JP2010138707A - Lpg fuel supply device of automobile engine - Google Patents

Abstract

An object of the present invention is to improve the burden on a fuel pump and improve fuel consumption by suppressing a rise in temperature of an LPG due to heating of a fuel path in an engine room and enabling a fuel supply pressure to be set low.
A first gap is formed as a double wall having two openings (71, 72) including a connection port (31) of a fuel hose (3), and a base end of an outer pipe (81) is formed in the opening (71). Is connected to the fuel hose 3 to form the second gap 8 and the other opening 72 is formed with an air intake pipe 101 having an air inlet 101 opened at the front end 21 of the vehicle body 2 at the tip. 10 is connected to the first air gap 7 formed between the outer walls 71 and 72 of the fuel distributor 4 and the outer pipe of the fuel pump communicating with the first air gap 7. And is discharged from an air discharge port 111 communicating with the second gap 8 formed at the tip of the outer pipe 81 disposed around the fuel hose 3.
[Selection] Figure 1

Description

  The present invention relates to an LPG fuel supply device for an automobile engine, and more particularly to an LPG fuel supply device for supplying LPG fuel stored in a fuel tank mounted on a vehicle body to the engine in a liquid state.

  Conventionally, as a system for supplying LPG to a spark ignition type automobile engine, instead of degassing the LPG of a cylinder with a vaporizer and sucking it into an intake air flow with a mixer, the fuel injection valve remains in a liquid state without being reduced in pressure. It has been proposed to inject into an intake air stream.

  By the way, in an LPG fuel supply apparatus using a fuel injection valve, as disclosed in JP-A-59-82556 and JP-A-59-108855, if the internal pressure of the cylinder is used as the injection pressure almost as it is, The gas is easily gasified when subjected to environmental influences, the pressure is extremely fluctuated, and the measurement by the fuel injection valve becomes extremely inaccurate, so that the microfilm of No. 60-21997 (No. 61-138860) can be obtained. Japanese Patent Application No. Sho 60-177417 (Japanese Utility Model Publication No. Sho 62-87162), Japanese Unexamined Patent Publication No. 63-16160, Japanese Unexamined Patent Publication No. 63-16161, Japanese Unexamined Patent Publication No. 63-16162, As disclosed in Japanese Patent No. 63-18172, the cylinder LPG is further pressurized with a fuel pump to make it difficult to gasify, and then adjusted to a predetermined pressure with a pressure regulator. It has been considered to be the injection pressure.

  In such an LPG fuel supply device, LPG has a lower boiling point than gasoline, and it is necessary to set the injection pressure so that it does not evaporate due to the heat of the running engine or the like. In the LPG fuel supply device of the so-called returnless system, the LPG flow rate that moves in the fuel rail arranged close to the engine is smaller than that of the so-called return system that circulates surplus fuel accompanying the injection. LPG temperature tends to increase.

Therefore, in order to prevent LPG vaporization in the LPG fuel supply device of the returnless system, it is necessary to set the fuel supply pressure higher than that of the LPG fuel supply device of the return system, which increases the load of the fuel pump, Not only will the power consumption increase, but the durability of the fuel pump will deteriorate and the fuel consumption of the engine will also deteriorate.
JP 59-82556 A JP 59-108855 A Microfilm of Japanese Utility Model No. 60-21997 (Japanese Utility Model Application No. 61-138860) Microfilm of Japanese Utility Model No. 60-177417 (Japanese Utility Model Application No. 62-87162) Japanese Patent Laid-Open No. 63-16160 JP-A-63-16161 JP-A-63-16162 JP 63-18172 A

  The present invention relates to a fuel path (especially a fuel path in an engine room) in an LPG fuel supply device in which the LPG of a cylinder is further pressurized with a fuel pump, adjusted to a predetermined pressure with a pressure regulator, and injected into an intake pipe from a fuel injection valve. An object of the present invention is to improve the burden on the fuel pump and the fuel consumption of the engine (vehicle) by suppressing the increase in the temperature of the LPG due to the heating of the engine and making the fuel supply pressure low.

