KR20020020570A - Pressure control system of lpg bombe - Google Patents

Abstract

PURPOSE: A pressure control system of an LPG(Liquefied Petroleum Gas) bombe is provided to let an LPG injection system stably operate even in an inferior condition and to remove the cause of a danger of gas leakage. CONSTITUTION: A pressure control system of an LPG bombe comprises an LPG bombe(1), an air cleaner(2), an air dryer(3), an air pump(4), a control valve(5), an air cut-off solenoid(6), an LPG bombe pressure sensor(7), and a fuel supply sensing assembly(8). If the pressure of the LPG bombe falls to a level lower than a reference pressure, the air pump is driven. Clean air passes through the air dryer while losing moisture. The air is compressed in the air pump. The compressed air is delivered to the LPG bombe by passing through the cut-off solenoid. With the compressed air, the pressure inside the LPG bombe reaches a predetermined level. Then, the air pump is stopped while the cut-off solenoid is shut off. Therefore, the pressure inside the LPG bombe is kept in a predetermined level.

Description

Pressure Control System of LPG Bombe

The present invention relates to an Elpigi Bombe system for an LPG fuel supply device, and more particularly, to an injection-type Elpigi Bombe pressure control system.

The LPG fuel supply device of the mixer type in the LPI fuel vehicle is showing a limit to satisfy the recently tightened vehicle emission regulations. Currently, developed countries' exhaust gas regulations cannot satisfy the existing mixer type LPG system, and therefore, LPG systems in developed countries have to be replaced by injection methods.

In addition, the LPG system of the mixer type always carries the risk of backfire caused by the internal combustion engine due to the characteristics of the fuel.In the way that the gasoline engine, which is the base of the LPG engine, controls the ignition timing in accordance with the tightening of the exhaust gas regulation, With this change, the ignition timing electronic control engine has a very high possibility of backfire (combustion and explosion of fuel in the intake manifold), making it difficult to use a conventional LPG mixer type system.

In order to solve the above problems, developed countries in Europe are applying the injection type LPG system, which always requires a constant pressure (higher than atmospheric pressure) in LPG cylinders. Edo rarely goes below freezing, and the high proportion of propane in the composition of LPG fuel (70:30 in winter) allows LPG cylinders to be maintained at low temperatures. However, some countries, including Korea, have very cold temperatures (less than 10 degrees below zero) and low proportions of propane due to the composition of LPG fuels (30:70 winter) and below atmospheric pressure below 10 degrees. In this case, therefore, the current system for supplying liquid LPG fuel at the pressure in the LPG cylinder cannot receive the required fuel supply.

Therefore, it is necessary to develop a system for maintaining the pressure in the LPG cylinder above a certain level required by the injection type LPG system.

Currently, LPG fuel pumps are applied to obtain a high pressure to maintain a liquid phase even at a normal engine operating temperature (about 80 ° C) in the liquid injection LPG system. However, due to the characteristics of LPG fuel, it is difficult to maintain lubrication, and it is difficult to fundamentally prevent the risk of gas leakage accidents. Therefore, an expensive system is constructed to solve this problem. The price of the system is high because the system is expensive, and electrical devices with contacts for the operation of the pump in the LPG cylinder are exposed to the LPG gas in the LPG cylinder and the risk of explosion due to inadvertent sparking cannot be excluded. It is difficult to manufacture and construct (large volume fuel pump must be put in the cylinder), and it is difficult to maintain lubrication because it is difficult to maintain lubrication.

An object of the present invention is to solve the problems of the conventional LLP injection system in the above-mentioned LPI vehicle to enable a low-cost environmentally friendly low pollution LPG injection system to operate stably under poor conditions, the risk of gas leakage accidents The goal is to build a safe LPG fuel system that is fundamentally removed. In order to achieve this task, the pressure in the LPG cylinder is pumped and pressurized into the LPG cylinder to maintain the pressure required by the injection system (normally 1 bar or more than atmospheric pressure). However, this pressurization causes problems when LPG fuel is filled at a certain level when the fuel in the LPG cylinder is almost at the bottom. As the fuel rises from the bottom during charging, the pressure in the LPG cylinder rises. This can cause the fuel to stop charging midway. Therefore, it is a feature of the present invention to maintain the pressure in the LPG cylinder at a predetermined level (5 Bar) at all times during charging.

1 is a system schematic diagram of the present invention;

2 is a cross-sectional view of the control valve applied to the present invention

3 is a cross-sectional view of the fuel supply sensor (magnetic) of the present invention.

4 is a cross-sectional view of a fuel supply sensor (contact switch) of the present invention.

