combustion cylinder crankpins 31, 36, the combustion cylinder crankpins 32, 35, and the compression cylinder crankpins 33, 34 are arranged around the rotation center axis. They are arranged at intervals of 120 °. In the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4, the crank radii, that is, the strokes are all set equal. The combustion cylinder connecting rods 21, 22, 25, 26 and the compression cylinder connecting rods 23, 24, the connecting rod lengths are all set equal. The length of the connecting rod here is the pitch between the large and small end portions (distance between the piston pin central axis and the crankpin central axis). The hydrogen engine in the present embodiment is a four-cycle engine. In the combustion cylinders 1, 2, 5, and 6, in-cylinder injection of hydrogen gas (hydrogen gas combustion) is performed by the combustion cylinder 1, the combustion cylinder 5, the combustion cylinder 6, By performing in the order of the combustion cylinder 2, the bias of the combustion period is suppressed. Then, the hydrogen gas compressed in the compression cylinder 3 is discharged between the injection of the hydrogen gas in the combustion cylinder 5 and the injection of the hydrogen gas in the combustion cylinder 6, and the hydrogen gas compressed in the compression cylinder 4 Is discharged between the injection of hydrogen gas in the combustion cylinder 2 and the injection of hydrogen gas in the combustion cylinder 1.

  The masses of the combustion cylinder pistons 11, 12, 15, 16 and the compression cylinder pistons 13, 14 are set to be equal, including the piston pin. The masses of the connecting rods 21, 22, 25, 26 for the combustion cylinders and the connecting rods 23, 24 for the compression cylinders are set to be equal, and the connecting rods 21, 22, 25, 26 for the combustion cylinders and the connecting rods for the compression cylinder are connected. The center of gravity positions of the rods 23 and 24 are also set to be equal. In this embodiment, the masses of the reciprocating motion parts (including the piston, piston pin, and small end of the connecting rod) in the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4 are all set equal. Yes.

  Further, the masses of the combustion cylinder crankpins 31, 32, 35, 36 and the compression cylinder crankpins 33, 34 are all set equal, so that the combustion cylinder crankpins 31, 32, 35, 36 and The mass moments of the compression cylinder crank pins 33 and 34 are set to be equal. Furthermore, the center of gravity of the crankshaft 20 is set so as to be positioned on the rotation center axis of the crankshaft 20, and the crankshaft 20 alone has a weight balance (static balance). In this embodiment, the mass moments of the rotational motion parts (including the crankpin and the large end of the connecting rod) in the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4 are all set equal. The mass moment here is (mass) × (distance of the center of gravity from the rotation center of the crankshaft 20).

  In this embodiment, since the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4 form an in-line 6 cylinder, the moment of inertia force due to the reciprocating motion portion and the rotational motion portion can be balanced. In addition, the inertial force due to the rotary motion part and the primary and secondary inertial forces (engine rotation primary and secondary components of the inertial force) due to the reciprocating motion part can also be balanced. Thus, in the present embodiment, the inertial force and the moment of inertial force generated in each of the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 4 are converted into the combustion cylinders 1, 2, 5, 6 and the compression cylinders. It is possible to equilibrate (or nearly equilibrate) the whole of 3 and 4.

  In the present embodiment, the maximum forces acting on the crankshaft 20 (compression cylinder crankpins 33 and 34) by the pressure of hydrogen gas in the compression cylinders 3 and 4 are equal to each other (or substantially equal to each other). ), The pressure ratio of the compression cylinders 3 and 4 and the pressure receiving area of each of the compression cylinder pistons 13 and 14 (area of the portion receiving the hydrogen gas pressure in the cylinder) are set. Further, the maximum force acting on the crankshaft 20 (compression cylinder crankpins 33, 34) by the pressure of hydrogen gas in the compression cylinders 3, 4 is increased by the pressure of the gas in the combustion cylinders 1, 2, 5, 6 to the crankshaft 20 ( The pressure ratio of the compression cylinders 3 and 4 and the pressure reception of the compression cylinder pistons 13 and 14 so as to be equal to (or substantially equal to) the maximum force acting on the combustion cylinder crankpins 31, 32, 35, 36). The area is set.

