Patent Application
20080168769
This invention relates to internal combustion engines, including but not limited to fluid tubes for an internal combustion engine.
Internal combustion engines have fluid systems associated therewith that transfer many different kinds of fluids between different engine locations and components. A typical engine is a complicated engineered product, which may include 5,000 or more different components. Engines are also products that are produced in great quantities, so their assembly process and quality thereof is an important factor for any engine manufacturer.
Many different types of fluid connections may exist between engine components. These fluid connections may be arranged to transfer different types of fluids at different pressures, temperatures, and flow rates. One example of a component requiring fluid connections is a turbocharger. Turbochargers are used to extract energy from exhaust gas created during operation of the engine, and use the energy extracted to operate a compressor that compresses intake air of the engine. Turbochargers are typically lubricated with a flow of engine oil that passes through the turbocharger center housing.
A supply flow of oil to a turbocharger may be cooled, and may be supplied from an oil pump on the engine. After the flow has passed though the turbocharger, it may return to the engine through, primarily, the force of gravity. This means that a fluid drain connection between the turbocharger and the engine has to be at a low point, typically beneath the turbocharger. Such a connection, which lies beneath a component, is typically referred to as a “blind” connection because an assembly operator is not able to visually inspect the connection while installing the component that lies above it, in this case, the turbocharger.
There have been many attempts to improve the robustness of blind fluid connections during assembly of an engine. Many attempt to reduce positional variability in the positioning of the turbocharger on the engine in order to improve alignment of mating fluid connection components. Others, have moved the connecting fluid point between the components in a more visible location. All these methods may increase cost and complexity of the assembly process, and are partially effective in ensuring that a robust connection has been made.
Accordingly, there is a need for an improved blind fluid passage connection configuration for transferring fluid in an engine that is not complicated and time consuming to implement.
An assembly guide for a fluid connection includes a collar flange connected to an outer surface of a tube. The tube may have a first end connected to a first component, and a second end that is chamfered and protrudes from the component. A neck portion of the guide may be connected to the collar flange, and extend away from the collar flange. A guide portion of the guide may be connected to the neck portion, and may have a flared portion on a distal end that is opposite the neck portion.
The following describes an apparatus for and method of ensuring a proper fluid connection on a “blind” assembly of a fluid passage for an internal combustion engine. A blind assembly may be a step in an assembly process of an engine, during which an operator conducting the assembly step is not able to visually align and/or inspect a fluid connection. A detail cross-section view of a typical fluid connection configuration is shown for illustration in
The flow of oil draining from the center housing 104 during operation may be arranged to drain into a receiving part 122, typically a crankcase. The receiving part 122 has a fluid passage 124 formed therein for transporting the flow of oil from the center housing 104 into the receiving part 122. The receiving part 122 may have a receiving bore feature 126 formed at a distal end that is arranged to receive the tube 116 during assembly. The receiving bore 126 may form an internal cavity 128 having an inside surface 130. The internal cavity 128 may include a collar seal 132 disposed therein that is arranged to create a fluid seal between the tube 116 and the inside surface 130 when the tube 116 is inserted into the receiving bore feature 126.
The seal 132 may include a central opening 134 arranged to receive the tube 116. A plurality of ribs or sealing rings 136 may be formed in the seal 132 at different locations surrounding the central opening 134 for sealably engaging an outer surface of the tube 116 under unitary load conditions that achieve the desired sealing function. The seal 132 may also have a tapered inlet portion 138 for receiving and guiding the tube 116 into the central opening 134 during insertion.
In the condition shown in
The assembly guide 200 may be arranged to connect to a tube 216. The tube 216 may be similar to the tube 116 described above, having a first end arranged for press-press fitting or otherwise connecting to a component, and a rounded edge 218 at a second end. The assembly guide 200 may have a collar flange 202 formed at one end, a neck portion 204 connected to the collar flange 202, a guide portion 206 connected to the neck portion 204, and a flared portion 208 connected to the guide portion 206.
The collar flange 202 may be welded, brazed, swaged, or otherwise connected to the tube 216 along an interface 220. The interface 220 may advantageously be positioned closer to the first end of the tube 216 than the second end having the rounded edge 218. The guide portion 206 may be substantially cylindrical and surround the tube 216 concentrically along it's length. The flared portion 208 may flare away from the tube 216, and terminate at an edge 210 that is located beyond the rounded edge 218 of the tube 216. The assembly guide 200, as installed onto the tube 216, may define a guide opening 212 that surrounds a tube opening 214 concentrically around the rounded edge 218. The neck portion 204 may connect the guide portion 206 with the collar flange 202 and create a closed-end or a stop across from the guide opening 212.
A cross-section view of the assembly guide 200 disposed on a center-housing 304 in an un-assembled state is shown in
During installation of the center-housing 304, the receiving bore 326 of the component 322 advantageously enters the guide opening 212. An outer diameter 338 of the receiving bore 326 fits with and aligns to an inner surface 340 of the guide portion 206 of the assembly guide 200. Thusly, the tube 316 may advantageously remain centered and aligned with the receiving portion 326 and the seal 332, the outlet opening 334 of the tube 316 aligned with the inlet opening 336 of the seal 332, and there are advantageously no misalignment issues that may cause pinch points in the seal 332.
A cross-section view of the assembly guide in an as-installed position between the center-housing 304 and the component 322 is shown in
A flowchart for a method of accomplishing a blind fluid connection between a component having a drain tube and a receiving part having a bore is shown in
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
