KR20080107124A - Fuel supply device for construction equipment - Google Patents

Abstract

The present invention relates to a fuel supply device for heavy construction equipment, and specifically, installed on one side of an upper swing structure of a vehicle body, and having a tank fuel supply line for discharging fuel and a return line for returning residual fuel after combustion in an engine Tank; It is provided on the downstream side of the fuel tank to remove the water contained in the fuel sucked inside, and a separator fuel supply line selectively connected to the tank fuel supply line and a fuel supply line for discharging the fuel is removed water A water separator; An injection pump installed at a downstream side of the water separator and configured to generate a negative pressure so as to inject a fuel filtered with impurities into a combustion chamber of the engine by an injector through a main fuel filter through a fuel supply pump; A fuel control unit connected to the main fuel filter and the injection pump, the fuel control unit controlling a negative pressure of the fuel supplied to the injector; A return line installed downstream of the injection pump and the fuel tank, the return line forming a flow path such that the remaining fuel burned by the engine is pumped into the fuel tank; According to the present invention comprising a thermostat valve installed between the return line and the separator fuel supply line, the thermostat valve for opening and closing the throttle according to the temperature of the fuel circulating through the return line, It automatically detects the low temperature condition of fuel at startup and maintains the low temperature fuel cycle through the thermostat valve until it reaches the room temperature where wax is removed. It has a very good advantage.

Description

Fuel supply device for heavy construction equipment

1 is a schematic diagram showing a conventional excavator for construction equipment,

2 is a configuration diagram schematically showing a fuel supply device of the heavy construction equipment shown in FIG.

3 is a configuration diagram schematically showing a fuel supply device for construction equipment according to the present invention;

Figure 4 is a schematic diagram showing the fuel circulation flow via the thermostat valve when the fuel is at room temperature in accordance with the present invention,

Figure 5 is a schematic diagram showing the fuel circulation flow via the thermostat valve when the fuel is low temperature in accordance with the present invention.

Explanation of symbols used in the main part of the drawing

1: fuel tank 3: water separator

8: fuel supply pump 6: fuel filter

30: thermostat valve 36: piston

40: fuel temperature sensitive member

The present invention relates to a fuel supply device for construction equipment, and more particularly, to a fuel supply device for construction equipment using a thermostat valve that can suppress the generation of wax in the gas oil and prevent starting off when the cold engine is running. will be.

In general, diesel fuel, which is mainly used in diesel engines, causes paraffin wax to precipitate due to freezing in the fuel when the outside air temperature falls below about -15 ° C in winter due to the characteristics of the fuel. As a result, the fluidity of the fuel is significantly lowered compared with the normal temperature. In addition, if the diesel engine starts running after the paraffin wax component is precipitated in diesel, the wax component precipitated in the fuel passes through the fuel filter in the process of being sucked into the engine, thereby preventing the filter filter in the fuel filter. Therefore, it is known that the characteristics such as engine start-up of the vehicle, starting off, white smoke occurs.

In the engine system for heavy equipment, light oil is used as the main fuel. Fuel supplied to the engine via the fuel filter is injected by injecting about 10% to 20% through an injector, and the remaining 80% or more of the fuel tank is fuel tank. Is returned to. When the engine is operated in a cold and cold region, moisture is generated inside the fuel tank due to the temperature difference between the outside air and the fuel tank, and the paraffin wax contained in the fuel freezes, causing various problems in the fuel supply system. have.

1 is a schematic diagram of a conventional excavator for heavy construction equipment, Figure 2 is a schematic diagram of a conventional fuel supply device for heavy construction equipment. Typically, the cab 15 is disposed in front of the upper swing structure 14, the engine room 16 is installed at the rear of the cab 15, the cab 15 and the engine room 16 is a lower driving ( 17) is placed on top.

The conventional fuel supply device for heavy construction equipment is primarily filled in the water separator (3) through the tank fuel supply line (2) from the fuel pump (1) installed on one side of the engine room 16, in the water separator contained in the fuel Remove moisture

The fuel is then pumped by a relatively low pressure first fuel pump 4 and supplied to the engine side through the auxiliary fuel filter 5 and the supply line 6.