  Here, the maximum gas pressure in the combustion cylinders 1, 2, 5 and 6 is Pm, the supply pressure P0 of hydrogen gas to the compression cylinder 3, the pressure receiving area of the first-stage compression cylinder piston 13 is A1, and the combustion cylinder piston When the pressure receiving areas of 11, 12, 15, and 16 are Am, the pressure ratio P1 / P0 of the first-stage compression cylinder 3 is set to Pm / P0 × Am / A1. By setting the pressure ratio P1 / P0 of the compression cylinder 3 in this way, the maximum force P0 × P1 / P0 × A1 acting on the crankshaft 20 by the pressure of the hydrogen gas in the compression cylinder 3 is set to the combustion cylinders 1, 2, The maximum force Pm × Am acting on the crankshaft 20 can be made equal to the gas pressure of 5,6. Furthermore, when the pressure receiving area of the second-stage compression cylinder piston 14 is A2, the pressure ratio P2 / P1 of the second-stage compression cylinder 4 is set to A1 / A2 (= Pm / P1 × Am / A2). . By setting the pressure ratio P2 / P1 of the compression cylinder 4 in this way, the maximum force P1 × P2 / P1 × A2 acting on the crankshaft 20 due to the pressure of the hydrogen gas in the compression cylinder 4 is increased to the hydrogen gas in the compression cylinder 3. The maximum force P0 × P1 / P0 × A1 acting on the crankshaft 20 due to the pressure of and the maximum force Pm × Am acting on the crankshaft 20 due to the gas pressure of the combustion cylinders 1, 2, 5 and 6 may be made equal. it can.

  As an example, the displacement of the combustion cylinders 1, 2, 5, 6 is 2L, the maximum gas pressure Pm of the combustion cylinders 1, 2, 5, 6 is 15 MPa, and the supply pressure P0 of hydrogen gas to the compression cylinder 3 is 1 MPa. Consider a case. In that case, if the in-cylinder gas pressure at the start of compression of the combustion cylinders 1, 2, 5 and 6 is atmospheric pressure, and the charging efficiency of the combustion cylinders 1, 2, 5, and 6 is 1, the amount of air per cycle is 2.4 g. If hydrogen gas is stoichiometrically burned, the amount of air with respect to 1 mol of hydrogen gas is 2.387 mol, and the amount of air is 69 g with respect to 2 g of hydrogen gas. Therefore, the amount of hydrogen gas per cycle (relative to 2.4 g of air) is 2.4 × 2/69 = 0.0696 g, and the volume of 1 MPa hydrogen gas is 0.085 L. The accumulator 60 accumulates pressure by adjusting the closing timing of a suction valve (not shown) for opening and closing the suction port 3a of the compression cylinder 3 and setting the volume of the compression cylinder 3 at the start of compression to about 0.1L. An allowance can be given to the amount of hydrogen gas.

  In order to sonically inject hydrogen gas from the fuel injection valves 41, 42, 45, and 46 with respect to the maximum gas pressure Pm = 15 MPa in the combustion cylinders 1, 2, 5, and 6, for example, an injection pressure of about 30 MPa is required. The For example, the pressure ratio P1 / P0 of the first-stage compression cylinder 3 is set to about 10-20, and the pressure ratio P2 / P1 of the second-stage compression cylinder 4 is set to about 2-10. And by setting A1 = Am and P1 / P0 = 15, it becomes P0 * P1 / P0 * A1 = Pm * Am = 15 * A1. Furthermore, by setting A2 = A1 / 2 (= Am / 2) and P2 / P1 = 2, P1 * P2 / P1 * A2 = P0 * P1 / P0 * A1 = 15 * A1 (= Pm * Am) Thus, the pressure ratio of the entire compression cylinders 3 and 4 is 30.

  In the present embodiment, the combustion of hydrogen gas in the combustion cylinders 1, 2, 5, and 6 is diesel combustion by self-ignition, so the maximum pressure of the gas in the combustion cylinders 1, 2, 5, and 6 in one cycle is the engine. Almost no change with load fluctuation. The maximum gas pressure in the combustion cylinders 1, 2, 5, 6 can be set based on the compression ratio of the combustion cylinders 1, 2, 5, 6 and the polytropic index of the compression stroke. The pressure ratio of the compression cylinders 3 and 4 can be set based on the compression ratio of the compression cylinders 3 and 4 and the polytropic index of the compression stroke. Alternatively, the opening timing of a suction valve (not shown) that opens and closes the suction ports 3a and 4a of the compression cylinders 3 and 4 is adjusted, and the discharge valve that opens and closes the discharge ports 3b and 4b of the compression cylinders 3 and 4 (see FIG. The pressure ratio of the compression cylinders 3 and 4 can also be adjusted by adjusting the opening timing (not shown).

  When a reciprocating compressor for compressing hydrogen gas is provided separately from the hydrogen engine for in-cylinder injection of hydrogen gas at a high pressure, the configuration of the entire engine is increased by the provision of the reciprocating compressor. Furthermore, a cooling facility is also required to efficiently compress the hydrogen gas while suppressing the temperature rise. Furthermore, vibration and noise are likely to occur in the reciprocating compressor due to the pressure of the hydrogen gas and the inertial force generated by the compression operation of the hydrogen gas.

