Engine device

Abstract

To provide an engine device capable of suppressing contamination of an intake system component due to reduction of blow-by gas to a combustion chamber to suppress increase of cost required for the intake system component, and capable of prolonging a production life of the intake system component.SOLUTION: An engine device 1 runs with fuel containing a corrosive substance. The engine device 1 comprises a blow-by reduction injector 37a that reduces blow-by gas to a combustion chamber 21a of an engine 2. The corrosive substance contained in the fuel is ammonia or methanol.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an engine device that is operated by a fuel containing a corrosive substance. [Background technology]

[0002] Conventionally, some engine devices are operated by fuels containing corrosive substances such as ammonia and methanol. In addition, in engine devices, fuel gas supplied to the combustion chamber may leak into the crank chamber (crank case) as blow-by gas. Therefore, the engine device is required to treat such blow-by gas.

[0003] For example, Patent Document 1 discloses a blow-by gas recirculation device used in an internal combustion engine in which a turbocharger and an intercooler for cooling the intake gas pressurized by the turbocharger are provided on the intake passage, and the device includes an air introduction passage for introducing the intake gas in the intake passage into the crankcase of the internal combustion engine, and a gas recirculation passage for recirculating the blow-by gas in the crankcase of the internal combustion engine into the intake passage. The gas recirculation passage is connected to the intake passage on the intake upstream side of the turbocharger, thereby recirculating the blow-by gas in the crankcase to the intake passage and causing it to flow again into the combustion chamber. In addition, the air introduction passage is connected to the intake passage on the intake downstream of the turbocharger and on the intake upstream of the intercooler, thereby supplying a part of the air compressed by the turbocharger into the crankcase and ventilating the crankcase. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4383983 Summary of the Invention [Problem to be solved by the invention]

[0005] In the case of an engine device that runs on fuel containing corrosive substances, in the conventional technology such as Patent Document 1, toxic and corrosive fuel such as ammonia flows into the intake passage upstream in the intake direction, so that not only the intake passage but also intake system parts such as the turbocharger and intercooler are contaminated (corroded), and there is a concern that the replacement interval (product life) of the intake system parts will be shortened. To address this, it is necessary to use corrosion-resistant materials for the intake system parts or to apply corrosion-resistant coating, but in that case, there is a risk that the cost will increase and the product appeal will decrease.

[0006] In addition, in engine systems, blow-by gas is supplied to the combustion chamber together with normal fuel, and the blow-by gas is reused as fuel, which is expected to reduce fuel consumption. However, in conventional technology, the fuel components of the blow-by gas may blow from the intake port to the exhaust port during valve overlap in the combustion chamber, and may flow out to the exhaust side without being burned in the combustion chamber. In this case, the blow-by gas may mix with the exhaust gas, deteriorating the exhaust gas components and reducing the effect of reducing fuel consumption.

[0007] The present invention aims to provide an engine device that can suppress contamination of intake system components caused by the return of blow-by gas to the combustion chamber, thereby reducing the costs incurred for the intake system components and extending the product life of the intake system components. [Means for solving the problem]

[0008] In order to solve the above problems, the engine device of the present invention is an engine device that runs on fuel containing corrosive substances and is equipped with a blow-by reduction injector or blow-by reduction mixer that returns blow-by gas to the combustion chamber of the engine. Effect of the Invention

[0009] According to the present invention, an engine device is provided that can suppress contamination of intake system components caused by the return of blow-by gas to the combustion chamber, thereby reducing the costs incurred for the intake system components and extending the product life of the intake system components. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating an example of an engine device according to an embodiment of the present invention. [Diagram 2] 1 is a schematic diagram showing an example of a cylinder of an engine in an engine device according to an embodiment of the present invention. FIG. [Diagram 3] FIG. 4 is a schematic diagram showing an example of an engine device according to a first modified example of the present invention. [Figure 4] FIG. 11 is a schematic diagram showing an example of an engine device according to a second modified example of the present invention. [Diagram 5] FIG. 11 is a schematic diagram showing an example of an engine device according to a third modified example of the present invention. [Figure 6] FIG. 11 is a schematic diagram showing an example of a cylinder of an engine in an engine device according to a third modified example of the present invention. [Figure 7] FIG. 11 is a schematic diagram showing an example of a cylinder of an engine in an engine device according to a third modified example of the present invention. [Figure 8] FIG. 11 is a schematic diagram showing an example of an engine device according to a fourth modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An engine device 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, the engine device 1 includes an engine 2, an intake passage 3, an exhaust passage 4, a fuel supply passage 5, a turbocharger 6, and an intercooler 7. Furthermore, the engine device 1 includes a blow-by passage 8, a filter 9, an externally driven pump 10, and a control unit 11.

