Restitution coefficient measuring device and hardness measuring device

A restitution coefficient measuring device measuring a restitution coefficient of a measuring object, the restitution coefficient measuring device comprising:

• a holder that holds a spherical impact ball colliding with the measuring object;
• a shooting mechanism for shooting the impact ball held by the holder from the holder toward the measuring object;
• a speed measuring unit that measures both a collision speed at which the impact ball collides with the measuring object and a restitution speed at which the impact ball bounces from the measuring object;
• and
• a computing unit that calculates the restitution coefficient on the basis of the restitution speed with respect to the collision speed,
• wherein the holder has a tube portion having a tubular shape for holding the impact ball in a tube hole,
• wherein the shooting mechanism has a shooting member disposed on the other side in an axial direction from the impact ball and capable of moving in the tube hole in the axial direction, a energizing portion applying a energizing force to the shooting member toward one side in the axial direction, and a restriction portion restricting movement of the shooting member to one side in the axial direction,
• wherein the shooting member has a small diameter portion on one side in the axial direction, a large diameter portion having a larger diameter than the small diameter portion on the other side in the axial direction from the small diameter portion, and a stepped portion which is a step generated due to a difference between the diameters of the small diameter portion and the large diameter portion, and
• wherein the restriction portion is an engagement member engaging with the stepped portion.

A hardness measuring device measuring a hardness of a measuring object, the hardness measuring device comprising:

• a holder that bolds a spherical impact ball colliding with the measuring object with an elastic member;
• a shooting mechanism for shooting the impact ball held by the holder from the holder toward the measuring object;
• a speed measuring unit that measures both a collision speed at which the impact ball collides with the measuring object and a restitution speed at which the impact ball bounces from the measuring object;
• and
• a computing unit that calculates the hardness on the basis of the restitution speed with respect to the collision speed,
• wherein a hole for bleeding air is bored on any side surface of the holder, and
• wherein the elastic member is an independent member replaceable with respect to the holder and is disposed at an end portion of the holder in an axial direction.

A hardness measuring device measuring a hardness of a measuring object, the hardness measuring device comprising:

• a holder that holds a spherical impact ball colliding with the measuring object;
• a shooting mechanism for shooting the impact ball held by the holder from the holder toward the measuring object;
• a speed measuring unit that measures both a collision speed at which the impact ball collides with the measuring object and a restitution speed at which the impact ball bounces from the measuring object;
• and
• a computing unit that calculates the hardness on the basis of the restitution speed with respect to the collision speed,
• wherein the holder has a tube portion having a tubular shape for holding the impact ball in a tube hole,
• wherein the shooting mechanism leas a shooting member disposed on the other side in an axial direction from the impact ball and capable of moving in the tube hole in the axial direction, a energizing portion applying a energizing force to the shooting member toward one side in the axial direction, and a restriction portion restricting movement of the shooting member to one side in the axial direction,
• wherein the shooting member has a small diameter portion on one side in the axial direction, a large diameter portion having a larger diameter than the small diameter portion on the other side in the axial direction from the small diameter portion, and a stepped portion which is a step generated due to a difference between the diameters of the small diameter portion and the large diameter portion, and
• wherein the restriction portion is an engagement member engaging with the stepped portion.