  On the other hand, in the present embodiment, a cylinder (cylinder block and cylinder head) for forming the combustion cylinders 1, 2, 5, 6 and a cylinder (cylinder block and cylinder head) for forming the compression cylinders 3, 4 are used. And are common. Thus, the compressor (compression cylinders 3 and 4) which compresses hydrogen gas is incorporated in the hydrogen engine (cylinder 10), and the hydrogen engine and the compressor are integrated to inject the compressed hydrogen gas into the cylinder. The configuration of the entire engine can be reduced in size and cost. Furthermore, by compressing the hydrogen gas in the compression cylinders 3 and 4 and then injecting it into the combustion cylinders 1, 2, 5 and 6, even if the hydrogen gas pressure in the hydrogen tank decreases, In-cylinder injection can be performed stably. Therefore, engine operation with high thermal efficiency can be performed stably. Furthermore, the in-cylinder injection pressure of hydrogen gas can be further increased by compressing the hydrogen gas into a plurality of stages (two stages) by the compression cylinders 3 and 4.

  Furthermore, in this embodiment, the cooling system and the lubrication system for the compression cylinders 3 and 4 (compressor) can be shared with the combustion cylinders 1, 2, 5 and 6, so the cooling system and the lubrication system for the compressor can be used. There is no need to provide it separately. Therefore, the compression cylinders 3 and 4 can be efficiently cooled and lubricated. Moreover, the hydrogen gas can be efficiently compressed by cooling the hydrogen gas compressed by the coolers 61 and 62.

  Further, in the present embodiment, the inertial force and the moment of inertia generated in each of the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3 and 4 are represented by the combustion cylinders 1, 2, 5, 6 and the compression cylinders 3, 3, respectively. 4 can be balanced throughout. Therefore, the vibration and noise generated in the engine due to the inertial force and the moment of the inertial force can be greatly reduced.

  Further, in the present embodiment, the maximum force that acts on the crankshaft 20 by the pressure of the hydrogen gas in the compression cylinders 3 and 4 is the maximum force that acts on the crankshaft 20 by the pressure of the gas in the combustion cylinders 1, 2, 5, and 6. Can be equal to Therefore, vibration and noise generated in the engine due to in-cylinder gas pressure can be greatly reduced, and uneven rotation of the engine (crankshaft 20) can be suppressed.

  In the present embodiment, the hydrogen gas compressed in the compression cylinders 3 and 4 is accumulated in the accumulator 60 and then injected into the combustion cylinders 1, 2, 5 and 6, thereby varying the engine load, that is, the hydrogen gas injection amount. Even in this case, in-cylinder injection of hydrogen gas can be performed stably. Further, by adjusting the supply amount of hydrogen gas to the compression cylinder 3 by the hydrogen supply amount control valve 54, the pressure of the hydrogen gas accumulated in the accumulator 60 can be adjusted. Therefore, it is possible to suppress an excessive increase in pressure of the accumulator 60 due to excessive supply of hydrogen gas. Further, the pressure of the hydrogen gas accumulated in the accumulator 60 can also be adjusted by the pressure control valve 58. By adjusting the pressure of the hydrogen gas stored in the accumulator 60, the injection pressure corresponding to the in-cylinder pressure of the combustion cylinders 1, 2, 5, 6 can be set.

  Next, another configuration example of this embodiment will be described.

  In the configuration example shown in FIG. 4, compared to the configuration example shown in FIG. 1, an accumulator 64 is provided between the compression cylinder 3 and the compression cylinder 4 (between the check valve 55 and the suction port 4 a of the compression cylinder 4). Is provided. The accumulator 64 accumulates the hydrogen gas compressed in the first-stage compression cylinder 3. The hydrogen gas accumulated in the accumulator 64 is further compressed by being supplied to the second-stage compression cylinder 4. In this case, the check valve 55 provided in the hydrogen flow path 52 allows the flow of hydrogen gas in the direction from the discharge port 3 b of the compression cylinder 3 toward the accumulator 64, and the discharge port 3 b of the compression cylinder 3 from the accumulator 64. Shut off the flow of hydrogen gas in the direction toward. Although not shown in FIG. 4, a cooler that cools the hydrogen gas compressed by the compression cylinder 3 may be provided around the hydrogen flow path 52.

  Here, an example of the history of the hydrogen gas pressure in the compression cylinders 3 and 4 with respect to the crank angle is shown in FIG. In FIG. 5, the first stage shows the compression cylinder 3, and the second stage shows the compression cylinder 4. In the configuration example shown in FIG. 1, the compression cylinder 3 pauses the compression operation in the second half of one cycle shown in FIG. 2, and the compression cylinder 4 pauses the compression operation in the first half of the one cycle shown in FIG. On the other hand, in the configuration example shown in FIG. 4, the compression cylinders 3 and 4 perform the compression operation also in the first half of one cycle shown in FIG. 5. Therefore, in the configuration example shown in FIG. 4, the amount of hydrogen gas sucked in one time in the compression cylinders 3 and 4 can be reduced compared to the configuration example shown in FIG. 1.

