U.S. patent application number 11/655370 was filed with the patent office on 2007-05-24 for position sensor apparatus and method.
This patent application is currently assigned to BorgWarner Inc.. Invention is credited to Michael J. Halsig, Robert D. Keefover, Hal E. Pringle.
Application Number | 20070113825 11/655370 |
Document ID | / |
Family ID | 36087566 |
Filed Date | 2007-05-24 |
United States Patent
Application |
20070113825 |
Kind Code |
A1 |
Keefover; Robert D. ; et
al. |
May 24, 2007 |
Position sensor apparatus and method
Abstract
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.
Inventors: |
Keefover; Robert D.; (Lake
Orion, MI) ; Halsig; Michael J.; (Warren, MI)
; Pringle; Hal E.; (Bloomfield, MI) |
Correspondence
Address: |
WARN, HOFFMANN, MILLER & OZGA, P.C.
P.O. BOX 70098
ROCHESTER HILLS
MI
48307
US
|
Assignee: |
BorgWarner Inc.
Auburn Hills
MI
|
Family ID: |
36087566 |
Appl. No.: |
11/655370 |
Filed: |
January 19, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11029730 |
Jan 5, 2005 |
7191754 |
|
|
11655370 |
Jan 19, 2007 |
|
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|
10383194 |
Mar 6, 2003 |
6854443 |
|
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11029730 |
Jan 5, 2005 |
|
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|
60362032 |
Mar 6, 2002 |
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Current U.S.
Class: |
123/337 ;
123/399; 251/305; 73/114.36 |
Current CPC
Class: |
F16K 37/0041 20130101;
F16K 1/221 20130101; G01D 5/145 20130101; G01D 5/00 20130101; Y02T
10/40 20130101; F02D 2200/0404 20130101; G01D 5/2073 20130101; F02D
9/1065 20130101; F02D 41/0002 20130101; F02D 11/106 20130101; F02D
11/105 20130101 |
Class at
Publication: |
123/337 ;
123/399; 073/118.1; 251/305 |
International
Class: |
G01M 19/00 20060101
G01M019/00; F16K 1/22 20060101 F16K001/22; F02D 9/08 20060101
F02D009/08; F02D 11/10 20060101 F02D011/10 |
Claims
1. A control system comprising: a housing; a bore formed within
said housing; a moveable member positioned in said bore; and an
inductor connected to an end of said valve.
2. The electronic throttle control system of claim 1 further
comprising an induction sensor operably configured with said
inductor.
3. The electronic throttle control system of claim 2 wherein said
induction sensor has one or more pickup coils operably configured
with respect to an activation coil.
4. The electronic control system of claim 1 further comprising: a
motor operably associated with said throttle shaft for effecting
the movement of said throttle shaft; and an electrical connector
having connections with said induction sensor and said motor.
5. The control system of claim 1 further comprising: a connector
connected to said housing; and a flexible interconnect connected
between said induction sensor and said connector.
6. The electronic throttle control system of claim 1 wherein said
inductor is formed of wire bent into a sprocket-like shape.
7. The electronic throttle control system of claim 1 wherein said
induction sensor has at least two sets of three pickup coils
operable configured with respect to an activation coil.
8. The control system of claim 1 wherein said valve is a turbo
actuator valve for controlling engine compression.
9. The control system of claim 1 wherein said valve is an exhaust
gas recirculation valve.
10. The control system of claim 1 wherein said valve is a canister
purge valve.
11. The control system of claim 1 wherein said valve is a throttle
control valve.
12. An electronic throttle control system comprising: a housing; a
bore formed within said housing; a plate movably disposed within
said bore; a throttle shaft operably connected to said throttle
plate for facilitating movement of said throttle plate; an
induction sensor operably aligned with said throttle shaft; and an
inductor connected to an end of said throttle shaft in close
proximity to said induction sensor.
13. The electronic throttle control system of claim 12 wherein said
induction sensor has one or more pickup coils operably configured
with respect to an activation coil.
14. The electronic control system of claim 12 further comprising: a
motor operably associated with said throttle shaft for effecting
the movement of said throttle shaft, an electrical connector having
connections with said induction sensor and said motor.
15. The electronic throttle control system of claim 12 wherein said
inductor is formed of wire bent into a sprocket-like shape.
