System and method for charging a transmission accumulator
阅读说明:本技术 用于对变速器蓄积器充注的系统和方法 (System and method for charging a transmission accumulator ) 是由 约瑟夫·斯科特·斯莱顿 帕特里克·海卡 马克·戴维斯 哈菲兹·沙菲克·哈法吉 本杰明·鲁普利 于 2019-07-30 设计创作,主要内容包括:本公开提供了“用于对变速器蓄积器充注的系统和方法”。提供了一种包括离合器系统、蓄积器和控制器的变速器总成。所述离合器系统可以包括流动源。所述蓄积器可以经由电磁阀选择性地与所述流动源连通。所述控制器可以被编程为响应于检测到车辆停止并且所述蓄积器充注低于预定阈值,输出命令以打开所述电磁阀以从所述流动源快速地对所述蓄积器充注。所述预定阈值可以是700kPa与900kPa之间的蓄积器压力。所述控制器还可以被编程为响应于检测到所述蓄积器被充注到等于或高于所述预定阈值,向与所述变速器总成连通的发动机输出关闭命令并向所述电磁阀输出关闭命令。所述流动源可以是泵出回路或管路压力回路。(The present disclosure provides "systems and methods for charging a transmission accumulator. A transmission assembly including a clutch system, an accumulator, and a controller is provided. The clutch system may include a flow source. The accumulator may be selectively in communication with the flow source via a solenoid valve. The controller may be programmed to output a command to open the solenoid valve to quickly charge the accumulator from the flow source in response to detecting that the vehicle is stopped and the accumulator charge is below a predetermined threshold. The predetermined threshold may be an accumulator pressure between 700kPa and 900 kPa. The controller may be further programmed to output a close command to an engine in communication with the transmission assembly and a close command to the solenoid valve in response to detecting that the accumulator is charged at or above the predetermined threshold. The flow source may be a pump-out loop or a line pressure loop.)
1. A transmission assembly comprising:
a clutch system including a flow source;
an accumulator in selective communication with the flow source via a solenoid valve; and
a controller programmed to output a command to open the solenoid valve to rapidly charge the accumulator from the flow source in response to detecting that the vehicle is stopped and the accumulator charge is below a predetermined threshold.
2. The assembly of claim 1, wherein the predetermined threshold is an accumulator pressure between 700kPa and 900 kPa.
3. The assembly of claim 1, wherein the controller is further programmed to output a close command to an engine in communication with the transmission assembly and a close command to the solenoid valve in response to detecting that the accumulator is charged at or above the predetermined threshold.
4. The assembly of claim 1, wherein the flow source is one of a pump-out circuit or a line pressure circuit.
5. The assembly of claim 1, further comprising a check valve in fluid communication with the flow source and oriented parallel to the solenoid valve, and wherein the check valve is arranged with the accumulator to passively allow fluid to travel therethrough and fill the accumulator.
6. The assembly of claim 5, wherein the check valve is further arranged with the accumulator to identify a flow rate of fluid traveling through the check valve, and wherein the controller is further programmed to identify a pressure level of the accumulator based on the identified flow rate.
7. The assembly of claim 1, wherein the controller is further programmed to output the command to open the solenoid valve to rapidly charge the accumulator in response to detecting that the clutch system is holding a shift position during a stop of the vehicle.
8. A transmission assembly comprising:
a clutch system including a line pressure circuit;
an accumulator in selective communication with the line pressure circuit via a solenoid valve configured to selectively open and close to drain and fill the accumulator;
a check valve in passive fluid communication with the line pressure circuit and arranged in parallel with the solenoid valve; and
a controller programmed to output a command to open the solenoid valve to rapidly charge the accumulator from the line pressure circuit, then output a command to increase pressure within the line pressure circuit, and then output a command to close the solenoid valve when it is detected that the accumulator is charged to the predetermined threshold in response to detecting that the vehicle is stopped, the accumulator is charged below a predetermined threshold, and the transmission is held in a shift position.
9. The assembly of claim 8, wherein the controller is further programmed to output a command to shut down the engine after the solenoid valve is closed.
10. The assembly of claim 8, wherein the predetermined threshold is an accumulator pressure between 700kPa and 900 kPa.
11. The assembly of claim 8, wherein the check valve is further arranged with the accumulator to identify a flow rate of fluid traveling through the check valve, and wherein the controller is further programmed to identify a pressure level of the accumulator based on the identified flow rate.
12. The assembly of claim 8, further comprising a sensor in communication with the controller and arranged with the accumulator to identify a fill level of the accumulator.
13. The assembly of claim 8, wherein the transmission hold shift position reflects a vehicle condition in which the vehicle is stopped.
