1. Overview of the Control Valve
The i73 has a control valve that enables the bale cutting and film gripper functions to operate automatically from one hydraulic service. It has four cartridge valves in the valve block.
The image below (Fig. 1) indicates the location of the Bale Shear Hydraulic Control Valve within the machine structure.
2. Valve Component Identification (Fig. 2)
The valve block houses four main cartridge valves (see Fig. 2):
Ref. | Component Name | Function / Setting | Source Ref. |
|---|---|---|---|
1. | Relief Valve | Protects the machine structure from overload; set at 180 bar (nominal)
| Fig. 2
|
2. | Gripper P/O Holding Valve | Ensures the film grip is maintained on the film as the bale is split
| Fig. 2
|
3. | Gripper Close Sequence Valve | Gives priority to the film gripper to close and catch the film before the cutter frame closes
| Fig. 2
|
4. | Gripper Open Sequence Valve | Prevents oil pressure getting to film gripper to open until the main cylinders are fully open and the pressure spikes
| Fig. 2
|
3. Valve Details and Adjustment
A. Relief Valve (Ref. 1)
Purpose: The relief valve on the block protects the structure of the machine from overload when it is attached to telehandlers with hydraulic system that operate over 200 bar.
Nominal Setting: 180 bar.
B. Pilot Operated (P/O) Holding Valve (Ref. 2)
Purpose: The pilot operated holding valve ensures a film grip is maintained on the film as the bale is be split.
C. Gripper Close Sequence Valve (Ref. 3)
Description: The shorter of the two sequence valves (with red O ring).
Function: Gives priority to the film gripper to close and catch the film before the cutter frame closes to split the bale.
Setting: This is set at 100 bar.
Adjustment:
This valve rarely needs adjustment.
Its setting can be changed by adjusting the screw inside the cap.
Anticlockwise adjustment will reduce the pressure setting.
Caution: Be careful of the loose pin inside the cap.
D. Gripper Open Sequence Valve (Ref. 4)
Description: The longer sequence valve (with black O ring).
Function: Prevents oil pressure getting to the film gripper to open until the main cylinders are fully open and the pressure spikes.
Setting: It is set to open at 150 bar.
Adjustment:
On loaders with lower hydraulic pressure, the setting of this valve may need to be reduced to get the gripper to release.
Anticlockwise adjustment will reduce the setting pressure.
Caution: Beware of the pin in the cap.
4. Hydraulic Schematic
The image below is the hydraulic schematic for the 173 Bale Shear. Note the settings for valve T1 (150 bar) and T2 (100 bar).