Air Hammer Suspension Hammer Operation and Maintenance Guide

In the daily production of the free forging workshop, the air hammer is the most widely used medium and small-sized forging processing equipment. As the core basic working state of the air hammer, the suspension hammer directly affects the operation safety, production efficiency and equipment service life, and is a key skill that every forging worker must master proficiently.

Ⅰ. Working Principle of the Suspension Hammer

The suspended hammer state of the air hammer is a specific working mode achieved through the adjustment of the rotary valve of the air distribution mechanism. When the control handle is switched to the suspension hammer position, the upper rotary valve connects the upper part of the compression cylinder and the working cylinder to the atmosphere simultaneously, while the lower rotary valve connects the air passage between the lower part of the compression cylinder and the lower part of the working cylinder. At the same time, the check valve inside the lower rotary valve functions to prevent the backflow of compressed air in the working cylinder. At this point, the motor drives the compression piston to continuously perform up and down reciprocating motion. Compressed air can only stably enter the lower part of the working cylinder, continuously generating an upward lifting force, keeping the hammer head along with the hammer rod always suspended at the highest position of the stroke and preventing them from falling due to natural gravity.

In this state, the continuous operation of the compression cylinder will not drive the hammer head to produce a striking action. The hammer head always remains stably suspended in the air, providing safe and stable working conditions for auxiliary operations during the forging process.

Ⅱ. Core Application Scenarios of the suspension hammer State

The suspension hammer is a crucial state that connects various processing links in the forging process. In daily production, it is mainly used in three scenarios:

1. Workpiece loading, unloading and positioning: When changing forgings, placing or adjusting forging dies, or placing and placing dies, the hammer head should be suspended to leave sufficient operating space, preventing the hammer head from accidentally falling and injuring the hand or bumping the workpiece. This facilitates the operator to quickly complete the centering and alignment of the billet, preparing for subsequent forging processes such as upsetting, extending, and punching.

2. Auxiliary operation: During the forging process, checking the dimensions of the forgings, removing the oxide scale on the surface of the forgings with a wire brush, and adjusting the position of the shims on the anvil seat all need to be carried out in a suspended hammer state. This not only ensures operational safety but also prevents tool damage caused by accidental hammer strikes.

3. Equipment standby buffering: During short process intervals and waiting times for tool changes, adjusting the air hammer to the suspended hammer state can reduce unnecessary energy consumption and lower the wear of the transmission mechanism compared to keeping the equipment idling or in continuous standby mode for a long time.

Ⅲ. Safety Regulations for Suspension Hammer Operations

There are strict safety requirements for the operation of the suspension hammer. Violating the operation rules can easily cause equipment failure or safety accidents. Firstly, the duration of the suspension hammer operation must not exceed one minute. If the suspension hammer state is maintained for a long time, the hammer rod will rub violently with the guide sleeve under the continuous action of compressed air, rapidly accumulating heat and causing the temperature to soar. In mild cases, it may lead to deformation of the hammer rod due to heat and abnormal wear of the guide sleeve. In severe cases, it may result in the hammer rod getting stuck and the sealing parts being scratched, significantly shortening the service life of the core components. Secondly, when the hammer is suspended, the operator must not extend their hands into the working area between the upper anvil and the lower anvil. Even if the hammer head is in a suspended position, it is strictly prohibited to stay under the hammer head for a long time to prevent the hammer head from accidentally falling due to a malfunction of the gas distribution valve. Finally, after completing the auxiliary operation, the control handle should be promptly switched to the light strike position to allow the hammer head to slowly fall and touch the forging. Then, gradually adjust to the required strike force. It is strictly prohibited to quickly switch from the suspended hammer state to full-force continuous strike to avoid severe impact on the transmission mechanism of the air hammer.

Ⅳ. Common Faults and Maintenance Points of Suspension Hammers

In daily production, the failure of the suspended hammer is a common fault of air hammers. The most common problems include the hammer head being unable to suspend stably in the air and the hammer head slowly dropping in the suspended hammer state. Most of these faults are related to the component status of the air distribution mechanism: If the hammer head cannot be suspended, first check whether the check valve inside the downswing valve is worn or stuck. The accumulation of oxide scale on the sealing surface of the check valve and the failure of the spring force will cause the compressed air to flow back from the lower part of the working cylinder and fail to form sufficient lifting force. Just disassemble the downswing valve to remove foreign objects and replace the failed spring, and the normal suspension function of the hammer can be restored. If the hammer head drops slowly in the suspended hammer state, it is mostly because the sealing surface of the rotary valve is worn and the connection position of the air passage has shifted. It is necessary to regrind the mating surface of the rotary valve to ensure the accuracy of the air distribution. At the same time, check whether the piston rings of the working cylinder are worn and leaking, and replace the aged sealing parts in time.

During daily maintenance, it is necessary to regularly apply grease to the rotary valve of the air distribution mechanism and the hinge points of the operating lever. The sealing condition of the check valve should be disassembled and inspected once every quarter to prevent oxide scale and iron filings from entering the air passage and scratching the sealing surface, thereby reducing the occurrence of suspension hammer failures from the source.

Mastering the operation and maintenance methods of the suspension hammer correctly can not only give full play to the flexible and convenient operation advantages of the air hammer, but also effectively extend the service life of the equipment. It is an important foundation for the forging workshop to ensure safe production and improve processing efficiency.