[0012] Particularly in this embodiment, the engine device 1 is a gas engine that operates by feeding fuel (fuel gas) such as a gaseous fuel containing toxic and corrosive substances such as ammonia and methanol into the combustion chamber 21a of the engine 2. The fuel is supplied to the combustion chamber 21a as a mixture with air.

[0013] The engine 2 is, for example, a four-stroke engine, and is configured with a cylinder block 20 including a plurality of cylinders 21 and a crankcase 22. Although six cylinders 21 are illustrated in Fig. 1, the number of cylinders 21 is not limited to six. As shown in Figs. 1 and 2, each cylinder 21 is configured with a cylinder 23, a piston 24, and a cylinder head 25.

[0014] The cylinder 23 is formed, for example, in a cylindrical shape within the cylinder block 20, and the piston 24 is slidably housed within the cylinder 23. The cylinder head 25 is attached to the upper side of the cylinder 23, and a combustion chamber 21a is formed inside the cylinder 23 and the cylinder head 25. The cylinder head 25 is provided with an ignition device 26 that ignites fuel within the combustion chamber 21a. The ignition device 26 may be configured as a micro-pilot type device that injects a small amount of liquid fuel, or may be configured as a spark ignition type device using an ignition plug. Furthermore, the ignition device 26 may be configured to compress and ignite a mixture of gaseous fuel and liquid fuel.

[0015] Each cylinder 23 of the multiple cylinders 21 communicates with a crankcase 22, and a crankshaft 27 is rotatably supported by the crankcase 22. A piston 24 of each cylinder 21 is connected to the crankshaft 27 via a connecting rod 28, and the reciprocating motion of the piston 24 is converted into the rotational motion of the crankshaft 27 via the connecting rod 28.

[0016] The cylinder head 25 has an intake port 29 communicating with the combustion chamber 21a and an intake valve 30 that opens and closes the intake port 29. The combustion chamber 21a is connected to an intake passage 3 via the intake port 29, etc., and air or a mixture of air and fuel supplied from the intake passage 3 is introduced into the combustion chamber 21a. The cylinder head 25 also has an exhaust port 31 communicating with the combustion chamber 21a and an exhaust valve 32 that opens and closes the exhaust port 31. The combustion chamber 21a is connected to an exhaust passage 4 via the exhaust port 31, etc., and exhaust gas generated in the combustion chamber 21a is discharged to the exhaust passage 4.

[0017] In order to connect the intake passage 3 to the multiple cylinders 21, an intake manifold 33 having branched intake passages 33a branching from the intake passage 3 to each of the intake ports 29 of the multiple cylinders 21 is provided between the intake passage 3 and the engine 2. In addition, in order to connect the exhaust passage 4 to the multiple cylinders 21, an exhaust manifold 34 having branched exhaust passages 34a branching from the exhaust passage 4 to the multiple cylinders 21 is provided between the exhaust passage 4 and the engine 2. In FIG. 1, the intake manifold 33 is indicated by a dashed line, and the exhaust manifold 34 is indicated by a dashed line.

[0018] The intake passage 3 is connected to a plurality of cylinders 21 of the engine 2 and supplies compressed and cooled air to each cylinder 21. A mixture of air supplied from the intake passage 3 and fuel supplied from a fuel tank (not shown) via a fuel supply path 5 is supplied to a combustion chamber 21a of each cylinder 21. A supercharger 6 is provided upstream in the intake direction in the intake passage 3 for compressing air or a mixture of fuel and air flowing through the intake passage 3 and sending it downstream in the intake direction, and an intercooler 7 is provided downstream in the intake direction of the supercharger 6 for cooling the air flowing through the intake passage 3. The intake passage 3 may be provided with an air filter (not shown) for purifying fresh air and introducing it into the intake passage 3.

[0019] The exhaust passage 4 is connected to a plurality of cylinders 21 of the engine 2, and allows exhaust gas generated in each cylinder 21 to flow and be discharged.

