Gas fuel supply device for engine

Abstract

The present invention relates to a gaseous fuel supply device for an engine, in an engine system having an exhaust gas recirculation device, avoiding a malfunction caused by the entry of condensed water into an intake pipe pressure introduction pipe. A gas fuel supply device (100) for an engine comprises a fuel tank (1), a regulator (2), an intake passage (5) having a throttle valve (3) and a mixer (4), a fuel pipe (8), an engine (10), and an exhaust gas recirculation device (13) that recirculates a portion of exhaust gas to the intake passage as EGR gas. An intake pressure outlet (40) formed in the intake passage and a mounting portion (41) formed around the intake pressure outlet are further provided, an intake pressure inlet (30) is formed in the outer surface of the regulator, and the regulator is fixed to the mounting portion by a fixing member (31) in a state in which the intake pressure outlet and the intake pressure inlet directly and hermetically communicate with each other.

Description

Technical Field

[0001] The present invention relates to a gas fuel supply device for forming gaseous fuel stored in a liquid or high-pressure gas state into a gas at a specified pressure and supplying it to an engine. In particular, it relates to a gas fuel supply device for an engine having a regulator that has an intake pressure introduction function. Background Technology

[0002] In the past, in gaseous fuel supply devices that supplied engines with gaseous fuels such as LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), or hydrogen stored in liquid or high-pressure gaseous form, regulators were generally used to reduce the pressure and adjust it to a specified pressure before supplying it to the engine.

[0003] As shown in Japanese Patent Application Publication No. 2013-041375 (Patent Document 1) and Japanese Patent Application Publication No. 2019-067216 (Patent Document 2), there are known piston-type regulators that adjust the pressure of gas to a specified pressure by opening and closing a pressure regulating valve through a piston that is displaced in the axial direction.

[0004] The structure of such an existing example of a piston regulator is such that the main body is divided into a primary pressure chamber (inlet side) and a secondary pressure chamber (outlet side) by a piston, and a pressure regulating spring that applies force to the piston on the secondary pressure chamber side is provided in the spring chamber.

[0005] Furthermore, the force that pushes the piston toward the primary pressure chamber by the gas moving through the pressure regulating valve and from the primary pressure chamber to the secondary pressure chamber is balanced by the force that pushes the piston toward the secondary pressure chamber by the pressure regulating spring. The piston then moves in the axial direction, causing the pressure regulating valve to open and close to regulate the pressure.

[0006] Regarding spring chambers, there are known types such as closed spring chambers, spring chambers that are connected to the atmosphere through a through-hole, and spring chambers where the pressure inside the spring chamber is changed by introducing intake pressure.

[0007] As an example of introducing intake pressure into the regulator, for example... Figure 6 This application shows a gas fuel supply device disclosed as a prior art example in Japanese Patent Application Publication No. 2021-191952 (Patent Document 3), which was previously filed by the applicant of this application.

[0008] The gaseous fuel supply device in this existing example is an engine system in which high-pressure gaseous fuel stored in the fuel tank 1a is filled and its pressure is reduced to a specified pressure by the regulator 2a, and then supplied to the engine 9a via the fuel filter 3a, injector 4a, and fuel piping 5a from the mixer 7a located in the intake passage 6a and via the intake manifold 8a. The intake manifold pressure inlet pipe 10a connects the intake manifold 8a and the regulator 2a, and the intake manifold pressure is introduced into the regulator 2a to regulate the pressure of the discharged gaseous fuel.

[0009] However, when the intake manifold 8a and the regulator 2a are directly connected through the intake manifold pressure inlet pipe 10a, moisture such as condensate generated on the intake passage 6a side can enter the intake manifold pressure inlet pipe 10a from the pressure outlet 11a, causing a functional failure of the intake manifold pressure inlet pipe 10a.

[0010] In particular, as described Figure 6 As shown in the existing example, in an engine system with an exhaust gas recirculation (EGR) device that recirculates a portion of the exhaust gas, it is known that the EGR gas cooled by the EGR cooler 12a is prone to becoming below the dew point temperature, and therefore is prone to condensation in the intake passage 6a.

