Title of Invention

"FUEL LEAK TEST SYSTEM FOR FUEL INJECTION SYSTEM OF DIESEL ENGINE AND METHOD THEREOF"

Abstract A fuel leak test system for a fuel injection system of a diesel engine is provided which includes a cranking device, a mixer, an ultraviolet ray lamp, an ID system, and a PLC. The cranking device cranks a diesel engine in an engine assembly line. The mixer mixes fuel with fluorescent material and supplies a mixture of the fuel and the fluorescent material to the diesel engine. The ultraviolet ray lamp irradiates an ultraviolet ray around the fuel injection system of the diesej engine. The ID system has results of a fuel leak test that is performed input thereto based on a change of a color around the fuel injection system. The PLC receives the data on the fuel leak test from the ID system and controls operations of the fuel injection system and operations of devices of the engine assembly line.
Full Text FUEL LEAK TEST SYSTEM FOR FUEL INJECTION SYSTEM OF DIESEL ENGINE AND METHOD THEREOF
FIELD OF THE INVENTION
The present invention relates to a fuel leak determination system for a fuel injection system of a diesel engine and a method thereof. BACKGROUND OF THE INVENTION
Generally, a diesel engine is provided with a fuel injection system for compressing fuel to a high pressure and supplying the pressurized fuel into a combustion chamber, in order to develop output power. Such a fuel injection system for the diesel engine, as shown in FIG. 1, includes a high pressure pump 1, a common rail 3, a fuel pressure regulator 5, and an injector 7. Fuel that is pressurized to a high pressure by the high pressure pump 1 is supplied to a combustion chamber through the common rail 3 that is connected to a high pressure pipe 9 and the injector 7.
Because such fuel injection system provides highly pressurized fuel, fuel can leak at a case coupling portion "a" of the high pressure pump 1, a port-connecting portion "b" of the high pressure pipe 9, a connecting portion "c" of a cylinder block (not shown), a connecting portion "d" of the common rail 3, a connecting portion "e" of the fuel pressure regulator 5, and a connecting portion "f" of the injector 7.
As shown in FIG. 2, in a process for testing an assembled engine in an engine assembling line, a fuel leak test for a fuel injection system of a diesel engine is performed parallel with an engine performance test. That is, if a diesel

