Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
193 words
A tapping machining method comprising the steps of: (a) subjecting a workpiece to a predetermined thread cutting operation by performing a pulse distribution calculation based on pulses of a frequency proportional to a rotational velocity of a spindle and on a pitch of a screw; (b) applying pulses obtained by the pulse distribution calculation to a servo circuit to move a tapping tool in the depth direction; (c) continuing the pulse distribution calculation without pause and generating a spindle rotation reverse command when the tapping tool arrives at a commanded depth; (d) moving the tapping tool in the depth direction by the distributed pulses obtained by the pulse distribution calculation of said step (c) while the spindle is rotating in a forward direction due to inertia; (e) executing the following step after the spindle is rotated in the reverse direction: continuing the pulse distribution calculation based on pulses of a frequency proportional to a reverse rotation velocity and on the pitch of the screw, and withdrawing the tapping tool from the workpiece by moving the tapping tool in the withdrawal direction in accordance with the pulses obtained from the continued pulse distribution calculation.
Claim 2
Dependent Claim
193 words
A tapping machining method comprising the steps of: (a) subjecting a workpiece to a predetermined thread cutting operation by performing a pulse distribution calculation based on pulses of a frequency proportional to a rotational velocity of a spindle and on a pitch of a screw; (b) applying pulses obtained by the pulse distribution calculation to a servo circuit to move a tapping tool in the depth direction; (c) continuing the pulse distribution calculation without pause and generating a spindle rotation reverse command when the tapping tool arrives at a commanded depth; (d) moving the tapping tool in the depth direction by the distributed pulses obtained by the pulse distribution calculation of said step (c) while the spindle is rotating in a forward direction due to inertia; (e) executing the following step after the spindle is rotated in the reverse direction: continuing the pulse distribution calculation based on pulses of a frequency proportional to a reverse rotation velocity and on the pitch of the screw, and withdrawing the tapping tool from the workpiece by moving the tapping tool in the withdrawal direction in accordance with the pulses obtained from the continued pulse distribution calculation.
Claim 3
Dependent Claim
41 words
A tapping machining method according to claim 1, further comprising the steps of storing a tapping starting position in advance and ending the continued pulse distribution calculation in said step (e) when the tapping tool returns to the tapping starting position.
Claim 4
Dependent Claim
34 words
A tapping machining method according to claim 1, wherein a tap return signal is generated, further comprising the step of rotating the spindle in the reverse direction when the tap return signal is generated.
Claim 5
Dependent Claim
84 words
A tapping machining method according to claim 1, wherein said step (e) comprises: determining whether the rotational velocity of the spindle has attained a predetermined rotational velocity after the spindle reverse rotation command is generated in said step (c); inhibiting application of the distributed pulses to the servo circuit until the spindle actually rotates in the reverse direction after the predetermined rotational velocity is reached; and reapplying the distributed pulses to the servo circuit when the spindle starts to rotate in the reverse direction.
Claim 6
Dependent Claim
112 words
A tapping machining method according to claim 1, wherein said step (e) comprises: setting a number q of distributed pulses generated until the spindle attains a predetermined rotational velocity after the spindle reverse rotation command is generated in said step (c); determining whether an actual number of distributed pulses following generation of the spindle reverse rotation command has attained the value q; inhibiting application of the distributed pulses to the servo circuit until the spindle actually rotates in the reverse direction after the actual number of distributed pulses has attained the value q; and reapplying the distributed pulses to the servo circuit when the spindle starts to rotate in the reverse direction.
Claim 7
Dependent Claim
33 words
A tapping machining method according to claim 1, wherein said step (c) comprises generating the spindle reverse rotation command a predetermined period of time after the tapping tool arrives at the commanded depth.