[0020] The fuel supply path 5 supplies fuel from a fuel tank (not shown) to the engine 2. For example, the fuel supply path 5 has a plurality of branch fuel paths 5a that branch off to supply fuel to each of the plurality of cylinders 21, and the branch fuel paths 5a are connected to ends of branch intake flow paths 33a of an intake manifold 33 provided for each of the plurality of cylinders 21.

[0021] A main fuel supply device 35 is provided in the fuel supply path 5 to supply the fuel supplied through the fuel supply path 5 to the combustion chamber 21a of each cylinder 21. The main fuel supply device 35 is configured with, for example, a gas admission valve or a gas injector. For example, in order to supply fuel to each of the cylinders 21, a plurality of main fuel supply devices 35 are provided at the respective ends of the branch fuel paths 5a, and inject fuel at the ends of the branch intake passages 33a of the intake manifold 33 for each of the cylinders 21.

[0022] When fuel is supplied to each of the multiple cylinders 21, the main fuel supply device 35 injects fuel under the control of the control unit 11, and in order to prevent fuel from being blown away due to valve overlap in the combustion chamber 21a, the main fuel supply device 35 intermittently injects fuel so that the fuel is supplied to the combustion chamber 21a when the exhaust port 31 is closed and the intake port 29 is open.

[0023] The turbocharger 6 compresses the air or air-fuel mixture flowing through the intake passage 3 and sends it downstream in the intake direction. The turbocharger 6 has a turbine 6a and a compressor 6b. The turbine 6a is disposed in the exhaust passage 4, and the compressor 6b is disposed in the intake passage 3. The turbine 6a is rotated by the exhaust gas flowing through the exhaust passage 4, and the compressor 6b is driven by the rotational force of the turbine 6a, thereby compressing the air or air-fuel mixture flowing through the intake passage 3.

[0024] The blow-by path 8 is connected from the crankcase 22 to the fuel supply path 5. When fuel gas leaks from the combustion chamber 21a of each cylinder 21 into the crankcase 22, blow-by gas is generated in the crankcase 22, but the blow-by gas flows through the blow-by path 8. The blow-by path 8 is provided with a check valve 36 that prevents fuel from flowing from the fuel supply path 5 into the blow-by path 8.

[0025] By circulating the blow-by gas to the fuel supply path 5 via the blow-by path 8, the blow-by gas flows together with the fuel in the fuel supply path 5, and the blow-by gas is supplied together with the fuel to the combustion chamber 21a of each cylinder 21 by the main fuel supply device 35. In this way, the blow-by gas flows via the blow-by path 8 and the fuel supply path 5, and the main fuel supply device 35 functions as a blow-by reduction device 37, for example, a blow-by reduction injector 37a, which returns the blow-by gas to the combustion chamber 21a.

[0026] As described above, the main fuel supply device 35 is controlled by the control unit 11 to intermittently inject fuel. Similarly, the main fuel supply device 35 functioning as the blow-by return injector 37a intermittently injects blow-by gas supplied together with the fuel so as to return the blow-by gas to the combustion chamber 21a when the exhaust port 31 is closed and the intake port 29 is open, in order to prevent fuel from being blown away due to valve overlap in the combustion chamber 21a.

[0027] The filter 9 is provided on the upstream side in the flow direction of the blow-by gas in the blow-by path 8. The filter 9 separates oil mist contained in the blow-by gas flowing through the blow-by path 8 to produce an unburned air-fuel mixture, and is constituted by, for example, a mist separator.

[0028] The externally driven pump 10 is provided in the blow-by path 8 downstream of the filter 9 in the blow-by gas flow direction. The externally driven pump 10 is driven when the engine 2 is operating (when fuel is being supplied through the fuel supply path 5) and causes the blow-by gas to flow through the blow-by path 8 communicated with the crankcase 22, thereby sucking and / or pressurizing the blow-by gas and merging it into the fuel supply path 5. In addition, the externally driven pump 10 causes the blow-by gas to flow through the blow-by path 8, thereby ventilating the crankcase 22 and creating a negative pressure in the crankcase 22. This prevents the blow-by gas in the crankcase 22 from leaking from the crankcase 22 at a location other than the blow-by path 8, for example, preventing the blow-by gas from leaking from the crankcase 22 at a location where the crankshaft 27 is supported.

[0029] The externally driven pump 10 may be driven at the same intensity regardless of whether the engine 2 is running (operating) or not, and may cause the blow-by gas to flow at the same intensity. Alternatively, the externally driven pump 10 may be driven at a relatively high intensity when the engine 2 is operating, and driven at a relatively low intensity when the engine 2 is stopped. Alternatively, the externally driven pump 10 may be driven until a predetermined time has elapsed after the engine 2 is stopped, and then stopped being driven after the predetermined time has elapsed.

