Rotary control assembly

Abstract

A rotary control assembly (100) includes a housing (110), and a rotary control (120) supported in the housing (110). The rotary control (120) is rotatable around an axis of rotation (101). A printed circuit board (700) includes a transmission coil (TX) and a plurality of receiving coils (RX). A metal target (260) is fixedly connected to the rotary control (120) proximal to the printed circuit board (700). The metal target (260) is displaced relative to the plurality of receiving coils (RX) when the rotary control rotates (120) within the housing (110). The transmission coil (TX) induces Eddy currents within the metal target (260), which in turn induced a voltage in the receiving coils (RX), thereby allowing a position of the metal target (260) to be determined.

Description

ROTARY CONTROL ASSEMBLYCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 583,803, filed 2023-09-19.BACKGROUND

[0002] Rotary shifters in automobiles are a type of gear selector mechanism used to control the transmission of the vehicle. Instead of a column or floor-mounted shift lever, rotary shifters employ a dial or knob that the driver can turn to select the desired gear or transmission mode. Rotary shifters have become increasingly popular in modem vehicles for their space-saving design, improved aesthetics, and enhanced functionality. Rotary shifters are particularly beneficial when used in combination with electronic transmission control systems or electric drive trains. They can improve safety by preventing accidental gear shifts.

[0003] Within the context of the present application, the term “shifter” is used to broadly refer to a drive mode selector. It can be used with multi-speed transmissions in combination with internal combustion engines, and also for drive mode or direction selection in combination with an electric drivetrain. The rotary shifter is typically used to switch the automobile between a Drive, Reverse, and Neutral drive mode. The rotary control knob may provide access to additional drive modes, and optionally additional features.

[0004] The rotary shifter is typically a rotary control assembly that comprises a rotary knob that is rotatably supported in a housing, to which the driving modes are assigned over a rotational range. Driving modes can be selected by turning the rotary knob.

[0005] By way of example, a selector lever assembly for selecting and switching different driving modes in a vehicle transmission is known from U.S. Pat. App. Pub. No. US 2022 / 0373080. The selector lever assembly includes a permanent magnet on the end of a shaft element facing away from the rotary knob, which has a dedicated sensor thatcan detect its movement. A 3D sensor can preferably be used for this. The sensor is fixed in place in relation to the housing, such that the sensor is dedicated to the permanent magnet, thus enabling it to detect the movement of the permanent magnet, which is connected to the shaft element. The sensor is typically a Hall-effect type sensor.SUMMARY

[0006] In one example, a rotary control assembly includes a housing. A rotary control is supported in the housing. The rotary control is rotatable around an axis of rotation. The rotary control assembly further includes a printed circuit board with a transmission coil (TX) and a plurality of three receiving coils (RX). A metal target is fixedly connected to the rotary control proximal to the printed circuit board. The metal target is displaced relative to the plurality of receiving coils when the rotary control rotates within the housing.

[0007] The printed circuit board includes one or more electronic components configured to excite the transmission coil (TX) and induce Eddy currents in the metal target. The Eddy currents in turn induce voltages in the receiving coils (RX). The electronic components evaluate the voltages induced in the receiving coils (RX) to determine a position of the metal target and generate a drive mode signal for a vehicle based on the position of the metal target.

[0008] Generally, a plurality of receiving coils (RX) refers to two or more receiving coils (RX). The plurality of receiving coils (RX) may in particular be three receiving coils (RX) electrically connected to one another in a star configuration.

[0009] The metal target is preferably shaped as an annular sector. In particular, the metal target may be shaped as a flat annular sector extending over an angle of 90°.

[0010] The rotary control includes an externally accessible rotary knob, and a shaft fixedly connected to the rotary knob (210). The shaft includes an annular flange forming a lower end of the rotary control. The metal target is connected to the annular flange. The metal target may be fixed in a downwardly open cavity formed in the annular flange.

[0011] The rotary knob may include an annular engagement groove formed between outer cylindrical engagement sectors and inner cylindrical engagement sectors. A key may extend between the outer cylindrical engagement sectors and the inner cylindrical engagement sectors. The shaft may include a corresponding cylindrical engagement portion that is received within the annular engagement groove. The cylindrical engagement portion may include a positioning slot within which the key is received. Additionally, the shaft may include a plurality of hooks which engage corresponding window openings that extend through the outer cylindrical engagement sectors.

