Fluid discharge mechanism and internal combustion engine including mechanism

Abstract

To normally operate a discharge part while preventing deterioration of performance of the discharge part caused by exposure to high-temperature fluid.SOLUTION: A fluid discharge mechanism includes: a fluid system 14 in which fluid Gb can flow; a discharge part 16 that is connected to the fluid system 14 and capable of discharging the fluid Gb to an external space S of the fluid system 14 when pressure of the fluid Gb flowing in the fluid system 14 is first pressure or higher; a shut-off part 17 provided in the fluid system 14 to shut off the discharge part 16 from the fluid Gb; a heat suppression space 18 formed between the discharge part 16 and the shut-off part 17; and a communication part 35c communicating the heat suppression space 18 and the external space S.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fluid discharge mechanism and an internal combustion engine equipped with the mechanism. [Background technology]

[0002] For example, an internal combustion engine such as a diesel engine is provided with an exhaust gas flow path that joins exhaust gases discharged from the exhaust valves of each cylinder and discharges them to the outside through an exhaust port. A turbocharger is provided upstream of the exhaust port in this exhaust gas flow path, and the turbocharger's turbine rotates in response to the flow of exhaust gas, thereby operating a compressor that is coaxially connected to the turbine and is located in the air intake flow path from the fresh air intake to the intake valve. This compresses the air taken in and supplies it to the combustion chamber (see, for example, Patent Document 1).

[0003] Furthermore, this type of flow path is generally provided with a safety valve for releasing high-pressure exhaust gas when the exhaust gas pressure rises abnormally for some reason. That is, when the exhaust gas is in a normal flow state, the exhaust gas release port provided in the above flow path is blocked by the valve body of the safety valve which is biased by a spring or the like. However, when the exhaust gas pressure rises above a predetermined level, the force with which the high-pressure exhaust glass presses the valve body exceeds the biasing force of the spring, causing a gap to form between the valve body and the release port, and the high-pressure exhaust gas is discharged outside the above flow path (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-234733 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-126323 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the above-mentioned safety valve is provided at the relief port of the exhaust gas flow path, the portion of the safety valve located near the relief port is constantly exposed to exhaust gas. Because the exhaust gas from an internal combustion engine is hot, the portions of the safety valve that are relatively poor in heat resistance (such as the sealing portion that abuts against the valve body) are exposed to the high-temperature exhaust gas and heated, which may cause deterioration. If the sealing portion deteriorates, the sealing performance with the valve body will decrease, and there is a concern that exhaust gas may leak through the gap with the valve body.

[0006] The above-mentioned problem is not limited to safety valves installed in the exhaust gas flow path of an internal combustion engine, but can occur in any flow system in which a high-temperature fluid flows, and in any other system in which a part having the function of releasing the fluid outside the fluid system, such as a safety valve, is installed.

[0007] In view of the above circumstances, the technical problem to be solved in this specification is to prevent the performance of the fluid discharge portion from being deteriorated due to exposure to high-temperature fluid, while enabling the discharge portion to operate normally. [Means for solving the problem]

[0008] The above-mentioned problems are solved by a fluid discharge mechanism according to the present invention, which is characterized by comprising a fluid system through which a fluid can flow, a discharge part connected to the fluid system and capable of discharging the fluid to an external space of the fluid system when the fluid flowing through the fluid system is at or above a first pressure, a blocking part provided in the fluid system and blocking the discharge part from the fluid, a heat suppression space formed between the discharge part and the blocking part, and a communicating part communicating the heat suppression space with the external space.

[0009] As described above, the fluid discharge mechanism according to the present invention includes a blocking section that blocks the discharge section from the fluid, and a heat suppression space that suppresses heat transfer from the blocking section to the discharge section is interposed between the discharge section and the blocking section. This prevents the discharge section from being directly exposed to the fluid. This minimizes deterioration or damage caused by the discharge section rising above its heat resistance limit due to high-temperature fluid. Furthermore, by providing a communication section that connects the heat suppression space to the external space of the fluid system, even if the high-temperature fluid causes the temperature of the blocking section to rise and heat the adjacent heat suppression space, gas within the space can escape to the external space. This prevents the heat suppression space from expanding due to heating, which would cause excessive pressure on the discharge section and lead to unexpected discharge. As described above, the fluid discharge mechanism according to the present invention prevents the temperature rise of the discharge section and prevents deterioration of the discharge section, while avoiding unnecessary discharge of fluid and ensuring normal operation of the discharge section.