16. The electronic throttle control system of claim 12 wherein said
induction sensor has at least two sets of three pickup coils
operably configured with respect to an activation coil.
17. The electronic throttle control system of claim 12 wherein said
valve is a turbo actuator valve for controlling engine
compression.
18. The control system of claim 12 wherein said valve is an exhaust
gas recirculation valve.
19. The control system of claim 12 wherein said valve is a canister
purge valve.
20. The control system of claim 12 wherein said valve is a throttle
control valve.
21. The control system of claim 12 further comprising: a connector
connected to said housing; and a flexible interconnect connected
between said induction sensor and said connector.
22. The control system of claim 12 further comprising: a motor
operably associated with said throttle shaft for effecting the
movement of said throttle shaft; and an electrical connector having
connections with said induction sensor and said motor.
23. A control system comprising: a housing; a bore formed within
said housing; an actuator connected to said bore; an induction
sensor aligned with the actuator; an inductor connected to an end
of said actuator in close proximity to said induction sensor.
24. The electronic throttle control system of claim 23 wherein said
induction sensor has one or more pickup coils operably configured
with respect to an activation coil.
25. The electronic control system of claim 23 further comprising: a
motor operably associated with said throttle shaft for effecting
the movement of said throttle shaft, an electrical connector having
connections with said induction sensor and said motor.
26. The electronic throttle control system of claim 23 wherein said
inductor is formed of wire bent into a sprocket-like shape.
27. The electronic throttle control system of claim 23 wherein said
induction sensor has at least two sets of three pickup coils
operably configured with respect to an activation coil.
28. The control system of claim 23 wherein said actuator is a turbo
actuator for controlling engine compression.
29. The control system of claim 23 wherein said actuator is an
exhaust gas recirculation valve.
30. The control system of claim 23 wherein said actuator is a
canister purge valve.
31. The control system of claim 23 wherein said actuator is a
throttle control valve.
32. The control system of claim 23 further comprising: a connector
connected to said housing; and a flexible interconnect connected
between said induction sensor and said connector.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] 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.
FIELD OF THE INVENTION
[0002] The present invention generally relates to electronic
throttle control systems and more particularly to electronic
throttle control systems having non-contacting position
sensors.
BACKGROUND OF THE INVENTION
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
SUMMARY OF THE INVENTION
[0007] In accordance with the general teachings of the present
invention, a new and improved electronic throttle control system is
provided.
[0008] 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.
[0009] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0011] FIG. 1 is a cross-sectional view of an electronic throttle
control system, in accordance with the general teachings of the
present invention;
[0012] FIG. 2 is a cross-sectional side plan view taken about
section line X-X of FIG. 1, however, this particular view also
depicts a pre-molded casting that serves as one method of alignment
during assembly of the electronic throttle control system;
[0013] FIG. 3 is a cross-sectional plan view of the sensor assembly
taken about section line 3-3 on FIG. 1;
[0014] FIG. 4 depicts a perspective view of the throttle control
system taken about section line X-X in FIG. 1, wherein this
particular view depicts the use of an alignment tool that is used
to align the sensor assembly during assembly of the throttle
control system;
[0015] FIG. 4a is a cross-sectional view taken about section line
4a-4a of FIG. 5;
[0016] FIG. 4b is a cross-sectional view of the sensor assembly
being aligned using the alignment tool;
[0017] FIG. 5 depicts a perspective view taken about section line
X-X of FIG. 1, however, this particular embodiment incorporates the
use of alignment holes that are used as an alternate to the
alignment slots;
[0018] FIG. 6 depicts a schematic view of the operation of the
throttle control system;
[0019] FIG. 7 is an expanded perspective view of the throttle body
sensor arrangement and cover member;
[0020] FIG. 8 is an overhead plan view of the sensor arrangement
with a partial view of the throttle shaft and inductor positioned
near the sensor; and
[0021] FIG. 9 is a perspective partial view of the sensor aligned
with the throttle shaft and inductor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] 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.
[0023] Referring to FIG. 1 there is generally shown an electronic
throttle control system 10, in accordance with the general
teachings of the present invention.
[0024] 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).
[0025] 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.
[0026] 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.
