Dial shifter

A shifter mechanism for a transmission of a motor vehicle controlled by a transmission controller includes a central processing unit for transmitting a shifting request to the transmission controller, a dial shifter including a rotatable shifter knob and a rotation mechanism in communication with the rotatable shifter knob and about which the rotatable shifter knob rotates, and a sensor connected to the central processing unit for detecting rotation of the rotatable shifter knob.

TECHNICAL FIELD

The embodiments disclosed herein are related to shifting mechanisms for a transmission of a vehicle, and more specifically to dial shifters for shifting a transmission of a vehicle.

BACKGROUND

The shift device for the transmission of a motor vehicle is provided with a shift lever which is typically located in the center console. When there is no center console, or when the center console does not provide a space for installing the shift lever, the shift lever may also be provided adjacent to the steering column or on the instrument panel.

In a typical automatic transmission, the shift positions are arranged in the order of the P (parking) position, the R (reverse) position, the N (neutral) position and the D (drive) in that other. Oftentimes, a special forward travel position is provided in addition to the D (drive) position, and is typically located next to the drive position on the other side of the N position. Such an additional forward travel position is called as the S (sport mode) position, the 2 (second) position and the L (low speed) position depending on the purpose thereof. In the case of an electric vehicle or a hybrid vehicle, the additional forward travel position may consist of the B (regenerative braking) position. As the special forward travel position is designed for a special purpose such as increasing the engine brake and improving the response of the vehicle, it is selected only under special circumstances. As the additional forward travel position is located next to the D position, it is possible that the vehicle operator inadvertently selects the additional forward travel position, and it may irritate the vehicle operator.

Therefore, there is established a need to provide for an improved shifter device that maximizes the space in the passenger compartment of the motor vehicle that provides all of the required functionality regarding shifting, including a special shift operation from the D (drive) position to the additional forward travel position.

APPLICATION SUMMARY

According to one aspect, a shifter mechanism for a transmission of a motor vehicle controlled by a transmission controller includes a central processing unit for transmitting a shifting request to the transmission controller, a dial shifter including a rotatable shifter knob and a rotation mechanism in communication with the rotatable shifter knob and about which the rotatable shifter knob rotates, and a sensor connected to the central processing unit for detecting rotation of the rotatable shifter knob.

According to another aspect, a shifter mechanism for a transmission of a motor vehicle, the transmission controlled by a transmission controller including a dial shifter that can be manually advanced selectively in a first direction and a second direction, a sensor that detects a movement of the dial shifter, and a central processing unit for instructing the transmission controller to select a shift position of the transmission from a plurality of shift positions in a prescribed order according to a detection signal of the sensor, wherein the central processing unit is configured to cause the selected shift position to be changed in the prescribed order in correspondence to a rotational displacement of the dial shifter in each single shifting operation under normal condition, and to limit the selected shift position to be changed beyond a prescribed shift position depending on an initial shift position and an amount of the rotational movement of the dial shifter in a single shifting operation, and wherein the shift positions include a non-forward travel position, a D (drive) position for a normal forward travel and an additional forward travel position S for a special purpose arranged in that order in the first direction, and the central processing unit is configured to limit the change in the shift position from the non-forward travel position in a single shifting operation in the first direction to the D (drive) position without regard to the rotational displacement of the dial shifter beyond the D (drive) position.

According to yet another aspect, a shifter mechanism for a transmission of a motor vehicle, the transmission controlled by a transmission controller, including a dial shifter that can be manually advanced selectively in a first direction and a second direction. The dial shifter includes a rotatable shifter knob and a rotation mechanism in communication with the rotatable shifter knob and about which the rotatable shifter knob rotates. The shifter mechanism further includes a sensor that detects a movement of the dial shifter and a central processing unit for instructing the transmission controller to select a shift position of the transmission from a plurality of shift positions in a prescribed order according to a detection signal of the sensor. The central processing unit is configured to cause the selected shift position to be changed in the prescribed order in correspondence to a rotational displacement of the dial shifter in each single shifting operation under normal condition, and to limit the selected shift position to be changed beyond a prescribed shift position depending on an initial shift position and an amount of the rotational movement of the dial shifter in a single shifting operation. The shift positions include a non-forward travel position, a D (drive) position for a normal forward travel and a sport mode forward travel position S arranged in that order in the first direction. The central processing unit is configured to limit the change in the shift position from the non-forward travel position in a single shifting operation in the first direction to the D (drive) position without regard to the rotational displacement of the dial shifter beyond the D (drive) position. The transmission may be shifted from the D (drive) position to the sport mode forward travel position S in a second shifting operation in the first direction after the selection of the D (drive) position is completed in a first shifting operation without regard to the rotational displacement of the dial shifter beyond the D (drive) position.