[0011] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2013-041375 Patent Document 2: Japanese Patent Application Publication No. 2019-067216 Patent Document 3: Japanese Patent Application Publication No. 2021-191952 Summary of the Invention The technical problem that the invention aims to solve Therefore, the technical problem of the present invention is to avoid functional failure caused by condensate entering the intake manifold and being pressurized into the pipe in an engine system with an exhaust gas recirculation device.

[0012] means for solving problems The present invention, made to solve the aforementioned technical problems, comprises an engine gas fuel supply device including: a fuel tank storing gas fuel; a regulator for depressurizing the gas fuel; an intake passage having a throttle valve and a mixer sequentially arranged from the upstream side; a fuel pipe supplying gas fuel passing through the regulator to the mixer; an engine for burning the mixture supplied through the intake passage in the cylinder; exhaust gas being discharged from the exhaust passage; and an exhaust gas recirculation device that recirculates a portion of the exhaust gas as EGR (exhaust gas recirculation) gas from the EGR gas inlet back to the intake passage; characterized in that the engine gas fuel supply device includes: an intake pressure outlet formed in the intake passage; and a mounting portion formed around the intake pressure outlet; an intake pressure inlet is formed on the outer surface of the regulator; and the intake pressure outlet is directly connected to the intake pressure inlet. According to the present invention, by directly and airtightly connecting the intake pressure outlet of the regulator of the intake channel to the intake pressure inlet of the regulator, the intake pressure inlet pipe of the prior art is not required.

[0013] Therefore, not only can functional failures caused by moisture entering the intake manifold pressure inlet be avoided, but also, because no structure for pipe connection is required, it is easy to increase the diameter of the intake pressure inlet.

[0014] In this invention, the intake passage includes an intake manifold that distributes the air-fuel mixture to the cylinders, and the intake pressure outlet is formed in the intake manifold. In this case, the intake pressure supplied to each cylinder of the engine can be extracted and utilized.

[0015] In this invention, the EGR gas inlet is formed between the throttle valve and the mixer, and the intake pressure outlet is formed upstream of the EGR gas inlet. In this case, by taking the intake pressure from a position upstream of the EGR gas inlet, it is possible to more reliably prevent condensate from the exhaust gas recirculation device from entering the regulator.

[0016] In this invention, the intake pressure outlet is formed upstream of the throttle valve. In this case, by taking the intake pressure from a position upstream of the throttle valve, it is possible to more reliably prevent condensate from the exhaust gas recirculation device from entering the regulator.

[0017] Invention Effects According to the present invention, in the gas fuel supply device of the engine with a regulator, the intake pressure introduction function failure caused by condensate or the like can be avoided, and the regulator has an intake pressure introduction function. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the first embodiment of the present invention.

[0019] Figure 2 It is shown Figure 1 A cross-sectional view of the main parts surrounding the regulator in the illustrated embodiment.

[0020] Figure 3 yes Figure 2 A three-dimensional image.

[0021] Figure 4 This is a diagram illustrating a second embodiment of the present invention.

[0022] Figure 5 This is a diagram illustrating the third embodiment of the present invention.

[0023] Figure 6 This is a diagram showing existing examples.

[0024] Explanation of reference numerals in the attached figures 1: Fuel tank 2: Regulator 3: Throttle body, 4: Mixer 5: Air intake channel, 6: Fuel filter, 7: Injector 8: Fuel piping 9: Intake manifold 10: Engine, 11: Exhaust manifold 12: Exhaust passage, 13: Exhaust gas recirculation device; 14: EGR piping, 15: EGR cooler 16: EGR valve 17: EGR gas inlet 18: Turbocharger 19: Intercooler 20: Main body 201: Inlet / Outlet 202: Discharge outlet 21: Pressure regulating valve 22: Valve core, 221: Sealing components, 23: Valve seat, 24: Piston 241: Sealing components, 25: Pressure adjusting spring, 26: Entrance cover, 27: Export cover, 30: Intake pressure inlet, 31: Fixed components 40: Intake pressure outlet, 41: Installation Department 42: Sealing components 50: Intake pressure outlet, 60: Intake pressure outlet, 100: Engine gas fuel supply device, 200: Engine gas fuel supply device, 300: Engine gas fuel supply device, A: Primary pressure chamber, B: Secondary pressure chamber C: Spring chamber. Detailed Implementation

[0025] Hereinafter, with reference to the accompanying drawings, a method for carrying out the present invention will be described.