engine is completely assembled, a firing test is performed, and only engines that did not pass the firing test are reassembled. During the firing test, a worker performs a fuel leak test with unaided eyes. However, because the fuel is transparent and noises and vibrations are generated during the firing test, it is difficult for the worker to exactly detect the fuel leak.
The information disclosed in this Background of the Inventton section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art. SUMMARY OF THE INVENTION
An embodiment of the present invention provides a fuel leak test system and a method thereof for a fuel injection system of a diesel engine in which a fuel leak can be detected easily.
In a preferred embodiment of the present invention, the fuel leak test system for a fuel injection system of a diesel engine comprises a mixer, an engine cranking device, an ultraviolet ray lamp, an ID (identification) system, and a PLC (programmable logic controller). The mixer mixes fuel and fiuoresoent material. The engine cranking device cranks a diesel engine that is supplied with a mixture of the fuel and the fluorescent material by the mixer. The ultraviolet ray lamp is provided to the fuel injection system of the diesel engine that is cranked by the engine cranking device, and it irradiates an ultraviolet ray around the fuel injection system. The ID system is configured to have input results of a fuel leak test that is performed input thereto based on a change of a color around the fuel injection system while the ultraviolet ray lamp
irradiates ultraviolet around the fuel injection system. The PLC is configured to receive the data on the fuel leak test from the ID system and to control operations of the fuel injection system.
It is preferable that the engine cranking device comprises a motor and an air cylinder. The motor provides a rotational force, which the air cylinder advances or retreats a rotating axis coupler of the motor such that the rotating axis coupler is connected to the diesel engine or is separated from the diesel engine.
In a preferred embodiment of the present invention, the control algorithm for a fuel leak test system for a fuel injection system of a dtesel engine comprises: connecting an engine cranking device to an assembled diesel engine; cranking the diesel engine by operating the engine cranking device; supplying a mixture of fuel and fluorescent material to a fuel injection system of the diesel engine if the engine is cranked; irradiating an ultraviolet ray around the fuel injection system by operating an ultraviolet ray lamp; determining whether there is a fuel leak based on a change of a color around the fuel injection system while the ultraviolet ray is irradiated; reassembling the diesel engine if it is determined that there is a fuel leak; and separating the engine cranking device from the diesel engine and then discharging the diesel engine by operating a power conveyor if it is determined that there is not fuel leak.
The present invention therefore, provides a fuel leak test system for a fuel injection system of a diesel engine, comprising:
a cranking device configured to crank a diesel engine in an
engine assembly line;
a mixer configured to mix fuel with fluorescent material and to
supply a mixture of the fuel and the fluorescent material to the
diesel engine;
an ultraviolet ray lamp configured to irradiate an ultraviolet ray
around a fuel injection system of the diesel engine'
an ID (identification) system configured to have results of a fuel
leak test that is performed input thereto based on a change of a
color around the fliel injection system while the ultraviolet ray
lamp irradiates an ultraviolet ray around the fuel injection
system and
a PLC (programmable logic controller) configured to receive
the data on the fuel leak test from the ID system and to control
operations of the fuel injection system and operations of
devices of the engine assembly line.
In another preferred embodiment of the present invention, the fuel leak test system for a fuel injection system of a diesel engine comprises a cranking device, a mixer, an ultraviolet ray lamp, an ID (identification) system, and a PLC (programmable logic controller)
diesel engine In an engine assembly line. The mixer is configured to mix fuel with fluorescent material and to supply the mixture of the fuel and the fluorescent material to the diesel engine. The ultraviolet ray lamp is configured to irradiate ultraviolet ray around a fuel injection system of the diesel engine. The ID system is configured to have results of a fuel leak test that is performed input thereto based on a change of a color around the fuel injection system while the ultraviolet ray lamp irradiates ultraviolet around the fuel injection system. The PLC is configured to receive the data on the fuel \eak test from the ID system and to control operations of the fuel injection system and operations of devices of the engine assembly line.
It is preferable that the cranking device comprises a motor and an air cylinder. The motor provides a rotational force, and the air cylinder advances or retreats a rotating axis coupler of the motor such that the rotating axis coupler is connected to the diesel engine or is separated from the diesel engine.
In another embodiment of the present invention, the fuel leak test method for a fuel injection system of a diesel engine comprises: cranking the diesel engine in an engine assembly line; supplying a mixture of fuel and fluorescent material to the diesel engine through the fuel injection system; Irradiating an ultraviolet ray around the fuel injection system; and determining whether there is a fuel leak based on a change of a color around the fuel injection system while the ultraviolet ray is irradiated around the fuel injection system.
Preferably, the fuel leak test method further comprise controlling operations of devices of the engine assembly line based on a result of the fuel
13, an ultraviolet ray lamp 15, an ID (identification) system 17, and a PLC (programmable Logic Controller) 19.
The mixer 11 is configured to mix fuel from a fuel tank 23 and fluorescent material from a fluorescent material tank 21 and to supply the mixture to a mixture tank 25.
Because the fluorescent material is mixed with fuel, visibility of the mixture of fuel and the fluorescent material is improved, when compared to pure fuel. Preferably, a ratio of the fuel and the fluorescent material is 10:1.
The mixture of the fuel and the fluorescent material within the mixture tank 25 is supplied to a diesel engine 33 in a highly pressurized state through a common rail 29 and injectors 31 by an operation of a high pressure pump 27.
