Engine device

Abstract

The invention provides an engine device capable of suppressing pollution of an air intake system component caused by reduction of leakage gas into a combustion chamber, suppressing cost consumed by the air intake system component, and prolonging the service life of the air intake system component. An engine device (1) is provided with a leak reduction injector (37a) for reducing leak gas into a combustion chamber (21a) of an engine (2), the leak reduction injector (37a) operating using a fuel containing a corrosive material. The corrosive substance contained in the fuel is ammonia or methanol.

Description

Technical Field

[0001] The present invention relates to an engine arrangement operating with a fuel containing corrosive substances. Background Art

[0002] In the past, there was a structure in the engine device that used fuel containing corrosive substances such as ammonia and methanol to operate. In addition, in the engine device, the fuel gas supplied to the combustion chamber sometimes leaks into the crank chamber (crankcase) as blowby gas. Therefore, the engine device is required to treat this blowby gas.

[0003] For example, Patent Document 1 discloses a blowby gas recirculation device for an internal combustion engine in which a supercharger and an intercooler for cooling intake gas supercharged by the supercharger are arranged on an intake passage, and comprises: an air introduction passage for allowing intake gas in the intake passage to flow into a crankcase of the internal combustion engine; and a gas recirculation passage for allowing blowby gas in the crankcase of the internal combustion engine to flow back into the intake passage. The gas recirculation passage is connected to the intake passage on the intake upstream side of the supercharger, thereby allowing blowby gas in the crankcase to flow back into the intake passage and flow into the combustion chamber again. In addition, the air introduction passage is connected to the intake passage downstream of the supercharger and upstream of the intercooler, thereby supplying a portion of the air compressed by the supercharger into the crankcase to ventilate the crankcase.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 4383983 Summary of the invention

[0007] In the case of an engine device that operates using a fuel containing corrosive substances, in the prior art such as Patent Document 1, ammonia and other toxic / corrosive fuels flow into the intake direction upstream side of the intake passage, so that not only the intake passage is contaminated (corroded), but also the intake system components such as the supercharger and the intercooler are contaminated (corroded), and in addition, the replacement interval (product life) of the intake system components may be shortened. In this regard, it is necessary to use corrosion-resistant materials or apply corrosion-resistant coatings to the intake system components, but in this case, it may lead to increased costs and reduced product power.

[0008] In addition, in an engine device, blowby gas is supplied to a combustion chamber together with normal fuel, and the blowby gas is reused as fuel to expect a fuel consumption reduction effect. However, in the prior art, the fuel component of the blowby gas may leak from the intake port to the exhaust port when the valve of the combustion chamber overlaps, and thus flow out to the exhaust side without being burned in the combustion chamber. In this case, the blowby gas is mixed into the exhaust gas, causing the exhaust gas component to deteriorate, and the fuel consumption reduction effect is reduced.

[0009] An object of the present invention is to provide an engine device that can suppress contamination of intake system components caused by reduction of blowby gas to a combustion chamber, suppress the cost of intake system component consumption, and prolong the product life of the intake system components.

[0010] In order to solve the above-mentioned problems, an engine device according to the present invention operates using a fuel containing a corrosive substance, and includes a blowby reduction injector or a blowby reduction mixer for reducing blowby gas to a combustion chamber of the engine.

[0011] Effects of the Invention

[0012] According to the present invention, an engine device is provided that can suppress contamination of intake system components caused by reduction of blowby gas to a combustion chamber, suppress the cost of intake system components, and prolong the product life of the intake system components. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram showing an example of an engine device according to an embodiment of the present invention.

[0014] Figure 2 It is a schematic diagram showing an example of a cylinder of an engine of the engine device according to the embodiment of the present invention.

[0015] Figure 3 This is a schematic diagram showing an example of an engine device according to a first modified example of the present invention.

[0016] Figure 4 This is a schematic diagram showing an example of an engine device according to a second modified example of the present invention.

[0017] Figure 5 This is a schematic diagram showing an example of an engine device according to a third modified example of the present invention.

[0018] Figure 6 It is a schematic diagram showing an example of a cylinder of an engine of an engine device according to a third modified example of the present invention.

[0019] Figure 7It is a schematic diagram showing an example of a cylinder of an engine of an engine device according to a third modified example of the present invention.