Hereinafter will be described in detail with the accompanying drawings with respect to the pressure control system Elpji Bombe according to the present invention to achieve the object of the present invention as described above.

1 is a view schematically illustrating the Elpim bomb pressure control system of the present invention, the Elpension pressurization system according to the present invention is an air cleaner (2), an air dryer (3), an air pump (4) together with the Elpgi cylinder (1) ), Control valve (5), air cutoff solenoid (6), LPG cylinder pressure sensor (7) and fuel supply detection sensor (8). A port is installed, and a carbon canister (hydrocarbon adsorber) 10 of a gasoline vehicle is used. The carbon canister 10 is connected by using a T-type connector in the middle of the hose connected to the carbon canister 10 in the gasoline fuel tank in the case of a public car of gasoline and LPG (see FIG. 1).

As described above, when the external temperature is lowered in the injection type LPG fuel system and the pressure of the LPG cylinder is lowered to less than the prescribed constant pressure (about 2 Bar), the pressure sensor 7 attached to the LPG cylinder detects the air pump ( 4). Open the valve by operating the air cutoff solenoid (6) at regular intervals, and clean air passing through the air cleaner passes through the air dryer (3), removes moisture from the air, and compresses the air pump to high pressure (3 Bar). do. The compressed air thus sucked in opens the air intake check valve 51 at the control valve 5 and passes through the chuck valve and passes through the already open air cutoff solenoid 6 connected to the LPG cylinder as shown in FIG. 2. It is conveyed into the cylinder 1. When the pressure in the LPG cylinder 1 reaches more than the prescribed pressure by the compressed air, the pressure in the LPG cylinder is detected by the LPG cylinder pressure sensor 7, which first closes the air cutoff solenoid 6 and stops the air pump. Let's do it. The above operation is repeated and always to maintain the pressure in the LPG cylinder 1 above the prescribed or required pressure. Since the gas discharge check valve 52 of the control valve 5 is opened at a pressure 5 Bar higher than the pressure generated by the air pump, the compressed air is not discharged through the gas discharge check valve 52.

The operation of each component can be controlled through an engine ECU or by an electric circuit using a general relay.

As described above, when this pressurization system is operated, the air cutoff solenoid 6 is closed when the LPG fuel is charged because the LPG cylinder 1 is provided with air pressure even when the fuel is in the ground state. When fuel is injected from the tank, the fuel is filled and the pressure in the LPG cylinder (1) is gradually increased by the air charged inside the LPG cylinder (1). Injection becomes impossible. In other words, it can become impossible to charge before the fuel is fully charged. Therefore, during the filling of the LPG fuel, if the pressure in the LPG cylinder 1 rises above the pressure above the prescribed pressure (5 Bar), it is detected by the pressure sensor 7 attached to the inside of the LPG cylinder 1. Since the pressure inside the cylinder 1 can rise above the prescribed pressure even by an excessive rise in temperature, when detected by the fuel supply detection assembly 8 (see FIGS. 3 and 3) to detect that the fuel is being filled. By opening the air cutoff solenoid 6 by means of these two pressure sensors 7 and fuel supply sensing assembly 8, the compressed air in the LPG cylinder 1 is pushed out to the control valve 5, thereby controlling the control valve 5. When the pressure (5 Bar) specified in the gas discharge check valve is exceeded, the gas in the LPG cylinder (1) is blown out by the air cutoff solenoid (6) to reduce the pressure in the LPG cylinder (1). To be released.

The mixture of air and LPG gas in this way is dangerous. Therefore, the position of the inlet of the air cutoff solenoid 6 in the cylinder is always at the top of the LPG cylinder 1 to prevent the mixing of LPG gas in the discharge gas. The reason is that the LPG gas stays on the bottom or bottom side in the cylinder 1 because the specific gravity of the LPG gas is larger than the air, and the air stays on the top side in the inner space of the cylinder 1, To be released first. However, since some of the LPG gas may be mixed with the decompression gas, the released gas passes through the carbon canister 10 to collect the LPG gas to the outside air to prevent leakage of the LPG gas to the outside. This prevents the LPG gas from escaping.

The fuel supply detection assembly (8) in the LP system pressurization system of the present invention having such a configuration and function is installed to LPG fuel inlet (i) as shown in Figure 1 to supply fuel to the cylinder (1) 3 and 4 as the device.

As shown in FIGS. 3 and 4, the fuel supply assembly 8 has a flow path in the housing having a substantially "a" shape, and a check valve 811 and an overpressure relief valve 812 for preventing the overpressure in the flow path. The fuel supply relief valve 81 and the fuel supply detection sensor 82 are formed. When the fuel is injected, the backflow prevention check valve 811 is opened by the pressure of the injected fuel. Is to use the displacement when it is opened.

