JP2662459B2 - Indexing control device for tool post for NC lathe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an indexing control device for a tool post for an NC lathe, in particular, an NC
The present invention relates to an indexing control device for a tool post for an NC lathe that drives and controls a tool to a desired indexing position based on a processing command.

[Prior art] In the NC lathe, not only the NC control of the spindle on which the work is mounted, but also the NC control of the tool post indexing in which a plurality of tools are mounted and these tools are arbitrarily selected. ,
Various complicated processes can be continuously and unmannedly operated based on a predetermined program.

In such an NC lathe, indexing control of the tool post
It is extremely important to combine various machining by selecting various desired multiple tools, and since the positioning accuracy directly affects the machining accuracy, the indexing rotation speed is large and quick indexing is performed. There is a need for an indexing control device that can obtain high positioning accuracy.

Conventionally, index control of a tool post is divided into a turning motion of the tool post and a clamp / unclamp operation, and the turning motion of the tool post is generally driven by an inverter-controlled induction motor or hydraulic pressure. For the clamp / unclamp operation, the indexing surface of the tool post is detected by a position sensor and operated using a hydraulic valve. Is controlled based on the sequence.

Recently, the turret turning control of NC lathes is described in, for example,
As shown in Japanese Patent No. 296579, a tool post can be indexed at high speed using a servomotor.

In the tool post turning control, the tool post turning command angle is fixed at each indexing surface according to the number of indexing surfaces of the tool post as shown in FIG.

FIG. 5 (a) shows an example of a dodecagon tool post, and FIG. 5 (b) shows an example of a hexagon tool post.

FIG. 6 is a block diagram showing a configuration of a conventional indexing control device of a tool post for an NC lathe. The indexing control device has a program memory 1 for storing an indexing command of a tool post 12 and the like. The program memory 1 is connected to a program interpreting unit 2 for reading and interpreting an indexing command.

A sequence control unit 3 and a tool post indexing control unit 6 are connected in parallel to the program interpreting unit 2, and a data input for inputting a tool post turning command angle is input to the tool post indexing control unit 6. A servo motor controller 7 for controlling the device 4 and the servo motor 9 is connected.

Further, a position detector 10 for detecting the rotational position of the servo motor 9 is connected to the rotation shaft 9b of the servo motor 9, and the position detector 10 is connected to the servo motor controller 7 for controlling the servo motor 9. ing.

A gear 13 is fixed to the motor shaft 9a of the servomotor 9, and the gear 13 meshes with a gear 14 connected to a turret shaft 12a rotatably supported.

The tool post 12 is fixed to the turret shaft 12a, and the tool post 12 is driven to rotate in the direction of arrow A to obtain a desired indexing surface.

Although not shown in detail in the figure, a clamp / unclamp mechanism driven by a clamp / unclamp solenoid controlled by the sequence control unit 3 is incorporated in, for example, the reduction gear 14 of the reduction mechanism, The tool post 12 is turned by the servo motor 9 in the unclamped state, and when a predetermined indexing surface is obtained, a clamping operation is performed using a hydraulic cylinder.

Reference numeral 11 in the drawing denotes a limit switch for detecting a clamp / unclamp state.

 Next, the operation will be described.

The program interpreter 2 reads out the index of the tool post 12 stored in the program memory 1 and supplies a desired index to the sequence controller 3 and the tool post index controller 6.

Then, in the unclamped state, the servo motor control unit 7
The tool post 12 is turned by the servo motor 9,
When a predetermined indexing surface is obtained, the sequence controller 3 turns on the solenoid to perform a clamping operation.

[Problems to be Solved by the Invention] The conventional NC lathe tool post indexing control device is configured as described above, and the indexing teeth that determine the tool post indexing accuracy include machining during manufacturing. There is an aging of the indexing accuracy due to errors and prolonged use, and since the turning command angle of each indexing surface is fixed at each indexing surface, it is not possible to cope with machining errors and aging, and the indexing position There is a problem that a lot of time is spent for the adjustment, and the tooth surfaces of the index teeth collide with each other when the tool post is clamped, generating a loud noise.

In addition, due to the weight of the tool holder and tool attached to the tool post, it may not be possible to jump over the position where the indexing teeth are securely meshed or to perform accurate tool post indexing during turning positioning during tool post indexing. Was.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a tool post indexing machine that can accurately and stably perform indexing and can cope with machining errors and aging of indexing teeth. An object of the present invention is to provide a tool post indexing control device.

Means for Solving the Problems In order to achieve the above object, an NC lathe tool post indexing control device according to the present invention uses a servo motor to turn a tool post having a plurality of indexing surfaces for holding the tool. A device for controlling and indexing a desired indexing surface to an indexing position,
Angle detection means for detecting the angular position of the reference plane of the tool rest with respect to the indexing position, clamp state detection means for detecting the state in which the tool rest is clamped, and each of the angles represented by the angle from the reference plane The servo motor includes: a holding unit that holds an angular position of the indexing surface; and an output torque control unit that can reduce an output torque of the servo motor to zero.

Then, the index of the tool post is executed, and when it is detected that the tool post is clamped by the clamp state detection main stage, the output torque of the servomotor is set to zero by the output torque control means, and at this time, The angular position of the index surface held by the holding unit is updated based on the angular position of the reference plane detected by the angle detecting unit.