[0026] <First Implementation> Figure 1 The structure of the gas fuel supply device 100 for an engine according to the first embodiment of the present invention is shown.

[0027] The engine's gaseous fuel supply device 100 includes: a fuel tank 1 storing gaseous fuels such as LPG, CNG, or hydrogen; a regulator 2 for depressurizing and adjusting the high-pressure gaseous fuel delivered from the fuel tank 1; an intake passage 5 having a throttle valve 3 and a mixer 4 sequentially from the upstream side; a fuel pipe 8 supplying gaseous fuel, which has passed through the regulator 2 and reached a specified pressure, to the mixer 4 via a fuel filter 6 and an injector 7; an engine 10 connected to an intake manifold 9 and an exhaust manifold 11; and an exhaust gas recirculation device 13.

[0028] The air supplied via the throttle valve 3 and the gaseous fuel supplied via the fuel line 8 are mixed in the mixer 4 to form a mixture, which is then distributed to each cylinder of the engine 10 through the intake manifold 9, where it is ignited and burned.

[0029] The exhaust gas discharged from each cylinder passes through the exhaust manifold 11 and is discharged to the outside through the exhaust passage 12.

[0030] In this specification, the overall path of the intake system, including the intake manifold 9, to the engine 10 is defined as intake passage 5, and the overall path of the exhaust system, including the exhaust manifold 11, through the engine 10 is defined as exhaust passage 12.

[0031] In this embodiment, an exhaust gas recirculation (EGR) device 13 is provided between the exhaust manifold 11 and the intake passage 5.

[0032] The exhaust gas recirculation device 13 includes an EGR pipe 14, an EGR cooler 15, and an EGR valve 16, which uses a portion of the exhaust gas as EGR gas, allowing it to recirculate while returning from the EGR gas inlet 17 to the intake passage 5.

[0033] The EGR gas inlet 17 is located between the throttle valve 3 and the mixer 4 in the intake channel 5.

[0034] In addition, this embodiment includes a turbocharger 18 and an intercooler 19. The turbocharger 18 compresses the intake air by utilizing the flow of exhaust gas passing through the exhaust passage 12 side, and the intercooler 19 cools the compressed air.

[0035] Figure 2 This is a cross-sectional view showing the main parts surrounding the regulator 2. Figure 3 This is a perspective view of the regulator 2, which has a pressure regulating valve 21 composed of a cylindrical valve core 22 and an annular valve seat 23 within a cylindrical body 20.

[0036] The pressure regulating valve 21 adjusts the opening amount by changing the distance between the valve core 22 and the valve seat 23, thereby reducing the pressure of the high-pressure gas fuel sent from the fuel tank 1 (in the direction of the black arrow in the figure) to the specified pressure.

[0037] A piston 24 is fixed to the outer periphery of the valve core 22, and the valve core 22 and the piston 24 are capable of displacement in the axial direction.

[0038] The main body 20 is divided in an airtight manner by a sealing member 221 that contacts the outer periphery of the valve core 22 and a sealing member 241 that contacts the outer periphery of the piston 24, and has a primary pressure chamber A on the inlet 201 side, a secondary pressure chamber B on the outlet 202 side, and a spring chamber C located in the middle.

[0039] The spring chamber C contains the piston 24 and a pressure regulating spring 25 that applies force to the piston 24 in the direction of the secondary pressure chamber B.

[0040] Additionally, the regulator 2 has an inlet cover 26 installed at the inlet 201 and an outlet cover 27 installed at the outlet.

[0041] An air intake pressure inlet 30 is formed on the outer surface of the main body 20, which has the function of introducing the pressure in the air intake channel 5, i.e., the air intake pressure, into the spring chamber C through the air intake pressure inlet 30.