  In the above description of the present embodiment, among cylinders 1 to 6 arranged in series in the order of cylinder 1, cylinder 2, cylinder 3, cylinder 4, cylinder 5, and cylinder 6, cylinders 1, 2, 5, and 6 are hydrogen gas. The cylinders 3 and 4 are used as compression cylinders for compressing hydrogen gas. However, in the present embodiment, the cylinders 1, 3, 4, and 6 can be used as combustion cylinders, and the cylinders 2 and 5 can be used as compression cylinders. Alternatively, the cylinders 2, 3, 4, and 5 can be used as combustion cylinders, and the cylinders 1 and 6 can be used as compression cylinders. Also by the arrangement of the combustion cylinder and the compression cylinder, the deviation of the combustion period of hydrogen gas can be suppressed.

  In the above description of the present embodiment, hydrogen gas is used as the fuel gas to be compressed and burned. However, in this embodiment, fuel gas other than hydrogen gas, such as natural gas, can also be used, for example.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and can be implemented with a various form in the range which does not deviate from the summary of this invention. Of course.

1 is a diagram schematically showing an outline of an internal configuration of an internal combustion engine according to an embodiment of the present invention. It is a figure which shows an example of the log | history of the hydrogen gas pressure in the compression cylinder with respect to a crank angle. It is a figure which shows the outline of a structure of a crankshaft typically. It is a figure which shows typically the outline of the other internal structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows an example of the log | history of the hydrogen gas pressure in the compression cylinder with respect to a crank angle.

Explanation of symbols

  1, 2, 5, 6 Combustion cylinder, 3, 4 Compression cylinder, 10 Cylinder, 11, 12, 15, 16 Piston for combustion cylinder, 13, 14 Piston for compression cylinder, 20 Crankshaft, 21, 22, 25, 26 Connecting rod for combustion cylinder, 23, 24 Connecting rod for compression cylinder, 31, 32, 35, 36 Crank pin for combustion cylinder, 33, 34 Crank pin for compression cylinder, 41, 42, 45, 46 Fuel injection valve, 54 Hydrogen Supply amount control valve, 55, 56 Check valve, 58 Pressure control valve, 60, 64 Accumulator, 61, 62 Cooler.

Claims (10)

An internal combustion engine that generates power in a crankshaft by burning fuel gas in a cylinder,
A compression cylinder that compresses and outputs fuel gas by part of the power of the crankshaft;
A combustion cylinder in which fuel gas compressed in the compression cylinder is injected, and combustion is generated in the crankshaft by burning the injected fuel gas;
Is provided in a common cylinder. The internal combustion engine according to claim 1,
An internal combustion engine characterized in that the compression cylinder and the combustion cylinder are provided in a common cylinder so that the inertial force generated in each of the compression cylinder and the combustion cylinder is substantially balanced throughout the compression cylinder and the combustion cylinder. The internal combustion engine according to claim 1 or 2,
An internal combustion engine characterized in that the pressure ratio of the compression cylinder is set so that the maximum force acting on the crankshaft by the pressure of the compression cylinder is substantially equal to the maximum force acting on the crankshaft by the pressure of the combustion cylinder. The internal combustion engine according to any one of claims 1 to 3,
A combustion cylinder and a plurality of compression cylinders are provided in a common cylinder,
An internal combustion engine in which fuel gas is compressed in a plurality of stages by the plurality of compression cylinders. An internal combustion engine according to claim 4,
An internal combustion engine characterized in that the pressure ratio of each compression cylinder is set so that the maximum forces acting on the crankshaft by the pressure of each compression cylinder are substantially equal to each other. An internal combustion engine according to any one of claims 1 to 5,
A pressure accumulator for accumulating the fuel gas compressed in the compression cylinder is provided,
An internal combustion engine characterized in that fuel gas accumulated in an accumulator is injected into a combustion cylinder. The internal combustion engine according to any one of claims 1 to 6,
An internal combustion engine characterized in that a pressure regulator for adjusting the pressure of fuel gas injected into the combustion cylinder is provided. The internal combustion engine according to any one of claims 1 to 7,
An internal combustion engine comprising a supply amount regulator for adjusting a supply amount of fuel gas to a compression cylinder. An internal combustion engine according to any one of claims 1 to 8,
An internal combustion engine comprising a cooler for cooling fuel gas compressed in a compression cylinder. An internal combustion engine according to any one of claims 1 to 9,
The internal combustion engine, wherein the fuel gas is hydrogen gas.

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