[0012] The transmission coil (TX) and the plurality of receiving coils (RX) may be formed by traces within an annular portion of the printed circuit board. Electronic components may be arranged on an upper side of the printed circuit board inwardly of the annular portion. The electronic components may include an inductive sensor interface IC.

[0013] External connector terminals may extend perpendicularly from a lower side of the printed circuit board inwardly of the annular portion. An internal connector may be arranged on an upper side of the printed circuit board inwardly of the annular portion to connect the printed circuit board to a further printed circuit board.

[0014] The housing may include an outer wall and a partition wall extending between the outer walls. The metal target and the printed circuit board may be separated from one another by the partition wall.

[0015] The rotary control may include an externally accessible rotary knob and a shaft fixedly connected to the rotary knob. An annular bearing groove may extend upwardly from the partition wall around the axis of rotation. The shaft may include a cylindrical journal rotatably seated within the annular bearing groove.

[0016] The plurality of receiving coils (RX), i.e., the at least two receiving coils (RX), may be three receiving coils (RX) electrically connected to one another in a star configuration.

[0017] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore,there is no intention to be bound by any theory presented in the preceding background or the following detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a perspective front and top view of a rotary control assembly.

[0019] FIG. 2 is an exploded view of the rotary control assembly as in FIG. 1.

[0020] FIG. 3 is an exploded detailed view of a rotary control used within the rotary control assembly.

[0021] FIG. 4 is a perspective top view of a printed circuit board used within the rotary control assembly.

[0022] FIG. 5 is a perspective bottom view of the circuit board as in FIG. 4.

[0023] FIG. 6 is a perspective top, front, cross sectional view of the control assembly as in FIG. 1, a right side having been cut away.

[0024] FIG. 6 is a perspective top, front, right side cross sectional view into a left half of the control assembly as in FIG. 1 , a right half of the assembly having been cut away.

[0025] FIG. 7 is a perspective top, front cross sectional view into a rear half of the control assembly as in FIG. 1, a front half of the assembly having been cut away.DETAILED DESCRIPTION

[0026] FIGS. 1 - 7 show a rotary control assembly 100 in perspective view. The rotary control assembly 100 includes a housing 110. The housing 110 includes a housing body 500. A bottom cover 600 is secured to a bottom of the housing body 500 by a snap connection. A bezel 400 is snapped into a top of the housing body 500.

[0027] A user interface 105 is arranged on top of the housing 110 and extends through the bezel 400. The user interface 105 includes a rotary control 120. The rotary control 120 is accessible to a driver in form of a rotary knob 210. The rotary knob 210 has a driver-accessible serrated cylindrical shell surface 217. The rotary knob 210 can rotate around an axis of rotation 101.

[0028] Arranged centrally within the rotary control 120 is an indicator assembly 130. The indicator assembly 130 is fixedly connected to the housing 110. The rotary control 120 can rotate around the indicator assembly 130. The indicator assembly 130 includes a display 310. The display 310 includes translucent letters 311, 312, 313 overmolded therein. The translucent letters preferably include the letter “R” 312, the letter “N” 311 and the letter “D” 313. A display printed circuit board 340 is arranged within the indicator assembly 130. The translucent letters may be backlit by LEDs that are mounted on the display printed circuit board 340.

[0029] A push button 320 may be centrally arranged within the indicator assembly 130. The push button may be a “Park” button to switch the vehicle into a park mode and labeled “P.” The push button 320 may be upwardly biased by an elastic contact mat 330. The elastic contact mat 330 may, on a bottom side thereof, interact with the display printed circuit board 340 to close electrical connections within the display printed circuit board 340 when the push button 320 is pushed down. The elastic contact mat 330 may be translucent and act as a light guide.

[0030] The indicator assembly 130 is enclosed, on its side and bottom, by a canshaped indicator cover 350. The display printed circuit board 340, elastic contact mat 330, and push button 320 are sandwiched within the indicator cover 350. The display 310 forms a top face of the indicator assembly 130 and is connected to the indicator cover 350 by clips.

[0031] The indicator assembly 130 is fixedly connected to the housing body 500. The connection is made by a screw 351. The screw 351 is arranged within the axis of rotation 101 and secures the indicator cover 350 to an upper end of the housing body 500. A locating pin 532 extends upwardly from the housing body 500 and through a corresponding hole in a bottom wall of the indicator cover 350. The indicator cover 350 is thereby aligned with and rotationally fixed with respect to the housing body 500.