[0030] The control unit 11 is a computer such as an ECU (Engine Control Unit) that controls the operation of the engine 2, and includes a CPU, ROM, RAM, etc., and is configured to control each part of the engine 2. The control unit 11 may store various programs for controlling the engine 2, and control the engine 2 by reading and executing the programs.

[0031] In particular, the control unit 11 controls the timing of fuel injection by the main fuel supply device 35 and the timing of blow-by gas injection by the blow-by reduction injector 37a so that fuel does not blow by due to valve overlap in the combustion chamber 21a.

[0032] As described above, according to this embodiment, the engine device 1 is an engine device 1 that is operated by fuel containing a corrosive substance, and includes the blow-by reduction injector 37a that reduces blow-by gas generated in the crankcase 22 of the engine 2 to the combustion chamber 21a of the engine 2. The corrosive substance contained in the fuel is ammonia or methanol.

[0033] As a result, the engine device 1 includes the blow-by gas return injector 37a for returning the blow-by gas containing corrosive substances, and thus the return position of the blow-by gas can be set so as to suppress the flow of the blow-by gas through the intake passage 3, the turbocharger 6, the intercooler, and other intake system components. This minimizes contamination of the intake system components by the blow-by gas, and extends the replacement interval of the intake system components. In addition, the intake system components can be configured without using corrosion-resistant members or corrosion-resistant coatings against the blow-by gas, which suppresses an increase in the cost of the intake system components and a decrease in the marketability of the intake system components.

[0034] In addition, according to this embodiment, the engine device 1 is provided with a fuel supply path 5 that supplies fuel to the engine 2, and a blow-by path 8 connected from the crankcase 22 to the fuel supply path 5, and causes blow-by gas to flow through the blow-by path 8 and the fuel supply path 5 to the blow-by return injector 37a.

[0035] Specifically, according to this embodiment, the engine device 1 is equipped with a main fuel supply device 35 that supplies fuel supplied via the fuel supply path 5 to the combustion chamber 21a, and the main fuel supply device 35 functions as a blow-by return injector 37a that returns blow-by gas supplied together with the fuel via the fuel supply path 5 to the combustion chamber 21a.

[0036] As a result, the engine device 1 can suppress contamination of the intake passage 3 by blow-by gas by returning the blow-by gas to the fuel supply path 5 instead of the intake passage 3. In addition, since the fuel supply path 5 is originally intended to circulate fuel containing corrosive substances, there is no need to take any new pollution countermeasures against the return of blow-by gas containing corrosive substances.

[0037] In addition, according to this embodiment, the engine device 1 is equipped with an externally driven pump 10 that causes the blow-by gas to flow through the blow-by path 8, and the blow-by gas is sucked in and / or pressurized by the externally driven pump 10 and merged into the fuel supply path 5.

[0038] As a result, the engine device 1 can ventilate the crankcase 22 and create a negative pressure in the crankcase 22 by the externally driven pump 10. Therefore, it is possible to prevent the blow-by gas in the crankcase 22 from leaking from the crankcase 22 at a location other than the blow-by path 8.

[0039] In the above embodiment, in the engine device 1, an example has been described in which the fuel supply path 5 has a plurality of branch fuel paths 5a in order to supply fuel to each of the plurality of cylinders 21, and a plurality of main fuel supply devices 35 constituted by a gas admission valve, a gas injector, etc. are provided in each of the plurality of branch fuel paths 5a, but the present invention is not limited to this example.

[0040] 3, in the engine device 1, the fuel supply path 5 is configured without being branched into a plurality of branch fuel paths 5a, and a single main fuel supply device 35 configured with a gas mixing device such as a Venturi mixer or a single point injector may be provided at the end of the fuel supply path 5 and connected to the intake manifold 33 before being branched into the branch intake flow path 33a, or to the intake passage 3 immediately before the intake manifold 33. The main fuel supply device 35 mixes fuel with the air flowing through the intake passage 3 or the intake manifold 33.

[0041] In this first modified example, the main fuel supply device 35 functions as a blow-by reduction device 37, for example, a blow-by reduction mixer 37b, that returns blow-by gas to the combustion chamber 21a, and mixes the blow-by gas together with fuel into the air circulating through the intake passage 3 and the intake manifold 33.

