This application is based on and incorporates herein by reference Japanese Patent Application No. 2005-191592 filed on Jun. 30, 2005.
The present invention relates to a vehicle control system.
In general, a shift-by-wire system includes an actuator such as an electric motor for driving a shift range switchover valve to switch over a shift range position of an automatic transmission. In such a shift-by-wire system, a shift range position cannot be switched over when an actuator or a control circuit for controlling the actuator causes a failure. According to each of U.S. Pat. No. 5,094,115 (JP-A-3-255252) and U.S. Pat. No. 6,230,576 (JP-A-2000-170905), a shift-by-wire system has a redundant dual system, in which components are partially or entirely doubled.
According to US '115, an operating device (shift-by-wire system) has dual actuators and control circuits, so that the shift-by-wire system is capable of switching over a shift range position even when either the actuator or the control circuit causes a failure. According to US '576, a shift range switchover device (shift-by-wire system) has dual coils and drive circuits, so that the shift-by-wire system is capable of switching over a shift range position even when either one of the drive circuits causes a failure. However, in the above structures of the shift-by-wire systems, the number of components may be increased. Consequently, the shift-by-wire systems are made large in size due to increase in the number of components.
In general, actuators and control circuits are generally designed to have margins in load, voltage, and electric current. Accordingly, it is less frequently caused that an operation becomes impossible due to failure of an actuator and a control circuit themselves. A major factor causing a serious defect in operation is a trouble caused in a conductor or a connector, which electrically connects the actuator with the control circuit.
In addition, assembly works are necessary for connecting an actuator with a control circuit via a conductor and for laying the conductor. Accordingly, variation may be caused in manufacturing quality.
In view of the foregoing and other problems, it is an object of the present invention to produce a vehicle control system that is high in reliability.
According to one aspect of the present invention, a vehicle control system, which is for an automatic transmission, includes an actuator that manipulates the automatic transmission to switch a shift range position of the automatic transmission. The vehicle control system further includes a control circuit that controls the actuator such that the shift range position coincides with an instruction provided by the passenger. The actuator and the control circuit are integrated.
Alternatively, an automatic transmission system for a vehicle includes an automatic transmission. The automatic transmission system further includes an actuator that operates a shift range position of the automatic transmission. The automatic transmission system further includes a control circuit that controls the actuator such that the shift range position coincides with an instruction provided by a passenger. The actuator includes a housing that accommodates the control circuit.
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:
As shown in
The at least one electronic control circuit includes a shift-by-wire control circuit (SBW control circuit) 12. Specifically, the shift-by-wire control circuit 12 is fixed to the inner wall of the housing 11. The SBW control circuit 12 serves as a control circuit. In this structure, the electric motor 10 and the SBW control circuit 12 are made integral with each other.
The housing 11 is partially or wholly made of a conductive material such as iron, so that influences of noise from outside can be reduced. Thus, an erroneous operation of the SBW control circuit 12 caused by noise from outside can be steadily restricted. Conversely, noise generated inside the housing 11 can be restricted from leaking to outside, so that an external equipment outside of the housing 11 can be restricted from causing an erroneous operation. An interface unit 13 is made integral with the housing 11 to connect the SBW control circuit 12 to an external conductor.
For example, the electric motor 10 is a brushless switched reluctance motor (SR motor) using no permanent magnet. As shown in
As referred to
The SBW control circuit 12 further includes connector terminals 27, 28. The connector terminal 27 electrically connects the communication control element 26 with the in-vehicle LAN. The connector terminal 28 electrically connects the electric power source with the substrate 25. The connector terminal 27 and the connector terminal 28, respectively, are connected to connector pins 13a, 13b by wire bonding, for example. The connector pins 13a, 13b are provided on the interface unit 13.
Subsequently, a conductor for electrically connecting the SBW control circuit 12 with the electric motor 10 is described. As shown in
Specifically, the conductors 31 to 34 include a bus bar, for example. The bus bar may be a plate-shaped conductor formed of a conductive material such as metal, and hard to suffer breakage. Accordingly, the application of the bus bar for the conductors 31 to 34 can improve reliability thereof. As referred to
As referred to
The hall element 30b serves as a sensor. In this embodiment, the encoder 30 is a digital encoder that makes addition and subtraction of the number of pulses corresponding to a rotation angle of the rotor core 50. The hall element 30b is provided on the substrate 25, so that an exclusive substrate for the hall element 30b can be omitted. Thus, the number of components can be reduced. In addition, an exclusive substrate for the hall element 30b is omitted, so that a connector need not be additionally provided for electrically connecting the exclusive substrate for the hall element 30b with the substrate 25. Thereby, reliability can be further enhanced.
