EP0210485A2 — Control valve system for a four speed ratio autom…

Claim 1

Independent Claim 359 words

In a control system for a four speed automatic transmission for use in a vehicle driveline to deliver torque from an engine to vehicle traction wheels, said transmission having a driving shaft (10) powered by said engine, a driven shaft (36), multiple ratio gearing (42, 44 and 46) establishing multiple torque delivery paths between said driving (36) and driven shafts (38) and fluid pressure operated clutches and brakes (CL₁, CL₂ and CL₃ resp. B₁, B₂ and B₃) adapted to control the relative motion of the elements of said gearing (42, 44 and 46); a fluid pressure source (39), and clutch and brake servo means for activating and deactivating said clutches and brakes to effect speed ratio changes, conduit structure (Fig. 4A - 4D) connecting said pressure source with said servo means, multiple ratio shift valve structure including a 1-2 shift valve means (118) and a 3-4 shift valve means (122) in said conduit structure for controlling distribution of pump pressure to servo means (CL₂ resp B₁) to effect ratio changes, between a first ratio and a second ratio resp. between a third ratio and a fourth ratio; characterized by ; a 1-2 accumulator (642) comprising an accumulator cylinder (644) and an accumulator piston (646) cooperating with said cylinder to define a 1-2 accumulator chamber, said 1-2 accumulator chamber communicating with the servo means (CL₂-Servo) for effecting second speed ratio; a 3-4 accumulator (664) comprising an accumulator cylinder (666) and an accumulator piston (668) cooperating with said cylinder to define a 3-4 accumulator chamber, said 3-4 accumulator chamber communicating with the servo means (B₁-Servo) for effecting fourth speed ratio; an accumulator regulator valve means (126) for regulating pressure from said pressure source to produce a modulated accumulator control pressure, a common accumulator control pressure passage (638) connecting the output side of said accumulator regulator valve means (126) with each accumulator (642 resp. 664) whereby an accumulator control pressure is applied to each accumulator piston; and means for applying an added pressure force to said accumulator pressure regulator valve means (126) to modify the regulating changes (3-4) relative to the regulating characteristics thereof for the other of said ratio changes (1-2).

Claim 2

Dependent Claim 359 words

In a control system for a four speed automatic transmission for use in a vehicle driveline to deliver torque from an engine to vehicle traction wheels, said transmission having a driving shaft (10) powered by said engine, a driven shaft (36), multiple ratio gearing (42, 44 and 46) establishing multiple torque delivery paths between said driving (36) and driven shafts (38) and fluid pressure operated clutches and brakes (CL₁, CL₂ and CL₃ resp. B₁, B₂ and B₃) adapted to control the relative motion of the elements of said gearing (42, 44 and 46); a fluid pressure source (39), and clutch and brake servo means for activating and deactivating said clutches and brakes to effect speed ratio changes, conduit structure (Fig. 4A - 4D) connecting said pressure source with said servo means, multiple ratio shift valve structure including a 1-2 shift valve means (118) and a 3-4 shift valve means (122) in said conduit structure for controlling distribution of pump pressure to servo means (CL₂ resp B₁) to effect ratio changes, between a first ratio and a second ratio resp. between a third ratio and a fourth ratio; characterized by ; a 1-2 accumulator (642) comprising an accumulator cylinder (644) and an accumulator piston (646) cooperating with said cylinder to define a 1-2 accumulator chamber, said 1-2 accumulator chamber communicating with the servo means (CL₂-Servo) for effecting second speed ratio; a 3-4 accumulator (664) comprising an accumulator cylinder (666) and an accumulator piston (668) cooperating with said cylinder to define a 3-4 accumulator chamber, said 3-4 accumulator chamber communicating with the servo means (B₁-Servo) for effecting fourth speed ratio; an accumulator regulator valve means (126) for regulating pressure from said pressure source to produce a modulated accumulator control pressure, a common accumulator control pressure passage (638) connecting the output side of said accumulator regulator valve means (126) with each accumulator (642 resp. 664) whereby an accumulator control pressure is applied to each accumulator piston; and means for applying an added pressure force to said accumulator pressure regulator valve means (126) to modify the regulating changes (3-4) relative to the regulating characteristics thereof for the other of said ratio changes (1-2).

Claim 3

Dependent Claim 64 words

The combination as set forth in Claim wherein said accumulator pressure regulator valve means (126) includes a first control area (622/624), said shift valve structure being adapted to distribute pressure from said pressure source (298) to said first control area (622/624) during a 3-4 upshift interval whereby the optimum accumulator control pressure for said 3-4 accumulator is obtained to effect a smooth ratio change.

Claim 4

Dependent Claim 61 words

The combination as set forth in Claim 1 wherein said accumulator pressure regulator valve means (126) includes a control area (624/622), said shift valve structure being adapted to distribute pressure from said pressure source to said control area (620/622) during a 1-2 upshift interval whereby the optimum control pressure for said 1-2 accumulator is obtained to effect a smooth ratio change.

Claim 5

Dependent Claim 147 words

The combination as set forth in Claim 2 resp. 3 wherein said accumulator regulator valve means (126) includes a pressure regulator valve element (616) with a pressure area (620) thereon that is subjected to pressure from said pressure source, a valve spring (628) acting on said valve element (616) with a force that opposes the pressure force on said pressure area (620), a movable valve plunger (630) engaged by said spring (628), one side of said valve plunger (630) being in communication with the control area (622/624) on said accumulator pressure regulator valve means (126) whereby said plunger ((630) is shifted to a first position to compress said valve spring (628) when said control area (622/624) is pressurized, said plunger (630) assuming a second position corresponding to an increased valve spring position corresponding to an increased valve spring length when said control area (622/624) is not pressurized.

Claim 6

Dependent Claim 152 words

The combination as set forth in Claim 4 wherein the fluid connection between said 1-2 shift valve means (118) and the servo means (CL₂) for effecting second speed ratio is defined in part by a 1-2 accumulator capacitiy modulator (246) comprising a valve cavity (651), a valve element (652) in said valve cavitiy (651), said cavity communicating with said 1-2 shift valve means (118) and said last named servo means (CL₂), a control orifice (650) between said last named servo means and said 1-2 accumulator chamber, said valve element (652) restricting communication between said last named servo means (CL₂)when it is moved in one direction and opening such communication when it is movend in the opposite direction, upstream and downstream sides of said orifice (650) communicating with opposed sides of said valve element (652) whereby the pressure differential across said orifice tends to bias said valve element (652) in said one direction.

Control valve system for a four speed ratio automatic transmission including a dual range regulator valve for controlling independently two upshift ratio changes

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