The fuel supply sensor 82 has a magnetic type and a contact type. The magnetic type fuel supply sensor is shown in FIG. 4, and the contact type fuel supply sensor is shown in FIG. 5. Magnetic type fuel supply sensor is connected to the valve seat of the non-return check valve 81 to form a sensor rod 824, a magnet 821 is attached to the end of the sensor rod 824, and the sensor cover thereon When the magnetic sensor 823 is installed at 822, and the check valve 811 is opened when the fuel is filled, and the valve seat is moved downward, the magnet 821 connected thereto is moved downward and the magnetic force change at this time is performed. As a result, the magnetic sensor 823 detects that fuel is being supplied. (See Figure 4)

Then, as another embodiment of the fuel supply sensor 82, the contact type fuel supply sensor shown in FIG. 5 forms a rod 824 of the sensor on the valve seat of the non-return check valve 811 so as to be in contact with and detached from the sensor. The upper end of the rod 824 is assembled with a spring 826 so that the sensor rod 824 is elastically movable up and down, and the sensor ring 826 is fixed to the sensor rod 825 at the lower end of the spring 826. And a diaphragm 828 is fixed to the housing at the bottom of the sensor ring 827. When refueling check valve 811 is opened during fuel filling, and the valve seat moves downward, the sensor rod 824 in close contact therewith moves downward with the force of the sensor spring 826 and is connected to the sensor rod 824. The sensor ring 827 contacts the sensor plug to detect that fuel is being filled with an electrical signal.

The gas exhaust system of such a configuration should be controlled by a general electric circuit using a relay, since the key of the vehicle must be operated even when the key is turned off.

As described above, the present invention is to ensure that the pressure in the LPG cylinder, which is essential for the stable operation of the injection type LPG fuel system, is always maintained above the prescribed pressure, the cold temperature is low, and the ratio of propane in the composition of the LPG fuel is low. It is possible to apply the injection-type LPG fuel system that can satisfy environmentally-enhanced doubling gas regulations in countries such as low Korea.

Claims (8)

In the injection method of the fuel supply device of the LPI vehicle, the air cleaner 2, the air dryer 3, the air pump 4, the control valve 5, the air cutoff solenoid 6 together with the LPI cylinder 1 Elpium cylinder pressure control system composed of Elpium cylinder pressure sensor (7) and fuel supply detection assembly (8) to maintain the internal pressure of the Elpium cylinder (1) constant The air cleaner (2), the air dryer (3), the air pump (4), and the air cut-off solenoid (6) form a separate LPG cylinder air injection system so as to dry and clean the air. Pressure control system to increase the internal pressure of the LPG Bomb (1) The pressure control valve according to claim 1, wherein the fuel supply sensor (8), the air cutoff solenoid (6), and the Elpium cylinder pressure sensor (7) form a gas discharge system to reduce the internal pressure of the Elpium cylinder (1). system 2. The control valve (5) according to claim 1, wherein the control valve (5) forms a three-way flow passage and includes a one-way check valve 51 and a one-way gas discharge check valve 52 in the vertical flow passage and the horizontal flow passage, respectively. Elpim Bombe Pressure Control System The LPP cylinder pressure control system according to claim 1, wherein the fuel supply detection assembly (8) is composed of a fuel supply relief valve (81) and a fuel supply detection sensor (82). 6. The fuel supply relief valve (81) according to claim 5, wherein the fuel supply relief valve (81) is formed of a flow path in the housing in a shape of "a", and comprises a check valve 811 and an overpressure relief valve 812 for preventing overpressure in the flow path. Pressure control system The fuel supply sensor 82 is a sensor rod 824 fixed to the valve seat of the non-return check valve 81, a magnet 821 attached to the upper end of the sensor rod, the sensor formed thereon. ELPZ Bomb Pressure Control System, which is a magnetic fuel supply sensor composed of magnetic sensors 823 installed on the cover 822 6. The fuel supply detection sensor (82) according to claim 5, wherein the fuel supply detection sensor (82) forms a rod (824) of the sensor detachably from contact on the valve seat of the non-return check valve (811) and the upper end of the sensor rod (825) is a spring (826). Sensor rod 825 is assembled to elastically move up and down, the sensor ring 826 is fixed to the sensor rod 825 at the bottom of the spring 826 and the lower side of the sensor ring 826 Pressure control system, a contact type fuel supply sensor that allows the diaphragm 827 to be fixed to the housing