Gas fuel supply device for engine

Abstract

The present invention relates to a gas fuel supply device in which a regulator is connected to an intake passage side through a negative pressure conduit, and prevents moisture from entering the intake passage and hindering the introduction of negative pressure to the regulator. The gas fuel supply device of an engine comprises: a regulator (2) for reducing pressure and adjusting the high-pressure gas fuel filled and accumulated in a fuel tank (1); a mixer (7) for delivering the gas fuel reduced by the regulator (2) to a position downstream of a throttle valve (14) of an intake passage (6); and an engine system having a method of introducing exhaust gas delivered from an exhaust circulation device from an exhaust gas introduction port (20) arranged between the throttle valve (14) of the intake passage (6) and the mixer (7) and mixing with the gas fuel, and a pressure outlet (19) of an intake pipe pressure introduction pipe (10) introduced to the back side of a pressure receiving portion of the regulator is connected to a position upstream of the exhaust gas introduction port (20) on the intake passage (6) and downstream of the throttle valve (14).

Description

Technical Field

[0001] The present invention relates to a gas fuel supply device for forming gas fuel accumulated in a liquid or high-pressure gas state into gas of a specified pressure and supplying it to an engine, and in particular, to a gas fuel supply device for an engine, the gas fuel supply device having an intake pipe pressure introduction pipe that connects a regulator and an intake passage side to introduce intake pipe negative pressure. Background Art

[0002] Conventionally, as a gas fuel supply device for supplying a gas fuel such as LPG (liquefied petroleum gas) or CNG (compressed natural gas) to an engine, the following types of devices are known: Figure 4 As shown, the high-pressure gas fuel filled and accumulated in the fuel tank 1 is reduced in pressure to a specified pressure by the regulator 2, and is supplied to the engine 9 through the engine intake pipe (intake manifold) 8 from the mixer 7 arranged on the intake passage 6 through the fuel filter 3, the injector 4, and the fuel piping 5.

[0003] In addition, for example, the following technology is also recorded in Japanese Patent Gazette No. 2002-21642, etc.: the engine intake pipe 8 constituting the terminal side of the intake passage 6 is connected to the regulator 2 through an intake pipe pressure introduction pipe (MAP hose (Manifold Absolute Pressure hose)) 10 for introducing intake pipe negative pressure, thereby introducing the intake pipe negative pressure into the regulator 2 and utilizing it.

[0004] In this way, the intake pipe negative pressure generated on the intake passage 6 side is introduced into the regulator 2 via the intake pipe pressure inlet pipe 10, thereby achieving the following functions: correcting the control pressure of the regulator 2 according to the operating condition of the engine 9, or forcibly closing the connection between the main chamber and the secondary chamber in the regulator 2 when the engine stops, to prevent the outflow of gaseous fuel.

[0005] However, when the engine intake pipe 8 and the regulator 2 are directly connected via the intake pipe pressure introduction pipe 10, water such as condensed water generated on the intake passage 6 side intrudes into the intake pipe pressure introduction pipe 10 and becomes an obstacle, thereby causing obstruction in the transmission of negative pressure. If the intruded water solidifies, there is the following disadvantage: the function of the intake pipe pressure introduction pipe 10 cannot be basically exerted.

[0006] As described in Japanese Patent Application Publication No. 2018-21510, it is known that condensed water is frequently generated in the intake passage because the EGR gas of an exhaust gas recirculation (EGR) device that circulates part of the exhaust gas in the cylinder easily becomes below the dew point temperature. Figure 4 As shown in the engine system, an exhaust gas recirculation device including an EGR cooler 11, an EGR valve 12 and connecting pipes thereof is provided, so that condensed water is more likely to intrude into the intake pipe pressure introduction pipe 10 through the intake passage 6.

[0007] In addition, Figure 4 , reference numeral 13 is an engine exhaust pipe, reference numeral 14 is a throttle valve, reference numeral 15 is a turbocharger, reference numeral 16 is an intake passage of the turbocharger, reference numeral 17 is an exhaust passage of the turbocharger, and reference numeral 18 is an intercooler.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2002-21642

[0011] Patent Document 2: Japanese Patent Application Publication No. 2018-21510 Summary of the invention

[0012] Problem that the invention aims to solve

[0013] The present invention is made in view of the above-mentioned problems, and its subject is to prevent moisture from invading the intake pipe pressure introduction pipe and hindering the introduction of negative pressure into the regulator in a gas fuel supply device in which the regulator is connected to the intake passage side through the intake pipe pressure introduction pipe.