[0042] In addition, in the above-described embodiment, an example has been described in which the blow-by path 8 is connected to the fuel supply path 5 to merge the blow-by gas with the fuel, and the main fuel supply device 35, which supplies the fuel supplied via the fuel supply path 5 to the combustion chamber 21a of each cylinder 21, functions as a blow-by reduction device 37 such as a blow-by reduction injector 37a or a blow-by reduction mixer 37b that returns the blow-by gas to the combustion chamber 21a, but the present invention is not limited to this example.

[0043] For example, in the second and third modified examples, as shown in Fig. 4 and Fig. 5, in the engine device 1, the blow-by passage 8 is configured to merge the blow-by gas into the air-fuel mixture without being connected to the fuel supply passage 5, and a blow-by reduction device 37 such as a blow-by reduction injector 37a independent of the main fuel supply device 35 may be provided at the end of the blow-by passage 8. That is, the blow-by passage 8 causes the blow-by gas to flow directly to the blow-by reduction injector 37a. For example, the blow-by passage 8 is branched into a plurality of branch blow-by passages 8a corresponding to the plurality of cylinders 21, and a plurality of blow-by reduction injectors 37a independent of the main fuel supply device 35 are provided at the end of each of the plurality of branch blow-by passages 8a.

[0044] In the second and third modified examples, as in the above-described embodiment, the blow-by return injector 37a intermittently injects blow-by gas so that the blow-by gas is returned to the combustion chamber 21a when the exhaust port 31 is closed and the intake port 29 is open, in order to prevent fuel from being blown away due to valve overlap in the combustion chamber 21a.

[0045] 4, in the second modified example, a plurality of branch blow-by paths 8a of the blow-by path 8 are connected to the branch intake passages 33a of the intake manifold 33 for each of the cylinders 21, and a plurality of blow-by return injectors 37a provided in each of the branch blow-by paths 8a inject blow-by gas at the end of the branch intake passage 33a of the intake manifold 33 for each of the cylinders 21, thereby returning the blow-by gas to each combustion chamber 21a. In this case, the blow-by return injector 37a is preferably provided in the branch intake passage 33a downstream of the main fuel supply device 35 in the intake direction.

[0046] In the third modified example, as shown in FIG. 5, multiple branch blow-by paths 8a of the blow-by path 8 are connected to each cylinder head 25 of the multiple cylinders 21, and multiple blow-by return injectors 37a provided in each of the multiple branch blow-by paths 8a inject blow-by gas at the cylinder heads 25 of the multiple cylinders 21 to return it to each combustion chamber 21a.

[0047] In this case, the blow-by reduction injector 37a is provided in the cylinder head 25 in communication with the combustion chamber 21a so as to directly inject blow-by gas into the combustion chamber 21a, as shown in Fig. 6. Note that the main fuel supply device 35, such as a gas admission valve or a gas injector, may also be provided in the cylinder head 25 in communication with the combustion chamber 21a so as to directly inject fuel into the combustion chamber 21a.

[0048] 7, the blow-by reduction injector 37a is provided in the cylinder head 25 in communication with the intake port 29 so as to inject blow-by gas into the intake port 29 which is connected to the combustion chamber 21a. Note that a main fuel supply device 35 such as a gas admission valve or a gas injector may also be provided in the cylinder head 25 in communication with the intake port 29 so as to inject fuel into the intake port 29.

[0049] Alternatively, in a fourth modified example, as shown in FIG. 8, in the engine device 1, the blow-by passage 8 is connected to the intake manifold 33 before being branched into the branch intake passage 33a, or to the intake passage 3 immediately before the intake manifold 33, and a single blow-by reduction device 37, for example, a blow-by reduction mixer 37b, which is composed of a gas mixing device such as a Venturi mixer or a single point injector independent of the main fuel supply device 35, may be provided at the end of the blow-by passage 8. That is, the blow-by passage 8 directly flows the blow-by gas to the blow-by reduction mixer 37b. In this case, the main fuel supply device 35 is composed of a gas mixing device such as a Venturi mixer or a single point injector, and the blow-by reduction mixer 37b is preferably provided downstream of the main fuel supply device 35 in the intake direction. The blow-by reduction mixer 37b mixes the blow-by gas with the air flowing through the intake passage 3 or the intake manifold 33.

