The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
Referring now to
The vehicle system 10 further includes an engine starting system 22. The engine starting system 22 includes a flywheel ring gear 24, a starter motor 26 and a power system 28. The flywheel ring gear 24 is fixed for rotation with the crankshaft 14. The starter motor 26 selectively engages the flywheel ring gear 24, as explained in further detail below, to rotatably drive the crankshaft 14. In this manner, the engine 12 is cranked during a start-up routine.
The power system 28 includes an ignition switch or start button 30, an energy storage device (ESD) 32 (e.g., battery or super-capacitor), a fuse 34, a starter relay 36 and a neutral switch 38. The power system 28 enables the starter motor 26 to engage and drive the flywheel ring gear 24 based on an operator input (e.g., turning the ignition switch to START). The ESD 32 provides power to power the starter motor 26 and the neutral switch 38 ensures that the vehicle is in neutral before enabling power to the starter motor 26.
Referring now to
The actuator assembly 48 is driven by the SPA 50 and includes a spring 54, a collar 56 and an actuator arm 58. The actuator arm 58 is pivotable about an axis X and engages the SPA 50 at a first end and the collar 56 at a second end. The collar 56 is slidably disposed about the pinion shaft 44 and the spring 54 is positioned between the collar 56 and the pinion gear 46. The SPA 50 induces rotation of the actuator arm 58 about the axis X, which in turn induces linear movement of the collar 56 along the pinion shaft 44. Movement of the collar 56 towards the pinion gear 46 (i.e., away from the motor 42) induces corresponding linear movement of the pinion gear 46 through the spring 54. If the teeth of the pinion gear 46 are not immediately aligned with the teeth of the ring gear 34, the spring 54 is compressed to induce a biasing force against the pinion gear 46. Once the teeth are aligned, the biasing force pushes the pinion gear 46 into engagement with the ring gear 24.
The SPA 50 includes a solenoid 60, a spring 62 and an armature 64. The solenoid 60 induces linear movement of the armature 64 between a first position and a second position that respectively correspond with the engaged and disengaged positions of the pinion gear 46. The spring 62 biases the armature 64 into the first position. The solenoid 60 drives the armature 64 to the second position against the biasing force of the spring 62 based on the driver input. Once the solenoid 60 releases the armature 64 (e.g., after engine cranking is complete), the spring 62 biases the armature 64 back to the first position.
Referring now to
As illustrated in
Referring now to
In the case of the damped SPA 50, the velocity of the armature 64 steadily increases until the armature engages the damper 52. After the armature 64 engages the damper 52, the velocity increase or acceleration is reduced. At the point where the armature 64 is near the second position, there is a drop in the velocity and a subsequent oscillation that are both significantly less in intensity than with the traditional, un-damped system. As a result, noise generation is inhibited.
Referring now to
The first fluid port 90 enables intake and exhaust of the dampening fluid from the first chamber 78 based on the direction of movement of the piston 72. The second fluid port 92 enables intake and exhaust of the dampening fluid from the second chamber 80. The location of the second fluid port 92 relative to a start position of the piston 72 defines the first period of un-damped travel of the armature 64. More specifically, during armature 64 travel over a distance A, the dampening fluid is exhausted through the second fluid port 92 and the restrictor port 94. As the piston 72 achieves the distance A, the piston 72 closes the second fluid port 92 inhibiting fluid flow therethrough. In this manner, the restrictor port 94 is the only exhaust path available and the resultant back-pressure induces dampening of the velocity of the SPA 50.
Referring now to
For a first portion of travel, the extension 102 is not received into the restrictor port 100 and fluid is exhausted through the restrictor port 100 to enable un-dampened movement of the armature 64. Once the conical extension 102 is received into the restrictor port 100, the available area for fluid exhaust through the restrictor port 100 decreases. As a result, back-pressure builds in the second chamber 80 and dampens movement of the armature 64. The further the conical extension 102 is received into the restrictor port 100, increasingly less area is available for fluid exhaust and the dampening force correspondingly increases.
Referring now to
As the piston 72 travels towards the restrictor port, fluid is exhausted through both the second fluid port and the small fluid port 114 to enable un-dampened travel of the armature 64. Once the piston 72 achieves the second fluid port, the second fluid port is blocked by the piston 72 and the small fluid port 114 is the only available exhaust path. As a result, the back-pressure builds within the second chamber 80 and the armature 64 is dampened for the remainder of travel to the second position.
When the piston 72 moves back, fluid in the first chamber 78 is exhausted through the first fluid port. The ball 116 is moved against the bias force of the spring 118 to open the large fluid port 112, as a result of a low pressure in the second chamber 80. In this manner, fluid is drawn into the second chamber 80 through the large port 112 to enable the piston 72 to rapidly return to its starting position. Fluid is even more rapidly drawn into the second chamber 80 once the piston 72 moves past the second fluid port.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.