[0014] Means used to solve problems

[0015] The present invention made to solve the above-mentioned problem is a gas fuel supply device for an engine, comprising: a regulator, which reduces the pressure of high-pressure gas fuel filled and accumulated in a fuel tank; and a mixer, which delivers the gas fuel reduced in pressure by the regulator to a downstream position of a throttle valve in an intake passage, and has an engine system in which exhaust gas delivered from an exhaust gas recirculation device is introduced from an exhaust gas inlet port arranged between the throttle valve and the mixer on the intake passage and mixed with the gas fuel, characterized in that a pressure outlet of an intake pipe pressure inlet pipe for introducing the gas into the back side of a pressure-receiving portion of the regulator is connected to a position upstream of the exhaust gas inlet port on the intake passage and downstream of the throttle valve.

[0016] In addition, another invention made to solve the above-mentioned problem is a gas fuel supply device for an engine, comprising: a regulator, which reduces the pressure of the high-pressure gas fuel filled and accumulated in the fuel tank; and a mixer, which delivers the gas fuel reduced in pressure by the regulator to a downstream position of a throttle valve in an intake passage having a turbocharger upstream, and an engine system having a method of introducing the exhaust gas delivered from the exhaust gas recirculation device from an exhaust gas inlet port arranged between the throttle valve and the mixer on the intake passage and mixing with the gas fuel, characterized in that a pressure outlet of an intake pipe pressure inlet pipe for introducing the exhaust gas into the back side of the pressure-receiving portion of the regulator is connected to a position upstream of the exhaust gas inlet port on the intake passage and upstream of the throttle valve.

[0017] In particular, in the present invention, when the pressure outlet of the intake pipe pressure inlet pipe is connected to the upper position of the intake passage and the front end of the pressure outlet protrudes into the intake passage, exhaust condensate retained on the inner wall surface of the intake passage can be reliably prevented from intruding into the pressure outlet.

[0018] Effects of the Invention

[0019] According to the present invention, in a gas fuel supply device in which an intake passage and a regulator are connected by an intake pipe pressure introduction pipe, it is possible to effectively prevent moisture from entering the intake pipe pressure introduction pipe to hinder introduction of negative pressure into the regulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a layout diagram showing the structure of a gas fuel supply device according to a preferred embodiment of the present invention.

[0021] Figure 2 It is a cut-off representation Figure 1 A partially enlarged view of a portion of a connection portion of the embodiment shown, the connection portion being a connecting portion between a pressure extraction port of an intake pipe pressure introduction pipe and an intake passage.

[0022] Figure 3 It is a layout diagram showing the structure of the gas fuel supply device according to various embodiments of the present invention.

[0023] Figure 4 1 is a layout diagram showing the structure of a gas fuel supply device having a conventional exhaust gas recirculation device.

[0024] Description of Reference Numerals

[0025] 1 fuel tank, 2 regulator, 3 fuel filter, 4 injector, 5 fuel pipe, 6 intake passage, 7 mixer, 8 engine intake pipe, 9 engine, 10 intake pipe pressure introduction pipe, 11 EGR cooler, 12 EGR valve, 13 engine exhaust pipe, 14 throttle, 15 turbocharger, 16 intake passage, 17 exhaust passage, 18 intercooler, 19 pressure outlet, 20 exhaust gas introduction port. DETAILED DESCRIPTION

[0026] Hereinafter, a mode for carrying out the present invention will be described with reference to the drawings.

[0027] Figure 1 The structure of the gas fuel supply device of the preferred embodiment of the present invention is shown, which comprises: a regulator 2, which reduces the pressure of the high-pressure gas fuel such as LPG or CNG delivered from the fuel tank 1; a fuel piping 5, which delivers the gas fuel which is reduced in pressure to become a gas of a specified pressure to an intake passage 6 via a fuel filter 3 and an injector 4; and a mixer 7, which mixes the gas fuel delivered through the fuel piping 5 with air and delivers the mixture to the intake passage 6.

[0028] In addition, in the engine system having the gas fuel supply device, the engine exhaust pipe 13 and the intake passage 6 are connected by piping having an exhaust gas recirculation (EGR) device composed of an EGR cooler 11 and an EGR valve 12, so that a part of the exhaust gas of the engine 9 is returned to the intake passage 6 side as EGR gas and circulated.

[0029] Moreover, the pressure outlet 19 on the intake pipe pressure inlet pipe 10 for introducing the pressure into the back side of the pressure-receiving part of the regulator 2 is connected to a position upstream of the exhaust gas inlet 20 on the intake passage 6 and downstream of the throttle valve 14. The exhaust gas inlet 20 introduces the EGR gas from the EGR valve 12, and can introduce the intake pipe negative pressure into the air chamber (not shown) in the regulator 2 while automatically correcting the control pressure according to the operating condition of the engine 9.

[0030] Furthermore, in the drawings, reference numeral 13 is an engine exhaust pipe, reference numeral 15 is a turbocharger, reference numeral 16 is an intake passage of the turbocharger, reference numeral 17 is an exhaust passage of the turbocharger, and reference numeral 18 is an intercooler.

