|Publication number||US20070113825 A1|
|Application number||US 11/655,370|
|Publication date||May 24, 2007|
|Filing date||Jan 19, 2007|
|Priority date||Mar 6, 2002|
|Also published as||EP1688605A1, US7191754, US20050183695|
|Publication number||11655370, 655370, US 2007/0113825 A1, US 2007/113825 A1, US 20070113825 A1, US 20070113825A1, US 2007113825 A1, US 2007113825A1, US-A1-20070113825, US-A1-2007113825, US2007/0113825A1, US2007/113825A1, US20070113825 A1, US20070113825A1, US2007113825 A1, US2007113825A1|
|Inventors||Robert Keefover, Michael Halsig, Hal Pringle|
|Original Assignee||Borgwarner Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (1), Classifications (27)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation of 11/029,730 filed Jan. 5, 2005 which is a continuation-in-part of U.S. patent application Ser. No. 10/383,194 filed Mar. 6, 2003, issued as U.S. Pat. No. 6,854,443; which claims the benefit of U.S. Provisional Application No. 60/362,032, filed Mar. 6, 2002. The disclosures of the above applications are incorporated herein by reference.
The present invention generally relates to electronic throttle control systems and more particularly to electronic throttle control systems having non-contacting position sensors.
Traditional engine fuel control systems use a mechanical linkage to connect the accelerator pedal to the throttle valve. Engine idle speed is then controlled by a mechanical system that manipulates the pedal position according to engine load.
Since the mid-1970's electronic throttle control or “drive-by-wire” systems have been developed. Electronic throttle control systems replace the mechanical linkage between the accelerator pedal and the throttle valve with an electronic linkage. These types of systems have become increasingly common on modern automobiles.
Generally, at least one sensor is typically placed at the base of the accelerator pedal and its position is communicated to the engine controller. At the engine, a throttle position sensor and an electronically controlled motor then regulate the throttle to maintain a precise engine speed through a feedback system between the throttle position sensor and the electronically controlled motor. An example of an electronic throttle control system can be found with reference to U.S. Pat. No. 6,289,874 to Keefover, the entire specification of which is incorporated herein by reference.
In conventional electronic throttle control systems, the various components of the throttle position sensor stator and connector assembly are mounted to the casting of the throttle body. The connector assembly is also connected to the motor. The throttle position sensor is placed in close proximity with the rotating shaft of the throttle valve. The throttle position sensor used to provide data so that the angular position of the throttle valve can be determined. Typical conventional throttle control systems use contact sensors such as potentiometers as well as non-contact sensors such as Hall Effect sensors which incorporate a magnet and stator configuration. These conventional sensors can often be bulky and difficult to align during assembly. Furthermore, angular position sensors have been incorporated with applications other than throttle control valves. For example, angular position sensors may be used in conjunction with other systems such as turbo actuators and exhaust gas recirculation valves, canister purge valves and transmission shift valves.
In accordance with the general teachings of the present invention, a new and improved electronic throttle control system is provided.
A control system having a housing with a bore formed within the housing. A valve member is associated with the bore for controlling the passage of a fluid medium through the bore. An induction sensor is aligned with the valve and facilitates determining the valve position. An inductor is connected to an end of the valve member that is in close proximity to the induction sensor. It is contemplated that this control system can be used in a number of different applications including throttle control systems, turbo actuators, canister purge systems and shift control mechanisms. However, it is within the scope of this invention to incorporate the control system on virtually any type of vehicle system where it is possible to determine the position of a valve utilizing induction sensor technology.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
The system 10 generally includes a casting 12 that serves as a housing or support for the various components of the system. Formed within the casting 12 is a throttle bore 14 having a throttle plate 15 rotatably disposed inside the throttle bore 14. A throttle shaft 16 is attached to and extends across the throttle plate 15 and together the throttle plate 15 and throttle shaft 16 form an actuator that controls the flow of fluid medium through the throttle bore 14. The actuator can take other forms and the use of a throttle plate 15 and throttle shaft 16 in no way is intended to limit the scope of this invention. The throttle shaft 16 rotates the throttle plate 15 between the open and closed positions. The throttle shaft 16 is supported on both ends by a pair of bearings 18 to aid in the rotation of the throttle plate 15 and throttle shaft 16. At one end of the throttle shaft 16, a gear train 20 envelops the throttle shaft for effecting movement of the throttle shaft 16. Additionally, a spring system 22 is also provided at one end of the throttle shaft 16 as part of a fail-safe system (not shown).
