Hydraulic control system for a multiple mode electro-mechanical drive unit of an automatic transmission

Patent metadata

Field	Value
Publication number	US-9856974-B2
Application number	US-201514847456-A
Country	US
Kind code	B2
Filing date	Sep 8, 2015
Priority date	Sep 8, 2015
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle includes multiple torque transmitting mechanisms each including at least one friction clutch. Multiple clutch control valves are individually in fluid communication with one of the torque transmitting mechanisms and are operable when actuated to change a condition of the torque transmitting mechanisms from a clutch disconnected condition to a clutch engaged condition. Solenoid valves are individually paired with and in fluid communication with one of the clutch control valves. A normally open variable force solenoid valve is in fluid communication with the solenoid valves. Operation of the variable force solenoid valve sets a hydraulic pressure between any of the solenoid valves in an open condition and its paired clutch control valve.

First claim

What is claimed is:

1. A hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle, comprising:
multiple torque transmitting mechanisms each including at least one friction clutch;
multiple clutch control valves individually in fluid communication with one of the torque transmitting mechanisms and operable when actuated to change a condition of the torque transmitting mechanisms from a clutch disconnected condition to a clutch engaged condition;
multiple solenoid valves individually paired with and in fluid communication with one of the clutch control valves; and
a normally open variable force solenoid valve in fluid communication with the solenoid valves, operation of the variable force solenoid valve acting to set a hydraulic pressure between any of the solenoid valves in an open condition and any of the clutch control valves individually paired with the solenoid valves in the open condition.

2. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 1 , further comprising a main supply line containing a hydraulic fluid, each of the torque transmitting mechanisms connected to the main supply line when the clutch control valves are actuated.

3. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 2 , further including a pump operating to displace and pressurize the hydraulic fluid in the main supply line.

4. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 3 , wherein the pump is a fixed displacement pump.

5. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 2 , further including a combined hydraulic header, wherein each of the solenoid valves and the variable force solenoid valve is in fluid communication with the combined hydraulic header, operation of the variable force solenoid valve acting to set a hydraulic pressure of a hydraulic fluid in the combined hydraulic header.

6. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 1 , wherein the multiple torque transmitting mechanisms include four torque transmitting mechanisms defining vehicle drive mechanisms, and a fifth torque transmitting mechanism defining a braking clutch.

7. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 1 , further including a transmission control module connected to and commanding operation of each of the solenoid valves and the variable force solenoid valve.

8. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 7 , wherein the solenoid valves include a first, a second, a third, a fourth, and a fifth solenoid valve, any of the first, second, third, fourth, or fifth solenoid valves commanded to open by the transmission control module together with the paired clutch control valves are each exposed to a same hydraulic fluid pressure.

9. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 1 , wherein the multiple solenoid valves are individually operable in one of an off condition having the solenoid valve closed, and an on condition having the solenoid valve open.

10. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 1 , wherein predetermined ones of the solenoid valves are provided as variable force solenoid valves provided in a normally open condition, the predetermined ones of the solenoid valves permitting fluid communication to retain two of the clutch control valves in the clutch engaged condition during a default condition of the hydraulic control system wherein operational control of the solenoid valves is lost.

11. A hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle, comprising:
a main supply line containing a hydraulic fluid;
multiple torque transmitting mechanisms each including at least one friction clutch and each connected to the main supply line;
multiple clutch control valves each paired in fluid communication with one of the torque transmitting mechanisms and operable when actuated to change a condition of the torque transmitting mechanisms from a clutch disconnected condition to a clutch engaged condition;
multiple solenoid valves each operable in one of an off condition having the solenoid valve closed, and an on condition having the solenoid valve open, each of the solenoid valves paired with and in fluid communication with one of the clutch control valves and further in fluid communication with a combined hydraulic header; and
a normally open variable force solenoid valve in fluid communication with the combined hydraulic header, operation of the variable force solenoid valve acting to vary a hydraulic pressure of the hydraulic fluid in the combined hydraulic header, wherein the hydraulic pressure in the combined hydraulic header acts on any one or multiple ones of the solenoid valves in the on condition to actuate any of the clutch control valves paired with the any one or multiple ones of the solenoid valves in the on condition.

12. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 11 , further including a pressure regulating valve connected to the main supply line and acting to balance hydraulic operating pressure in the hydraulic control system.

13. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 11 , further including a gear and clutch arrangement having a first electric motor-generator and a second electric motor-generator defining the electro-mechanical drive unit.

14. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 13 , further including an exhaust backfill valve connected to a backfill circuit line, the backfill circuit line collecting hydraulic oil leakage from the clutch control valves to create a continuous flow of hydraulic oil to stators of the first electric motor-generator and the second electric motor-generator, and to clutches of the torque transmitting mechanisms.

15. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 11 , further including:
an actuator feed limit valve in fluid communication with the variable force solenoid valve operating to limit a maximum pressure applied to the solenoid valves; and
a boost accumulator in fluid communication with the actuator feed limit valve acting to limit pressure oscillations from operation of the solenoid valves, including operation of a variable force solenoid valve.

16. The hydraulic control system for a multiple mode electro-mechanical drive unit of a motor vehicle of claim 15 , further including:
a normally low (off) solenoid valve;
a blocking valve positioned between the normally low (off) solenoid valve and a predetermined one of the clutch control valves;
a hydraulic line connected to the main supply line and to the blocking valve; and
a blocking valve discharge line directing hydraulic oil from the blocking valve to the predetermined one of the clutch control valves;
wherein the blocking valve is operable during a default condition of the hydraulic control system wherein operational control of the solenoid valves is lost.

17. The hydraulic control system for a multiple mode electro-mechanical drive unit of a m

Assignees

• Gm Global Tech Operations Llc

Inventors

• Knoth Matthew R
• Foster Michael D
• Tryon Eric S

Classifications

• B60Y2200/92

  Hybrid vehicles · CPC title

• B60W10/11

  Stepped gearings · CPC title

• B60Y2300/182

  Selecting between different operative modes, e.g. comfort and performance modes · CPC title

• B60W20/00

  Control systems specially adapted for hybrid vehicles {(hybrid vehicle design, B60K6/00; electric vehicles B60L)} · CPC title

• F16H61/12

  Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures} · CPC title