The engine cranking device 13 is configured to crank the diesel engine 33. The engine cranking device 13 preferably includes a motor 35 that provides a rotational force and an air cylinder 39 to advance or retreat a rotating axis coupler 37 of the motor 35. In response to operations of the air cylinder 39, the rotating axis coupler 37 of the motor 35 is connected to the diesel engine 33 or is separated from the diesel engine 33, so that the power of the motor 35 can be selectively transmitted to the diesel engine 33.
The diesel engine 33 is supplied with the mixture of the fuel and the fluorescent material by the mixer 11.
The ultraviolet ray lamp 15 is configured to emit an ultraviolet ray around a fuel injection system including the high pressure pump 27, the common rail 29, and the injector 31. If the mixture of the fuel and the fluorescent material leaks from the fuel injection system and thereby the ultraviolet ray is applied to the
leak test.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of the invention, where:
FIG. 1 is a perspective view of a fuel injection system of a diesel engine;
FIG. 2 is a flowchart of a conventional engine performance test;
FIG. 3 is a flowchart of an engine performance test to which a fuel leak test according to an embodiment of the present invention is applied;
FIG. 4 schematically shows a fuel leak test system according to an embodiment of the present invention; and
FIG. 5 is a flowchart of a fuel leak test method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
As shown in FIG. 3, in an engine performance test process to which a fuel leak test method according to an embodiment of the present invention is applied, a fuel leak test is separately performed from a firing test for a diesel engine. That is, the firing test is performed only for a diesel engine that has passed the fuel leak test.
The fuel leak test system according to an embodiment of the present invention, as shown in FIG. 4, includes a mixer 11, an engine cranking device
fluorescent material, a change of color around fuel leak positions occurs. Consequently, by irradiating the ultraviolet ray around the fuel injection system, a person who performs the fuel leak test can easily detect a leak of fuel.
The ID system 17 is widely used in an engine assembly line for identifying types of engines, and it includes various data such as sequence order, working information, and engine type information. The ID system 17 preferably includes various components for data input and data communication such as an ID card, an ID antenna, an ID controller, an ID reader, an ID writer, etc. Furthermore, in the embodiment of the present invention, the ID system 17 is configured to have data on fuel leak determination input thereto that is determined based on a change of color around the fuel injection system by the Irradiation of the ultraviolet ray around the fuel injection system.
The PLC 19 receives data on the fuel leak determination from the ID system 17. The PLC 19 controls operations of the engine cranking device 13, the high pressure pump 27, the injector 31, and various devices of the engine assembly line, based on the fuel leak data.
A control algorithm of the fuel leak test system as stated above is shown in FIG. 5.
At first, in step ST10, the assembled diesel engine arrives at a specific position that is separate from a position for the firing test. After the leak test according to the embodiment of the present invention is performed, the firing test is performed. That Is, the firing test is performed only for an assembled diesel engine that has passed the fuel leak test. The arrival of the assembled diesel engine can be detected by an arrival detection sensor (not shown).
After the diesel engine 33 arrives, the rotating axis coupler 37 of the motor 35 is coupled to the diesel engine 33 through the operation of the air cylinder 39.
The motor 35 then operates, thereby cranking the diesel engine 33, in step ST30. The forward movement of the rotating axis coupler 37 can preferably be detected by a forward movement detection sensor (not shown).
During the cranking step ST30, a fuel supply step ST40 is performed. In the fuel supply step ST 40, the high pressure pump 27 is operated in response to the cranking of the diesel engine 33, and thereby the mixture of the fuel and the fluorescent material is supplied through the common rail 29 and the injector 31 to the diesel engine 33.
After the fuel supply step ST40, a fuel leak detection step ST50 is performed. In the fuel leak detection step ST50, the ultraviolet ray lamp 15 is operated to irradiate the ultraviolet ray around the fuel injection system, and whether the fuel is leaked from the fuel injection system is detected visually. As stated above, the fuel leak test can be performed based on the change of the color around the fuel injection system. The fuel leak detection step ST50 may include a step for inputting results of the fuel leak test to the ID system 17 and a step for transmitting the results of the fuel leak test from the ID system 17 to the PLC 19. The PLC 19, as stated above, controls operations of the engine cranking device 13, the high pressure pump 27, the injector 31, and various devices of the engine assembly line, based on the result of the fuel leak test.
If it is determined that there is a fuel leak in the fuel leak detection step ST50, the diesel engine 33 is reassembled.
On the other hand, if it is determined that there is no fuel leak in the fuel leak detection step ST50, the rotating axis coupler 37 of the motor 35 is separated from the diesel engine 33 through an operation of the air cylinder 39 In step ST60. The rearward movement of the rotating axis coupler 37 can preferably be detected by a rearward movement detection sensor (not shown).
After the step ST60, a diesel engine discharging step ST70 is performed. In the diesel engine discharging step ST70, the engine cranking device 13 is retreated and the diesel engine 33 is discharged from the assembly line through an operation of a power conveyor (not shown).
According to the embodiments of the present invention, by supplying the mixture of the fuel and the fluorescent material to the diesel engine, irradiating the ultraviolet ray around the fuel injection system, and then determining whether there is a fuel leak, the fuel leak test can be easily performed.
Although preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught which may appear to those skilled in the present art will still fall within the spirit and scope of the present invention, as defined in the appended claims.