Subsequently, a radiating structure of a heat emitting element is described. A switching element is described as an example of the heat emitting element.
In
The switching elements 21, 22, 23 respectively make contact with the housing 11 via metallic members 35, 36, 37. In this structure, heat of the switching elements 21, 22, 23 is released to the housing 11 via the metallic members 35, 36, 37. Thereby, radiating fins mounted to the respective switching elements can be reduced or downsized. Alternatively, when radiating fins are provided, and the radiating fins are the same in size, a further inexpensive heat emitting element can be applied since heat can be released to the housing 11 thereby improving efficiency in radiation.
In this example structure, the respective switching elements are made to contact with the housing 11 via the metallic members. However, the respective switching elements may be made to contact with the stator core 51 of the electric motor 10 via the metallic members. The respective switching elements may be made to contact with the housing 11 or the electric motor 10 via a radiating member or the substrate instead of the metallic members. The respective switching elements may be arranged closely to the housing 11 and the components of the electric motor 10, instead of being made to contact therewith. Each of the switching elements 21, 22, 23 is an example of a heat emitting element. The heat emitting element may include the control element 24.
Subsequently, a shift-by-wire system is described. The shift-by-wire system includes the electric motor 10 and the SBW control circuit 12. The shift-by-wire system may serve as a vehicle control system.
As shown in
An automatic transmission controller controls the automatic transmission 80. The automatic transmission controller includes multiple electromagnetic valves (not shown), a manual valve 85, and an automatic transmission control circuit (AT control circuit) 82.
This AT control circuit 82 is included in the at least one electronic control circuit that constructs the ECU. This AT control circuit 82 also serves as a control circuit. The electromagnetic valves (not shown) are accommodated in an oil pan 84 for controlling hydraulic pressure applied to the friction engagement elements.
The shift-by-wire system 60 is connected to an automatic transmission. As referred to
The shift-by-wire system 60 includes the electric motor 10, a conversion mechanism 61, and a range detector (not shown). The electric motor 10 is made integral with the SBW control circuit 12. The conversion mechanism 61 converts rotating drive force of the electric motor 10 into linear drive force to axially move the spool 81. The range detector (not shown) detects a present shift range position of the automatic transmission 80. The SBW control circuit 12 is connected to a range selector 67. A vehicle passenger selects a shift range via the range selector 67. The range selector 67 outputs a shift range switchover instruction to the SBW control circuit 12 for instructing switchover to an instructed shift range having been selected by the vehicle passenger. The range selector 67 is connected to the AT control circuit 82, so that the AT control circuit 82 is capable of outputting the shift range instruction to the SBW control circuit 12. The shift range instruction represents the shift range selected by the vehicle passenger.
The conversion mechanism 61 includes a control rod 62, a detent plate 63, a detent spring 64, and a roller 65. The control rod 62 is substantially perpendicular to the axis of the spool 81. One end of the control rod 62 with respect to the axial direction thereof is connected to the electric motor 10. The detent plate 63 is fixed to the control rod 62 to turn together with the control rod 62. The detent spring 64 is a blade spring supported by a cantilever at a predetermined fixing portion. The detent spring 64 biases the roller 65 toward the detent plate 63. The roller 65 is mounted at a tip end of the detent spring 64. The spool 81 engages with the detent plate 63. The spool 81 axially moves when the detent plate 63 turns. The detent plate 63 is a member in the form of a substantially arcuate-shaped plate. The detent plate 63 has multiple recesses 66 formed on the arcuate-shaped outer periphery thereof. Each of the recesses 66 corresponds to one of the shift range positions of the automatic transmission 80. When the spool 81 is moved, the shift range position of the automatic transmission 80 is switched over corresponding to the position of the spool 81. At this time, one of the recesses 66, which corresponds to the shift range position, and the roller 65 engage with each other, so that the detent plate 63 is restricted from turning.
Subsequently, the operation of the shift-by-wire system 60 is described.
The range selector 67 outputs shift range switchover instructions, so that the SBW control circuit 12 controls the rotation of the electric motor 10 in accordance with the number of the pulse count, which corresponds to the number of pulses output by the encoder 30. Specifically, the SBW control circuit 12 rotates the electric motor 10 while referring to the number of the pulse count, which corresponds to the rotation angle of the rotor core 50. The SBW control circuit 12 stops rotation of the electric motor 10 when a target number of the pulse count is achieved. Thus, the SBW control circuit 12 turns the detent plate 63 to a position corresponding to the shift range (instructed shift range) on the basis of the shift range switchover instructions.