At the extreme end of the throttle shaft 16, a substantially U-shaped sensor rotor 24 is fastened thereto. Although the rotor 24 is shown as being substantially U-shaped, it should be appreciated that the rotor 24 may be configured in any number of shapes, including but not limited to a cylindrical or flat member. The rotor 24 is preferably nested in close proximity to sensor stator 26 and together the two generally form a sensor assembly 27. Thus, it should be appreciated that the rotor 24 is capable of rotating about the stator 26. Although the stator 26 is shown as being substantially U-shaped, it should be appreciated that the stator 26 may be configured in any number of shapes, including but not limited to a flat member.
The axial position of the rotor 24 is preferably maintained by controlling the axial position at which it is attached to the throttle shaft 16; however, this position can be fixed or adjustable.
The stator 26 is fastened to a printed circuit board 32, which is preferably fastened to the housing 12. Axial position control is preferably maintained by attaching the printed circuit board 32 to a controlled fixed surface such as the casting 12. Tight radial position control is preferably maintained between the rotor 24 and the stator 26 through the assembly process or through dimensional control of the printed circuit board 32 and a fixed surface such as the casting 12. This tight radial positioning is preferably maintained by carrying out an alignment method which may incorporate an alignment means. One method of alignment involves the use of pre-molded slots (depicted in
The printed circuit board 32 and the stator 26 are preferably fastened in place by one or more fasteners (not shown) that are inserted through one or more apertures 34 formed on the surface of the casting 12 adjacent to the printed circuit board 32.
Fastened to the printed circuit board 32 is a preferably flexible interconnect 36 that electrically connects the printed circuit board 32 to a connector 38. The flexible interconnect 36 reduces stress on the printed circuit board 32 and allows the printed circuit board 32 to be positioned separately from the connector 38. The connector is preferably fastened to the casting 12. The connector 38 is in turn electrically connected to a motor 40 which is preferably fastened to the casting 12. Several types of motors may be within the scope of this invention. For instance the motor may be a brush motor, a DC motor, a brushless motor, a solenoid, pneumatic or a stepper motor. Any type of actuator that can facilitate the rotation of the shaft 16 may be implemented.
As mentioned above,
After the sensor stator is properly aligned the printed circuit board 32 can be fastened to the casting 12 with fasteners 34. Once the printed circuit board 32 is secure the alignment tool 42 can be disengaged since the sensor stator 26 is not in proper alignment. After securing the printed circuit board 32 and the sensor assembly (not shown) the electrical connector 38 can be aligned and fastened 39 to the casting 12. The flexible interconnect 36 allows electrical connector 38 and the printed circuit board 32 to be assembled independent of each other so that the sensor stator 26 does not become misaligned during completion of assembly.
The alignment tool 42 in this embodiment has six fingers 46 that align with the slots 44. The fingers 46 on the alignment tool 42 are flexible and are capable of bending to grasp onto the sensor stator 26. Once the printed circuit board 32 is fastened to the casting 12, the alignment tool 42 can be easily removed by simply pulling the alignment tool 42 away from the printed circuit board 32.
Once the printed circuit board 32 is fastened to the casting the electrical connector 38 can also independently be aligned and fastened to the casting 12. Once again the flexible interconnect 36 plays an important role by allowing the electrical connector 38 and the printed circuit board 32 to each be aligned and fastened to the casting 12 independently of each other. This eliminates the possibility of misalignments of the sensor assembly 27 when the electrical connector 38 is connected to the casting. Additionally, as stated earlier the use of the flexible interconnect 36 also prevents misalignment of the sensor assembly 27 during thermal expansion which may occur during normal operation of the throttle control system 10.
In operation, the present invention functions by employing feedback between the various sensor systems (e.g., sensor rotor/sensor stator) and the various control assemblies (e.g., the motor) in order to properly position the throttle plate so as to achieve optimal performance of the electronic throttle control system. The present invention can be employed in any type of rotary actuator employing a position sensor.
The electrical connector of the throttle control system 10 also receives power 60 from a power source. The power is distributed through the electrical connector to the motor and the sensor stator via the flexible interconnect and sensor stator.
