In heavy machine tool work, manual loading and unloading usually consists of:

• Lift the blank in
• Align the part
• Clamp with multi-point tooling
• Machining wait
• Release the tooling
• Lift the finished part out
• Clean the table and tooling
• Prepare the next part

When the cycle is stable, the part range is fairly uniform and the machine runs for long stretches, those repeated motions can be joined by an automation system. The machining characteristic here is heavy parts and long cycle times, where the gain comes from less crane waiting and more consistent clamping — which is exactly what makes the repeated motions worth fixing.

Taking Qizhong as the example: Qiqihar Heavy CNC builds heavy lathes, floor-type boring and milling machines and large machining equipment, so the automation is usually a transfer and alignment concept.

The system does not simply put a robot where an operator stood. It makes the following run in a fixed order:

1. Feeding
2. Picking
3. Clamping
4. Machining
5. Unloading
6. Collection

Add automated part storage and frequent manual replenishment turns into:

1. Storage buffer
2. Automatic feeding
3. Robot picking
4. CNC machining
5. Finished-part collection

The concept for a Qizhong heavy machine tool therefore has to be designed from the whole production cycle, not from a robot model number.

A typical automatic cycle can be designed as:

1. Blank in
2. Buffer area or off-machine clamping table
3. Part location and alignment
4. Heavy gantry or overhead structure picks
5. Into the Qizhong heavy machine tool, above the table
6. Part lowered into position
7. Multi-point tooling and hydraulic clamping
8. Machine confirms the clamped state
9. Spindle starts machining
10. Machining complete
11. Tooling released
12. Heavy mechanism removes the finished part
13. Table and tooling cleaned
14. Finished part collected or passed to the next operation

Each of those motions needs its own state confirmation, for example:

• Is the part in position
• Did the heavy mechanism grip reliably
• Are the clamps closed and locked
• Is the safety area clear
• Has the machining program finished
• Was the finished part removed safely
• Have the table and tooling been cleaned

The part is brought in from above the table by a heavy mechanism, so the plant headroom, the floor loading, the table load capacity and the opening range of the guards all have to be confirmed in the design.

The stability of an automatic system comes from the interlocks between those states, not from robot speed alone.

01 Gantry robot loading and unloading

A gantry robot normally runs on a fixed path. It suits: machines that stay in position and stand in a row, a clear loading path, a fairly stable part range with continuous batches, a defined cycle, and one robot serving several machines. Typical structure: automated part storage → gantry robot → machine → finished-part collection.

02 Six-axis robot loading and unloading

A six-axis robot has a larger working envelope. It suits: handling motions that are complex or need the part flipped, several machines plus an inspection station, a wide part range with frequent changeover, and connecting deburring, washing or inspection. Typical flow: storage → robot → machine → robot → inspection or finished-part area.

03 Automated part storage and feeding

Automated part storage is the link that turns manual bar handling into buffering: blanks queue in the magazine and the robot takes them to the cycle, so replenishment becomes a scheduled batch job instead of a per-part one. It suits sites that want to lengthen the replenishment interval, a fairly uniform part range that can be supplied by tray or basket, night shifts or long unattended stretches, and several lathes sharing one feeding and collection route.

Choosing between them

The handling unit and the feeding method are two separate decisions: they can be chosen independently or combined.

When two Qizhong heavy machine tools have cycles, part sizes and a layout that suit shared feeding, the following can be designed:

1. Storage magazine
2. Gantry or robot
3. heavy machine tool 1
4. heavy machine tool 2
5. Finished-part collection

That forms one multi-machine automation cell. A one-to-two configuration has to be calculated on:

• The cycle time of both machines
• The robot pick-and-place time
• The door opening time of both machines
• The part weight
• The robot payload
• The robot travel
• The distance between the two machines
• The storage capacity
• The scheduling logic when both machines finish at the same time

Not every pair of machines can share one robot. If the two cycles differ widely, or the machines stand too far apart, the robot path, the buffering method and the feeding structure have to be re-assessed.

Whether a part suits automated loading is decided by the part first. Across the typical work of a heavy machine tool, the common candidates are:

Whether a specific part suits automatic loading has to be confirmed on size, weight, shape, material, cycle time, clamping method, locating datum and the pose it arrives in. A name such as "shaft" or "disc" on its own is not a conclusion.

In automated loading the machine fixture is a critical link. On a heavy machine tool the clamping form is purpose-made tooling with hydraulic clamping, and the system has to consider:

• Heavy tooling and clamp type
• Synchronisation of the multi-point clamping
• Part locating and alignment datum
• Clamping pressure and lock confirmation
• Part-present detection
• Interference between the tooling, the crossbeam, the spindle and the guideways
• Space to remove the finished part
• Chip evacuation and table cleaning

Typical working cycle:

1. Heavy mechanism picks the part
2. Enters above the table
3. Part located and aligned
4. Multi-point tooling clamped
5. Clamping and locking confirmed
6. Heavy mechanism withdraws to the safe area
7. Spindle starts machining
8. Released and cleaned

The machine only moves to the next state after clamping and locking are confirmed. Heavy parts remove a lot of material, so chip evacuation and residue on the table directly affect location accuracy. Automated loading is therefore not simply "pick it up and put it in".

Neither option is automatically better; the shop decides.

The final choice also depends on the plant headroom, the floor loading, the part weight and shape, the cycle, the beam length, the number of machines and the safety area.

A project lands on the shop floor when these are verified:

01 Part location

Whether the part reaches the pick-up position reliably.

02 Fixture

Whether the robot gripper holds parts in different states reliably.

03 Machine interface

Whether the robot and the machine exchange run states reliably.

04 Cycle time

Whether the robot cycle matches the machine cycle.

05 Exception handling

How the system pauses, resets and recovers from a failed pick, a machine alarm or a part that is not in position.

06 Safety

Safety door, light curtain, safety area, emergency stop, robot safety and the human-robot boundary.

07 Manual takeover

Whether an operator can step in quickly when the automation trips.

A stable automatic system is not only one that completes its motions in normal running: it is one that recovers safely and in a controlled way from an abnormal state.