[0020] Figure 8 This is a schematic diagram showing an example of an engine device according to a fourth modified example of the present invention.

[0021] Description of Reference Numerals

[0022] 1…engine device; 2…engine; 3…intake passage; 4…exhaust passage; 5…fuel supply path; 6…supercharger; 7…intercooler; 8…leakage path; 9…filter; 10…externally driven pump; 11…control unit; 20…cylinder block; 21…cylinder; 21a…combustion chamber; 22…crankcase; 23…cylinder block; 24…piston; 25…cylinder head; 26…ignition device; 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 device; 36…check valve; 37…leakage reduction device; 37a…leakage reduction injector; 37b…leakage reduction mixer. DETAILED DESCRIPTION

[0023] An engine device 1 as an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown, the engine device 1 includes an engine 2, an intake passage 3, an exhaust passage 4, a fuel supply path 5, a supercharger 6, and an intercooler 7. The engine device 1 also includes a leakage path 8, a filter 9, an external drive pump 10, and a control unit 11.

[0024] In this embodiment, the engine device 1 is a gas engine that operates by injecting fuel (gas) such as gas 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 mixed gas with air.

[0025] The engine 2 is, for example, a four-stroke engine, and is configured by including a cylinder block 20 with a plurality of cylinders 21 and a crankcase 22 . Figure 1 Six cylinders 21 are shown in the figure, but the number of cylinders 21 is not limited to six. Figure 1 and Figure 2 As shown, the cylinder 21 is constructed to include a cylinder block 23 , a piston 24 and a cylinder head 25 .

[0026] The cylinder 23 is formed into a cylindrical shape in the cylinder block 20, for example, and the piston 24 is slidably accommodated in the cylinder 23. The cylinder head 25 is mounted on the upper side of the cylinder 23, and the combustion chamber 21a is formed inside the cylinder 23 and the cylinder head 25. An ignition device 26 for igniting the fuel in the combustion chamber 21a is provided in the cylinder head 25. The ignition device 26 may be a micro-pilot type device that injects a small amount of liquid fuel, or may be a spark ignition type device using a spark plug. In addition, a structure may be formed to compress and ignite a mixed gas of gas fuel and liquid fuel.

[0027] Each cylinder body 23 of the plurality of cylinders 21 is connected to a crankcase 22, and a crankshaft 27 is rotatably supported by the crankcase 22. The 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.

[0028] 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 the intake passage 3 via the intake port 29 and the like, and air or a mixed gas of air and fuel supplied from the intake passage 3 is introduced into the combustion chamber 21a. In addition, the cylinder head 25 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 the exhaust passage 4 via the exhaust port 31 and the like, and exhaust gas generated in the combustion chamber 21a is discharged to the exhaust passage 4.

[0029] In order to connect the intake passage 3 and the plurality of cylinders 21, an intake manifold 33 having a branch intake flow path 33a branching from the intake passage 3 to each intake port 29 of the plurality of cylinders 21 is provided between the intake passage 3 and the engine 2. In addition, in order to connect the exhaust passage 4 and the plurality of cylinders 21, an exhaust manifold 34 having a branch exhaust flow path 34a branching from the exhaust passage 4 to the plurality of cylinders 21 is provided between the exhaust passage 4 and the engine 2. Figure 1 In FIG. 3 , the intake manifold 33 is shown by a dotted line, and the exhaust manifold 34 is shown by a dashed line.

[0030] 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 mixed gas 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 on the upstream side of the intake direction in the intake passage 3, which compresses the air flowing through the intake passage 3 or the mixed gas of fuel and air and sends it to the downstream side in the intake direction, and an intercooler 7 is provided on the downstream side of the intake direction of the supercharger 6, which cools the air flowing through the intake passage 3. In addition, an air filter (not shown) is provided in the intake passage 3, which purifies new air and introduces it into the intake passage 3.

[0031] 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.

[0032] The fuel supply path 5 supplies the fuel supplied from the fuel tank (not shown) to the engine 2. For example, the fuel supply path 5 has a plurality of branch fuel paths 5a branched to supply fuel to the plurality of cylinders 21, respectively, and the branch fuel paths 5a are connected to the ends of the branch intake flow paths 33a of the intake manifold 33 provided for each of the plurality of cylinders 21.

