In the last issue of《Dimensional classroom》Li，Xiaowei took you to understand the Hummer vibration compaction technology.#2 Rolling speed setting，Current period《Dimensional classroom》Xiaowei will take you.Learn Hummer Vibratory Compaction Technology#3 Vibration frequency adjustment。Through this video，You will learn that the Hummer roller deals with the compaction of different types of asphalt pavement.，How to set the vibration frequency reasonably。A lot of dry goods，It is suggested to collect and study。

When the roller is working on the road surface to be compacted with high bearing capacity，Rollers are prone to runout patterns.，Commonly known as“Jump”Phenomenon。Usually, the operator can judge by himself by observing the abnormal sound of the steel wheel during the compaction process.，And equipped HCM The Hummer Compaction Gauge roller can monitor the drum runout pattern via an acceleration sensor built into the drum。Appearance of beat pattern，Because as compaction proceeds,，The road surface becomes harder, and the reaction force of the steel wheel is greater.，Causing the steel wheel to bounce to a greater height than the theoretical amplitude，As a result, the compaction energy of the next impact of the drum on the ground cannot be effectively transmitted。

In case of vehicle tripping，One way to deal with it is to adjust the vibration frequency.。With a Hummer HD 138i For example，It can be adjusted through the frequency adjustment button on the operation panel.，The recommended adjustment range for low frequency and large amplitude is 25-43 Hz；The recommended adjustment range of small amplitude at high frequency is 25-60 Hz。Decrease the frequency while keeping the same choice of magnitude and amplitude，The angular velocity at which the eccentric mass rotates will slow down，The exciting force becomes smaller，O that the pressing force of the steel wheel to the ground is reduced.。Accordingly，The reaction of the drum to the ground is also reduced，So that that occurrence of the vehicle jump phenomenon is effectively relieved。

If the frequency cannot be reduced any further,，While the machine is still in bounce mode，The hand can be switched to a small amplitude but still remain in a high frequency range。If you jump out of the car，The operator can continue to reduce the frequency in the small amplitude mode.，Until the beat mode is eliminated。It should be noted that，The rolling speed must be adjusted simultaneously with the vibration frequency.，Match each other to ensure reasonable impact spacing，O as to obtain an ideal compaction effect.。Refer to the specific method for adjustment of rolling speed#2 videos。（Click to view）

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