[0027] 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 FIG. 2) in the casting so
each of the individual components can be aligned by sliding into
the slots. A second method of alignment (depicted in FIGS. 4, 4a,
4b) uses an alignment tool to hold the stator and printed circuit
board in place. And yet a third method of alignment (depicted in
FIG. 5.) use of tapered pins 50 that are inserted between the
stator and rotor during attachment of the printed circuit board to
the casting. Each of these alignment means will be described in
greater detail later in this description.
[0028] 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.
[0029] 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.
[0030] FIG. 2 is a cross-sectional side plan view taken about
section line X-X of FIG. 1, however, this particular view also
depicts a pre-molded casting that serves as one method of alignment
during assembly of the electronic throttle control system. As shown
the electronic throttle control system 10 has a casting or housing
12 which houses all of the individual components of the system. The
printed circuit board 32 and the electrical connector 38 are each
independently mountable to the casting 12. This is accomplished
through the use of a flexible interconnect which connects the
printed circuit board 32 and the electrical connector 38. The
flexible interconnect allows signals to be communicated between the
electrical connector 38 and the sensor assembly 27 and is capable
of bending or flexing to accommodate for a range of varying spatial
distribution between the printed circuit board 32 and the
electrical connector 38. One of the main advantages of this feature
is that during assembly it is important to maintain proper air gap
between the rotor and the stator so that the sensor will function
properly. The flexible interconnect 36 allows the printed circuit
board 32, which is fastened to the stator (not shown), to be
independently and perfectly aligned with the rotor and the valve
shaft, while still allowing for the electrical connector 38 to be
independently aligned and connected to the casting. Not only does
this feature provide an advantage during assembly of the electronic
throttle control system 10 it also compensates for thermal
expansion among the various components of the system 10. For
example, thermal expansion can occur unevenly among each of the
components of the system 10. It is possible for thermal expansion
to occur in the printed circuit board region 32 before it occurs at
the electrical connector 38. While actual movement caused by
thermal expansion is relatively small, it can cause misalignment or
changes in the air gap space between the stator and rotor thus
affecting the performance of the sensor assembly 27.
[0031] As mentioned above, FIG. 2 illustrates one particular method
of aligning the electrical connector 38 and the printed circuit
board 32. The casting 12 of this particular embodiment has
pre-molded alignment depressions. The printed circuit board 32 and
sensor assembly 27 can be aligned by placing the printed circuit
board 32 within a board depression 33. Once the printed circuit
board 32 is aligned it can be fastened to the housing 12 with
fasteners 34. The electrical connector 38 can then be aligned by
placing the electrical connector 38 within a connector depression
37. Once the electrical connector 38 is aligned it can then be
fastened to the housing 12 with fasteners 39.
[0032] FIG. 3 is a cross-sectional plan view of the sensor assembly
27 taken about section line 3-3 on FIG. 1. The sensor assembly 27
consists of a sensor rotor 24, a sensor stator 26, a magnet layer
28 and an air gap 30. As shown the sensor stator 26 is disposed
inside of a nested region of the sensor rotor 24. Disposed on the
surface of the sensor rotor 24 is a magnet layer 28. The sensor
rotor 24 and sensor stator 26 are positioned so they are not
touching and there will be an air gap 30 between the surface of the
sensor stator 26 and the magnet 28 layer on the surface of the
sensor rotor 24. A sensor assembly of this type is generally
referred to as a non-contact sensor, such as a Hall Effect sensor.
Examples of prior art Hall Effect sensors are known in the art and
can be found with reference to U.S. Pat. No. 5,528,139 to Oudet et
al., U.S. Pat. No. 5,532,585 to Oudet et al., and U.S. Pat. No.
5,789,917 to Oudet et al., the entire specifications of which are
incorporated herein by reference. However, it is possible for the
sensor assembly to incorporate other non-contact or contact sensors
that require precise alignment of the sensor assembly.
[0033] FIG. 4 depicts a perspective view of the throttle control
system taken about section line X-X in FIG. 1, wherein this
particular view depicts the use of an alignment tool 42 that is
used to align the sensor assembly 27 during assembly of the
throttle control system 10. As can be seen, the printed circuit
board 32 has a number of slots 44 on its surface which defined the
perimeter of the sensor stator 26. The slots 44 allow the insertion
of an alignment tool 42 which is used to engage the printed circuit
board 32 and the sensor stator 26 so that the printed circuit board
32 and the sensor stator 26 can be properly aligned in relation to
the sensor rotor (not shown) during assembly.