[0033] The fuel supply path 5 is provided with a main fuel supply device 35 for supplying 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 composed of, for example, a charge valve, a gas injector, etc. For example, in order to supply fuel to each of the plurality of cylinders 21, the plurality of main fuel supply devices 35 are provided at the respective ends of the plurality of branch fuel paths 5a, and the fuel is injected at the ends of the branch intake flow paths 33a of the intake manifold 33 of each of the plurality of cylinders 21.

[0034] When supplying fuel to each of the multiple cylinders 21, the main fuel supply device 35, when injecting fuel under the control of the control unit 11, supplies fuel to the combustion chamber 21a at a timing of closing the exhaust port 31 and opening the intake port 29 so as to intermittently inject the fuel without causing fuel leakage due to valve overlap of the combustion chamber 21a.

[0035] The supercharger 6 compresses the air or mixed gas flowing through the intake passage 3 and sends it to the downstream side in the intake direction. The supercharger 6 includes a turbine 6a and a compressor 6b. The turbine 6a is arranged in the exhaust passage 4, and the compressor 6b is arranged 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 mixed gas flowing through the intake passage 3.

[0036] The leakage path 8 is connected to the fuel supply path 5 from the crankcase 22. Fuel gas leaks from the combustion chamber 21a of each cylinder 21 to the crankcase 22, and when blowby gas is generated in the crankcase 22, the blowby gas flows through the leakage path 8. The leakage path 8 is provided with a check valve 36 that prevents fuel from flowing from the fuel supply path 5 to the leakage path 8.

[0037] The blowby gas flows through the fuel supply path 5 via the blowby path 8, so that the blowby gas flows through the fuel supply path 5 together with the fuel, and the blowby gas is supplied to the combustion chamber 21a of each cylinder 21 together with the fuel by the main fuel supply device 35. In this way, the blowby gas flows through the blowby path 8 and the fuel supply path 5, and the main fuel supply device 35 functions as a leakage reduction device 37, such as a leakage reduction injector 37a, which reduces the blowby gas to the combustion chamber 21a.

[0038] Regarding the main fuel supply device 35, as described above, when the fuel is intermittently injected under the control of the control unit 11, the main fuel supply device 35 functioning as a leakage reduction injector 37a also intermittently injects the leakage gas supplied together with the fuel in a manner that restores the leakage gas to the combustion chamber 21a at a timing when the exhaust port 31 is closed and the intake port 29 is opened so that no leakage of the fuel occurs due to valve overlap in the combustion chamber 21a.

[0039] The filter 9 is provided on the upstream side of the flow direction of the blowby gas in the blowby path 8. The filter 9 separates the oil mist contained in the blowby gas flowing through the blowby path 8 into an unburned mixed gas and is constituted by, for example, a demister.

[0040] The externally driven pump 10 is arranged on the leakage path 8 at a position downstream of the filter 9 in the flow direction of the leakage gas. When the engine 2 is operating (running) (fuel is supplied in the fuel supply path 5), the externally driven pump 10 is driven to make the leakage gas flow in the leakage path 8 connected to the crankcase 22, thereby sucking and / or increasing the pressure of the leakage gas and merging it with the fuel supply path 5. In addition, the externally driven pump 10 makes the leakage gas flow in the leakage path 8, thereby ventilating the crankcase 22 and forming a negative pressure in the crankcase 22. As a result, the leakage of the leakage gas in the crankcase 22 from the parts other than the leakage path 8, for example, the leakage from the crankcase 22 at the shaft support part of the crankshaft 27 is suppressed.

[0041] In addition, regardless of whether the engine 2 is working (running), the external drive pump 10 can be driven with the same intensity to make the leakage gas flow with the same intensity. Alternatively, it can be formed as follows: when the engine 2 is running, the external drive pump 10 is driven with a stronger intensity, and on the other hand, when the engine 2 is stopped, the external drive pump 10 is driven with a weaker intensity. Alternatively, the external drive pump 10 can be driven until a specified time has passed after the engine 2 is stopped, and the drive can be stopped after the specified time has passed.

