The present disclosure relates generally to a transmission electronic shifter and, more particularly, to a poly-stable lever style electronic shifter with dual mechanical detents.
More and more vehicles are being equipped with electronic shifters (“e-shifters”) to place the vehicle's automatic transmission into a desired gear state. Electronic shifters can replace the traditional console mounted P-R-N-D-L mechanical shift lever and are typically implemented as levers, which can be pushed up/down or sideways, and/or buttons to effect gear changes. The typical mono-stable lever type electronic shifter returns to its original or home position after it has been manipulated by the driver. A more recent development is to have a multi-position stable or poly-stable e-shifter that retains an actuator setting that represents a driver requested transmission gear state. With the poly-stable e-shifter, the shift lever can retain a manipulated position of the shift lever and, as such, is preferred by many drivers. The shift-by-wire transmissions associated with these mono-stable and poly-stable e-shifters typically do not include a mechanical cable or link to the e-shifter and the associated additional detent member that is incorporated within the mechanically shifted transmission. Accordingly, there is a need for improvement in the relevant art.
In one form, an electronic shifter assembly for a shift-by-wire transmission is provided in accordance with the teachings of the present disclosure. The electronic shifter assembly can include a shift lever assembly and a dual mechanical detent system. The shift lever assembly can include a shift lever and a pivot base that is pivotably coupled to a base of the electronic shifter assembly. The dual mechanical detent system can include first and second mechanical detent systems. The first mechanical detent system can have a first detent plunger biased into engagement with a first detent cam member that has a first cam surface profile. The second mechanical detent system can have a second detent plunger biased into engagement with a second detent cam member that has a second cam surface profile. The first and second detent plungers can be coupled to the pivot base and can be configured to move relative to the respective first and second cam surface profiles with movement of the shift lever assembly. The first and second mechanical detent systems can each be configured to releasably retain the shift lever assembly in a selected one of a plurality of transmission gear selection locations.
In another form, an electronic shifter assembly for a shift-by-wire transmission is provided in accordance with the teachings of the present disclosure. The electronic shifter assembly can include a poly-stable shift lever assembly and a dual mechanical detent system. The poly-stable shift lever assembly can include a shift lever and a pivot base pivotably coupled to a base of the electronic shifter assembly. The dual mechanical detent system can be housed within a housing of the base and can include a first mechanical detent system and a second mechanical detent system. The first mechanical detent system can have a first detent plunger biased into engagement with a first detent cam member that has a first cam surface profile. The second mechanical detent system can have a second detent plunger biased into engagement with a second detent cam member that has a second cam surface profile. The first and second detent plungers can be coupled to the pivot base and can be configured to move relative to the respective first and second cam surface profiles with movement of the shift lever assembly. The first and second mechanical detent systems can each be configured to independently releasably retain the shift lever assembly in a selected one of a plurality of transmission gear selection locations.
Further areas of applicability of the teachings of the present disclosure will become apparent from the detailed description, claims and the drawings provided hereinafter, wherein like reference numerals refer to like features throughout the several views of the drawings. It should be understood that the detailed description, including disclosed embodiments and drawings referenced therein, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the present disclosure, its application or uses. Thus, variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure.
With initial reference to
As discussed above, one of the benefits of a poly-stable electronic shifter includes an ability for a shift lever to remain in a position it is placed in by a driver for selecting a transmission gear. Typical transmission gears to be selected are park, reverse, neutral and drive (PRND). As also discussed above, electronic shifters do not include a mechanical cable or link to the transmission, as would be the case for a mechanical shifter associated with a mechanically shifted transmission. The cable and shift systems of the mechanically shifted transmissions can also include a detent system incorporated into the transmission, which can aid (via the cable or link) in retaining the shift lever in its current position and can provide damping to the system.
Accordingly, a poly-stable electronic shifter assembly 10 with a dual mechanical detent system for use with a shift-by-wire automatic transmission is provided in accordance with various aspects of the present disclosure. In one exemplary configuration, the poly-stable electronic shifter assembly 10 can include the dual mechanical detent system housed within the shifter assembly. The dual mechanical detent system can provide redundancy to prevent an undesired shift event to the extent there would be a potential malfunction of one of the dual mechanical detent systems. The dual mechanical detent system can also provide for a more robust shift system with improved tightness and feel to a user, as will be discussed in greater detail below.
With continuing reference to
The base 26 can be adapted to be fixedly attached to a vehicle, such as in association with the center console 14 shown in
The shift lever assembly 30 can include a shift lever 74, a shift knob 78 and a shift lever pivot base 82. The shift lever 74 can include a first or upper end 86 coupled to the shift knob 78 and a second or lower end 90 fixed to the shift lever pivot base 82. The shift lever pivot base 82 can include a body 94 defining a central bore 98 and first and second body members 102, 106 extending in opposite directions from central bore 98. In the exemplary configuration illustrated, the first and second body members 102, 106 can extend in directions substantially in-line or substantially parallel to the travel axis 72 of the shift lever assembly 30, which will be discussed in greater detail below.
