JP2765752B2 - Numerical control unit - Google Patents

Description

The present invention relates to a numerical control device for controlling a numerically controlled machine tool having a turret capable of indexing a tool.

(Prior Art) FIG. 3 is a schematic perspective view showing an example of a numerically controlled lathe having a turret capable of indexing a tool. Each station of the turret supported by the tool post 2 has a structure in which a tool can be mounted, and a tool used for processing the workpiece 3 can be indexed to a cutting position by rotating the turret 1. it can.

FIG. 4 is a diagram showing a turret operation sequence at the time of a tool indexing command. When a tool indexing command is issued, the turret 1 is unclamped, the indexing positioning teeth 4 of the turret 1 are removed from the indexing positioning teeth 5 of the tool rest 2, and the turret 1 can be turned (unclamping sequence S1). Next, the turret 1 turns so that the command tool comes to the cutting position (turning sequence S2). Finally, the turret 1 is clamped to engage the indexing positioning teeth 4 of the turret 1 with the indexing positioning teeth 5 of the tool post 2 (clamp sequence S3), and the tool indexing is completed.

FIG. 5 is a block diagram showing an example of a conventional numerical control device for controlling the turret operation sequence described above. When each program has a tool indexing command, the machining program analysis unit 100 generates a tool indexing command CID and sends it to the tool indexing sequence control unit 210 in the tool indexing control unit 200.

Upon receiving the tool indexing command CID from the machining program analyzer 100, the tool indexing sequence controller 210 executes unclamping so that the tool indexing sequence follows the flow of S1, S2, and S3 shown in FIG. Commands are sequentially transmitted to the unit 220, the turning execution unit 230, and the clamp execution unit 240. That is, the tool indexing sequence control unit 210 first sends an unclamping command CUC to the unclamping execution unit 220, and waits for the unclamping answer unit AUC to be returned from the unclamping execution unit 220. And unclamped answer AUC
Is returned, the turn command CRT is sent to the turn execution unit 230.
And waits for the turning answer part ART to be returned from the turning execution unit 230. Then, when the turning answer ART is returned, a clamp command CCL is transmitted to the clamp executing unit 240, and the system waits for the clamp answer ACL to be returned from the clamp executing unit 240. Then, when the clamp answer ACL is returned, the tool index answer AID is returned to the machining program analysis unit 100.

Here, the timing at which the tool indexing sequence control unit 210 sends out the clamp command CCL to the clamp executing unit 240, in other words, the timing at which the turning execution unit 230 returns the turning answer ART to the tool indexing sequence control unit 210, will be described.

Upon receiving the turning command CRT from the tool indexing sequence control unit 210, the target turning angle position calculating unit 231 in the turning execution unit 230 calculates the target turning angle position θ _G based on the indexing tool number information TN in the turning command CRT. Calculate and calculate angular position command
232 and the turn completion determination unit 236.

The angle position command calculation unit 232 is a target turning angle position calculation unit 231.
Generating a turning angle position command theta _C for each sampling in positioning to the target slewing angular position theta _G came sent from to be sent to the speed command calculation unit 233.

Speed command computation unit 233 sends out to generate a turning speed specified theta _V corresponding to the pivot angle position command theta _C came sent from the angular position calculation unit 232 to the motor 234, the motor 234 turning velocity command theta _V Rotate according to.

Attached to the motor shaft position detector 235 sends the turning completion judging unit 236 together detect the current turning angular position theta _P returned to the angular position command calculating unit 232.

The angular position command calculation unit 232 determines the turning angle until the current turning angle position θ _P sent from the position detector 235 matches the target turning angle position θ _G sent from the target turning angle position calculation unit 231. It continues to generate a position command theta _C.

The turning completion determining unit 236 includes the current turning angle position θ _P sent from the position detector 235 and the target turning angle position calculating unit 23.
The target turning angle position θ _G sent from 1 is compared, and when they match, the turning answer ART is returned to the tool indexing sequence control unit 210.

As described above, the turret 1 is completely turned to the target turning angle position θ _G
Until the process reaches, the sequence cannot be shifted to the clamp sequence S3.

(Problem to be Solved by the Invention) FIG. 6 is a time chart of turning and clamping by the numerical control device described above. Note that “turning operation” indicates a change in the turning speed, and “clamping operation” indicates the operation of the clamping cylinder.

As shown in the figure, the turning answer ART Once reached the target slewing angular position theta _G T1 is ON, the clamp command CCL is ON at the same time. Then, when the clamp command CCL is turned on, the clamp execution unit 240 immediately sends a command to the clamp control hydraulic unit. However, the clamping cylinder starts operating at time T2, which is later than time T1 by TCD.
The clamp operation delay time TCD is generated by the operation time of the solenoid, the transmission time of the hydraulic pressure, and the like. Therefore, actually a blank time occurs in up to begin clamping the turret 1 from the completion position to the target slewing angular position theta _G, thereby a problem that the tool indexing time is extended.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a numerical control device capable of eliminating a blank time from the completion of a turning operation of a turret to the start of a clamping operation and shortening a tool indexing time. To provide.