[0050] In the second, third and fourth variants, as in the above-described embodiments, the externally driven pump 10 draws in and / or pressurizes the blow-by gas by causing the blow-by gas to flow through a blow-by path 8 connected to the crankcase 22, thereby supplying the blow-by gas via the blow-by path 8 to blow-by reduction devices 37 such as multiple blow-by reduction injectors 37a and blow-by reduction mixers 37b.

[0051] As described above, according to the second, third or fourth modified example, the engine system 1 is provided with a blow-by path 8 that is connected from the crankcase 22 to a blow-by reduction device 37, such as the blow-by reduction injector 37a or the blow-by reduction mixer 37b, and that circulates blow-by gas to the blow-by reduction device 37, such as the blow-by reduction injector 37a or the blow-by reduction mixer 37b.

[0052] As a result, by providing the engine device 1 with a dedicated blow-by path 8 for circulating blow-by gas, the flow of blow-by gas through intake system components such as the intake passage 3, turbocharger 6, intercooler, etc. can be suppressed, thereby minimizing contamination of the intake system components by blow-by gas and lengthening the replacement intervals for the intake system components.

[0053] Furthermore, according to the second, third or fourth modified example, the engine device 1 includes a fuel supply path 5 that supplies fuel to the engine 2, a main fuel supply device 35 that supplies the fuel supplied via the fuel supply path 5 to the combustion chamber 21a, and an externally driven pump 10 that causes blow-by gas to flow through the blow-by path 8, and a blow-by reduction device 37 such as a blow-by reduction injector 37a or a blow-by reduction mixer 37b is provided independently of the main fuel supply device 35, and the blow-by gas is sucked in and / or pressurized by the externally driven pump 10 and supplied to the blow-by reduction device 37 such as the blow-by reduction injector 37a or the blow-by reduction mixer 37b.

[0054] Specifically, according to the second or third modified example, in the engine device 1, the blow-by reduction injector 37a reduces the blow-by gas to the combustion chamber 21a by injecting the blow-by gas directly into the combustion chamber 21a, or by injecting the blow-by gas into the intake port 29 connected to the combustion chamber 21a, or by injecting the blow-by gas into the end of the intake manifold 33 connected to the combustion chamber 21a.

[0055] As a result, by providing the engine unit 1 with a dedicated blow-by path 8 for circulating blow-by gas, the flow of blow-by gas can be suppressed not only in the intake system components but also in the fuel supply path 5 and main fuel supply device 35. Therefore, contamination of the fuel supply path 5 and main fuel supply device 35 by blow-by gas can be minimized and the replacement intervals for the fuel supply path 5 and main fuel supply device 35 can be extended.

[0056] Moreover, according to the second or third modified example, in the engine system 1, the blow-by return injector 37a intermittently injects the blow-by gas.

[0057] This makes it possible to suppress the fuel components of the blow-by gas from blowing through the intake port 29 to the exhaust port 31 and flowing out to the exhaust side without being burned during valve overlap of the combustion chamber 21a in the engine device 1. Therefore, it is possible to suppress the mixing of the blow-by gas with the exhaust gas, suppress the deterioration of the exhaust gas properties caused by the blow-by gas, and improve the effect of reducing fuel consumption.

[0058] In addition, the present invention can be modified as appropriate within the scope that does not contradict the gist or concept of the invention that can be read from the claims and the entire specification, and engine devices involving such modifications are also included in the technical concept of the present invention.

[0059] [Appendix to the invention] The following will provide an overview of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0060] <Appendix 1> An engine device that is operated by a fuel containing a corrosive substance, An engine device comprising a blow-by reduction injector or a blow-by reduction mixer for reducing blow-by gas into a combustion chamber of the engine.

[0061] <Appendix 2> a fuel supply path that supplies the fuel to the engine; a blow-by passage connected to the fuel supply passage, 2. The engine device according to claim 1, wherein the blow-by gas is caused to flow to the blow-by reduction injector or the blow-by reduction mixer via the blow-by path and the fuel supply path.

[0062] <Appendix 3> a main fuel supply device that supplies the fuel supplied through the fuel supply path to the combustion chamber, The engine apparatus according to claim 2, wherein the main fuel supply device functions as the blow-by reduction injector or the blow-by reduction mixer that returns the blow-by gas supplied together with the fuel via the fuel supply path to the combustion chamber.

[0063] <Appendix 4> an externally driven pump for causing the blow-by gas to flow through the blow-by path; 4. The engine device according to claim 3, wherein the blow-by gas is sucked and / or pressurized by the externally driven pump and merged into the fuel supply path.