[0010] Furthermore, in the fluid release mechanism according to the present invention, the release section may be an opening / closing valve device that has a valve body that moves in response to the pressure of the fluid and a biasing member that biases the valve body against the pressure of the fluid, and in which the valve body closes the gap between the fluid system and the external space when the fluid pressure is less than a first pressure and opens when the pressure is equal to or greater than the first pressure.

[0011] By configuring the release section as an on-off valve device that can be switched between a closed state and an open state by moving the valve body in this way, it is possible to set the pressure (first pressure) at which the fluid is released relatively easily, for example, by simply adjusting the biasing member, and therefore it is possible to control and keep the pressure in the fluid system constant according to the application and specifications.

[0012] In addition, in the fluid discharge mechanism according to the present invention, the blocking section may be configured to block the discharge section from the fluid when the fluid is at a pressure less than a second pressure, and to release the blocked state when the fluid is at or above the second pressure.

[0013] According to the above configuration, the blocking state can be released when the pressure reaches or exceeds a predetermined pressure (second pressure). Therefore, for example, if the fluid system is an exhaust gas flow path of an internal combustion engine described below, even if unburned flammable gas or the like remains in the exhaust gas and abnormally ignites the gas, causing the pressure to rise instantaneously, it is possible to release the blocking state by the blocking section, reduce the pressure of the fluid, and allow the fluid to escape to the external space of the fluid system.

[0014] Furthermore, when the blocking section is configured as described above, the second pressure may be set to a value lower than the first pressure.

[0015] By setting the second pressure lower than the first pressure in this way, instantaneous pressure increases can be handled by the shut-off section, and when a response is required by the release section (opening / closing valve device), the shut-off state by the shut-off section is released in advance, and the fluid system and the release section are brought into communication, allowing the release section to smoothly release the high-pressure fluid.

[0016] Furthermore, in the fluid discharge mechanism according to the present invention, the fluid system may have an exhaust pipe connected to the combustion chamber of the internal combustion engine, the discharge section may be connected to the exhaust pipe, and a blocking section may be arranged between the exhaust pipe and the discharge section, the discharge section and the blocking section may be connected by a connecting pipe, and a heat suppression space may be defined by the discharge section, the blocking section, and the connecting pipe.

[0017] The fluid release mechanism described above is characterized by preventing the deterioration of the sealing performance of the safety valve due to exposure to high-temperature fluid as described above, while allowing the safety valve to operate normally. Therefore, it can be suitably provided, for example, as an internal combustion engine equipped with this fluid release mechanism, a combustion chamber connected to the upstream side of the fluid system, and a supercharger connected to the downstream side of the fluid system. [Effects of the Invention]

[0018] As described above, the fluid discharge mechanism according to the present invention makes it possible to prevent the performance of the discharge section from deteriorating due to exposure to high-temperature fluid, while allowing the discharge section to operate normally and properly protecting the fluid system. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a conceptual diagram of an internal combustion engine equipped with a fluid discharge mechanism according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of a main part of the fluid discharge mechanism shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, the details of a fluid discharge mechanism according to one embodiment of the present invention will be described with reference to the drawings. In this embodiment, the internal combustion engine will be described as a diesel engine used to supply torque to a power generating motor of a ship or to rotate a propeller shaft of a ship.

[0021] Fig. 1 is a conceptual diagram of an internal combustion engine 10 according to one embodiment of the present invention, particularly illustrating a portion related to intake and exhaust. As shown in Fig. 1, this internal combustion engine 10 has a plurality of cylinders (cylinders 11) arranged in series, and includes a combustion chamber 12 for each cylinder 11, an intake gas passage 13 for supplying intake gas Ga to the combustion chamber 12, an exhaust gas passage 14 for discharging exhaust gas Gb from the combustion chamber 12, a turbocharger 15, an on-off valve device 16, a rupture disc device 17, and a heat suppression space 18. Here, the exhaust gas passage 14 corresponds to the exhaust pipe and, therefore, the fluid system according to the present invention. Furthermore, the on-off valve device 16 corresponds to the release section according to the present invention, and the rupture disc device 17 corresponds to the shutoff section according to the present invention.