(Means for Solving the Problems) The present invention relates to a numerical control device for controlling a numerically controlled machine tool having a turret capable of indexing a tool. A numerical control unit that controls a speed, an unclamping unit that performs unclamping control that makes the turret pivotable, a clamp executing unit that performs control of a clamp that fixes the turret, A delay time storage unit that stores a delay time from when a clamp command is issued until the turret actually starts a clamping operation by the clamp execution unit, a turning speed storage unit that stores a turning speed of the turret, Calculating the angle at which the turret turns within the delay time from the delay time and the turning speed; and calculating the target turning angle position of the turret. Calculating a clamp command start angle representing the position of the turret at the time when the time corresponding to the delay time is calculated backward from the completion of the turning operation of the turret. This is achieved by issuing the turret clamping command when the turret turning angle position detected during the turning of the turret becomes the clamp command start angle.

(Operation) In the present invention, the turret clamp command is issued during the turret turning in anticipation of the clamp operation delay time, so that the blank time from the completion of the turret turning operation to the start of the clamp operation is eliminated, and the tool is removed. The indexing time can be reduced.

(Embodiment) FIG. 1 is a block diagram showing an example of a numerical controller according to the present invention in correspondence with FIG. 5, and the same components are denoted by the same reference numerals and description thereof is omitted.

The clamp operation delay time TCD and the turning speed VRT are stored in advance in the delay time storage unit 310 and the turning speed storage unit 320, respectively.

Turning angle of the clamp command start angle calculating section 300 clamping operation delay time TCD and the turning velocity VRT based on delay time read from the storage unit 310 (hereinafter referred to as clamp command start angle theta _D) to calculate the turning It is sent to completion determination section 236.

Then, during the turning, the turning completion determining unit 236 receives the target turning angle position θ _G from the target turning angle position calculating unit 231, the current turning angle position θ _P from the position detector 235, and the clamp command start angle calculating unit 300. Command start angle θ _D
| Θ _G −θ _P | ≦ θ _D whether or not to return the turning answer ART to the tool indexing sequence control unit 210 based on the three elements
It is determined based on the condition

FIG. 2 is a time chart of turning and clamping by the numerical controller described above.

As shown in the figure, the turning answer ART is turned on at time T1 '.
At the same time, the clamp command CCL turns ON. Then, the turning operation is' also continues thereafter, the time T1 'time T1 operation is completed reaches the target turning angular position theta _G when T2', further elapsed clamping operation delay time TCD from. On the other hand, the clamp operation starts at a time T2 'after a lapse of the clamp operation delay time TCD from the time T1'. Therefore, the completion of the turning operation and the start of the clamping operation are both at the time T2 ', and the blank time between the completion of the turning operation and the start of the clamping operation, which has been conventional, can be eliminated.

(Effects of the Invention) As described above, according to the numerical controller of the present invention, the clamp operation can be started at the same time as the completion of the turret turning operation by issuing the clamp command at the optimal timing during the turret turning. Therefore, the tool indexing time can be reduced, and the machining process can be started quickly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a numerical control device of the present invention, FIG. 2 is a time chart of turning and clamping by the device of the present invention, and FIG. 3 is an example of a numerical control lathe having a turret capable of indexing a tool. FIG. 4 is a diagram showing a turret operation sequence at the time of a tool indexing command, FIG. 5 is a block diagram showing an example of a conventional numerical controller, and FIG. It is a time chart. 1 ... turret, 2 ... turret, 3 ... workpiece, 4,5
… Index positioning teeth, 100… Machining program analysis unit, 200… Tool index control unit, 210… Tool index sequence control unit, 220… Unclamp execution unit, 230… Turret rotation execution unit, 231 …… Target turning angle position calculator, 2
32 ... Angle position command calculator, 233 ... Speed command calculator, 2
34 ... Motor, 235 ... Position detector, 236 ... Turn completion determination unit, 240 ... Clamp execution unit, 300 ... Clamp command start angle calculation unit, 310 ... Delay time storage unit, 320 ... Turn speed Storage unit.

Claims (1)

(57) [Claims] A numerical control device for controlling a numerically controlled machine tool having a turret capable of indexing a tool, a numerical control unit for controlling a position and a speed of the turret to be turned, and a turret capable of turning the turret. An unclamping execution unit that executes control of unclamping to be performed, a clamping execution unit that executes control of a clamp that fixes the turret, and the turret is actually moved by the clamping execution unit after a turret clamping command is issued. A delay time storage unit that stores a delay time until the start of the clamping operation, a turning speed storage unit that stores the turning speed of the turret, and an angle at which the turret turns within the delay time, the delay time and the turning. By calculating from the speed and calculating backward from the target turning angle position of the turret, the time before the turning operation of the turret is completed A clamp command start angle calculation unit that calculates a clamp command start angle representing the position of the turret at the time when the time corresponding to the delay time is calculated backward, and the turning angle position of the turret detected during turning of the turret is A numerical control device wherein a turret clamping command is issued when a clamping command starting angle is reached.