The fuel introduced to the engine 7 side through the supply line 6 is pumped by the main fuel supply pump 8 and then passed through the main fuel filter 9 to the fuel control unit 10. It is injected through the injector 12 at high pressure by the injection pump 11 controlled by the combustion inside the engine.

Typically, all the fuel introduced on the injector 12 is not injected and burned, and only about 10% to 20% of the supply is combusted, and the remaining 80% or more is returned to the fuel tank 1 via the return line 13. To achieve a series of fueling cycles.

By the way, in the conventional fuel supply device for heavy construction equipment as described above is supplied to the engine (7) side with the wax component remaining in the fuel during operation in a cold region, and returned to the fuel tank (1) for fuel supply The wax is unresolved for a long time, and the wax is pumped again and circulated through the supply line 6, the respective fuel filters 5 and 9, the fuel supply pump 8, and the like. The components are adsorbed on the fuel filter or cause clogging, causing an abnormality in the fuel supply, and in severe cases, there is a problem that causes engine starting failure and starting off.

Therefore, in order to solve the above-mentioned problem,

When the engine is cold in cold cold regions, the engine can be started and shut down by circulating through the thermostat valve without returning the fuel returned from the engine to the fuel tank until it reaches room temperature. The purpose is to provide a fuel supply device for heavy construction equipment that can be prevented.

In order to achieve the above object, the present invention

A fuel tank installed at one side of the upper swing structure of the vehicle body and having a tank fuel supply line for discharging fuel and a return line for returning residual fuel after combustion in the engine;

It is provided on the downstream side of the fuel tank to remove moisture contained in the fuel sucked therein, and a separator fuel supply line selectively connected to the tank fuel supply line and a fuel supply line for discharging the fuel from which water is removed. A water separator;

An injection pump installed at a downstream side of the water separator and configured to generate a negative pressure so as to inject a fuel filtered with impurities into a combustion chamber of the engine by an injector through a main fuel filter through a fuel supply pump;

A fuel control unit connected to the main fuel filter and the injection pump, the fuel control unit controlling a negative pressure of the fuel supplied to the injector;

A return line installed downstream of the injection pump and the fuel tank, the return line forming a flow path such that the remaining fuel burned by the engine is pumped into the fuel tank;

And a thermostat valve installed between the return line and the separator fuel supply line, the thermostat valve opening and closing the throttle according to the temperature of the fuel circulating through the return line. .

According to the present invention, the return line is a fuel supply for heavy construction equipment consisting of a first return line communicating with the injection line formed on the downstream side of the injection pump from the thermostat valve and a second return line communicating with the fuel tank. It features a device.

In addition, the thermostat valve may include a flow side inlet port connected to the first return line;

A return side outlet port connected to the second return line;

A supply side inlet port connected to the tank fuel supply line;

A supply side outlet port connected to the separator fuel supply line;

A chamber formed inside the valve body and communicating with the fuel tank and the water separator, the fuel returned from the engine side;

A fuel temperature sensitive member installed in the chamber in such a manner as to be in contact with the fuel to expand and contract in a linear manner according to the temperature of the fuel;

A first piston head and a second piston head having seat portions are formed at both ends of the longitudinal direction, respectively, and the second piston head is configured to generate the stroke movement corresponding to the contraction and expansion sections of the fuel temperature sensitive member. A piston fixed to the temperature sensitive member; And

A first throttle valve formed in the chamber, wherein the fuel temperature sensitive member is partially closed when contracted and opened when inflated, and a second throttle valve which is opened when the fuel temperature sensitive member is contracted and closed when inflated; Characterized in that the fuel supply device for heavy construction equipment made.

In addition, the fuel temperature sensitive member is characterized in that the fuel supply device for construction equipment made of amalgam penetration rods that can be contracted or expanded in the longitudinal direction in accordance with the fuel temperature.

In addition, the fuel temperature sensitive member is characterized in that the fuel supply device for heavy construction equipment to form a maximum contraction position when the temperature of the fuel is 5 ° C or less, and a maximum expansion position when the temperature of the fuel is 30 ° C or more. .

