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| Illustration 1 | g03713877 |
Standard joystick | |
| Functions of the Switches on the Joysticks | |
| Left Hand Joystick | |
| Front Button | Magnet Control |
| Thumbwheel (Left Movement - Rear) | N/A for the standard joystick Medium pressure function ( Counterclockwise or LH) (1) |
| Thumbwheel (Right Movement - Rear) | N/A for the standard joystick Medium pressure function ( Clockwise or RH) (1) |
| Rear Button (Down Left) | Horn |
| Rear Button (Down Right) | Swing Brake |
| Right Hand Joystick | |
| Front Button | Boom Float Switch ( Disable Function) or Hydraulic Modulation Switch ( Enable Function) |
| Thumbwheel (Left Movement - Rear) | (N/A for the standard joystick) Cab Riser (Up), Hammer, Auxiliary ( Counterclockwise), and Joystick Steering ( Left) |
| Thumbwheel (Right Movement - Rear) | (N/A for the standard joystick) Cab Riser (Down), Hammer, Auxiliary ( Clockwise), and Joystick Steering ( Right) |
| Rear Button (Down Left) | One Touch Low Idle |
| Rear Button (Down Right) | Heavy Lift Function |
| ( 1 ) | Joystick on machines that are equipped with optional functions |
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| Illustration 2 | g03714250 |
Cross section of joystick (9) Port for bucket (open) (RH joystick) (10) Port for boom lower (RH joystick) (11) Port for bucket close (RH joystick) (12) Port for boom (raise) (RH joystick) (13) Port for swing left (LH joystick) (14) Port for stick out (LH joystick) (15) Port for swing right (LH joystick) (16) Port for stick in (LH joystick) (17) Hydraulic control unit (18) Plunger (19) Return spring (20) Control spring (21) Passage (22) Line to tank (23) Pilot pressure supply line from pilot manifold (24) Line to main control valve (25) Plate | |
Each pilot control valve has four valves that control two operations. The left pilot control valve has two valves for the stick and two valves for the swing. The right pilot control valve has two valves for the boom and two valves for the bucket.
When the joystick is moved to the right, plate (25) tilts to the left. Plate (25) pushes down on plunger (18) . The seat pushes control spring (20) and return spring (19) . The force of the control spring (20) moves control spool (17) downward and passage (21) is opened. The oil can go through the passages and out of port (24) through the line to the main control valve. The oil pressure that is generated at the pilot control valve moves the main control valve spools. This permits oil flow to the implements.
The oil at the opposite end of the main control valve stem flows through the port return passage and to the return chamber. The oil then flows through port (22) to the hydraulic tank.
Return spring (19) in the pilot control valve provides the necessary force in order to allow joysticks to return to the NEUTRAL position when released.
When the joystick is actuated, control springs (20) are compressed. This causes control spool (17) to move downward. Control spool (17) controls the pilot oil pressure to the main control valve. The pilot pressure that is delivered to the main control valve is proportional to the travel distance of the joystick.
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| Illustration 3 | g03716483 |
Typical joystick schematic showing ports 1 through 4. | |
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| Illustration 4 | g02404657 |
Joystick pressure curves (ports 1 and 3) (A) Pressure (bar) (A1) 24 ± 2.5 (A2) 11.5 ± 1.2 (A3) 6 ± 0.4 (B) Operating angle (degrees) (B1) 2 degrees 30' ± 1 degree 10' (B2) 11 degrees 50' ± 2 degrees (B3) 22 degrees ± 1 degree 35' (B4) 23 degrees 15' ± 1 degree | |
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| Illustration 5 | g02404700 |
Joystick pressure curves (Ports 2 and 4) (C) Pressure (bar) (C1) 6 ± 0.4 (C2) 11.5 ± 1.2 (C3) 24 ± 0.6 (D) Operating angle (degrees) (D1) 2 degrees 30' ± 1 degrees 10' (D2) 11 degrees 20' ± 2 degrees (D3) 18 degrees 20' ± 1 degrees | |
The pilot pressure that is delivered to the main control valve is proportional to the travel distance of the joystick. Refer to Illustration 4 and Illustration 3. The amount of change in the flow rate from the main control valve to the implements and/or motors is proportional. The proportion is based off the change in pilot pressure from the joysticks.
For information regarding the joystick steering option, refer to Systems Operation, "Joystick Steering Hydraulic System".