When the electric motor 10 rotates within a range of a predetermined number of the pulse count, in which the target number of the pulse count is included, the SBW control circuit 12 evaluates whether a shift range detection signal of the shift range detector changes to the state corresponding to the instructed shift range. When the shift range detection signal changes to the state corresponding to the instructed shift range, the SBW control circuit 12 determines switchover to the instructed shift range position to be made and stops supplying electric current to the electric motor 10.
With the shift-by-wire system 60 according to this embodiment, the SBW control circuit 12 is fixed to the housing 11 whereby the electric motor 10 and the SBW control circuit 12 are made integral with each other. For example, when the electric motor 10 and the SBW control circuit 12 are made independently, an additional connector becomes necessary for electrically connecting the electric motor 10 with the SBW control ECU 12 via a conductive wire. By contrast, in the above structure, the electric motor 10 and the SBW control circuit 12 are made integral with each other, so that the electric motor 10 can be directly connected with the SBW control circuit 12 via a conductive wire. Thus, an additional connector need not be provided. Consequently, the number of connectors, which are high in failure rate, can be reduced, so that the shift-by-wire system 60 can be improved in reliability.
Further, the electric motor 10 and the SBW control circuit 12 are made integral with each other, so that a manufacturing work for electrically connecting the electric motor 10 with the SBW control circuit 12 can be facilitated. A manufacturing work for laying a wire harness or the like can be reduced, so that mount quality and assembly quality can be improved.
Furthermore, the electric motor 10 and the SBW control circuit 12 are improved in reliability by reducing the number of connectors, so that the construction of the electric motor 10 and the SBW control circuit 12 can be simplified. Therefore, the number of components is not increased and reliability of the shift-by-wire system 60 can be improved while downsizing the shift-by-wire system 60. Therefore, the shift-by-wire system 60 becomes small in size, high in reliability, and excellent in mount quality.
Further, the SBW control circuit 12 is accommodated in the housing 11 of the shift-by-wire system 60, so that the conductor need not be taken to the outside the housing 11. Therefore, the conductor can be restricted from being pinched by components constructing the vehicle, so that the conductor can be restricted from causing breakage and short circuit. Thus, reliability of the shift-by-wire system 60 can be improved.
Further, the electric motor 10 and the SBW control circuit 12 are made integral with each other in the shift-by-wire system 60, so that the conductor can be shortened. The conductor may become an antenna receiving noise. In this structure, the conductor can be shortened, so that an erroneous operation of the SBW control circuit 12 due to influences of noise can be reduced. Thus, reliability of the SBW control circuit 12 can be improved.
Further, the electric motor 10 and the SBW control circuit 12 are made integral with each other to decrease a distance between the electric motor 10 and the SBW control circuit 12. Therefore, the conductor is decreased in resistance, so that the shift-by-wire system 60 is totally improved in energy efficiency.
The bus bar is an example of the conductor. The conductor may include a wire harness.
As shown in
In this example structure, the wire harness 76 is fixed as a conductor. Alternatively, a bus bar may be fixed when the bus bar constructs the conductor.
In addition, when the hall element 30b is provided on an area excluding the substrate 25, the conductor is preferably fixed to the inner wall face of the housing 11 such that the conductor connects the hall element 30b with the SBW control circuit 12. In this structure, the conductor, which connects the hall element 30b with the SBW control circuit 12, can be restricted from causing breakage and short circuit due to being pinched by another component.
As shown in
In this example structure, the wire harness 76 is embedded in the housing 11, as a conductor. Alternatively, in a structure in which a bus bar constructs the conductor, the bus bar may be embedded in the housing 11.
In addition, when the hall element 30b is to be provided on an area excluding the substrate 25, the conductor, which connects the hall element 30b with the SBW control circuit 12, is preferably embedded in the housing 11 likewise. In this structure, the conductor, which connects the hall element 30b with the SBW control circuit 12, can be restricted from causing breakage and short circuit due to being pinched by other components.
As shown in
As shown in
The wire harness 75 in the second embodiment may be provided to the electric motor 10 such that the wire harness 75 is fixed to the housing 11, as a conductor.
As shown in
The wire harness 76 in the third embodiment may be provided to the electric motor 10 such that the wire harness 76 is embedded in the housing 11, as a conductor.
In the above embodiments, the shift-by-wire system (vehicle control system) is used for the automatic transmission 80 that is operated in accordance with the shift range position switched by the passenger. The vehicle control system 60 includes the actuator and the control circuit 12. The actuator manipulates the shift range position. The control circuit 12 controls the actuator such that the shift range position coincides with an instruction provided by the passenger. The actuator and the control circuit (12) are integrated.
The above structures of the embodiments can be combined as appropriate.
Various modifications and alternations may be diversely made to the above embodiments without departing from the spirit of the present invention.
Number | Date | Country | Kind |
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2005-191592 | Jun 2005 | JP | national |