14. The assembly of claim 8, wherein the controller is further programmed to output a command to vent the accumulator in response to detecting a command to crank the engine during a restart operation of a stop/start sequence such that fluid from the accumulator fills the line pressure circuit and clutches of the clutch system.
15. A method of charging a transmission accumulator, comprising:
in response to detecting a vehicle stop condition and the accumulator pressure level being below a predetermined pressure threshold, outputting, via the controller, an activation command to open a solenoid valve in fluid communication with the accumulator and the flow source and to output a flow source pressure increase command such that fluid may flow into the accumulator via the solenoid valve to fill at least to the predetermined pressure threshold and such that stop/start programming may be operated.
Technical Field
The present disclosure relates to the field of hydraulic control systems for automatic transmissions of motor vehicles. More specifically, the present disclosure relates to a transmission assembly including an accumulator and a solenoid valve.
Background
Many vehicles are used over a wide range of vehicle speeds, including both forward and reverse movements. However, some types of engines can only operate efficiently within a narrow speed range. Therefore, a transmission capable of efficiently transmitting power at various gear ratios is often employed. When the vehicle is at low speed, the transmission is typically operated at a high gear ratio such that it multiplies the engine torque to increase acceleration. Operating the transmission at low gear ratios at high vehicle speeds allows engine speeds associated with quiet, fuel efficient cruising. Typically, the transmission has a housing mounted to the vehicle structure, an input shaft driven by the engine crankshaft, and an output shaft that typically drives the wheels via a differential assembly that allows the left and right wheels to rotate at slightly different rotational speeds as the vehicle turns.
Discrete ratio transmissions are capable of transmitting power via a variety of power flow paths, each power flow path being associated with a different gear ratio. A particular power flow path is established by engaging a particular shifting element (such as a clutch or brake). Shifting from one gear ratio to another involves changing which shift elements are engaged. In many transmissions, the torque capacity of each shift element is controlled by directing fluid at the shift element at a controlled pressure. The controller adjusts the pressure by sending an electrical signal to the valve body.
To conserve fuel, some vehicles include stop/start programming to automatically shut off the engine when the vehicle is stopped in a driving gear, such as waiting at a red traffic light. The engine is then automatically started when the driver lifts his or her foot from the brake pedal. It is important that the vehicle starts accelerating as soon as the driver depresses the accelerator pedal. To achieve this, it may be necessary to keep engaging one or more shift elements. Because the engine-driven pump does not provide pressurized fluid when the engine is off, a different source of pressurized fluid, such as an accumulator, may be included.
During various types of driving, when the accumulator is not sufficiently filled, a stop/start event may be requested. For example, during city driving, the stop/start request may be repeated without increasing the engine speed or driver demand sufficiently to raise the line pressure high enough to fully charge the accumulator. This scenario may produce inconsistent restart splice times and inconsistent splice feel because the accumulator is not sufficiently filled.
Disclosure of Invention
A transmission assembly includes a clutch system, an accumulator, and a controller. The clutch system includes a flow source. The accumulator is selectively in communication with the flow source via a solenoid valve. The controller is programmed to output a command to open the solenoid valve to quickly charge the accumulator from the flow source in response to detecting that the vehicle is stopped and the accumulator charge is below a predetermined threshold. The predetermined threshold may be an accumulator pressure between 700kPa and 900 kPa. The controller may be further programmed to output a close command to an engine in communication with the transmission assembly and a close command to the solenoid valve in response to detecting that the accumulator is charged at or above the predetermined threshold. The flow source may be a pump-out loop or a line pressure loop. The assembly may include a check valve in fluid communication with the flow source and oriented parallel to the solenoid valve. The check valve may be arranged with the accumulator to passively allow fluid to travel therethrough and fill the accumulator. The check valve may also be arranged with the accumulator to identify a flow rate of fluid flowing through the check valve. The controller may also be programmed to identify a pressure level of the accumulator based on the identified flow rate. The controller may be further programmed to output the command to open the solenoid valve to rapidly charge the accumulator in response to detecting that the clutch system is holding a shift position during a stop of the vehicle.