[0042] 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 various parts of the engine 2. The control unit 11 can store various programs for controlling the engine 2, read out and execute the programs to control the engine 2.

[0043] In particular, the control unit 11 controls the injection timing of the fuel injected by the main fuel supply device 35 and the injection timing of the blowby gas injected by the blowby reduction injector 37a so as not to cause leakage of fuel due to valve overlap of the combustion chamber 21a.

[0044] As described above, according to the present embodiment, the engine device 1 is an engine device 1 that operates using fuel containing corrosive substances, and includes a blowby reduction injector 37a that reduces blowby 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.

[0045] Thus, the engine device 1 is provided with a blowby reduction injector 37a for reducing the blowby gas containing corrosive substances, so that the blowby gas reduction position can be set in a manner to suppress the flow of the blowby gas in the intake system components such as the intake passage 3, the supercharger 6, and the intercooler. Therefore, the degree of contamination of the intake system components by the blowby gas can be suppressed to a minimum, and the replacement interval of the intake system components can be prolonged. In addition, the intake system components can be constructed by omitting corrosion-resistant components and corrosion-resistant coatings for the blowby gas, thereby suppressing the increase in the cost of the intake system components and suppressing the decline in the commercial power of the intake system components.

[0046] In addition, according to the present embodiment, the engine device 1 comprises: a fuel supply path 5 that supplies fuel to the engine 2; and a leakage path 8 that is connected to the fuel supply path 5 from the crankcase 22, and the leakage gas flows to the leakage reduction injector 37a via the leakage path 8 and the fuel supply path 5.

[0047] Specifically, according to this embodiment, the engine device 1 has 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 leakage reduction injector 37a that reduces the leakage gas supplied together with the fuel via the fuel supply path 5 to the combustion chamber 21a.

[0048] Thus, the engine device 1 reduces the blowby gas to the fuel supply path 5 instead of the intake path 3, thereby suppressing the blowby gas from contaminating the intake path 3. In addition, the fuel supply path 5 is originally based on the premise of allowing fuel containing corrosive substances to flow, so no new anti-pollution measures are required for reducing the blowby gas containing corrosive substances.

[0049] According to the present embodiment, the engine device 1 includes the externally driven pump 10 for causing the blowby gas to flow through the blowby path 8 , and the blowby gas is sucked and / or pressurized by the externally driven pump 10 and merged with the fuel supply path 5 .

[0050] Thus, the engine device 1 can ventilate the crankcase 22 using the externally driven pump 10 and create a negative pressure in the crankcase 22. Therefore, the blowby gas in the crankcase 22 can be prevented from leaking from the crankcase 22 at locations other than the blowby path 8.

[0051] In addition, the following example is described in the above embodiment: in the engine device 1, in order to supply fuel to multiple cylinders 21 respectively, the fuel supply path 5 has multiple branch fuel paths 5a, and multiple main fuel supply devices 35 composed of inflation valves, gas injectors, etc. are respectively arranged in the multiple branch fuel paths 5a, but the present invention is not limited to this example.

[0052] For example, in the first variant, Figure 3 As shown, it can be formed as follows: in the engine device 1, the fuel supply path 5 is configured not to branch into a plurality of branch fuel paths 5a, and a single main fuel supply device 35 composed of a gas mixing device such as a venturi mixer and a single point injector is provided at the end of the fuel supply path 5, and is connected to the intake manifold 33 before the branch intake flow path 33a is branched, and the intake passage 3 immediately in front of the intake manifold 33. The main fuel supply device 35 mixes the fuel with the air flowing in the intake passage 3 and the intake manifold 33.

[0053] In the first modification, the main fuel supply device 35 functions as a leakage reduction device 37 for reducing the blowby gas to the combustion chamber 21 a , such as a leakage reduction mixer 37 b , so that the blowby gas is mixed with fuel in the air flowing through the intake passage 3 and the intake manifold 33 .

[0054] In addition, in the above-mentioned embodiment, the following example is described: in the engine device 1, the leakage path 8 is connected to the fuel supply path 5 so that the leakage gas and the fuel merge. In addition, the main fuel supply device 35 that supplies the fuel supplied by the fuel supply path 5 to the combustion chamber 21a of each cylinder 21 functions as a leakage reduction device 37 such as a leakage reduction injector 37a and a leakage reduction mixer 37b that restores the leakage gas to the combustion chamber 21a, but the present invention is not limited to this example.

