Boring tool used for machining small-hole-diameter step type round hole inner cavity and provided with replaceable tool head

[0014] The present invention will be described in detail below in conjunction with the drawings:

[0015] A boring tool with a replaceable cutter head used for processing the inner cavity of a small-diameter round hole with a stepped hole. The boring tool includes a cutter bar (1) and a cutter head holder (2). A barrel-shaped cavity is provided on the cutter bar (1) (3) A cutter head holder (2) is connected to the cavity port (4) of the barrel-shaped cavity (3), and the cutter head and cutter rod connecting threads (6) are respectively provided on the cutter head holder (2) And the annular positioning step (9), the cutter head seat (2) is screwed into the cavity port (4) through the connecting thread (6) of the cutter head and the cutter rod, and the central axis (10) of the annular positioning step (9) It is coincident with the center axis (11) of the tool bar (1), and the blade (7) is fixed on the cutter head seat (2) through the top wire (8); when machining the hole-shaped cavity, it encounters For stepped holes, only need to unscrew the tool head holder (2) and replace with another tool head holder of the size corresponding to the stepped hole to continue processing. There is no need to replace the tool holder, which avoids re-clamping and centering of the tool Positioning improves the machining accuracy and efficiency; the tool holder and tool head adopt high-precision positioning step surfaces to ensure the perfect combination of tool holder and tool head.

[0016] The barrel-shaped cavity (3) is filled with lead or copper eccentric spherical particles (5), the diameter of the eccentric spherical particles (5) is 3.5 mm, and the total volume of the filled eccentric spherical particles (5) The ratio of the volume to the barrel-shaped cavity (3) is 70:100.

[0017] The barrel-shaped cavity (3) is filled with copper powder, and the ratio of the volume of the filled copper powder and the eccentric spherical particles (5) to the volume of the barrel-shaped cavity (3) is 70:100, so The ratio of the volume of the canned copper powder to the volume of the filled eccentric spherical particles (5) is 1:5.

[0018] When the exciting force is small or instantaneously excited, the relative motion speed between the eccentric spherical particles (5) will be very small, and the eccentric spherical particles (5) and its copper powder in the cavity will mainly slide relatively In this state, the eccentric sphere particles (5) are mainly frictional energy dissipation; when the excitation force increases or continuous excitation force is applied, the eccentric sphere particles (5) will accelerate and rotate at high speed due to the eccentricity. For movement, the tool holder mainly relies on the plastic deformation of the eccentric spherical particles (5) colliding with the inner wall of the tool holder to absorb energy, that is, the so-called changing the dynamic stiffness of the tool to avoid resonance.

[0019] The material of the tool shank and the tool head of the present invention is selected (W6 high-speed steel) and quenched to a hardness of 63-66 HRC to increase the hardness. In the present invention, a lead ball or a copper ball is selected as the damping particles. The specific parameters are as follows:

[0020] Damping material name density Elastic Modulus Shear modulus Features copper 8.9 108 39 Good plasticity lead 11.34 17 7 Good plasticity

[0021];

[0022] When the speed of the vibration reduction tool is not high, the vibration reduction effect is mainly achieved by the strength of the material of the tool holder. At this time, the movement of the damping particles and the inner cavity wall is mainly sliding friction to absorb energy. When the speed continues to increase That is, when resonance is reached, the damping particles in the inner cavity mainly collide with the cavity wall. At this time, the mutual collision between the damping particles causes irreversible plastic deformation of the damping particles, which absorbs the flutter energy to achieve the vibration reduction effect.