  In order to solve the above problems, the present invention provides an LPG fuel stored in a fuel tank mounted on a vehicle body that is pressurized by an electric fuel pump so as to be adjusted to a predetermined pressure and is supplied to an engine in an engine room by a fuel hose. In an LPG fuel supply device for an automobile engine, which is sent to a fuel distributor having a fuel injection valve arranged and injected into the engine from the fuel injection valve, two openings including at least a connection port of the fuel hose are provided on the outer wall of the fuel distributor. And a base end of an outer pipe disposed around a portion of the fuel hose disposed in the engine room in an opening including a connection port of the fuel hose in the first gap. Is connected to form a second gap between the fuel hose and the other opening through the engine room at the tip. An air introduction pipe that forms an air intake opening that is open to the front is connected, and a first air gap that is formed between the external air introduced from the air intake and the outer wall of the fuel distributor, and the first air gap. To the second gap formed between the outer pipe of the fuel pump that communicates with the gap of the fuel pump, and the air exhaust that communicates with the second gap formed at the tip of the outer pipe disposed around the fuel hose. By discharging from the outlet, the LPG fuel supplied into the fuel distributor and the fuel hose is cooled, thereby preventing the LPG fuel from being vaporized due to the environmental temperature in the engine room.

  Moreover, in this invention, it cools forcibly further by attaching an electric air discharger to the air discharge port connected to the said 2nd space | gap formed in the front-end | tip of the outer pipe | tube arrange | positioned around the said fuel hose. In particular, when it is difficult to introduce outside air from the air intake port, such as when driving at low speeds or when the vehicle is stopped, the outside air is forcibly introduced into the outer tube around the fuel hose by the electric air discharger and cooled. To do. At this time, the electric air discharger is driven and controlled by a signal from a fuel temperature sensor attached to the fuel distributor, so that the electric air discharger can be automatically operated for efficient operation.

  According to the present invention, the temperature of the LPG in the fuel supply path arranged in the engine room due to heating of the engine is suppressed, so that the fuel supply pressure can be set low, thereby reducing the burden on the fuel pump. In addition, the fuel efficiency of the vehicle can be improved.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows an outline of a part of an LPG fuel supply device for an automobile engine according to the present invention in an engine room 1 and shows LPG fuel stored in a fuel tank (not shown) mounted on a vehicle body 2. Is pressurized to a predetermined pressure by an electric fuel pump (not shown) and sent to a fuel distributor (fuel rail) 4 in the engine room 1 by a fuel hose 3 from a plurality of fuel injection valves 6. This is a conventionally known returnless system that injects the fuel into the engine 5.

  The outer wall of the fuel distributor 4 has at least two openings 71 and 72 at the connection port 31 and the tip of the fuel hose 3, and a first gap 7 is formed as a double wall. An outer pipe 81 disposed around a portion of the fuel hose 3 disposed in the engine room 1 is connected to the opening 71 including the connection port 31 of the fuel hose 3 in the gap 7 of the first gap 7. Two voids 8 are formed.

  The other opening 72 of the fuel distributor 4 is connected to an air introduction pipe 10 having an air intake port 101 penetrating the engine room 1 at the tip and opening in the front portion 21 of the vehicle body 2. Has been.

  Further, an electric air discharger (electric blower) 11 in which an air discharge port 111 is exposed to the outside of the engine room 1 is installed in the vicinity of the tip of the outer pipe 8 disposed around the fuel hose 3 in the engine room 1. The distal end of the outer pipe 81 disposed around the fuel hose 3 is airtightly connected to the suction port 112 of the electric air discharger 11 in a communicating state.

  Furthermore, in the present embodiment, a fuel temperature sensor 13 is disposed on the inner wall of the fuel distributor 4 and a sensor signal from the fuel temperature sensor 13 is sent to the fuel of the engine 4 mounted on the vehicle body 2. It is configured to be sent to an electronic control unit (ECU) 14 which also serves to drive and control the injection valve 6 and the like, and to operate according to a control signal from the electronic control unit (ECU) 14.

  Next, the use in the present embodiment will be described. When an engine key (not shown) is turned on and the engine is started, power is applied to a power supply circuit (not shown) of the electric air discharger 11. The temperature of the inner wall of the fuel distributor 4 (that is, the temperature of the LPG in the fuel distributor 4) transmitted from the temperature sensor 13 disposed on the inner wall of the fuel distributor 4 when the electronic control unit (ECU) 14 is operated. Receive.

  For example, when the vehicle is stopped for a certain time, the temperature of the engine 5 is not high, and the temperature signal from the temperature sensor 13 is equal to or lower than a predetermined temperature, the LPG temperature in the fuel distributor 4 is high. In addition, since there is no fear of vaporization as it is, there is no need to transmit a drive signal for operating the electronic air discharger 11 from the electronic control unit (ECU) 14, and the electric air discharger 11 is also stopped. .

  Next, when the operation of the engine 5 is started as the vehicle travels, the temperature in the engine room 1 gradually increases as the engine 5 burns, and the fuel distributor 4 and the fuel hose in the engine room 1 are increased. A fuel path such as 3 will be exposed to high temperatures.