[0022] The intake gas passage 13 is mainly for compressing gas (usually air) taken in through an intake port 19 and sending it to the combustion chamber 12 of each cylinder 11. It has a main intake passage 20 with the intake port 19 at its upstream end, and an auxiliary intake passage 21 branching off from the main intake passage 20 and connected to the combustion chamber 12 of each cylinder 11. A compressor 22 of the turbocharger 15 is disposed in the main intake passage 20 downstream of the intake port 19. An intercooler (not shown) is also disposed in the main intake passage 20 downstream of the compressor 22. With this configuration, outside air taken in through the intake port 19 is compressed by the compressor 22 and supplied to the combustion chamber 12 through the main intake passage 20 and the auxiliary intake passage 21. The high-temperature air is cooled by the intercooler (not shown) disposed downstream of the compressor 22, and the cooled compressed air is supplied to the combustion chamber 12.

[0023] The exhaust gas flow path 14 is for discharging exhaust gas generated in the combustion chamber 12 from the internal combustion engine 1, and has a main exhaust passage 24 with an exhaust port 23 at its downstream end, and a secondary exhaust passage 25 that merges with the main exhaust passage 24 to connect the combustion chamber 12 and the main exhaust passage 24. In this embodiment, two main exhaust passages 24 (a first main exhaust passage 24a and a second main exhaust passage 24b) are provided, and three secondary exhaust passages 25 (25a, 25b) are connected to each of the main exhaust passages 24a, 24b. The main exhaust passages 24a, 24b merge and lead to a turbine 26 of the turbocharger 15, and the exhaust port 23 is disposed downstream of the merged passage. With this configuration, exhaust gas discharged from the combustion chamber 12 reaches the main exhaust passages 24a, 24b through the sub-exhaust passages 25a, 25b, and passes through the turbine 26 disposed downstream of the main exhaust passages 24a, 24b, driving the turbine 26, and the exhaust gas is discharged from the exhaust port 23. In addition, driving the turbine 26 drives the compressor 22 connected to the turbine 26, and air taken in from the intake port 19 into the main intake passage 20 is compressed and supplied to the combustion chamber 12.

[0024] The on-off valve device 16 serving as a release section includes a valve element 27 that moves in response to pressure applied to an end face 27a, a biasing member 28 that biases the valve element 27 against the pressure, a first base 29 and a second base 30 that sandwich the valve element 27 and the biasing member 28, and a seal portion 31 that can abut against the valve element 27 when the valve element 27 is in a closed state. At least a portion of the outer periphery of the valve element 27 or the biasing member 28 communicates with the external space S of the exhaust gas flow path 14. When the valve element 27 moves away from the seal portion 31, gas in the space facing the end face 27a of the valve element 27 (here, the heat suppression space 18) can be released into the external space S through a gap between the valve element 27 and the seal portion 31. The biasing member 28 can be formed of an elastic member such as a compression spring. The seal portion 31 can be formed of graphite from the standpoint of pressure resistance and other factors.

[0025] In this embodiment, the biasing member 28 biases the connecting portion 32 that is connected to the valve body 27. The valve body 27 is biased in a predetermined direction by the biasing member 28 via the connecting portion 32, so that it can come into close contact with the seal portion 31. The first base 29 on which the seal portion 31 is provided is provided with a communication hole 29a that communicates with the adjacent exhaust gas flow path 14, and an end face 27a of the valve body 27 comes into contact with the heat suppression space 18 through the communication hole 29a.

[0026] The on-off valve device 16 configured as described above is configured to switch between an open state and an closed state depending on the pressure in the heat suppression space 18. Specifically, when the pressure in the heat suppression space 18 is less than a first pressure, the valve element 27 remains in close contact with the seal portion 31 to block the passage between the main exhaust path 24 (24a) and the external space S, and when the pressure in the heat suppression space 18 is equal to or greater than the first pressure, a gap is generated between the valve element 27 and the seal portion 31, and the main exhaust path 24 (24a) is opened to the external space S through the gap.

[0027] In this embodiment, one on-off valve device 16 having the above configuration is connected to each of the main exhaust passages 24a, 24b. In Fig. 1, the on-off valve device 16 is connected to the upstream end of the first main exhaust passage 24a, but the connection position of the on-off valve device 16 is not particularly limited. In the configuration shown in Fig. 1, the on-off valve device 16 can be connected to any position as long as it is not near the turbocharger 15.