A transmission assembly includes a clutch system, an accumulator, a check valve, and a controller. The clutch system includes a line pressure circuit. The accumulator is in selective communication with the line pressure circuit via a solenoid valve configured to be selectively opened and closed to drain and fill the accumulator. The check valve is in passive fluid communication with the line pressure circuit and is arranged in parallel with the solenoid valve. The controller is programmed to output a command to open the solenoid valve to rapidly charge the accumulator from the line pressure circuit, then output a command to increase pressure within the line pressure circuit, and then output a command to close the solenoid valve when it is detected that the accumulator is charged to the predetermined threshold in response to detecting that the vehicle is stopped, that the accumulator is charged below the predetermined threshold, and that the transmission is held in a shift position. The controller may also be programmed to output a command to shut down the engine after the solenoid valve is closed. The predetermined threshold may be an accumulator pressure between 700kPa and 900 kPa. The check valve may also be arranged with the accumulator to identify a flow rate of fluid flowing through the check valve. The controller may also be programmed to identify a pressure level of the accumulator based on the identified flow rate. The assembly may also include a sensor in communication with the controller and arranged with the accumulator to identify a fill level of the accumulator. The transmission hold shift position may reflect a vehicle condition in which the vehicle is stopped. The controller may also be programmed to output a command to vent the accumulator in response to detecting a command to crank the engine during a restart operation of a stop/start routine such that fluid from the accumulator fills the line pressure circuit and clutches of the clutch system.
A method of charging a transmission accumulator includes outputting, via a controller, an activation command to open a solenoid valve in fluid communication with the accumulator and a flow source and outputting a flow source pressure increase command such that fluid may flow into the accumulator via the solenoid valve to fill at least to a predetermined pressure threshold and such that stop/start programming may be operated in response to detecting a vehicle stop condition and an accumulator pressure level below the predetermined pressure threshold. The predetermined pressure threshold may be a pressure between 700kPa and 900 kPa. The method may also include outputting, via the controller, a command to vent the accumulator in response to detecting a command to crank the engine during a restart operation of a stop/start procedure such that fluid from the accumulator fills the flow source and clutches of the clutch system. The output of the activate command may also be in response to detecting that the transmission remains in a shift position during the vehicle stop condition. The method may further include orienting a check valve in fluid communication with the flow source parallel to the solenoid valve. Detecting whether the accumulator is equal to or above a predetermined pressure threshold may further include one of: (i) the controller identifies an accumulator pressure level based on a fluid flow rate of fluid traveling through the check valve, or (ii) the controller identifies the accumulator pressure level based on information received from a sensor of the accumulator.
Drawings
FIG. 1 is a schematic diagram illustrating one example of a transmission system.
FIG. 2 is a schematic diagram illustrating an example of a fluid supply subsystem for the hydraulic control system of the transmission of FIG. 1.
FIG. 3 is a schematic diagram illustrating an example of a portion of a shift element control subsystem of a hydraulic control system for the transmission of FIG. 1.
FIG. 4 is a flowchart illustrating an example of a control strategy for operating the transmission assembly.
Detailed Description
Embodiments of the present disclosure are described herein. However, it is to be understood that the disclosed embodiments are merely examples and that other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As one of ordinary skill in the art will appreciate, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combination of features shown provides a representative embodiment for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.
FIG. 1 is a schematic diagram illustrating an example of a vehicle transmission assembly. The bold solid line represents the mechanical power flow connection. The thin solid line indicates the flow of the hydraulic fluid. The dashed lines indicate the flow of the information signal. Power is typically supplied at the
Most of the shift elements within the
To reduce energy consumption, the internal combustion engine may be turned off when the vehicle is stopped (such as waiting at a red light). Then, when the driver releases the brake pedal, the engine is restarted. To ensure that the driveline is ready to transmit power as soon as the engine is started, it is desirable to keep some shifting elements engaged while the engine is off. To accomplish this, pressurized fluid is allowed to flow into
Fig. 2 is a schematic diagram showing an example of a portion of
During normal operation, the anti-reflux valve 36 is open, allowing fluid to flow freely from the pump out
The primary regulator valve 48 may regulate the displacement of the
When the vehicle is stopped, such as when waiting at a traffic light, the
During engine off periods,
FIG. 3 is a schematic diagram showing a portion of a clutch control subsystem, which may also be referred to herein as a clutch system. It is contemplated that the clutch system may have an alternative configuration of clutches connecting the flow source (such as pump out
Although a single valve is shown for simplicity, the system may also include a latch valve or other auxiliary valve. Similarly, the clutch 2 apply
FIG. 4 is a flowchart illustrating an example of an activated control strategy (generally referred to herein as control strategy 200) for selectively and quickly charging an accumulator of a vehicle transmission assembly to support stop/start programming. In
In
In
In the event the accumulator pressure level is equal to or above the predetermined pressure threshold, the controller may optionally initiate stop/start programming in operation 208. In the event that the accumulator pressure level is below the predetermined pressure threshold, the controller may confirm that the vehicle engine is running and the transmission is maintaining the shift position in
In
In
In the event that the controller detects that the accumulator is at or above the predetermined pressure threshold in
In another example, the clutch of the clutch system may be vented downward and emptied once the engine or impeller stops rotating. This may result in sudden turbine speed changes and overly robust clutch engagement during a restart operation of the stop/start programming. To address these issues, the accumulator may be commanded to drain immediately upon detection of a command to crank the engine during a stop/start programmed restart operation. The discharge of the accumulator may fill a line pressure circuit, which in turn may fill a clutch of the clutch system in communication therewith.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously mentioned, the features of the various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art will recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. Accordingly, embodiments described as less desirable with respect to one or more characteristics than other embodiments or prior art implementations are not outside the scope of the present disclosure and may be desirable for particular applications.