[0055] For example, in the second variant and the third variant, Figure 4 , Figure 5 As shown, it can be formed as follows: in the engine device 1, the leakage path 8 is configured to be not connected to the fuel supply path 5 so that the leakage gas and the mixed gas merge, and in addition, the leakage reduction device 37 such as the leakage reduction injector 37a independent of the main fuel supply device 35 is provided at the end of the leakage path 8. That is, the leakage path 8 allows the leakage gas to flow directly to the leakage reduction injector 37a. For example, the leakage path 8 branches into a plurality of branch leakage paths 8a corresponding to the plurality of cylinders 21, respectively, and in addition, a plurality of leakage reduction injectors 37a independent of the main fuel supply device 35 are respectively provided at the ends of the plurality of branch leakage paths 8a.

[0056] In the second and third variants, as in the above-mentioned embodiment, the leakage reduction injector 37a intermittently injects the leakage gas in a manner that restores the leakage gas to the combustion chamber 21a at a timing when the exhaust port 31 is closed and the intake port 29 is opened so as not to cause leakage of fuel due to valve overlap in the combustion chamber 21a.

[0057] In the second variant, if Figure 4 As shown, the plurality of branch leakage paths 8a of the leakage path 8 are connected to the branch intake flow paths 33a of the intake manifold 33 of each of the plurality of cylinders 21, and the plurality of leakage reduction injectors 37a respectively provided in the plurality of branch leakage paths 8a inject the leakage gas at the end of the branch intake flow paths 33a of the intake manifold 33 of each of the plurality of cylinders 21 to reduce the leakage gas to each combustion chamber 21a. In this case, the leakage reduction injector 37a may be provided in the branch intake flow path 33a at a position downstream of the main fuel supply device 35 in the intake direction.

[0058] In the third variation, if Figure 5 As shown, multiple branch leakage paths 8a of the leakage path 8 are connected to each cylinder head 25 of the multiple cylinders 21. In addition, multiple leakage reduction injectors 37a respectively arranged in the multiple branch leakage paths 8a inject leakage gas into the cylinder heads 25 of the multiple cylinders 21 and reduce it to each combustion chamber 21a.

[0059] In this case, if Figure 6 As shown, the leakage reduction injector 37a is provided in the cylinder head 25 in a state of being communicated with the combustion chamber 21a in a manner of directly injecting the leakage reduction gas into the combustion chamber 21a. In addition, the main fuel supply device 35 such as the charging valve and the gas injector can also be provided in the cylinder head 25 in a state of being communicated with the combustion chamber 21a in a manner of directly injecting the fuel into the combustion chamber 21a.

[0060] Or, if Figure 7 As shown, the leakage reduction injector 37a is provided in the cylinder head 25 in a state of being communicated with the intake port 29 in such a manner as to inject the leakage gas into the intake port 29 communicated with the combustion chamber 21a. In addition, the main fuel supply device 35 such as the charging valve and the gas injector may also be provided in the cylinder head 25 in a state of being communicated with the intake port 29 in such a manner as to inject the fuel into the intake port 29.

[0061] Or, in the fourth variation, if Figure 8 As shown, it can be formed as follows: in the engine device 1, the leakage path 8 is connected to the intake manifold 33 before the branch intake flow path 33a is branched, and the intake passage 3 immediately in front of the intake manifold 33, and in addition, a single leakage reduction device 37 composed of a gas mixing device such as a venturi mixer and a single point injector independent of the main fuel supply device 35, for example, a leakage reduction mixer 37b is provided at the end of the leakage path 8. That is, the leakage path 8 directly allows the leakage gas to flow to the leakage reduction mixer 37b. In this case, it can be formed as follows: the main fuel supply device 35 is composed of a gas mixing device such as a venturi mixer and a single point injector, and the leakage reduction mixer 37b is provided on the downstream side of the main fuel supply device 35 in the intake direction. The leakage reduction mixer 37b mixes the leakage gas with the air flowing in the intake passage 3 and the intake manifold 33.