[0028] The rupture disc device 17 serving as a blocking unit is disposed so as to block gas in the main exhaust passage 24 (here, the first main exhaust passage 24a) from the valve element 27 of the on-off valve device 16. Here, the rupture disc device 17 is composed of a rupture disc 33 and a holding unit 34 that holds the rupture disc 33. In this embodiment, a flange 24d extending outward is provided at an opening 24c of the tubular member that forms the main exhaust passage 24. In addition, a connecting pipe 35 is interposed between the rupture disc device 17 and the on-off valve device 16, and the holding unit 34 of the rupture disc device 17 is sandwiched between a first flange 35a of the connecting pipe 35 and the flange 24d of the tubular member that forms the main exhaust passage 24, thereby fixing the rupture disc device 17 between the main exhaust passage 24 and the connecting pipe 35. Furthermore, by fixing the second flange 35b of the connecting pipe 35 and the first base 29 of the on-off valve device 16 to each other, the on-off valve device 16 is attached to the opening 24c of the main exhaust passage 24 via the connecting pipe 35 and further the rupture disc device 17.

[0029] Here, the rupture disc device 17 is configured so that when the exhaust gas Gb is less than a second pressure, the rupture disc 33 blocks the on-off valve device 16 from the exhaust gas Gb, and when the exhaust gas Gb is equal to or greater than the second pressure, the rupture disc 33 ruptures to connect the main exhaust passage 24 to the heat suppression space 18. In this case, the second pressure at which the rupture disc 33 ruptures is preferably set to a value lower than the first pressure at which the on-off valve device 16 is opened.

[0030] The heat suppression space 18 is provided between the on-off valve device 16 and the rupture disc device 17. In this embodiment, the heat suppression space 18 is defined by the connecting pipe 35, the rupture disc device 17, and the on-off valve device 16. A through hole 35c that penetrates the connecting pipe 35 in the radial direction is provided in a partial circumferential region of the connecting pipe 35, and this through hole 35c functions as a communication portion that communicates the heat suppression space 18 with the external space S of the exhaust gas flow path 14. Naturally, the dimension of this through hole 35c is smaller than the inner diameter of the connecting pipe 35, and is set to, for example, 3 mm or less, preferably 2 mm or less. On the other hand, from the viewpoint of smoothly discharging gas from the heat suppression space 18, the dimension of the through hole 35c is set to 0.5 mm or more, preferably 1.0 mm or more.

[0031] The exhaust gas flow path 14 configured as described above, the on-off valve device 16, the rupture disc device 17, and the heat suppression space 18 constitute a fluid discharge mechanism according to the present invention.

[0032] As described above, the fluid discharge mechanism according to this embodiment or the internal combustion engine 10 equipped with this fluid discharge mechanism includes the rupture disc device 17 that isolates the on-off valve device 16 from the exhaust gas Gb flowing through the exhaust gas flow path 14, and the heat suppression space 18 that suppresses heat transfer from the rupture disc device 17 to the on-off valve device 16 is interposed between the on-off valve device 16 and the rupture disc device 17. This prevents the on-off valve device 16, particularly the seal portion 31, which has relatively poor heat resistance, from being directly exposed to the exhaust gas Gb. This makes it possible to minimize deterioration or damage to the on-off valve device 16 (particularly the seal portion 31) caused by the high-temperature exhaust gas Gb exceeding its heat resistance limit. Furthermore, by providing the through-hole 35c that communicates the heat suppression space 18 with the external space S of the exhaust gas flow path 14, even if the high-temperature exhaust gas Gb increases the temperature of the rupture disc device 17 and heats the adjacent heat suppression space 18, the gas in the heat suppression space 18 can be released to the external space S. This prevents the heat suppression space 18 from expanding due to heating and becoming high-pressure. It also prevents excessive pressure from acting on the valve element 27 of the on-off valve device 16, causing an unexpected release. As described above, the fluid release mechanism according to this embodiment makes it possible to prevent the on-off valve device 16 from deteriorating by suppressing a temperature rise in the on-off valve device 16, while also preventing unnecessary release of exhaust gas Gb and allowing the on-off valve device 16 to operate normally.

[0033] In this embodiment, the release portion is an on-off valve device 16 having a valve element 27 that moves in response to the gas pressure received by the end surface 27a, and a biasing member 28 that biases the valve element 27 against the gas pressure. By using the on-off valve device 16 as the release portion in this manner, it is possible to set the pressure (first pressure) at which the exhaust gas Gb is released relatively easily, for example, simply by adjusting the biasing member 28. Therefore, it is possible to control and keep the pressure in the exhaust gas flow path 14 constant depending on the application and specifications.