The user input signal 64 is a value that indicates the user's desired throttle position. The user input signal 64 can be generated from a user input such as, an accelerator pedal (not shown).
The throttle position signal 62 is generated by the sensor stator via the printed circuit board, the flexible interconnect and the electrical connector. The throttle position signal 62 is a value that indicates the present angular position of the throttle plate (not shown). In a preferred embodiment of the invention the throttle position signal is an analog position signal. However, it is in the scope of this invention to have a throttle position signal that is digital.
The ECU analyzes the values of the user input signal 64 and the throttle position signal 62 to determine if the throttle position signal 62 matches the user input signal 64. If the two signal values do not match then the ECU will generate a control signal 66 to the motor which is inputed to the throttle control system 10 via the electrical connector. The motor receives the control signal 66 and actuates the throttle body so that actual angular position of the throttle valve matches the desired angular position of the user which will be confirmed by the ECU when the throttle position signal 62 and the user input signal 64 both match.
The printed circuit board serves as a housing for the sensor stator 26. In a preferred embodiment of the invention, the sensor stator generates an analog to position signal that travels through wiring (not shown) on the printed circuit board. The position signal then exits the printed circuit board through the flexible interconnect and travels to the ECU via the electrical connector. The printed circuit board preferably has no logic, however, it may contain resistors, capacitors, and amplifiers necessary for the position signal. However, it should be understood that it is within the scope of this invention to incorporate a printed circuit board that has logic functions.
In addition to carrying the position signal, the flexible interconnect also supplies power from the electrical connecter to the sensor stator via the printed circuit board. In an embodiment where the printed circuit board has Logic functions it should also be understood that the flexible interconnect would also be capable of carrying a user input signal to the motor. The flexible interconnect can have many physical forms. For example, in the present embodiment the flexible interconnect may be bare metal wires, however, it is possible to use a ribbon wire or plastic coated wires in embodiments where the flexible interconnect will need to insulated.
The preferred embodiment of the invention has an external ECU. The ECU receives a position signal from the sensor stator. This signal indicates the angular position of the throttle plate. The ECU also receives a user input signal that indicates the user's desired angle of the throttle plate. The ECU takes the values of the user input signal and the position signal and generates a control signal based on the values. The control signal is sent to the motor and causes the motor to rotate the gear train, the throttle shaft and throttle plate (see
The induction sensor 102 operates by measuring fluxuation of a high frequency magnetic field. An activation coil 112 circumscribes the pickup coils 110. When energized, the activation coil 112 induces a high frequency magnetic field between the actuation coil 112 and the pickup coils 110, that in turn causes a secondary high frequency magnetic field to be induced between the inductor 106 and the pickup coils 110. The secondary magnetic field is strongest when the sprockets of the inductor 106 are aligned with one of the pickup coils 110. As the throttle shaft 104 rotates the secondary magnetic field between the inductor 106 and the pickup coils 110 will fluctuate as the inductor 106 is misaligned with one set of pickup coils 110 and moves into alignment with the second set of pickup coils 110. Each set of three pickup coils 110 will generate a signal from which the throttle position can be derived. As the throttle shaft 104 moves out of alignment with the first set of pickup coils 110, it will move into alignment with the second set of pickup coils 110, thus the signal values from each set of pickup coils will be inverted and have unequal slopes. As the inductor 106 is rotated in and out alignment among the various sets of pickup coils 110, the secondary magnetic field generated between the inductor 106 and a particular set of pickup coils 110 will become disrupted which in turn disrupts the high frequency magnetic field generated between the activation coil 112 in the pickup coils 110. The disruption of the magnetic field between the activation coil 112 and the pickup coils 110 is what the throttle position signal is derived from.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7594494 *||Jan 19, 2007||Sep 29, 2009||Borgwarner Inc.||Assembly with non-contacting position sensor|
|U.S. Classification||123/337, 73/114.36, 251/305, 123/399|
|International Classification||G01M99/00, F02D9/10, F02D11/10, F16K1/22, F02D9/08|
|Cooperative Classification||F16K37/0041, F02D9/1065, F16K1/221, G01D5/145, F02D2200/0404, F02D11/106, F02D41/0002, Y02T10/42, G01D5/00, F02D11/105|
|European Classification||F02D9/10L, G01D5/00, F02D11/10B, F02D11/10D, F02D41/00D, F16K1/22B, F16K37/00D, G01D5/14B1|