Hydraulic clutch system for automatic emergency braking and remote starting of manual transmission vehicles

Patent metadata

Field	Value
Publication number	US-10808772-B2
Application number	US-201816154531-A
Country	US
Kind code	B2
Filing date	Oct 8, 2018
Priority date	Oct 8, 2018
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A hydraulic clutch system that enables automatic emergency braking (AEB) and remote start of a manual transmission vehicle. The hydraulic clutch system includes a piston-operated hydraulic cylinder or other accumulator to store a charge of hydraulic fluid that can be selectively routed to the clutch and discharged under electronic control to thereby disengage the clutch independently of any operator input via the clutch pedal. By doing so, the system can provide an improved AEB response that slows or stops the vehicle without stalling the engine. The system may also be used to provide remote start capability to the vehicle by automatically disengaging the clutch as part of a remote start sequence of operations.

First claim

The invention claimed is:

1. A hydraulic clutch system having electronically-actuated automatic clutch disengagement for use in a manual transmission vehicle, comprising:
a hydraulic cylinder having a supply of hydraulic fluid therein;
a clutch pedal operatively connected to the hydraulic cylinder so as to force at least some of the hydraulic fluid out of the hydraulic cylinder and thereby pressurize the hydraulic fluid when the clutch pedal is depressed;
an accumulator storing a charge of the hydraulic fluid and operable to force at least some of the hydraulic fluid out of the accumulator and thereby pressurize the hydraulic fluid;
a clutch that, when engaged, couples an engine of the vehicle to a transmission of the vehicle, wherein the clutch disengages the engine from the transmission in response to receiving the pressurized hydraulic fluid from either the hydraulic cylinder or the accumulator, thereby preventing motive power from the engine to be transferred to the transmission;
an actuator having at least a first position and a second position corresponding to respective first and second modes of operation of the hydraulic clutch system; and
a controller electrically connected to the actuator to switch the actuator from the first position to the second position;
wherein, when the actuator is in the first position, the hydraulic clutch system is operable in a first mode in which the clutch may be operated by a driver of the manual transmission vehicle using the clutch pedal, and when the actuator is in the second position, the hydraulic clutch system is operable in a second mode in which the clutch is disengaged by the pressurized hydraulic fluid from the accumulator independently of any driver input to the clutch pedal,
wherein the actuator switches from the first position to the second position in response to a clutch activation signal received by the actuator from the controller so as to cause the hydraulic clutch system to switch to the second mode in which the clutch is disengaged by the pressurized hydraulic fluid from the accumulator, and wherein the controller is operable, in response to receiving a clutch disengagement command, to generate the clutch activation signal when at least the following two conditions exist: the clutch is engaged and the accumulator is charged, and
wherein the clutch disengagement command is received as part of a remote start event that involves, prior to receipt of the clutch disengagement command, an electronically-controlled setting or setting confirmation of a vehicle brake, and that involves, after generation of the clutch activation signal and disengagement of the clutch by the pressurized hydraulic fluid from the accumulator, starting the engine and operating the controller to switch the hydraulic clutch system out of the second mode and into one or more subsequent modes that permit recharging of the accumulator and operation of the clutch by the driver using the clutch pedal.

2. The hydraulic clutch system defined in claim 1 , wherein the clutch disengagement command is received as part of an automatic emergency braking event and wherein, following generation of the clutch activation signal and disengagement of the clutch by the pressurized hydraulic fluid from the accumulator, the controller operates to switch the hydraulic clutch system out of the second mode and into one or more subsequent modes that permit recharging of the accumulator and operation of the clutch by the driver using the clutch pedal.

3. The hydraulic clutch system defined in claim 1 , wherein the actuator comprises a solenoid valve interconnected between the hydraulic cylinder, accumulator, and clutch so as to selectively route the hydraulic fluid among the hydraulic cylinder, accumulator, and clutch, and wherein the solenoid valve has a plunger that moves between different positions within the solenoid valve, the solenoid valve further comprising at least one solenoid that, when energized, causes the plunger to move between at least two of the positions so as to switch the hydraulic clutch system between the first and second modes of operation.

4. The hydraulic clutch system defined in claim 3 , wherein the solenoid valve includes a plurality of input ports, at least one of each of which is connected to the hydraulic cylinder, accumulator, and clutch so as to provide fluidic communication of the hydraulic fluid between the solenoid valve and the hydraulic cylinder, accumulator, and clutch, and wherein the plunger includes one or more passageways that selectively connect different combinations of the ports together depending on at which of the at least two positions the plunger is located.

5. The hydraulic clutch system defined in claim 3 , further comprising a third mode of operation, wherein, when the hydraulic clutch system is in the first mode, the plunger is at a first one of the positions in which the hydraulic cylinder is in fluidic communication with the clutch, when the hydraulic clutch system is in the second mode, the plunger is at a second one of the positions in which the accumulator is in fluidic communication with the clutch, and when the hydraulic clutch system is in the third mode, the plunger is at a third one of the positions in which the hydraulic cylinder is in fluidic communication with the accumulator such that the accumulator can be recharged with pressurized hydraulic fluid by the driver depressing the clutch pedal.

6. The hydraulic clutch system defined in claim 1 , wherein the actuator comprises a housing having a solenoid and plunger that moves between the first and second positions, wherein the first position corresponds to an extended position in which the plunger protrudes from the housing, and the second position corresponds to a retracted position in which the plunger is retracted at least partially into the housing, wherein the plunger is biased into the first position and moves from the first position to the second position in response to energization of the solenoid.

7. The hydraulic clutch system defined in claim 6 , wherein the accumulator comprises a second hydraulic cylinder having a piston that moves between positions adjacent first and second ends of the second hydraulic cylinder, wherein the piston is biased towards the second end, and wherein the plunger is disposed between the first and second ends at a location that, when in its extended position, interferes with movement of the piston towards the second end such that the accumulator holds the charge of hydraulic fluid when the plunger is in the extended position and discharges the charge of hydraulic fluid out of the accumulator when the plunger is moved to the retracted position by energization of the solenoid to thereby free the piston to move towards the second end under force of the bias on the piston.

8. A hydraulic clutch system having electronically-actuated automatic clutch disengagement for use in a manual transmission vehicle, comprising: a hydraulic cylinder having a supply of hydraulic fluid therein;
a clutch pedal operatively connected to the hydraulic cylinder so as to force at least some of the hydraulic fluid out of the hydraulic cylinder and thereby pressurize the hydraulic fluid when the clutch pedal is depressed;
an accumulator storing a charge of the hydraulic fluid and having a piston biased so as to force at least some of the hydraulic fluid out of the accumulator and thereby pressurize the hydraulic fluid;
a clutch that couples an engine of the vehicle to a transmission of the vehicle and that disengages the engine from the transmission in response to receiving the pressurized hydraulic fluid from either the hydraulic cylinder or the accumulator;
a distribution valve interconnected between the hydraulic cylinder, accumulator, and

Assignees

• Gm Global Tech Operations Llc

Inventors

• Carlson Eric
• Howe David
• Cousins William L
• Craig David A
• Kwon Alex

Classifications

• F02N11/103

  according to the vehicle transmission or clutch status · CPC title

• F16D2048/0203

  with an accumulator; Details thereof · CPC title

• F16D2500/3026

  Stroke · CPC title

• F16D2025/081

  Hydraulic devices that initiate movement of pistons in secondary cylinders for actuating clutches, i.e. primary cylinders · CPC title

• B60W10/02

  including control of driveline clutches · CPC title