The body 94 can include an upper end or surface 110 and a lower end or surface 114, as shown for example in
Pivotably coupled in this manner, the shift lever assembly 30 can be pivotable as a unit relative to base 26 and gate guide 70 along travel axis 72 among the PRND gear selection locations 144 (
The PRND gear selection locations 144 can include a park (P) gear selection location 152, a reverse (R) gear selection location 156, a neutral (N) gear selection location 160, and a drive (D) gear selection location 164, as shown in
With particular reference to
The first mechanical detent system 188 can include a first detent plunger 196 and a first detent cam member 202. Similarly, the second mechanical detent system 192 can include a second detent plunger 206 and a second cam member 210. The first and second detent plungers 196, 206 can be configured to engage and cooperate with the respective first and second cam members 202, 210, as will be discussed in greater detail below.
In the exemplary configuration illustrated in the various figures, the first and second detent plungers 196, 206 can be positioned in first and second bores 214, 218 defined by the respective first and second body members 102, 106 of shift lever pivot base 82. With particular reference to
The first and second cam members 202, 210 can each be attached to the base 26 such that the shift lever assembly 30 and first and second detent plungers 196, 206 associated therewith move relative to the cam members 202, 210. In the exemplary configuration illustrated in
The first and second cam members 202, 210 can each include a first end 240 positioned toward or facing the shift lever 74 and a second opposed end 244. The first and second cam members 202, 210 can define an overall arcuate surface 248 (
For example, each of the cam surfaces 250 can define detent positions 254 corresponding to the PRND gear selection locations 144. In particular, the first cam member 202 can define a park detent position 254A, a reverse detent position 254B, a neutral detent position 254C and a drive detent position 254D starting from the second end 244. The second cam member 210 can define the same positions, but starting from the first end 240, as best shown in
It should be appreciated that the first and second cam members 202, 210 can include a suitable width in the lateral direction so as to have the capability to handle lateral movement of the shift lever assembly 30 and thus corresponding lateral movement of the detent plungers 196, 206. For example, the shift lever assembly 30 may be moved laterally along or parallel to the lateral axis 148 to the manual-automatic gear selection locations. In this example, the cam members 202, 210 can include a cam surface profile having sufficient width to handle such lateral movement of the detent plungers 196, 206, as well as incorporate corresponding detent positions 260, as best shown in
As briefly discussed above, each of the first and second detent plungers 196, 206 can be biased into engagement with the cam surfaces 250 of the respective first and second cam members 202, 210. In particular, the upper ends 228 can be biased into engagement with the respective cam surfaces 250. As the shift lever assembly 30 is pivoted from the park gear selection location 152 along travel axis 72 to the drive gear selection location 164, the upper end 228 of the first detent plunger 196 can engagingly follow the cam member profile 250 of first cam member 202 from the second end 244 toward the first end 240. During such movement of the shift lever assembly 30, the upper end 228 of the second detent plunger 206 can simultaneously engagingly follow the cam member profile 250 of the second cam member 210 from the first end 240 toward the second end 244.
The detent plungers 196, 206 can be tuned in connection with a size and shape of the detent grooves 254 to provide a desired resistance to movement of the shift lever assembly in a fore/aft direction along travel axis 72 between the various detent grooves 254A-254D corresponding to the PRND gear selection locations 144. In one exemplary implementation, the spring rate of the biasing members 232 associated with the detent plungers 196, 206 can be varied to provide the desired resistance and tactile feedback to the user as to the PRND gear selection locations 144 and movement between such locations. In another exemplary implementation, a depth of the detent grooves 254 can be varied to provide the desired resistance and tactile feedback. In these examples, a larger spring rate and/or a larger detent groove depth can provide greater frictional resistance to movement between one PRND gear selection location and another PRND gear selection location.
In operation, each of the first and second mechanical detent systems 188, 192 can function together as the dual mechanical detent system 38 to releasably maintain a desired gear selection position of the shift lever assembly 30. The first and second mechanical detent systems 188, 192 can each have the capability to independently releasably maintain the desired gear selection position of the shift lever assembly 30 in the event of a potential malfunction with one of the first and second mechanical detent systems 188, 192. Thus, the dual mechanical detent system can provide redundancy to prevent an undesired shift event to the extent there would be a potential malfunction of one of the first and second mechanical detent systems. As discussed above, the dual mechanical detent system can also provide for a more robust shift system with improved tightness and a feel to a user.
It should be understood that the mixing and matching of features, elements, methodologies and/or functions between various examples may be expressly contemplated herein so that one skilled in the art would appreciate from the present teachings that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise above.
This application claims the benefit of U.S. Provisional Ser. No. 61/895,201, filed Oct. 24, 2013.
Number | Date | Country | |
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61895201 | Oct 2013 | US |