[0032] The housing body 500 is of generally cuboid design. It includes outer walls 510 that extend parallel to the axis of rotation 101. A partition wall 515 extends between the outer walls 510. The partition wall 515 divides the housing body 500 into a lowerhousing chamber 517 and an upper housing chamber 516. The outer walls 510 include upper housing walls 511 above the partition wall 515 and lower housing walls 512 below the partition wall 515.

[0033] The rotary control 120 includes the externally accessible rotary knob 210 and a hollow shaft 250 that is co-rotatingly fixed to the rotary knob 210. The shaft 250 is rotatably connected to the housing body 500 by a slide bearing 520. The slide bearing 520 includes an annular bearing groove 521 that extends upwardly from the partition wall 515 around the axis of rotation 101. A journal 270 extends downwardly from an upper face 256 of the shaft 250. The journal 270 is rotatably seated within the annular bearing groove 521. The journal 270 is a cylindrical body arranged within the axis of rotation 101. The journal 270 extends downwardly from an upper face 256 of the shaft 250 at a radially inner end of the upper face 256.

[0034] A flange 251 extends radially outwardly at a lower end of the shaft 250. The flange 251 includes a downwardly open cavity 252. A metal target 260 is fixed within the downwardly open cavity 252. The metal target is arranged such that it is flush with the flange 251.

[0035] The metal target 260 has the shape of an annular sector. The metal target 260 has an angular width of 90 degrees. An inner radius of the annular sector is between 20 mm and 30 mm. An outer radius of the annular sector is between 30mm and 40 mm. A radial extension of the annular sector is between 5 mm and 15 mm.

[0036] The metal target 260 is electrically conductive, and magnetically not permanently magnetized.

[0037] The metal target 260 may be a stamped sheet metal part having a thickness of 0.5 mm to 2 mm. The metal target 260 may be fixed to the flange 251 by an adhesive or by ultrasonic welding. The metal target 260 may also be overmolded into the flange 251. In that case, the metal target 260 may have a trapezoidal cross-sectional shape. A top surface of the metal target 260 is then larger than a bottom surface thereof. For example, a flat top surface of the metal target 260 may span an area of 495 mm2and a flat bottom surface of the metal target 260 may span an area of 450 mm2.

[0038] The rotary control 120 includes a haptic feedback mechanism in form of a variable mechanical resistance. The mechanical resistance is generated by a detent 540. The detent 540 is upwardly biased by a spring 541. A lower end of the spring 541 is supported on the partition wall 515. An upper end of the spring 541 is supported on a head 542 of the detent 540. The head 542 of the detent 540 has a rounded tip. The rounded tip engages notches 257 formed on a bottom of the upper face 256 of the shaft 250. A total of sixteen notches 257 are circumferentially evenly distributed. The rotary control 120 thereby assumes a stable latched position upon rotation by 22.5 degrees or multiples thereof.

[0039] The detent 540 is hollow and seated on a detent pin 519. The detent pin 519 extends upwardly from the partition wall 515 within a hollow-cylindrical detent guide 518. A bottom of the hollow-cylindrical detent guide 518 may be formed by a downward extension below the partition wall 515.

[0040] The rotary control 120 includes the operator-accessible rotary knob 210 and the operator -inaccessible shaft 250. The rotary knob 210 has an annular engagement groove 213 formed between outer cylindrical engagement sectors 211 and inner cylindrical engagement sectors 212. A key 214 extends between the outer cylindrical engagement sectors 211 and the inner cylindrical engagement sectors 212. The shaft 250 includes a cylindrical engagement portion 253 that is received within the annular engagement groove 213. The cylindrical engagement portion 253 includes a positioning slot 254 within which the key 214 is received. The shaft 250 includes a plurality of circumferentially distributed hooks 255 which engage corresponding window openings 215 that extend through the outer cylindrical engagement sectors 211, thereby providing a snap-fit connection between the rotary knob 210 and the shaft 250.

[0041] A printed circuit board 700 is fixed to the housing body 500 from below. The printed circuit board 700 may have a rectangular shape. The printed circuit board 700 is aligned relative to the housing body 500 by two guide pins 501 that extend downwardly below the partition wall 515. The guide pins 501 extend through holes 701, 703 on crosswise comers of the printed circuit board 700. The printed circuit board 700 isfastened to the housing body 500 by two screws 502 that extend through further holes 702, 704 proximal to the remaining comers of the printed circuit board 700.

