Block Machine in Sri Lanka

The following are some real-world examples of repairs to core components of cement brick machines:
Main Cylinder Failure Case
Failure Symptoms: The hydraulic pressure display on a Haiyuan HF-1100 brick machine at a brick factory was low, resulting in poor-looking and insufficiently strong bricks. The main cylinder also exhibited a tendency to slide downward, and the locking screws repeatedly broke.
Repair Process: The manufacturer's technicians initially adjusted the parameters and cleaned and adjusted the solenoid valve, but the problem remained unresolved. Later, the main cylinder was removed and found to be severely damaged, with screws loose and embedded on the top. The technicians simply polished the cylinder liner with a portable grinder, replaced the main cylinder seal, and reinstalled it. However, a power outage prevented the machine from relieving pressure immediately, causing the locking screws to break again. Ultimately, it was determined that the main cylinder was severely damaged and required a replacement to completely resolve the issue.
Pressure Sensor Failure Case
Failure Symptoms: The main oil pump on the Haiyuan HF-1100 brick machine at the brick factory failed to start, causing the machine to shut down. Repair Process: Inspection revealed a burned-out pressure sensor. After replacing the pressure sensor, the brick machine resumed normal operation, demonstrating that the proper functioning of the pressure sensor is crucial for the machine's startup and pressure control.

Motor Failure Case

Failure Symptom: A 315kW motor on the lower stage of a 60-brick machine at a brick factory was operating weakly and unable to pull the machine. Loosening the belt from the traction pulley allowed the motor to rotate, but tightening the traction pulley belt prevented the motor from rotating and the armature current from increasing dramatically.

Repair Process: Maintenance personnel first measured the motor winding insulation and inspected the carbon brushes, finding no obvious problems. After disconnecting the motor from the machine and operating it independently, they tested the excitation and armature currents, finding them within normal ranges. A mechanical problem was suspected, but the maintenance personnel opened the machine housing for inspection and found no issues. Later, they discovered a subtle pause in the motor at low speeds. Applying slight force to the motor connector caused the armature current to increase dramatically, ruling out a mechanical problem. Inspection of the controller revealed a faulty rectifier module. After replacing the module, the problem persisted. Finally, while cleaning dust from the motor, they discovered that the wiring between the motor's commutation windings was disconnected. It turned out that the terminals had been improperly pressed during a previous repair, causing the wiring to heat up and become loose. After the motor was sent for repair and the machine was installed and tested, the problem was resolved.

Mold Failure Case

Failure Symptom: The mold of a cement brick machine at a brick factory cracked, affecting the quality of the bricks.

Repair Process: Inspection revealed that the lower die pressure was too low, and the mold vibration amplitude exceeded 4mm, exceeding the normal range (normal amplitude should be controlled between 2-4mm). Maintenance personnel adjusted the lower die pressure regulating valve, gradually increasing the lower die pressure until the mold vibration amplitude was controlled within 4mm. This alleviated the mold cracking problem and improved the quality of the bricks.