[0034] In addition, in this embodiment, the blocking unit is a rupture disc device 17 having a rupture disc 33 and a holding unit 34 that holds the rupture disc 33, and is configured so that the rupture disc 33 blocks the on-off valve device 16 from the exhaust gas Gb when the exhaust gas Gb is less than a second pressure and ruptures when the exhaust gas Gb is equal to or greater than the second pressure. The rupture disc 33 has superior responsiveness (immediate opening) compared to the on-off valve device 16. Therefore, when the rupture disc 33 is used connected to the exhaust gas flow path 14 of the internal combustion engine 10 as in this embodiment, even if unburned combustible gas or the like remains in the exhaust gas Gb and abnormally ignites the gas, causing an instantaneous rise in pressure, it is possible to immediately establish communication between the exhaust gas flow path 14 and the heat suppression space 18, reduce the pressure of the exhaust gas Gb, and allow the exhaust gas Gb to escape to the external space S of the exhaust gas flow path 14.

[0035] Although one embodiment of the present invention has been described above, the fluid discharge mechanism according to the present invention can also have other configurations than those described above without departing from the spirit of the invention.

[0036] For example, in the above embodiment, the on-off valve device 16 is used as the release part, but of course, this is not limited to this. Any configuration can be adopted as long as the exhaust gas Gb can be released from the exhaust gas flow path 14 to the external space S when the exhaust gas Gb reaches a predetermined pressure (first pressure).

[0037] Furthermore, in the above embodiment, the rupture disc device 17 is used as the blocking part, but of course, the present invention is not limited to this. Any configuration can be adopted as long as it can block the on-off valve device 16 (release part) from the exhaust gas flow path 14 when the exhaust gas Gb pressure is less than a predetermined pressure (second pressure) and can establish a communication state between the exhaust gas flow path 14 and the on-off valve device 16 when the pressure is equal to or greater than the predetermined pressure (second pressure).

[0038] Furthermore, in the above explanation, a flow path such as the exhaust gas flow path 14 is exemplified as an example of a fluid system through which the fluid to be released can flow, but a fluid reservoir such as a tank in which the fluid is retained or stored may also be the target of the release section and the blocking section. Furthermore, in the above explanation, the exhaust gas flow path 14 is exemplified as an example of a flow path through which the fluid to be released can, of course, be the target of the release of fluid flowing through a flow path other than this. For example, a coolant flow path, an engine oil lubrication path, etc. may also be connected to the release section. In other words, the present invention may be applied to a coolant flow path or an engine oil lubrication path. [Explanation of symbols]

[0039] 10 Internal combustion engine 11 cylinders 12 Combustion chamber 13 Intake gas flow path 14 Exhaust gas flow path 15. Turbocharger 16 On-off valve device 17 Rupture disc device 18 Heat suppression space 19 Air intake 20 Main intake passage 21 Auxiliary intake duct 22 Compressor 23 Exhaust port 24, 24a, 24b Main exhaust passage 25, 25a, 25b Secondary exhaust passage 26 Turbine 27 Valve body 28 biasing member 29 First base 30 Second base 31 Seal part 32 Connecting part 33 Rupture disc 34 Holding part 35 Connecting pipe 35c through hole Ga Intake gas Gb exhaust gas S External space

Claims

1. a fluid system through which a fluid can flow; a discharge part connected to the fluid system and capable of discharging the fluid to an external space of the fluid system when the fluid flowing through the fluid system is at or above a first pressure; a blocking portion provided in the fluid system and blocking the discharge portion from the fluid; a heat suppression space disposed between the discharging portion and the blocking portion; a communication portion that communicates the heat suppression space with the external space; A fluid discharge mechanism comprising:

2. The fluid discharge mechanism according to claim 1 , wherein the blocking section is configured to block the discharge section from the fluid when the fluid pressure is less than a second pressure, and to release the blocked state when the fluid pressure is equal to or greater than the second pressure.

3. The fluid discharge mechanism according to claim 2 , wherein the second pressure is set to a value higher than the first pressure.

4. the fluid system includes an exhaust pipe connected to a combustion chamber of the internal combustion engine; 2. The fluid discharge mechanism according to claim 1, wherein the discharge section is connected to the exhaust pipe, the blocking section is disposed between the exhaust pipe and the discharge section, the discharge section and the blocking section are connected by a connecting pipe, and the heat suppression space is defined by the discharge section, the blocking section, and the connecting pipe.

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