The first throttle valve is partially closed by the first piston head when the thermostat valve becomes 5 ° C. or lower, and the second throttle valve is formed in an open position from the seat of the second piston head. The heavy equipment fuel supply device is configured so that 90% of the fuel introduced into the chamber is in communication with the water separator.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the fuel tank leakage prevention structure for construction equipment according to the present invention.

Figure 3 is a schematic view showing a fuel supply device for construction equipment according to the present invention, Figure 4 is a schematic diagram showing the fuel circulation flow via the thermostat valve when the temperature of the fuel in accordance with the present invention, Figure 5 is a schematic diagram showing the fuel circulation flow via the thermostat valve when the temperature of the fuel is low temperature in accordance with the present invention.

Fuel supply device for heavy construction equipment according to the present invention is applied to a conventional excavator, loader, hydraulic shovel, etc., the fuel tank (1), the water separator (3), the primary pump (4), the engine which is configured in the fuel supply system The fuel supply pump 8 and the main fuel filter 9 included in the (7) side can be configured to be compatible with each other, and therefore, the same reference numerals will be used.

As shown in Figure 3 and 5, the fuel supply device for heavy construction equipment according to the invention,

A fuel tank 1 installed on one side of the upper swinging body 14 of the vehicle body and having a tank fuel supply line 21 for discharging fuel and a return line 22 for returning residual fuel after combustion on the engine 7 side. );

It is installed on the downstream side of the fuel tank (1) to remove the water contained in the fuel sucked therein, and the separator fuel supply line (23) and selectively connected to the tank fuel supply line 21 and the water is removed A water separator 3 having a fuel supply line 6 through which fuel is discharged;

It is installed on the downstream side of the water separator (3), the fuel supply pump (8) through the main fuel filter (9) to filter the impurities filtered to the combustion chamber inside the engine (7) by the injector (12) An injection pump 11 forming a negative pressure;

A fuel control unit (10) connected to the main fuel filter (8) and the injection pump (11) and controlling a negative pressure of the fuel supplied to the injector (12);

A return line (22) installed downstream of the injection pump (11) and the fuel tank (1) and forming a flow path such that the remaining fuel burned by the engine (7) is pumped into the fuel tank (1);

It is installed between the return line 22 and the separator fuel supply line 23, the thermostat valve 30 for opening and closing the throttle according to the temperature of the fuel circulating through the return line 22; It is done by

The return line 22 communicates from the thermostat valve 30 to the fuel tank 1 and the first return line 22a communicating with an injection line 24 formed downstream of the injection pump 11. Consisting of a second return line 22b.

In addition, the thermostat valve 30 may include a return side inlet port 31 connected to the first return line 22a; A return side outlet port 32 connected to the second return line 22b; A supply side inlet port 33 connected to the tank fuel supply line 21; A supply side outlet port 34 connected to the separator fuel supply line 23; A chamber (35) formed inside the valve body and in which fuel returned from the engine (7) side is in communication with the fuel tank (1) and the water separator (3); A fuel temperature sensitive member (40) installed in the chamber (35) in contact with the fuel so as to extend and contract in a linear manner according to the temperature of the fuel; The first piston head 36a and the second piston head 36b having seat portions are formed at both ends of the longitudinal direction, respectively, and stroke movements corresponding to the contraction and expansion sections of the fuel temperature sensitive member 40 occur. A piston to which the second piston head 36b is fixed to one side of the fuel temperature sensitive member 40; And a first throttle valve 37 formed in the chamber 35 and partially closed when the fuel temperature sensitive member 40 contracts and opened when expanded, and when the fuel temperature sensitive member 40 contracts. And a second throttle valve 38 which is opened and closed when inflated.

It demonstrates with reference to FIG. 4 and FIG.

When the fuel temperature sensitive member 40 expands, the piston 36 makes a stroke movement in the left direction, and the first throttle valve 37 is opened by the first piston head 36a and simultaneously The second throttle valve 38 is closed by the second piston head 36b (see FIG. 4). On the other hand, when the fuel temperature sensitive member 40 is contracted, the piston 36 makes a stroke movement in the right direction, and the first throttle valve 37 is part of the first piston head 36a. At the same time as closing, the second throttle valve 38 is opened by the second piston head 36b (see FIG. 5).

