This volume explains the oscillation property of a spring when a block with mass (M) is placed on the spring with the constant (k).

• When you release the load of this block that was pressing the spring toward the direction shown in [Fig.1], the energy storage property of the spring causes the block to continue oscillating in a vertical direction.
• Oscillation frequency at this time is the natural frequency (f₀) calculated using the following formula:
• The term "Natural frequency" refers to oscillation properties specific to a spring, indicating how many times the vibration is repeated within a certain amount of time.
• The value of natural frequency is determined by the two variables: the mass (M) of a load placed (or a handing load) and the spring constant (k). Therefore, even when you stretch out the spring or when you slightly pull the spring before releasing, the natural frequency stays the same.
• [Fig.2] explains the effect of the mass (A), the effect of the spring constant (B), and the effect of vibration frequency (C), using actual examples.
• Here are some examples utilizing this spring's natural frequency as effective properties.

  Case examples effectively utilizing the spring's natural frequency

  Pressing machine	}	Vibration-proof design and vibration-proofing material
  Automobile

  [Example] Use with a damper to absorb shock from the device.

  E.g. Semiconductor equipment ----- vibration-proof design and vibration-proofing material

  [Example] According to the vibration frequency transmitted from the surrounding area, anti-vibration measures, use of vibration-proof rubber, coil springs, and air suspension are incorporated, as appropriate, into semiconductor equipment (such as precision positioning equipment) that is susceptible to even subtle vibration.

  Notes

  The term "Vibration isolation" (vibration control, vibration absorption) refers to a measure preventing oscillatory propagation to the surrounding area by supporting the vibration-generating equipment with vibration-proofing material.

  Vibration removal refers to a measure taken for equipment to be protected from the effect of vibration transmitted from the outside.

• Choose a spring whose natural frequency (f₀) does not correspond with that of the entire machine (f). (The entire machine is viewed as the spring system here.) Otherwise, the machine needs to be designed to have a different natural frequency from the spring's frequency.
• When the spring's natural frequency (f₀) corresponds with that of the entire machine (f), it causes a resonance, maximizing the machine vibration that may trigger accidents, including equipment damage as chatter marks or fracture.