1. Field of the Invention
The present invention relates to a coupling device for use with a fuel injector and, more particularly, to a coupling device (connector bridge) used to connect solenoid wires to an end cap assembly while maintaining the solenoid wires away from a control valve of the fuel injector.
2. Background Description
Many internal combustion engines are designed to use fuel injectors. In such a typical internal combustion engine, the fuel injector is mounted partly within the combustion chamber of the engine, with the control valve mechanism mounted beneath the valve covers of the engine. In this type of configuration, the control valve mechanism which, in some conventional injectors, include solenoids and end caps, are connected to an engine wire harness assembly via solenoid wires. The engine wire harness, in turn, is connected to a driver which provides or delivers a current to the solenoids for providing control to the fuel injector, itself.
In general, the driver delivers a current or voltage to an open side of an open coil solenoid via the solenoid wires. The magnetic force generated in the open coil solenoid will shift a spool into the open position so as to align grooves or orifices (hereinafter referred to as “grooves”) of the control valve body and the spool. The alignment of the grooves permits the working fluid (i.e., hydraulic fluid) to flow into an intensifier chamber from an inlet portion of the control valve body. The high-pressure fluid then acts on an intensifier piston which, in turn, compresses fuel located within a high-pressure plunger chamber. As the pressure in the high-pressure plunger chamber increases, the fuel pressure rises above a needle check valve opening pressure. At the prescribed fuel pressure level, the needle check valve will shift against a needle spring and open the injection holes in a nozzle tip for injection.
At the end of the cycle, the driver will deliver a current or voltage to the closed coil solenoid. The magnetic force generated in the closed coil solenoid will shift the spool into the closed position so as to align grooves of the spool with ejection or discharge ports of the control valve body. This alignment permits the working fluid to flow from the intensifier chamber, through the discharge ports and then be ejected from the control valve body, via the discharge ports. The discharge of the working fluid is at a high pressure. Once the working fluid is discharged, it is captured and reused by the injector. Of course, fuel injectors may vary in their functionality such as fuel injectors with needle back pressure systems and the like; however, the above description is generally descriptive of the basic functioning of the fuel injector.
In these types of systems, however, the solenoid wires are permanently connected to the end caps and are routed over the discharge ports and adjacent the rocker arm assemblies of the engine. The wire harness assemblies for the solenoid wires are also located adjacent the rocker arm assemblies in such a manner that the solenoid wires must bridge the gap between the open and closed coil solenoid and the wire harness assembly (which is approximately 150 mm). In such a harsh environment, the solenoid wires are subject to failure, from such causes as:
The present invention is directed to overcoming one or more of the problems as set forth above.
In a first aspect of the present invention, a coupling device includes a body portion adapted to be mated with an end cap assembly of a fuel injector. The body portion has a connecting portion spanning between a first electrical connector and a second electrical connector at opposing ends of the body portion. A first set of conductive leads connects the first electrical connector to a first set of solenoid wires and a second set of conductive leads connects the second electrical connector to a second set of solenoid wires. The first set of conductive leads spans the connecting portion to connect the first electrical connector and the first set of solenoid wires. In embodiments, the first set of conductive leads and the second set of conductive leads are electrically isolated from each other and are molded into the body portion, including the connecting portion.
In another aspect of the present invention, the coupling has a main body portion having a first and second shoulder, an end body adjacent to the second shoulder, first and second housings extending from the first and second shoulders and a connecting portion. The connecting portion connects the first shoulder and the second shoulder. A first and second set of solenoid wires partially extend within the end body portion and a first set of terminals are associated with the first housing and a second set of terminals are associated with the second housing. A first set of conductive leads electrically connect the first set of terminals to the first set of solenoid wires and spans the connecting portion. Also, a second set of conductive leads electrically connects the second set of terminals to the second set of solenoid wires. In embodiments, the conductive leads are molded in the main body portion and more specifically in the connecting portion.
In yet another aspect of the present invention, a device for coupling a wire harness to a fuel injector is provided. This device includes a coupling device having a body portion having a connecting portion connecting a first housing and a second housing at opposing ends thereof. The housings each house first and second terminal portions, respectively. A first set of conductive leads spans the connecting portion to connect the first terminal portion to a first set of solenoid wires and a second set of conductive leads connects the second terminal portion to a second set of solenoid wires. An end cap assembly is coupled to the coupling device and includes a first housing at a first side for housing a first end cap terminal and a second housing at a second side for housing a second end cap terminal. The first terminal portion and the first end cap terminal are electrically couplable to one another, and the second terminal portion and the second end cap terminal are electrically couplable to one another.
In embodiments of this and other aspects, the body portion may include a first shoulder and a second shoulder and an end body portion adjacent to the second shoulder. The first housing extends from the first shoulder and the second housing extends from the second shoulder. The connecting portion connects the first shoulder and the second shoulder. The first and second housings of the end cap include a first and second cavity that couples with the first and second housing of the coupling device, respectively. A locking device may be provided for locking the first housing and the second housing of the coupling device to the first housing and the second housing of the end cap, respectively. Additionally, the first and second set of conductive leads and the first and second set of solenoid wires may be molded into the coupling device. In further embodiments, the terminal portions of either the coupling device or the end caps may be (i) female-type electrical connectors, (ii) male-type electrical connectors, (iii) opposing spring-like electrical connectors and (iv) contact plates. The connecting portion fits about the end cap assembly.