In the present invention, the fuel temperature sensitive member 40 is fixed to one side of the second piston head 36b, the maximum contraction position is formed when the temperature of the fuel is 5 ℃ or less, the temperature of the fuel 30 The maximum expansion position is formed when it is above C. The temperature of the fuel below 5 ° C is a criterion for determining the low temperature state of the fuel, the temperature of the fuel 30 ° C or more can be understood as a reference for determining the room temperature state of the fuel.

In the present invention, the first piston head 36a, which strokes as the fuel temperature sensitive member 40 is contracted to the maximum contraction position in the low temperature state of the fuel, is approximately 10 of the fuel introduced into the thermostat valve 30. A partially closed state is maintained to drain% to the second return line 22b side, and the fuel returned to the fuel tank 1 is circulated to the engine 7 side through the supply side inlet port 33 and the outlet port 34. .

Preferably, the thermostat valve 30 is partially closed by the first piston head 36a when the temperature of the fuel is 5 ° C. or lower, and the second throttle valve 38 Is formed in the open position from the seat portion of the second piston head 36b so that 90% of the fuel introduced into the chamber 35 communicates with the water separator 3,

In addition, the fuel temperature sensitive member 40 is preferably composed of an amalgam penetration rod that can be contracted or expanded in the longitudinal direction according to the fuel temperature.

On the other hand, the fuel temperature sensitive member 40 has a handle 42 protruding to the outside of the thermostat valve 30, the handle is manufactured by a manual shut-off valve (shut-off valve) from the outside The operator considers manual operation by the operator for the fuel temperature response.

In the configuration of the present invention, the separator fuel supply line 23 constitutes a check valve 43, the check valve 43 of the fuel sucked from the fuel tank 1 toward the water separator 3 side. It performs a function to prevent backflow.

Hereinafter, the operation and effect of the fuel supply device for heavy construction equipment according to the present invention.

In the fuel supply device for heavy equipment according to the present invention, when the temperature of the fuel is at room temperature when the engine is started in a cold cold air region, the fuel temperature sensitive member 40 expands to move the piston 30 to the left.

At this time, all the fuel introduced into the thermostat valve 30 through the first return line 22a passes through the first fully opened first throttle valve 37 and then passes through the second return line 22b to form the fuel tank ( Returning to 1), a series of normal temperature fuel circulation cycles are formed which are circulated to the water separator 3 side via the supply side inlet port 33 and the supply side outlet port 34 (see FIG. 4).

On the other hand, when the temperature of the fuel is a low temperature at which the wax component can be generated, most of the fuel introduced into the chamber 35 in the thermostat valve 30 through the first return line 22a melts the wax component. A series of low temperature fuel circulation cycles are allowed to be circulated to the water separator 3 via the second throttle valve 38 supply side outlet port 34, which is fully open until an acceptable room temperature is reached (FIG. 5). Reference).

That is, when the temperature of the fuel is at a low temperature of 5 ° C. or lower, the fuel temperature sensitive member 40 is contracted. At this time, the piston 36, the second piston head 36b is fixed to one side of the fuel temperature sensitive member 40 is to move the stroke in the right direction as shown in FIG.

At this time, the first throttle valve 37 is partially closed by the separation of the seat portion of the first piston head 36a and the second throttle valve 38 is completely removed from the seat portion of the second piston head 36b. Is spaced apart and opened, which causes most of the fuel (approximately 90%) introduced into the chamber 35 of the thermostat valve 30 to detect the temperature of the fuel at 30 ° C. or higher in the fuel temperature sensitive member 40. The main fuel supply pump 8, the fuel filter 9, and the high-pressure injection pump 11 installed at the water separator 3, the primary pump 5, the fuel supply line 6, and the engine 7 are circulated. .

As such, the thermostat valve 30 is connected to the chamber 35 through the first throttle valve 37 partially closed by the first piston head 36a on the low temperature fuel circulation cycle at which the temperature of the fuel is 5 ° C. or lower. 10% of the fuel introduced into the tank is returned to the fuel tank 1.

On the other hand, when the fuel reaches the room temperature state, the fuel temperature sensitive member 40 expands again to stroke the piston in the left direction as shown in FIG.