We claim:
1. A fuel leak test system for a fuel injection system of a diesel engine, comprising:
a cranking device configured to crank a diesel engine in an
engine assembly line;
a mixer configured to mix fuel with fluorescent material and to
supply a mixture of the fuel and the fluorescent material to the
diesel engine;
an ultraviolet ray lamp configured to irradiate an ultraviolet ray
around a fuel injection system of the diesel engine'
an ID (identification) system configured to have results of a fuel
leak test that is performed input thereto based on a change of a
color around the fuel injection system while the ultraviolet ray
lamp irradiates an ultraviolet ray around the fuel injection
system and
a PLC (programmable logic controller) configured to receive
the data on the fuel leak test from the ID system and to control
operations of the fuel injection system and operations of
devices of the engine assembly line.
2 A fuel leak test system as claimed in claim 1 wherein the cranking device comprises:
a motor providing a rotational forces and
an air cylinder for advancing or retreating a rotating axis
coupler of the motor such that the rotating axis coupler is
connected to the diesel engine or is separated from the diesel
engine.
3. A fuel leak test method by a fuel leak test system as claimed in claim 1
for a fuel injection system of a diesel engine, comprising:
cranking the diesel engine in an engine assembly line;
supplying a mixture of fuel and fluorescent material to the
diesel engine through the fuel injection system;
irradiating an ultraviolet ray around the fuel injection system
and
determining whether there is a fuel leak based on a change of
color around the fuel injection system while the ultraviolet ray
is irradiated around the injection system.
4. The fuel leak test method as claimed in claim 3 comprising controlling
operations of devices of the engine assembly line based on a result of the
fuel leak test.
.5. A fuel leak test system for a fuel injection system of a diesel engine
substantially as herein described with reference to the accompanying
drawings. 6. A fuel leak test method for a fuel injection system of a diesel engine
substantially as herein described with reference to the accompanying
drawings.


Documents:

786-del-2004-abstract.pdf

786-del-2004-claims.pdf

786-del-2004-complete specification(granted).pdf

786-del-2004-correspondence-others.pdf

786-del-2004-correspondence-po.pdf

786-del-2004-description (complete).pdf

786-del-2004-drawings.pdf

786-del-2004-form-1.pdf

786-del-2004-form-19.pdf

786-del-2004-form-2.pdf

786-del-2004-form-3.pdf

786-del-2004-form-5.pdf

786-del-2004-gpa.pdf


Patent Number 244033
Indian Patent Application Number 786/DEL/2004
PG Journal Number 47/2010
Publication Date 19-Nov-2010
Grant Date 15-Nov-2010
Date of Filing 26-Apr-2004
Name of Patentee HYUNDAI MOTOR COMPANY
Applicant Address 231,YANGJAE-DONG,SEOCHO-KU,SEOUL,KOREA
Inventors:
# Inventor's Name Inventor's Address
1 CHO CHANG RAE DONGRAE DAEWOO APT.,203-404,1459,ONCHEON 3-DONG,DONGRAE-GU,BUSAN-CITY,KOREA
PCT International Classification Number F02M 65/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10-2003-0030938 2003-05-15 Republic of Korea