Simple Valve Control

1 / 20

Simple Valve Control - PowerPoint PPT Presentation

Simple Valve Control. Purpose. The valve body and associated mechanisms are designed to control the fluid flow to the various clutch pistons and servos within the transmission The valve body must control the following fluid flow properties Timing (when does it flow) Rate (how much flows)

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

PowerPoint Slideshow about 'Simple Valve Control' - kory

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Simple Valve Control

Purpose
• The valve body and associated mechanisms are designed to control the fluid flow to the various clutch pistons and servos within the transmission
• The valve body must control the following fluid flow properties
• Timing (when does it flow)
• Rate (how much flows)
• Pressure
Hydraulic Basics

Apply Pin

Pressure x Area = Force

90 PSI x 4.9 in2 = 441 pounds force

• Pascal’s Law
• Force = Area x Pressure
• Area = Force ÷ Pressure
• Pressure = Force ÷ Area

Piston (2.5” diameter) (4.9 in2 area)

Drum

Line Pressure (90 PSI)

Basic Hydraulics
• Flow vs. Pressure when fluid is passing through an orifice

Flow

90 PSI

27 PSI

Basic Hydraulics
• Flow vs. Pressure when fluid is passing through an orifice

Increased Spring Pressure = Reduced Flow = Higher Apply pressure

Reduced Flow

90 PSI

57 PSI

Basic Hydraulics
• Holding pressure

No Flow = No Pressure Drop

No Flow

90 PSI

90 PSI

Basic Hydraulics
• Holding Pressure

Exhaust/Bleed creates flow

Minimal Flow Creates small pressure drop

Minimal Flow

90 PSI

70 PSI

Basic Hydraulics
• Servo Release

Orifice creates a pressure drop = slow release

Flow

0 PSI

30 PSI

Basic Hydraulics

Spacer Plate

• Checkball use

(Release)

Checkball

Flow

0 PSI

90 PSI

Basic Hydraulics

Spacer Plate

• Checkball use

(Apply)

Checkball (Seals release passage)

Flow

90 PSI

40 PSI

Spool Valve Features

Valleys

Faces

Lands

Types of Valves
• Balanced
• Controls pressure
• Pressure regulator
• Governor
• TV
• Modulator
• Unbalanced
• Directs pressure
• Shift valves
• Sequencing
• Positions another valve or prevents unwanted function
• Reverse lockout (idiot valve)
• Low control valve (TH-350)
Balanced Valve
• Forces on valve in opposite directions are balanced at a certain point
• Used to modulate pressure

Exhaust

Line Pressure

Unbalanced Valve
• During the operation of an unbalanced valve, the forces in one direction or the other will be greater
• Shift valves

1-2 Shift Valve (i.e. Powerglide)

Line Pressure

Governor Pressure

Modulator Pressure

Passage to low band servo

Passage to high clutch

Scheduling Valve
• Scheduling valves are used to prevent unwanted actions from occurring
• (i.e. shift to M1 @ 80 MPH)

TH 350 Low Control Valve @ 20 MPH in D

To 1-2 Shift Valve

M1Oil

Governor Oil

15 Pounds

10 PSI

M1Oil

1 in2 Valve

Scheduling Valve
• Scheduling valves are used to prevent unwanted actions from occurring
• (i.e. shift to M1 @ 80 MPH)

TH 350 Low Control Valve @ 80 MPH in D

To 1-2 Shift Valve

M1Oil

Governor Oil

40 PSI

15 Pounds

M1Oil

1 in2 Valve

Scheduling Valve
• Scheduling valves are used to prevent unwanted actions from occurring
• (i.e. shift to M1 @ 80 MPH)

TH 350 Low Control Valve @ 80 MPH in M1

To 1-2 Shift Valve

M1Oil (60 PSI)

Governor Oil

15 Pounds

40 PSI

M1Oil

1 in2 Valve