The first throttle valve 37 is completely opened apart from the seat portion of the first piston head 36a while the second throttle valve 38 is completely closed by the seat portion of the second piston head 36b. The fuel introduced into the thermostat valve 30 is all fuel tank 1 via the first return line 22a, the chamber 35, the first throttle valve 37, and the second return line 22b. Is returned to the water separator 3 via the supply side inlet port 33 and the supply side outlet port 34.

Therefore, the fuel supply device for heavy construction equipment according to the present invention operates the thermostat valve 30 to detect the temperature of the fuel when the engine is started in a cold cold region and to repeat the low temperature fuel circulation cycle when the engine is cold. do.

The above description of the present invention is intended to explain in detail enough that one of ordinary skill in the art to which the present invention pertains can easily carry out the invention, and thus the technical spirit and scope of the present invention are limited. It does not mean that.

As described above, the fuel supply device for heavy construction equipment according to the present invention automatically detects the low temperature state of the fuel when the engine is started in a cold cold region to reach a low temperature fuel through the thermostat valve until the wax component is removed to room temperature Maintaining the circulation cycle has the advantage that the effect is very excellent, such as preventing the engine from starting poorly and starting off.

Claims (6)

A fuel tank installed at one side of the upper swing structure of the vehicle body and having a tank fuel supply line for discharging fuel and a return line for returning residual fuel after combustion in the engine; It is provided on the downstream side of the fuel tank to remove the water contained in the fuel sucked inside, and a separator fuel supply line selectively connected to the tank fuel supply line and a fuel supply line for discharging the fuel is removed water A water separator; An injection pump installed at a downstream side of the water separator and configured to generate a negative pressure so as to inject a fuel filtered with impurities into a combustion chamber of the engine by an injector through a main fuel filter through a fuel supply pump; A fuel control unit connected to the main fuel filter and the injection pump, the fuel control unit controlling a negative pressure of the fuel supplied to the injector; A return line installed downstream of the injection pump and the fuel tank, the return line forming a flow path such that the remaining fuel burned by the engine is pumped into the fuel tank; And a thermostat valve installed between the return line and the separator fuel supply line and configured to open and close the throttle according to the temperature of the fuel circulating through the return line. . The method according to claim 1, The return line is a fuel supply device for heavy construction equipment, characterized in that consisting of a first return line communicated to the injection line and the fuel tank formed on the downstream side of the injection pump from the thermostat valve . The method according to claim 1, The thermostat valve includes a return side inlet port connected to the first return line; A return side outlet port connected to the second return line; A supply side inlet port connected to the tank fuel supply line; A supply side outlet port connected to the separator fuel supply line; A chamber formed inside the valve body and communicating with the fuel returned from the engine side to the fuel tank and the water separator; A fuel temperature sensitive member installed in the chamber in such a manner as to be in contact with the fuel to expand and contract in a linear manner according to the temperature of the fuel; A first piston head and a second piston head having seat portions are formed at both ends of the longitudinal direction, respectively, and the second piston head is configured to generate the stroke movement corresponding to the contraction and expansion sections of the fuel temperature sensitive member. A piston fixed to the temperature sensitive member; And A first throttle valve formed in the chamber, wherein the fuel temperature sensitive member is partially closed when contracted and opened when inflated; and a second throttle valve that is opened when the fuel temperature sensitive member is contracted and closed when inflated Fuel supply device for construction equipment, characterized in that consisting of. The method according to claim 3, The fuel temperature sensitive member is a fuel supply device for heavy equipment, characterized in that consisting of amalgam penetration rods that can be contracted or expanded in the longitudinal direction in accordance with the fuel temperature. The method according to claim 4, The fuel temperature sensitive member forms a maximum contraction position when the temperature of the fuel becomes 5 ° C. or less, and forms a maximum expansion position when the temperature of the fuel becomes 30 ° C. or more. The method according to claim 1 or 3, The first throttle valve is partially closed by the first piston head when the thermostat valve reaches a temperature of 5 ° C. or lower, and the second throttle valve is formed in an open position from the seat portion of the second piston head so that the chamber The heavy equipment fuel supply device, characterized in that the fuel introduced therein is configured to communicate with the water separator. .

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