  At this time, when the vehicle is traveling in the present embodiment, outside air is introduced as traveling wind from the air intake port 101 provided in the front surface 21 of the vehicle body 2, and the air distributor 10 The electric air discharger is sent to the second gap 8 formed between the first gap 7 formed between the outer wall and the outer pipe 81 of the fuel hose 3 communicating with the first gap 7. 11 air discharge ports 111.

  At this time, since the outside air passing through the first gap 7 and the second gap 8 is lower than the ambient temperature in the engine room 1, the fuel distributor 4 and the fuel distributor 4 in the first gap 7 and the second gap 8 Heat exchange is performed between the fuel hose 3 and the LPG inserted therein, and the temperature rise of the LPG is suppressed. Therefore, even if the ambient temperature in the engine room 1 rises, there is no fear of vaporization even if the pressure of the LPG in the fuel distributor 4 and the fuel hose 3 is not increased more than necessary.

  In addition, when the vehicle is not traveling when the engine 1 is operated or is traveling at a low speed for a long time, it is difficult to introduce outside air from the air intake port 101, and the fuel distributor 4 and the fuel hose 3 In this embodiment, the temperature of the LPG is detected by the fuel temperature sensor 13 installed in the fuel distributor 4 and transmitted to the electronic control unit (ECU) 14 to be preset. When the temperature exceeds the specified temperature, an operation signal is transmitted from the electronic control unit (ECU) 14 to the electric air discharger 11 to operate the electric air discharger 11, and the air intake provided in the front surface 21 of the vehicle body 2 by the suction. Between the first air gap 7 formed between the air introduction pipe 10 and the outer wall of the fuel distributor 4, and the outer pipe 81 of the fuel hose 3 communicating with the first air gap 7. It is sent to the second gap 8 to be formed and discharged from the air discharge port 111 of the electric air discharger 11, and in the first gap 7 and the second gap 8, the fuel distributor 4 and the fuel hose 3 and these The heat exchange is performed with the LPG inserted in the, so that the temperature rise of the LPG is suppressed.

  The operation control of the electric air discharger 11 by the fuel temperature sensor 13 and the electronic control unit (ECU) 14 is always performed, and the electric air is discharged only when the temperature of the LPG in the engine room 1 exceeds a predetermined temperature. It is only necessary to operate the ejector 11, which is very economical.

  As described above, in the present embodiment, the temperature of the LPG in the fuel distributor 4 and the fuel hose 3 disposed in the engine room 1 can be set to a low fuel supply pressure by using outside air regardless of the traveling state of the vehicle. As a result, it is possible to improve the burden on the fuel pump and the fuel consumption of the vehicle. In particular, when the vehicle is in a running state, it is not necessary to operate the electric air discharger 11, and in this respect also useless energy is required. It will also improve fuel efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic explanatory drawing which shows embodiment of this invention.

Explanation of symbols

1 engine room, 2 vehicle body, 3 fuel hose, 4 fuel distributor, 5 engine, 6 fuel injection valve, 7 first air gap, 8 second air gap, 10 air introduction pipe, 13 fuel temperature sensor, 31 connection port, 71, 72 Opening, 81 Outer pipe, 101 Air intake

Claims (3)

  The LPG fuel stored in a fuel tank mounted on the vehicle body is pressurized by an electric fuel pump, adjusted to a predetermined pressure, and sent to a fuel distributor having a fuel injection valve disposed in an engine in an engine room by a fuel hose. In an LPG fuel supply device for an automobile engine that is injected into an engine from a fuel injection valve, a first gap is formed as a double wall having two openings including at least a connection port of the fuel hose on an outer wall of the fuel distributor. A base end of an outer tube disposed around a portion of the fuel hose disposed in the engine room is connected to an opening including a connection port of the fuel hose in the first gap, and a second end is provided between the fuel hose and the second end. And the other opening has an air inlet formed in the front end thereof through the engine room and opened in the front of the vehicle body. An inlet pipe is connected between the first gap formed between the outside air introduced from the air inlet and the outer wall of the fuel distributor, and the outer pipe of the fuel pump communicating with the first gap. The fuel distributor and the fuel hose are fed to the second gap to be formed and discharged from an air discharge port communicating with the second gap formed at the tip of the outer pipe disposed around the fuel hose. An LPG fuel supply device for an automobile engine, wherein the LPG fuel supplied to the inside is cooled to prevent the LPG fuel from being vaporized due to the environmental temperature in the engine room.   The automobile engine according to claim 1, wherein an electric air discharger is attached to an air discharge port communicating with the second gap formed at a tip of an outer pipe arranged around the fuel hose. LPG fuel supply system. 3. The LPG fuel supply device for an automobile engine according to claim 2, wherein the electric air discharger is driven and controlled by a signal from a fuel temperature sensor attached to the fuel distributor.

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