[0064] <Appendix 5> The engine device according to claim 1, further comprising a blow-by passage connected to the blow-by reduction injector or the blow-by reduction mixer for circulating the blow-by gas to the blow-by reduction injector or the blow-by reduction mixer.

[0065] <Appendix 6> a fuel supply path that supplies the fuel to the engine; a main fuel supply device that supplies the fuel supplied through the fuel supply path to the combustion chamber; an externally driven pump for causing the blow-by gas to flow through the blow-by path, the blow-by reduction injector or the blow-by reduction mixer is provided independently of the main fuel supply device, The engine device according to claim 5, wherein the blow-by gas is sucked and / or pressurized by the externally driven pump and supplied to the blow-by reduction injector or the blow-by reduction mixer.

[0066] <Appendix 7> The engine device described in Appendix 6, characterized in that the blow-by reduction injector injects the blow-by gas directly into the combustion chamber, or injects the blow-by gas into an intake port communicating with the combustion chamber, or injects the blow-by gas into an end of an intake manifold connected to the combustion chamber.

[0067] <Appendix 8> 8. The engine device according to claim 1, wherein the blow-by gas reduction injector intermittently injects the blow-by gas.

[0068] <Appendix 9> 9. The engine device according to any one of claims 1 to 8, wherein the corrosive substance is ammonia or methanol. [Explanation of symbols]

[0069] 1 Engine unit 2 Engine 3 Intake passage 4 Exhaust passage 5 Fuel supply route 6. Turbocharger 7. Intercooler 8 Blow-by path 9 Filters 10 Externally driven pump 11 Control unit 20 Cylinder block 21 cylinders 21a Combustion chamber 22 Crankcase 23 Cylinder 24 Piston 25 Cylinder head 26 Ignition system 27 Crankshaft 28 Connecting rod 29 Intake port 30 Intake valve 31 Exhaust port 32 Exhaust valve 33 Intake manifold 34 Exhaust manifold 35 Main fuel supply system 36 Check valve 37 Blow-by reduction device 37a Blow-by reduction injector 37b Blow-by reduction mixer

Claims

1. An engine device that is operated by a fuel containing a corrosive substance, An engine device comprising a blow-by reduction injector or a blow-by reduction mixer for reducing blow-by gas into a combustion chamber of the engine.

2. a fuel supply path that supplies the fuel to the engine; a blow-by passage connected to the fuel supply passage, 2. The engine apparatus according to claim 1, wherein the blow-by gas is circulated to the blow-by reduction injector or the blow-by reduction mixer via the blow-by path and the fuel supply path.

3. a main fuel supply device that supplies the fuel supplied through the fuel supply path to the combustion chamber, The engine apparatus according to claim 2, characterized in that the main fuel supply device functions as the blow-by reduction injector or the blow-by reduction mixer that returns the blow-by gas supplied together with the fuel via the fuel supply path to the combustion chamber.

4. an externally driven pump for causing the blow-by gas to flow through the blow-by path; 4. The engine apparatus according to claim 3, wherein the blow-by gas is sucked and / or pressurized by the externally driven pump and is made to flow into the fuel supply path.

5. 2. The engine apparatus according to claim 1, further comprising a blow-by passage connected to the blow-by reduction injector or the blow-by reduction mixer for circulating the blow-by gas to the blow-by reduction injector or the blow-by reduction mixer.

6. a fuel supply path that supplies the fuel to the engine; a main fuel supply device that supplies the fuel supplied through the fuel supply path to the combustion chamber; an externally driven pump for causing the blow-by gas to flow through the blow-by path, the blow-by reduction injector or the blow-by reduction mixer is provided independently of the main fuel supply device, 6. The engine apparatus according to claim 5, wherein the blow-by gas is sucked and / or pressurized by the externally driven pump and is supplied to the blow-by reduction injector or the blow-by reduction mixer.

7. The engine device according to claim 6, characterized in that the blow-by reduction injector injects the blow-by gas directly into the combustion chamber, or injects the blow-by gas into an intake port connected to the combustion chamber, or injects the blow-by gas into an end of an intake manifold connected to the combustion chamber.

8. 8. The engine apparatus according to claim 7, wherein the blow-by gas reduction injector intermittently injects the blow-by gas.

9. 2. The engine apparatus according to claim 1, wherein the corrosive substance is ammonia or methanol.

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