[0042] In this embodiment, an intake pressure outlet 40 is formed on the outer surface of the intake manifold 9, and a mounting portion 41 with multiple threaded holes is formed around the intake pressure outlet 40.

[0043] In addition, an O-ring, i.e. a sealing member 42, is disposed around the intake pressure outlet 40.

[0044] Furthermore, a feature of the present invention is that, in a state where the intake pressure outlet 40 and the intake pressure inlet 30 are directly and airtightly connected, the regulator 2 is fixed to the mounting portion 41 by a fixing screw, i.e., a fixing member 31.

[0045] The voltage regulation function of the regulator in this embodiment will be explained below.

[0046] The gaseous fuel introduced from the fuel tank 1 into the primary pressure chamber A is moved to the secondary pressure chamber B by the force of the pressure regulating spring 25 disposed in the spring chamber C, passing through the valve core 22 which is in the default open state.

[0047] If the pressure in the secondary pressure chamber B rises due to the gaseous fuel moving into the secondary pressure chamber B, the piston 24 overcomes the force exerted by the pressure regulating spring 25 on the piston 24 in the direction of the secondary pressure chamber B and is pressed towards the primary pressure chamber A.

[0048] Furthermore, the intake pressure in the intake passage 5, which passes through the intake pressure outlet 40 and is introduced from the intake pressure inlet 30, is introduced into the spring chamber C, thereby causing a pressure change in the spring chamber C, which in turn affects the piston 24.

[0049] Thus, by balancing the force of the pressure regulating spring 25 pushing the piston 24 towards the secondary pressure chamber B, the force of the gaseous fuel moving from the primary pressure chamber A to the secondary pressure chamber B through the pressure regulating valve 21 pushing the piston 24 towards the primary pressure chamber A, and the pressure in the spring chamber C that changes due to the introduced intake pressure, the piston 24 is displaced in the axial direction, causing the pressure regulating valve 21 to open and close to regulate the pressure.

[0050] According to this embodiment, the intake pressure outlet 40 is directly and airtightly connected to the intake pressure inlet 30, eliminating the need for the intake pipe pressure inlet pipe of the prior art.

[0051] Therefore, not only can functional failures caused by moisture entering the intake manifold pressure inlet pipe be avoided, but also because no pipe connection structure is required, it is easy to increase the diameter of the intake pressure inlet 30.

[0052] As an advantage of the increased diameter of the intake pressure inlet 30, in addition to the expected improvement in the responsiveness of the intake pressure inlet, even if condensation is attached to the inner circumferential surface of the intake pressure inlet 30, there is no need to worry about intake pressure inlet function failure because the diameter is larger than that of the intake manifold pressure inlet in the conventional example.

[0053] <Second Implementation> Figure 4 The second embodiment of the present invention shows a gas fuel supply device 200 for an engine, and the... Figure 1 The first embodiment shown is basically the same, with the same structure labeled with the same reference numerals. The difference is that the intake pressure outlet 50 is formed in the intake passage 5 at a position upstream of the EGR gas inlet 17 and downstream of the throttle valve 3.

[0054] In this embodiment, an intake pressure outlet 50 is formed on the outer surface of the intake passage 5, which is upstream of the intake manifold 9. Furthermore, with... Figure 2 A mounting portion 41 with multiple threaded holes is formed around the intake pressure outlet 40. Similarly, a mounting portion 41 with multiple threaded holes is formed around the intake pressure outlet 50, and an O-ring, i.e., a sealing member 42, is arranged around the intake pressure outlet 50.

[0055] Furthermore, with the intake pressure outlet 50 formed in the intake channel 5 directly and airtightly connected to the intake pressure inlet 30 of the regulator 2, the regulator 2 is fixed to the mounting part 41 by a fixing screw, i.e., a fixing member 31.

[0056] EGR gas containing moisture sent from the exhaust gas recirculation device 13 moves downstream of the engine 10 from the EGR gas inlet 17. Therefore, by forming the intake pressure outlet 50 at a position upstream of the EGR gas inlet 17, it is possible to prevent condensate from entering from the intake pressure outlet 40.