[0062] In the second variant, the third variant, and the fourth variant, as in the above-mentioned embodiment, the external drive pump 10 causes the leakage gas to flow in the leakage path 8 connected to the crankcase 22 to attract and / or increase the pressure of the leakage gas, thereby supplying the leakage reduction device 37 such as multiple leakage reduction injectors 37a, leakage reduction mixers 37b, etc. via the leakage path 8.

[0063] As described above, according to the second variant, the third variant or the fourth variant, the engine device 1 has a leakage path 8, which is connected from the crankcase 22 to the leakage reduction device 37 such as the leakage reduction injector 37a or the leakage reduction mixer 37b, and allows the leakage gas to flow to the leakage reduction device 37 such as the leakage reduction injector 37a or the leakage reduction mixer 37b.

[0064] Therefore, the engine device 1 has a dedicated leakage path 8 for the flow of the leakage gas, thereby being able to suppress the flow of the leakage gas in the intake passage 3, the supercharger 6, the intercooler and other intake system components. Therefore, the degree of contamination of the intake system components by the leakage gas can be suppressed to a minimum, and the replacement interval of the intake system components can be prolonged.

[0065] In addition, according to the second variant, the third variant or the fourth variant, the engine device 1 includes: a fuel supply path 5, which supplies fuel to the engine 2; a main fuel supply device 35, which supplies the fuel supplied by means of the fuel supply path 5 to the combustion chamber 21a; and an external drive pump 10, which makes the leakage gas flow in the leakage path 8, and a leakage reduction device 37 such as a leakage reduction injector 37a or a leakage reduction mixer 37b is independently arranged relative to the main fuel supply device 35, and the external drive pump 10 is used to suck the leakage gas and / or increase its pressure and supply it to the leakage reduction device 37 such as the leakage reduction injector 37a or the leakage reduction mixer 37b.

[0066] Specifically, according to the second variant or the third variant, in the engine device 1, the leakage reduction injector 37a directly injects the leakage gas into the combustion chamber 21a, or injects the leakage gas into the intake port 29 connected to the combustion chamber 21a, or injects the leakage gas into the end of the intake manifold 33 connected to the combustion chamber 21a, thereby reducing the leakage gas to the combustion chamber 21a.

[0067] Therefore, the engine device 1 has a dedicated leakage path 8 for the circulation of the leakage gas, which can not only suppress the circulation of the leakage gas in the intake system components, but also suppress the circulation of the leakage gas in the fuel supply path 5 and the main fuel supply device 35. Therefore, the degree of contamination of the fuel supply path 5 and the main fuel supply device 35 by the leakage gas can be suppressed to a minimum, and the replacement interval of the fuel supply path 5 and the main fuel supply device 35 can be prolonged.

[0068] Furthermore, according to the second modification or the third modification, in the engine device 1, the blowby reduction injector 37a injects the blowby gas intermittently.

[0069] Thus, in the engine device 1, it is possible to prevent the fuel component of the blowby gas from leaking from the intake port 29 to the exhaust port 31 and flowing out to the exhaust side without being burned during the valve overlap of the combustion chamber 21a. Therefore, it is possible to prevent the blowby gas from mixing into the exhaust gas, prevent the exhaust gas properties from being deteriorated due to the blowby gas, and improve the fuel efficiency reduction effect.

[0070] The present invention can be modified appropriately within the scope of the gist or concept of the invention that can be understood from the claims and the entire specification, and the technical concept of the present invention also includes an engine device accompanied by such modification.

[0071] [Additional Notes on the Invention]

[0072] The following is a supplementary note of the summary of the invention extracted from the above-mentioned embodiment. In addition, each structure and each processing function described in the following supplementary note can be selected and combined arbitrarily.

[0073] <Note 1>

[0074] An engine device, which operates using a fuel containing a corrosive substance, is characterized in that:

[0075] The engine device includes a blowby reduction injector or a blowby reduction mixer for reducing the blowby gas to a combustion chamber of the engine.

[0076] <Note 2>

[0077] The engine device according to Supplementary Note 1 is characterized in that:

[0078] The engine device comprises:

[0079] a fuel supply path that supplies the fuel to the engine; and

[0080] a leakage path connected to the fuel supply path,

[0081] The blowby gas flows toward the blowby reduction injector or the blowby reduction mixer via the blowby path and the fuel supply path.