[0031] According to the present embodiment, the EGR gas containing moisture sent out from the EGR valve 12 generates moisture such as condensed water at the position where it enters the intake passage 6 from the exhaust gas inlet 20. However, the pressure outlet 19 of the intake pipe pressure inlet pipe 10 for introducing the gas into the back side of the pressure-receiving portion of the regulator 2 is connected to a position upstream of the exhaust gas inlet 20 in the intake passage 6 for introducing the EGR gas from the EGR valve 12. This prevents moisture from intruding into the intake pipe pressure inlet pipe 10, and reliably prevents the negative pressure introduction function of introducing negative pressure into the regulator 2 from being obstructed due to the intrusion of moisture into the intake pipe pressure inlet pipe 10.

[0032] In addition, in this embodiment, if Figure 2 As shown, the pressure outlet 19 of the intake pipe pressure introduction pipe 10 is connected to an upper position of the intake passage 6 and a front end of the pressure outlet 19 protrudes into the intake passage 6 .

[0033] Most of the moisture such as condensed water generated at the position where the moisture-containing EGR gas sent out from the EGR valve 12 enters the intake passage 6 from the exhaust gas inlet port 20 is accumulated below the intake passage 6. Therefore, the condensed water will not invade from the outlet 19 of the intake pipe pressure inlet pipe 10. Moreover, since the front end of the pressure outlet 19 protrudes into the intake passage 6, the exhaust condensed water retained on the inner wall surface of the intake passage 6 can be reliably prevented from invading the intake pipe pressure inlet pipe 20 from the pressure outlet 19.

[0034] Figure 3 Another embodiment of the present invention is shown, which is basically the same as the Figure 1 The embodiment shown is the same, except that the pressure outlet 19 of the intake pipe pressure inlet pipe 10 for introducing pressure into the back side of the pressure-receiving part of the regulator 2 is connected to a position upstream of the exhaust gas inlet port 20 on the intake passage 6 and upstream of the throttle valve 14.

[0035] According to this embodiment, Figure 1Similar to the illustrated embodiment, not only is the pressure outlet 19 of the intake pipe pressure inlet pipe 10 for introducing air into the back side of the pressure-receiving portion of the regulator 2 connected to the upstream of the exhaust gas inlet port 20 on the intake passage 6, but the pressure outlet 19 of the intake pipe pressure inlet pipe 10 is also moved upstream of the throttle valve 14 on the intake passage 6. As a result, the EGR gas containing water delivered from the EGR valve 12 is blocked by the throttle valve 14 at the position where the condensed water and other water are entered into the intake passage 6 from the exhaust gas inlet port 20. In addition, water is prevented from intruding into the intake pipe pressure inlet pipe 10. Therefore, it is possible to more reliably prevent the negative pressure introduction function of introducing negative pressure into the regulator 2 from being hindered due to the intrusion of water into the intake pipe pressure inlet pipe 10.

[0036] Furthermore, in the present embodiment, the pressure outlet 19 on the intake passage 6 for introducing pressure into the regulator 2 is moved upstream of the throttle valve 14. Assuming that in the case of a naturally aspirated engine, the pressure introduced into the regulator 2 does not become a negative pressure, and the effect of regulating the fuel pressure cannot be obtained, but the present embodiment is an engine having a turbocharger 15, so the fuel pressure can be increased under high load (supercharged state).

Claims

1. A gas fuel supply device for an engine, comprising: a regulator for reducing the pressure of high-pressure gas fuel filled and accumulated in a fuel tank; and a mixer for delivering the gas fuel reduced in pressure by the regulator to a position downstream of a throttle valve of an intake passage, and having an engine system in which exhaust gas delivered from an exhaust gas recirculation device is introduced from an exhaust gas inlet port disposed between the throttle valve and the mixer on the intake passage and mixed with the gas fuel, characterized in that: A pressure take-out port of an intake pipe pressure introduction pipe for introducing pressure to the back side of the pressure receiving portion of the regulator is connected to a position upstream of the exhaust gas introduction port and downstream of the throttle valve on the intake passage.

2. A gas fuel supply device for an engine, comprising: a regulator for reducing the pressure of high-pressure gas fuel filled and accumulated in a fuel tank; and a mixer for delivering the gas fuel reduced in pressure by the regulator to a position downstream of a throttle valve of an intake passage having a turbocharger upstream, and an engine system having a method of introducing exhaust gas delivered from an exhaust gas recirculation device from an exhaust gas inlet port disposed between the throttle valve and the mixer on the intake passage and mixing with the gas fuel, characterized in that: A pressure take-out port of an intake pipe pressure introduction pipe for introducing pressure to the back side of the pressure receiving portion of the regulator is connected to a position upstream of the exhaust gas introduction port on the intake passage and upstream of the throttle valve.

3. The gas fuel supply device according to claim 1 or 2, characterized in that: The pressure outlet of the intake pipe pressure introduction pipe is connected to an upper position of the intake passage, and a front end of the pressure outlet protrudes into the intake passage.

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