DETAILED DESCRIPTION

Referring toFIG. 1, a vehicle10is provided with an internal combustion engine12as a power source, and the output of the engine12is transmitted to wheels14via a front axle16via an automatic transmission18. The driven road wheels of the vehicle10of the illustrated embodiment consist of front wheels, but embodiments are equally applicable to rear wheel drive vehicles where rear wheels consist of driven road wheels and four wheel drive vehicles where both the front and rear wheels consist of driven road wheels. The automatic transmission18of the illustrated embodiment consists of a multi gear stage automatic transmission system having four forward drive stages and one reverse drive stage, but may also consist of a continuously variable transmission (CVT). The motor vehicle may have additional drive stages, and the embodiments illustrated should not be viewed as limiting the concepts addressed herein. The motor vehicle10may also be an electric vehicle fitted with an electric motor instead of an internal combustion engine or a hybrid vehicle fitted with an electric motor in combination with the engine12.

The vehicle10may also include a control unit20incorporated with the transmission18, a central processing unit (“CPU”)22for controlling the control unit20with a microcomputer, ROM, RAM, peripheral circuits, input/output interfaces and various drivers, a dial shifter24for manually selecting the gear range of the transmission18, a vehicle speed sensor26for detecting the traveling speed of the vehicle10, an accelerator pedal sensor28for detecting the displacement of the accelerator pedal30and a brake pedal sensor32for detecting the depression of the brake pedal34or the engagement of the brake device. The CPU22may be integrally formed within the control unit20, or, as illustrated inFIG. 1, the CPU22may be part of a separate computer processing system within the vehicle10.

The control unit20performs a shift control whereby the gear range of the transmission18is selected according to the operation of the dial shifter24and detection and processing by the CPU22, and the gears of the transmission18are changed according to the selected gear range and the operating condition of the engine12, in addition to controlling the operation of the engine12. The shifting of the gears is performed via the control unit20by a known method by those skilled in the art, such as shifting solenoid valves provided in a hydraulic circuit of the transmission18. When the vehicle10consists of an electric vehicle or a hybrid vehicle, the control unit20may also controls the driving and regenerating action of a motor generator as well.

As illustrated inFIGS. 2 and 3, the dial shifter24is cylindrically shaped, and is located on a portion of an instrument panel36of the vehicle10. The provision of the dial shifter24on the instrument panel36provides for the more efficient usage of the inner space of the passenger compartment of the motor vehicle10. The dial shifter24may typically have a diameter of between 50-55 mm, although dial shifters of additional sizes may be employed. The dial shifter24may be configured to be rotated in either direction, clockwise or counter-clockwise, and to provide detent action such that the operator of the vehicle10is able to sense, through tactile sensation, rotational movement of the dial shifter24, and to further prevent the dial shifter24from rotating without operator input.

Specifically, as illustrated inFIG. 4, the dial shifter24may include a rotatable shifter knob40that is in communication with a rotation mechanism42attached to the instrument panel36and about which the shifter knob40rotates. Additionally, the dial shifter24includes a sensor44for detecting the position and rotation of the dial shifter24.

In the embodiment illustrated inFIG. 4, the detent action is provided by a plurality of alternating peaks50and detents52disposed on an inner circumferential surface54of the shifter knob40. A plunger56disposed within the rotation mechanism42for engaging the inner circumferential surface54of the shifter knob40is biased outwardly into contact with the inner circumferential surface54of the shifter knob40by a spring58in communication with the plunger56for biasing the plunger56in a radially outward direction and into contact with the inner circumferential surface54of the shifter knob40. As the shifter knob40is rotated, the plunger56, which is biased outwardly by the spring58, travels radially inward and outward of the rotation mechanism42as the distal end60of the plunger56contacts the alternating peaks50and detents52. When the operator of the vehicle10is finished rotating the shifter knob40, the bias of the spring58will cause the plunger56to come to rest in one of the detents52.