[0082] <Note 3>

[0083] The engine device according to Supplementary Note 2 is characterized in that:

[0084] The engine device includes a main fuel supply device that supplies the fuel supplied via the fuel supply path to the combustion chamber.

[0085] The main fuel supply device functions as the blowby reduction injector or the blowby reduction mixer that causes the blowby gas supplied together with the fuel through the fuel supply path to be reduced to the combustion chamber.

[0086] <Note 4>

[0087] The engine device according to Supplementary Note 3 is characterized in that:

[0088] The engine device includes an externally driven pump that causes the blowby gas to flow through the blowby path.

[0089] The blowby gas is sucked and / or pressurized by the external drive pump and merged with the fuel supply path.

[0090] <Note 5>

[0091] The engine device according to Supplementary Note 1 is characterized in that:

[0092] The engine device includes a blowby path connected to the blowby reduction injector or the blowby reduction mixer and allowing the blowby gas to flow to the blowby reduction injector or the blowby reduction mixer.

[0093] <Note 6>

[0094] The engine device according to Supplementary Note 5 is characterized in that:

[0095] The engine device comprises:

[0096] a fuel supply path for supplying the fuel to the engine;

[0097] a main fuel supply device that supplies the fuel supplied via the fuel supply path to the combustion chamber; and

[0098] an externally driven pump that causes the leaked gas to flow in the leaked path,

[0099] The leakage reduction injector or the leakage reduction mixer is independently arranged relative to the main fuel supply device,

[0100] The blowby gas is sucked and / or pressurized by the external drive pump and supplied to the blowby reduction injector or the blowby reduction mixer.

[0101] <Note 7>

[0102] The engine device according to Supplementary Note 6 is characterized in that:

[0103] The blow-by reduction injector directly injects the blow-by gas 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 a terminal end of an intake manifold connected to the combustion chamber.

[0104] <Note 8>

[0105] The engine device according to any one of Supplementary Notes 1 to 7, characterized in that:

[0106] The leak reduction injector intermittently injects the leak gas.

[0107] <Note 9>

[0108] The engine device according to any one of Supplementary Notes 1 to 8, characterized in that:

[0109] The corrosive substance is ammonia or methanol.

Claims

1. An engine device, which operates using a fuel containing a corrosive substance, characterized in that: The engine device includes a blowby reduction injector or a blowby reduction mixer for reducing the blowby gas to a combustion chamber of the engine.

2. The engine device according to claim 1, characterized in that: The engine device comprises: a fuel supply path that supplies the fuel to the engine; and a leakage path connected to the fuel supply path, The blowby gas flows toward the blowby reduction injector or the blowby reduction mixer via the blowby path and the fuel supply path.

3. The engine device according to claim 2, characterized in that: The engine device includes a main fuel supply device that supplies the fuel supplied via the fuel supply path to the combustion chamber. The main fuel supply device functions as the blowby reduction injector or the blowby reduction mixer that causes the blowby gas supplied together with the fuel through the fuel supply path to be reduced to the combustion chamber.

4. The engine device according to claim 3, characterized in that: The engine device includes an externally driven pump that causes the blowby gas to flow through the blowby path. The blowby gas is sucked and / or pressurized by the external drive pump and merged with the fuel supply path.

5. The engine device according to claim 1, characterized in that: The engine device includes a blowby path connected to the blowby reduction injector or the blowby reduction mixer and allowing the blowby gas to flow to the blowby reduction injector or the blowby reduction mixer.

6. The engine device according to claim 5, characterized in that: The engine device comprises: a fuel supply path for supplying the fuel to the engine; a main fuel supply device that supplies the fuel supplied via the fuel supply path to the combustion chamber; and an externally driven pump that causes the leaked gas to flow in the leaked path, The leakage reduction injector or the leakage reduction mixer is independently arranged relative to the main fuel supply device, The blowby gas is sucked and / or pressurized by the external drive pump and supplied to the blowby reduction injector or the blowby reduction mixer.

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

8. The engine device according to claim 7, characterized in that: The leak reduction injector intermittently injects the leak gas.

9. The engine device according to claim 1, characterized in that: The corrosive substance is ammonia or methanol.

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