Testing device for fuel injectors
First Claim
1. A method of testing a fuel injector of the type having a fuel discharge passage, a tip sealing valve capable of sealing the passage to control the discharge of fuel therethrough, and means for defining a path for the circulation of fuel therealong, said path including a port which lies adjacent the discharge passage, said method comprising the steps of sealing the discharge passage by the tip sealing valve;
- circulating fuel along said path by way of fuel supply and fuel return lines connected thereto;
closing the fuel supply and fuel return lines to retain the path of the injector and the fuel lines in communication therewith full of fuel; and
attempting to introduce a predetermined quantity of fuel into one of the fuel lines which is in communication with the path of the injector, the success or failure of said attempt to introduce fuel indicating the presence or absence, respectively, of fuel leakage from the injector.
1 Assignment
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Accused Products
Abstract
A known type of fuel injector has a discharge passage which can be closed off by a tip sealing valve and provision for circulating fuel in the vicinity of the discharge passage. In order to test that the passage is completely closed by the tip sealing valve, the passage is closed, and the injector is blocked off from the supply and return lines while remaining full of fuel. An attempt is made to introduce more fuel into the injector and, if a significant amount can be introduced, it means that there is leakage from the injector, presumably through the discharge passage.
37 Citations
16 Claims
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1. A method of testing a fuel injector of the type having a fuel discharge passage, a tip sealing valve capable of sealing the passage to control the discharge of fuel therethrough, and means for defining a path for the circulation of fuel therealong, said path including a port which lies adjacent the discharge passage, said method comprising the steps of sealing the discharge passage by the tip sealing valve;
- circulating fuel along said path by way of fuel supply and fuel return lines connected thereto;
closing the fuel supply and fuel return lines to retain the path of the injector and the fuel lines in communication therewith full of fuel; and
attempting to introduce a predetermined quantity of fuel into one of the fuel lines which is in communication with the path of the injector, the success or failure of said attempt to introduce fuel indicating the presence or absence, respectively, of fuel leakage from the injector. - View Dependent Claims (2, 3, 4)
- circulating fuel along said path by way of fuel supply and fuel return lines connected thereto;
- 5. In combination, a fuel injector of the type having a fuel discharge passage, a tip sealing valve capable of sealing the passage to control the discharge of fuel therethrough and means defining a path for the circulation of fuel therealong, said path including a part which lies adjacent the discharge passage, and a device for use in testing said fuel injection valve, said device comprising a valve body defining fuel inlet and fuel outlet ports and fuel supply and fuel return ports, said fuel supply port being connected to said circulation path on one side of said part adjacent the discharge passage and said fuel return port being connected to said circulation path on another side of said part adjacent the discharge passage, a piston displaceable in a cylinder in the body, the piston having apertures therethrough whereby, in one extreme position of the piston in the cylinder, the fuel inlet and the fuel supply ports are in communication with each other and the fuel outlet and the fuel return ports are in communication with each other, displacement of the piston from the first extreme position to the other extreme position in the cylinder progressively closing off said fuel supply port from the fuel inlet port and said fuel return port from the fuel outlet port and discharging the contents of the cylinder through a duct to the fuel supply port.
- 11. A device used in the testing of a fuel injector of the type having a fuel discharge passage, a tip sealing valve capable of sealing the passage to control the discharge of fuel therethrough and means defining a path for the circulation of fuel therealong, said path including a part which lies adjacent the discharge passage, said device comprises a valve body defining fuel inlet and fuel outlet ports and fuel supply and fuel return ports, means for connecting said fuel supply port to said circulation path on one side of said part adjacent the discharge passage, means for connecting said fuel return port to said circulation path on another side of said part adjacent the discharge passage, a piston displaceable in a cylinder in the body, the piston having apertures therethrough whereby, in one extreme position of the piston in the cylinder, the fuel inlet and the fuel supply ports are in communication with each other and the fuel outlet and the fuel return ports are in communication with each other, displacement of the piston from the first extreme position to the other extreme position in the cylinder progressively closing off said fuel supply port from the fuel inlet port and said fuel return port from the fuel outlet port and discharging the contents of the cylinder through a duct to the fuel supply port.
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16. A device as claimed in clam 15, wherein said means comprises a switch actuable when the pressure in said duct exceeds a predetermined value.
Specification