In yet another embodiment of the present invention, a fuel injector assembly is provided. The fuel injector assembly includes a fuel injector having a control valve body, an intensifier housing coupled to the control valve body and a nozzle assembly coupled to the intensifier housing. The assembly further includes a coupling device having a body portion having a connecting portion spanning between a first housing and a second housing, each of which house first and second terminal portions, respectively. The coupling device further includes a first set of conductive leads spanning the connecting portion to connect the first terminal portion to a first set of solenoid wires. A second set of conductive leads connects the second terminal portion to a second set of electrical connector leads. An end cap of the assembly is coupled to the coupling device and the control valve. The end cap assembly includes a first housing extending from a first side and housing a first end cap terminal portion and a second housing extending from a second side and housing a second end cap terminal portion. The first terminal portion and the first end cap terminal portion are electrically couplable to one another, and the second terminal portion and the second end cap terminal portion are electrically couplable to one another. In embodiments, the connecting portion fits about the control valve.
In yet still another embodiment of the present invention, a method is provided for manufacturing a coupling device. The method includes the steps of:
The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:
a shows a cross sectional view of the end cap design of
b shows a cross sectional view of the end cap design of
a and 7b show another embodiment the coupling device and the end cap of an embodiment of the present invention;
a and 8b show an embodiment the coupling device and the end cap of the present invention;
a and 9b show an embodiment the coupling device and the end cap of the present invention;
a and 10b show an embodiment the coupling device and the end cap of the present invention;
The present invention is directed to a coupling device used with a fuel injector. The coupling device (referred to also as a connector bridge) is adapted to be coupled and decoupled to an end cap of a control valve of the fuel injector. The coupling device of the present invention is also designed to maintain the solenoid wires away from the rocker arm assemblies and fluid discharge ports of the fuel injector, itself. These features ensure that the rocker arm assemblies as well as the fluid being ejected from the fuel injector will not fray, fatigue or otherwise cause a failure of the solenoid wires. The coupling device also ensures that the solenoid wires remain substantially stationary thereby preventing any fatigue or failure of the solenoid wires caused by vibrational events. As a further advantage of the present invention, any failure of the solenoid wires, terminals to the end cap assembly or other parts may easily be replaced by simply removing and replacing the coupling device of the present invention. That is, by using the coupling device of the present invention there is no need to cut the solenoid wires, and remove and disassemble the fuel injector due a failure of a part.
Referring now to
Still referring to
In embodiments, in the coupled state, the housings 20a and 20b of the coupling device 10 are sized and shaped to fit within the respective cavities 36a and 36b of the end caps. In this manner, the respective terminals of the end caps and coupling device, in the coupled state, are in electrical contact. A projection 40a and 40b extends from an exterior part of the respective housing 34a and 34b, corresponding to and aligning with the clips or other fastening devices 26a and 26b. In an alternative embodiment, the housings 34a and 34b of the end caps may be sized and shaped to fit within the respective cavities 22a and 22b of the coupling device. The projections 40a and 40b extend from an exterior part of the respective housings of the coupling device, corresponding to and aligning with the clips or other fastening devices extending from the end caps. The combination of the clips and projections provide for a locking mechanism, as shown in
a shows a cross sectional view of the end cap design of
It should be understood that the coupling device 10 of the present invention is designed, basically, to the shape of the control valve 31 and more particularly to align with the placement of the end caps. Accordingly, the coupling device 10 of the present invention, and more particularly the connecting portion 18 and the housings may have other configurations or sizes depending on the size and shape of the fuel injector. Thus, the coupling device is not limited to the shape and size shown in
a and 7b show another embodiment of the coupling device and the end cap of the present invention. In the embodiments of 7a through 9b, each of the end cap housings is generally depicted as reference numeral 34 and each of the coupling device housings is generally depicted as reference numeral 20. In
a and 8b show another embodiment the coupling device and the end cap of the present invention. In this embodiment, the coupling device housing 20 has male-type connector terminals 70 and the end cap housing 34 has two sets of opposing spring-like connectors 74. In the coupled state, the male-type connector terminals 70 are sandwiched between and are in electrical communication with each respective set of opposing spring-like connectors 74. A groove 76 is provided in each housing 20, between each connector terminal 70. Additionally, a projection or separator portion 78 is provided in each housing 34 of the end caps 32, between inner ones 74a of the opposing spring-like connectors 74. This features helps in the alignment of the housings of the end caps and the coupling device (i.e., terminals thereof) and further prevents electrical shorting or communication between the non-respective terminals.
a and 9b show another embodiment the coupling device and the end cap of the present invention. In this embodiment, the housing 20 includes opposing spring-like connectors 80 and the end cap housing 34 includes male-type connector terminals 82. In the coupled state, each of the male-type connector terminals 82 is sandwiched between and in electrical communication with each respective opposing spring-like connector 80. Much like that shown in
a and 10b show another embodiment the coupling device and the end cap of the present invention. In this embodiment, the coupling device housing 20 has plate-like connector terminals 84 and the end cap housing 34 has two sets of opposing spring-like connectors 74. This type of configuration is referred to as a knife-blade connection. In the coupled state, the plate-type connector terminals 84 are in electrical communication with each respective set of opposing spring-like connectors 74. Again, a groove 76 and separator portion 78 is provided in this embodiment.
While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims.
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Number | Date | Country | |
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20040124252 A1 | Jul 2004 | US |