[0057] <Third Implementation Method> Figure 5 The third embodiment of the present invention shows a gas fuel supply device 300 for an engine, and the... Figure 1 The first embodiment shown is basically the same, with the same structure labeled with the same reference numerals. The difference is that the intake pressure outlet 60 is formed in the intake channel 5 at a position upstream of the EGR gas inlet 17 and upstream of the throttle valve 3.

[0058] In this embodiment, an intake pressure outlet 60 is formed on the outer surface of the intake passage 5, which is upstream of the intake manifold 9. Furthermore, with... Figure 2 A mounting portion 41 with multiple threaded holes is formed around the intake pressure outlet 40. Similarly, a mounting portion 41 with multiple threaded holes is formed around the intake pressure outlet 60, and an O-ring, i.e., a sealing member 42, is arranged around the intake pressure outlet 60.

[0059] Furthermore, with the intake pressure outlet 60 formed in the intake channel 5 and the intake pressure inlet 30 of the regulator 2 in direct and airtight communication, the regulator 2 is fixed to the mounting part 41 by the fixing screw, i.e. the fixing member 31.

[0060] The EGR gas containing moisture delivered from the exhaust gas recirculation device 13 moves downstream of the engine 10 from the EGR gas inlet 17, and because of the throttle valve 3, the intake pressure outlet 60 is formed upstream of the EGR gas inlet 17, which can more reliably prevent condensate from entering from the intake pressure outlet 60.

[0061] Furthermore, the first to third embodiments shown in this specification are engine systems with turbochargers, therefore, the intake pressure in the intake passage fluctuates between negative pressure, atmospheric pressure, and positive pressure depending on the operating conditions of the turbocharger.

[0062] On the other hand, in a naturally aspirated engine system without a turbocharger, the intake pressure in the intake passage fluctuates between negative pressure and atmospheric pressure, for example, due to intake pulsation.

[0063] Even with such changes in intake pressure, the present invention, which directly and airtightly connects the intake pressure outlet formed in the intake passage and the intake pressure inlet formed in the regulator, still performs the intake pressure introduction function in the intake passage. Moreover, it does not require an intake pipe pressure inlet pipe as in previous inventions. Therefore, it avoids intake pressure introduction function failures caused by condensation, etc., and it is also easy to increase the diameter of the intake pressure inlet.

[0064] Furthermore, the first to third embodiments shown in this specification are engine systems with turbochargers, but the present invention can also be implemented in naturally aspirated engine systems without turbochargers.

Claims

1. A gas fuel supply device for an engine, comprising: The fuel tank contains gaseous fuel. The regulator adjusts the pressure of the gaseous fuel. The intake passage, from the upstream side, contains a throttle valve and a mixer. Fuel piping supplies gaseous fuel, which has passed through the regulator, to the mixer. The engine, which causes the air-fuel mixture supplied through the intake manifold to burn in the cylinders and exhausts the gas through the exhaust manifold, and An exhaust gas recirculation device, wherein a portion of the exhaust gas is used as exhaust gas recirculation gas and recirculated from the exhaust gas recirculation gas inlet to the intake passage; characterized in that... The gas fuel supply device of the engine has: An intake pressure outlet is formed in the intake passage, and The mounting portion is formed around the intake pressure outlet; An air intake pressure inlet is formed on the outer surface of the regulator. With the intake pressure outlet and the intake pressure inlet directly and airtightly connected, the regulator is fixed to the mounting part by a fixing member.

2. The gas fuel supply device for the engine according to claim 1, characterized in that, The intake passage includes an intake manifold that distributes the air-fuel mixture to the cylinder. The intake pressure outlet is formed in the intake manifold.

3. The gas fuel supply device for the engine according to claim 1, characterized in that, The exhaust gas recirculation inlet is formed between the throttle valve and the mixer. The intake pressure outlet is located upstream of the exhaust gas recirculation inlet.

4. The gas fuel supply device for the engine according to claim 3, characterized in that, The intake pressure outlet is located upstream of the throttle valve.

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