In an alternate embodiment, illustrated inFIG. 5, the detent action is provided by a plurality of alternating peaks50and detents52disposed on an outer circumferential surface62of the rotation mechanism42. A plunger56disposed within the shifter knob40for engaging the outer circumferential surface62of the rotation mechanism42is biased inwardly into contact with the outer circumferential surface62of the rotation mechanism42by a spring58in communication with the plunger56for biasing the plunger56in a radially inward direction and into contact with the outer circumferential surface62of the rotation mechanism52. As the shifter knob40is rotated, the plunger56, which is biased inwardly by the spring58, travels radially outward and inward of the rotation mechanism42as the distal end60of the plunger56contacts the alternating peaks50and detents52. When the operator of the vehicle10is finished rotating the shifter knob40, the bias of the spring58will cause the plunger56to come to rest in one of the detents52.

In yet another alternate embodiment, illustrated inFIG. 6, the detent action is provided by a plurality of alternating peaks50and detents52disposed on an outer circumferential surface62of the rotation mechanism42and a cantilever spring66biased inwardly from an inner circumferential surface54of the shifter knob40and in contact with the outer circumferential surface62of the rotation mechanism42. The cantilever spring66engages the plurality of alternating peaks50and detents52of the rotation mechanism42. When the operator of the vehicle10is finished rotating the shifter knob40, the bias of the cantilever spring66will force the cantilever spring66to come to rest in one of the detents52.

In yet a further alternate embodiment, illustrated inFIG. 7the detent action is provided by a plurality of alternating peaks50and detents52disposed on an inner circumferential surface54of the shifter knob40and a cantilever spring66biased outwardly from an outer circumferential surface62of the rotation mechanism42. The cantilever spring66engages the plurality of alternating peaks50and detents52of the shifter knob40. When the operator of the vehicle10is finished rotating the shifter knob40, the bias of the cantilever spring66will force the cantilever spring66to come to rest in one of the detents52.

Any other detent mechanisms known to those skilled in the art may be applied to enable the operator of the vehicle10to sense rotation of the shifter knob40by tactile sensation. One such detent action can be achieved by using the detent mechanism as the one disclosed in U.S. Pat. No. 7,971,498. Besides the mechanical detent mechanisms described herein, the detent mechanisms may also include magnetorheological fluid detents alternatively engaged and disengaged by the application of a localized electromagnetic field, haptic feedback mechanisms known to those skilled in the art, and electrically controlled brakes to electrically provide detents and limit rotation of the knob in methods known to those skilled in the art.

As shown inFIGS. 2 and 3, a display panel72is provided in a part of the instrument panel36surrounding the dial shifter24, and includes markings for the shift positions, such as P, R, N, D and S. The display panel72is provided with an internal lighting arrangement such that any selected one of the shift positions is illuminated. The arrangement of the shift positions is not limited by the illustrated embodiment, but may be selected as desired without departing from the spirit of the present disclosure. For instance, these shift positions may be arranged in either a clockwise or a counter-clockwise direction. An L position or a 2 position may be provided in succession to the S position or instead of the S position. The B position may also be provided instead of the S position.

As discussed, a sensor44is used to detect rotation of the shift knob40about the rotation mechanism42. In one embodiment, illustrated in theFIG. 4, the sensor44may be a Hall effect sensor80, which creates current pulses in response to magnets82in the shift knob40passing the Hall effect sensor80during rotation of the shift knob40.

In another embodiment, as illustrated inFIG. 5, the sensor44may be a potentiometer90integrated with the rotation mechanism42which provides a signal to the CPU22to identify rotation of the shifter knob40.

In yet another embodiment, illustrated inFIG. 6, the sensor44may be a contact switch100that provides a signal to the CPU22indicating rotation of the shifter knob40based upon indentations102in the shifter knob40contacting the contact switch40.