[0042] The printed circuit board 700 includes a transmission coil TX and a plurality of receiving coils RX. The transmission coil TX and the receiving coils RX are formed by traces within two or more layers of the printed circuit board 700. The traces are arranged within an annular portion 710 of the printed circuit board 700. The plurality of receiving coils RX may include three receiving coils that are electrically connected in a star (Y) configuration.

[0043] The annular portion 710 may have an inner diameter of 50 mm to 60 mm and an outer diameter of 60 mm to 80 mm. The annular portion 710 may have a radial width between 5 mm and 15 mm.

[0044] The transmission coil TX and the receiving coils RX interact with the metal target 260 in form of an inductive position sensor. The metal target 260 is displaced relative to the plurality of receiving coils RX when the rotary control 120 rotates within the housing 110. The position of the metal target 260 relative to the receiving coils RX may be used to generate a drive mode output of the rotary control assembly 100. Alternatively, the rotary control assembly 100 may assume a predetermined state when power is applied, for example a “Park” drive mode. Thereafter, a drive mode output of the rotary control assembly 100 may be determined by rotation of the rotary control 120 relative to its initial orientation upon power on.

[0045] The printed circuit board 700 and the metal target 260 are arranged on opposite sides of and separated by the partition wall 515. That is, the inductive sensing is effected through the partition wall 515. This allows the printed circuit board 700 to be encapsulated in the lower housing chamber 517 while the shaft 250 and the metal target 260 are arranged in the upper housing chamber 516.

[0046] A lower face of the metal target 260 may be arranged at a distance between 3 mm and 6 mm above an upper face of the printed circuit board 700. The flange 251 extends parallel to the printed circuit board 700.

[0047] In inductive position sensors, a transducer is a coil set composed of a transmission (Tx) coil and receiving (Rx) coils, connected to an inductive position sensor interface integrated circuit (IC). Within the coil set, a circular transmission (Tx) coil generates a cylindrically symmetric AC magnetic field. The Tx coil is actively driven by the interface IC at a carrier frequency, which may be in the 2-5 MHz range. The Tx coil field excites Eddy currents in the metal target 260, which generates a secondary field, named the target field. As the metal target 260 only covers a circular sector of 90°, the target field is not rotationally symmetrical, but has an angular dependency.

[0048] The receiving (Rx) coils are designed to capture the target field while being insensitive to the Tx field. The sensor makes use of the multiple Rx coils in order to allow a ratiometric angle calculation independent from the signal strength. The position of the metal target 260 is then used to derive a drive mode signal.

[0049] The operating principle of inductive position sensors is described in the paper “High speed inductive position sensor for E-machines” by L. Lugani et al., the contents of which is incorporated by reference in its entirety.

[0050] The inductive sensing principle is superior to traditional Hall effect type sensors that use permanent magnets. In particular, inductive sensing is less sensitive to magnetic fields generated by high currents of electric drivetrains than Hall-effect type sensors. The positioning of the metal target 260 relative to the TX and RX coils is less susceptible to mechanical tolerances than positioning of a permanent magnet relative to a 3D Hall effect sensor.

[0051] To enable a space-saving design, electronic components 722 are arranged on an upper side of the printed circuit board 700 inwardly of the annular portion 710. The electronic components 722 may include an inductive sensor interface IC, a microprocessor, a network transceiver and power supply components for interfacing to a vehicle power distribution system. The network transceiver may interface the microprocessor to a vehicle CAN, Flexray, LIN, or Ethernet bus.

[0052] External connector terminals 730 extend perpendicularly from a lower side of the printed circuit board 700 inwardly of the annular portion 710. The external connectorterminals 730 extend through a correspondingly shaped connector 610 of the bottom cover 600 to form a downwardly open vehicle connector. The rotary control assembly 100 can be connected to a vehicle’s power and signal distribution system through the connector 610.

[0053] An internal connector 721 may also be placed on an upper side of the printed circuit board 700 inwardly of the annular portion 710 to connect the printed circuit board 700 to the display printed circuit board 340. The printed circuit board 700 and the display printed circuit board 340 are connected by a flat cable 341 that passes through a slot in the housing body 500 inwardly of that annular bearing groove 521.