[0034] 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.
[0035] 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.
[0036] FIG. 4a is a cross-sectional view taken about section line
4a-4a of FIG. 5. The sensor stator 26 is connected to the printed
circuit board 32 and the alignment tool 42 is used to position the
sensor stator 26 in the nested region of the rotor 24. Once the
printed circuit board 32 is fastened to the casting 12, alignment
of the sensor stator 26 and the sensor rotor 24 will be maintained
and the alignment tool 42 may be removed.
[0037] FIG. 4b is a cross-sectional view of the sensor assembly
being aligned using the alignment tool. The rotor alignment tool 42
can have various configurations. The stator 26 can be positioned at
the tip of the rotor alignment tool 42 and can be temporarily
engaged to the tip of the rotor alignment tool 42 by pressing the
stator 26 onto the tool. The tool 42 can then be used to align the
stator 26 and the rotor 24 so that a proper air gap 30 is achieved.
The tips of the tool 42 help aid in forming the proper air gap by
holding the stator in place during fastening.
[0038] FIG. 5 depicts a perspective view taken about section line
X-X of FIG. 1, however, this particular embodiment incorporates the
use of alignment holes 52 that are used as an alternate to the
alignment slots. During assembly and alignment of the printed
circuit board 32 and stator 26 with respect to the magnet 28 and
rotor 24, individual tapered pins 50 are inserted through the
alignment holes 52 in a manner similar to the alignment tool 42
depicted in FIG. 5. The tapered pins 50 are used to align the
sensor stator 26 with respect to the magnets 28 of the rotor 24 so
that a properly spaced air gap 30 is created during assembly. Once
the printed circuit board 32 is fastened to the casting 12 the
tapered pins 50 are then removed. In this particular embodiment of
the invention the pins 50 are tapered to prevent over-insertion and
ease the insertion and retraction of the pins 50, however, it is
possible to use pins 50 of virtually any type of configuration.
[0039] 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.
[0040] 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.
[0041] FIG. 6 depicts a schematic view of the operation of the
throttle control system. The throttle control system 10 operates
using an external electrical control unit (ECU). The ECU is a logic
circuit that receives a user input signal 64 and a throttle
position signal 62 and generates a control signal 66 to the motor
via the electrical connector.
[0042] 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.
[0043] 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).
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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 FIGS. 1-2) so the throttle
plate reaches the angle desired by the user.
[0049] FIGS. 7-9 depict an alternate embodiment of the invention
incorporating an induction sensor. As shown in FIG. 7 there is an
induction sensor 102. The induction sensor 102 is a flat sensor,
however, it is within the scope of this invention for the induction
sensor 102 to have some other shape depending on the spatial
requirements of certain designs. The induction sensor 102 is
connected to the connector 38 via the flexible interconnect 36. The
flexible interconnect 36 allows the induction sensor 102 to be
positioned independently from the electrical connector 38, so that
proper alignment can be obtained between the sensor 102 and an
inductor 106 positioned at the end of a throttle shaft 104.
[0050] FIG. 8 shows an overhead plan view of the connector 38,
sensor 102 and flexible interconnect 36 positioned relative to the
throttle shaft 104. The end of the throttle shaft 104 is positioned
in close proximity to but does not contact the sensor 102. The
inductor 106 is positioned near the end of the throttle shaft 104.
The inductor 106 is in the form of a single copper loop that is
bent in a sprocket-like shape.
[0051] FIG. 9 shows a close-up perspective view of the sensor 102
positioned near the throttle shaft 104 and inductor 106. The sensor
102 has two layers (not shown) of printed circuit board (PCB) 108.
Three sets of two pickup coils 110 (i.e., 6 pickup coils total)
traverse between the layers of printed circuit board 108. As
discussed below, each set of pickup coils 110 generates a signal
value that can be used to determine the position of the throttle
valve 106. It is within the scope of this invention to use a
greater or lesser number of pickup coils.
[0052] 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.
[0053] 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.
* * * * *