Finally, in a still further embodiment, as illustrated inFIG. 7, a rotary encoder110is provided on the back side of the instrument panel36, and is configured to detect the angular displacement of the rotation mechanism42. The detection signal of the rotary encoder110is forwarded to the CPU22, and is used by the control unit20of the transmission18. Any other method of detecting rotation of the dial shifter24known to those skilled in the art may also be employed.

As shown inFIG. 1, the control unit20includes a shift position selecting unit120and a gear ratio selecting unit122. The shift position selecting unit120changes the current shift position to a new shift position depending on the signal sent by the CPU22to the control unit20based on the operator of the vehicle10rotating the shift knob40of the dial shifter24. Each time the sensor44registers a clockwise rotation of the shifter knob40by a prescribed angle (approximately 20 degrees in the illustrated embodiment), which is illustrated inFIG. 8, the control unit20changes the shift position by one stage. For instance, if the current shift position is the P position, and the dial shifter24is turned clockwise direction by 40 degrees, the control unit20changes the shift position by two stages, and sets the shift position to the N position. When turning the dial shifter24, the dial shifter24may slightly overshoot the intended shift position when attempting to select the D position. In that case, the gear selection is returned back to the D position. The detent mechanism of the dial shifter24then finally settles the shift position at D. In such a case, it can be said that the dial shifter24was turned from the initial position to the D position. At any event, the angular displacement of any shift operation is determined as that between the initial angular position and the final angular position as a result of a single shifting operation.

When an angular displacement of 60 degrees or more is made without a pause, the D position is still selected. “Without a pause” in this case may mean that the dial shifter24was turned by a certain angle without being held stationary for more than a prescribed time period, such as 300 milliseconds (ms). Turning of the dial shifter24without a pause can be regarded as a single shifting operation. If there is a pause of more than 300 ms, the process of turning the dial shifter24is considered as being completed, and any subsequent rotation of the dial shifter24is considered as a second shifting operation which is separated from the first shifting operation by the pause. For instance, if the dial shifter24is turned in one direction and then in the opposite direction without a pause of more than 300 ms during the whole process, it is no different from turning the dial shifter24directly from the initial position to the final position without reversing the direction of dial shifter24.

In order to select the S position, the vehicle operator must first select the D position, and the dial shifter must remain in the D position for a specified period of time, such as at least 300 ms. Upon the selection of the D position, the S position may be selected by then rotating the shift knob in a clockwise direction. The delay in selecting the S position prevents the operator of the vehicle10from accidentally or inadvertently selecting the S position when most operators will use the D position.

The shift device is configured such that the P position is selected at the start up of the vehicle10. Therefore, if the engine12is disengaged prior to moving the shift back to the P position, the shift mechanism resets to the P position for the next time the vehicle10is started.

While the shifting has been described in a clockwise direction for moving from P to D/S, and counterclockwise to move from D/S to P, the shifting mechanism may be embodied such that the dial shifter24is rotated in a counterclockwise direction for moving from P to D/S, and clockwise direction to move from D/S to P.

In another embodiment, illustrated inFIG. 7, a first fixed stop126extends radially outward from the outer circumferential surface60of the rotation mechanism42, and a second fixed stop128extends radially inward from the inner circumferential surface54of the shifter knob40. When the two fixed stops126,128come together, rotation in the direction of contact is stopped to prevent continuous rotation of the dial shifter24. Any other method of limiting rotation of the dial shifter24known to those skilled in the art, such as by mechanical, electrical, or magnetic methods, may also be applied.

In one embodiment, the S position places the transmission18into a sport mode which transfers control of the transmission18to a pair of paddle shifters132located adjacent the steering wheel130of the vehicle10.

In addition, the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the disclosure of the embodiments is intended to be illustrative, but not limiting, of the scope of the embodiments, which is set forth in the claims.

While particular embodiments and applications have been illustrated and described herein, it is to be understood that the embodiments are not limited to the precise construction and components disclosed herein and that various modifications, changes, and variations may be made in the arrangement, operation, and details of the methods and apparatuses of the embodiments without departing from the spirit and scope of the embodiments as defined in the appended claims.