According to the present invention, there is provided a transmission assembly having: a clutch system including a flow source; an accumulator in selective communication with the flow source via a solenoid valve; and a controller programmed to output a command to open the solenoid valve to rapidly charge the accumulator from the flow source in response to detecting that the vehicle is stopped and the accumulator charge is below a predetermined threshold.
According to one embodiment, the predetermined threshold is an accumulator pressure between 700kPa and 900 kPa.
According to one embodiment, the controller is further programmed to output a close command to an engine in communication with the transmission assembly and a close command to the solenoid valve in response to detecting that the accumulator is charged at or above the predetermined threshold.
According to one embodiment, the flow source is one of a pump-out loop or a line pressure loop.
According to one embodiment, the above invention is further characterized by a check valve in fluid communication with the flow source and oriented parallel to the solenoid valve, and wherein the check valve is arranged with the accumulator to passively allow fluid to travel therethrough and fill the accumulator.
According to one embodiment, the check valve is further arranged with the accumulator to identify a flow rate of fluid traveling through the check valve, and wherein the controller is further programmed to identify a pressure level of the accumulator based on the identified flow rate.
According to one embodiment, the controller is further programmed to output the command to open the solenoid valve to rapidly charge the accumulator in response to detecting that the clutch system is holding a shift position during a stop of the vehicle.
According to the present invention, there is provided a transmission assembly having: a clutch system including a line pressure circuit; an accumulator in selective communication with the line pressure circuit via a solenoid valve configured to selectively open and close to drain and fill the accumulator; a check valve in passive fluid communication with the line pressure circuit and arranged in parallel with the solenoid valve; and a controller programmed to output a command to open the solenoid valve to rapidly charge the accumulator from the line pressure circuit, then output a command to increase pressure within the line pressure circuit, and then output a command to close the solenoid valve when it is detected that the accumulator is charged to the predetermined threshold in response to detecting that the vehicle is stopped, the accumulator is charged below a predetermined threshold, and the transmission is held in a shift position.
According to one embodiment, the controller is further programmed to output a command to shut down the engine after the solenoid valve is closed.
According to one embodiment, the predetermined threshold is an accumulator pressure between 700kPa and 900 kPa.
According to one embodiment, the check valve is further arranged with the accumulator to identify a flow rate of fluid traveling through the check valve, and wherein the controller is further programmed to identify a pressure level of the accumulator based on the identified flow rate.
According to one embodiment, the above invention is further characterized by a sensor in communication with the controller and arranged with the accumulator to identify a fill level of the accumulator.
According to one embodiment, the transmission hold shift position reflects a vehicle condition in which the vehicle is stopped.
According to one embodiment, the controller is further programmed to output a command to vent the accumulator in response to detecting a command to crank the engine during a restart operation of a stop/start sequence such that fluid from the accumulator fills the line pressure circuit and clutches of the clutch system.
In accordance with the present invention, a method of charging a transmission accumulator is provided having outputting, via a controller, an activation command to open a solenoid valve in fluid communication with the accumulator and a flow source and output a flow source pressure increase command such that fluid may flow into the accumulator via the solenoid valve to at least fill to a predetermined pressure threshold and such that stop/start programming may be operated in response to detecting a vehicle stop condition and an accumulator pressure level below the predetermined pressure threshold.
According to one embodiment, the predetermined pressure threshold is a pressure between 700kPa and 900 kPa.
According to one embodiment, the above invention is further characterized by outputting a command via the controller to vent the accumulator in response to detecting a command to crank the engine during a restart operation of a stop/start procedure such that fluid from the accumulator fills the flow source and the clutch of the clutch system.
According to one embodiment, outputting the activate command is further in response to detecting that a transmission remains in a shift position during the vehicle stop condition.
According to one embodiment, the above invention is further characterized by orienting a check valve in fluid communication with the flow source parallel to the solenoid valve.
According to one embodiment, detecting whether the accumulator is equal to or above a predetermined pressure threshold further comprises one of: (i) the controller identifies an accumulator pressure level based on a fluid flow rate of fluid traveling through the check valve, or (ii) the controller identifies the accumulator pressure level based on information received from a sensor of the accumulator.
- 上一篇:一种医用注射器针头装配设备
- 下一篇:一种混合动力液压系统及车辆