[0054] While the present invention has been described with reference to exemplary embodiments, it will be readily apparent to those skilled in the art that the invention is not limited to the disclosed or illustrated embodiments but, on the contrary, is intended to cover numerous other modifications, substitutions, variations and broad equivalent arrangements that are included within the spirit and scope of the following claims.

Claims

CLAIMSWhat is claimed is:

1. A rotary control assembly (100), comprising: a housing (110); a rotary control (120) supported in the housing (110), the rotary control (1 0) being rotatable around an axis of rotation (101); a printed circuit board (700) including a transmission coil (TX) and a plurality of receiving coils (RX); and a metal target (260) fixedly connected to the rotary control (120) proximal to the printed circuit board (700), whereby the metal target (260) is displaced relative to the plurality of receiving coils (RX) when the rotary control (120) rotates within the housing (110).

2. The rotary control assembly (100) as in claim 1, wherein the printed circuit board (700) includes one or more electronic components (722) configured to excite the transmission coil (TX) and induce Eddy currents in the metal target (260), which Eddy currents in turn induce voltages in the receiving coils (RX), evaluate the voltages induced in the receiving coils (RX) to determine a position of the metal target (260), and generate a drive mode signal for a vehicle based on the position of the metal target (260).

3. The rotary control assembly (100) as in claim 1, wherein the metal target (260) is shaped as an annular sector.

4. The rotary control assembly (100) as in claim 1, wherein the metal target (260) is shaped as a flat annular sector extending over an angle of 90°.

5. The rotary control assembly (100) as in claim 1, wherein the rotary control (120) comprises an externally accessible rotary knob (210), and a shaft (250) fixedly connected to the rotary knob (210), and wherein the shaft (250) includes an annular flange (251) forming a lower end of the rotary control (120), and wherein the metal target (260) is connected to the annular flange (251).

6. The rotary control assembly (100) as in claim 5, wherein the metal target is fixed in a downwardly open cavity (252) formed in the annular flange (251).

7. The rotary control assembly (100) as in claim 5, wherein the rotary knob (210) comprises an annular engagement groove (213) formed between outer cylindrical engagement sectors (211) and inner cylindrical engagement sectors (212), wherein a key (21 ) extends between the outer cylindrical engagement sectors (210) and the inner cylindrical engagement sectors (212), wherein the shaft (250) comprises a cylindrical engagement portion (253) that is received within the annular engagement groove (213), wherein the cylindrical engagement portion (253) includes a positioning slot (254) within which the key (214) is received, and wherein the shaft (250) comprises a plurality of hooks (255) which engage corresponding window openings (215) that extend through the outer cylindrical engagement sectors (211).

8. The rotary control assembly (100) as in claim 1, wherein the transmission coil (TX) and the plurality of receiving coils (RX) are formed by traces within an annular portion (710) of the printed circuit board (700).

9. The rotary control assembly (100) as in claim 8, wherein electronic components (722) are arranged on an upper side of the printed circuit board (700) inwardly of the annular portion (710), and wherein electronic components (722) include an inductive sensor interface IC.

10. The rotary control assembly (100) as in claim 8, wherein external connector terminals (730) extend perpendicularly from a lower side of the printed circuit board (700) inwardly of the annular portion (710).

11. The rotary control assembly (100) as in claim 8, wherein an internal connector (721) is arranged on an upper side of the printed circuit board (700) inwardly of the annular portion (710) to connect the printed circuit board (700) to a further printed circuit board (340).

12. The rotary control assembly (100) as in claim 1, wherein the housing (110) comprises an outer wall (510) and a partition wall (515) extending between the outer walls, wherein the metal target (260) and the printed circuit board (700) are separated by the partition wall (515).

13. The rotary control assembly (100) as in claim 12,wherein the rotary control (120) comprises an externally accessible rotary knob (210), and a shaft (250) fixedly connected to the rotary knob (210), and wherein an annular bearing groove (521) extends upwardly from the partition wall (515) around the axis of rotation (101), and wherein the shaft (250) includes a cylindrical journal (270) rotatably seated within the annular bearing groove (521).

14. The rotary control assembly (100) as in claim 1, wherein the plurality of receiving coils (RX) consists of three receiving coils (RX) electrically connected to one another in a star configuration.

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