[Operation] With the configuration described above, the angular position of the indexing surface is updated for each indexing operation, and it is possible to cope with a change in the indexing position due to a processing error or aging. Therefore, it is not necessary to adjust the indexing angle.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an indexing control device for a tool post for an NC lathe according to the present invention, and FIG. 2 is a diagram showing a drive transmission section from a servo motor to a tool post in the present invention.

The indexing control device has a program memory 1 for storing an indexing command and the like for the tool post 12, and a program interpreting unit 2 for reading and interpreting the indexing command is connected to the program memory 1.

The program interpreting unit 2 includes a sequence control unit 3 and a tool post indexing angle as a holding unit for holding an indexing angle which is an angular position of each indexing surface expressed by an angle from a predetermined reference plane. The command memory 5 is connected in parallel. As shown in FIG. 5, the tool post indexing angle command memory 5 stores an indexing surface and an angular position of the indexing surface in association with each other, and this angle position becomes an angle command in the control. In addition, in the case of FIG. 5, the index surface T1 serves as a reference surface, and the angular positions of the other index surfaces are based on this. Further, the tool post indexing angle command memory 5 is connected to a data input device 4 for inputting an initial set value and a change value of the angular position of each indexing surface, and a tool post indexing control unit 6.

A servo motor control unit 7 for controlling a servo motor 9 is connected to the tool post indexing control unit 6, and the servo motor control unit 7 is provided with an output torque control for making the output torque of the servo motor 9 zero. A torque command zero command unit 8 as means is connected, and the torque command zero command unit 8 is connected to a limit switch 11 as clamp state detecting means for detecting a clamp state of the tool rest.

Furthermore, the servomotor 9 is provided on the rotation axis of the servomotor 9.
Position detector 10 as angle detecting means for detecting the angular position of the tool rest reference plane by detecting the rotational angle position of
Is connected, and the position detector 10 is connected to the servo motor control unit 7 for controlling the servo motor 9 and the AND circuit 15, and the AND confirmation circuit 15 receives the clamp confirmation signal from the limit switch 11. The output of the AND circuit 15 is inputted to the tool post indexing angle command memory 5.

FIG. 2 shows a drive transmission unit from the servo motor to the tool post in detail.
Are rotatably supported by a turret shaft 12a.

Further, to the tool rest 12, a Carvic-type indexing positioning tooth 17, which will be described later, is fixed.

On the other hand, a servo motor 9 is fixed to the other surface of the tool rest base 16, and a gear shaft 9 a of the servo motor 9 is
The gear 13 is fixed, and the gear 13 meshes with a gear 14 rotatably supported.

The tool rest gear 18 meshes with a speed reduction pinion 19 provided integrally with the gear 14, whereby the rotational driving force of the servo motor 9 is reduced and transmitted to the tool rest 12. I have.

FIG. 2 shows a state in which the clamp / unclamp mechanism of the tool post 12 is incorporated into the tool post base 16, and the Carvic-type indexing positioning teeth 17 face the tool post 12 side as shown in the figure. The indexing teeth 17a are also provided, and similarly, the side surface of the tool post base 16 itself is parallel to the inner periphery of the indexing teeth 17 of the Carbic type indexing.
20, the same number of indexing teeth are engraved on the same plane, and both positioning teeth 17, 20 are formed.
Have the same phase.

Further, the tool post base 16 is provided with a clamper 21 which can slide in the axial direction of the turret shaft 12a, and the clamper 21 has a Carvic-type indexing member facing the positioning teeth 17, 20 as shown in FIG. Fixed teeth 21a are provided.

Therefore, as shown in FIG. 2, when the racumper 21 is moving rightward by the electromagnetic solenoid, the carvic-type indexing fixed teeth 21a mesh with the positioning teeth 17, 20 at the same time, and at this selected position. The tool post 12 is indexed and positioned.

The clamper 21 is slidable leftward in FIG. 2 by an electromagnetic solenoid. As a result, the indexing fixed teeth 21a are separated from the positioning teeth 17, 20. In this state, the tool rest 12 Is unclamped from the tool rest base 16 and can be turned to any indexing position by the servo motor 9.

FIG. 3 shows an example of the NC command, in which the addresses "N001" and "N010" are a sequence for commanding the tool post indexing. These tool post assignments are performed during the NC command for driving the NC lathe. Order is included.

Then, “T0101” and “T020” in the indexing command
2 '' is a specific indexing command in the embodiment,
A two-digit number following "T" commands the indexing surface of the tool post, and the two digits following this indicate a known tool offset.

Further, “X800” and “Z800” are position commands of the feed axes X and Z-axis when performing tool post indexing, respectively.

The preferred embodiment of the present invention has the above configuration, and its operation will be described in detail below with reference to the flowchart of FIG.

A machining program as shown in FIG. 3 is stored in the program memory 1, and the program interpreting section 2 sends the machining program (for example, “T010”) from the program memory 1.
By reading and interpreting 1)), the tool post indexing surface is recognized from the tool post indexing command (step S1).

Then, an index angle command corresponding to the tool post indexing surface recognized by the program interpretation unit 2 is read from the tool post indexing angle command memory 5 (see FIG. 5) (Step S).
2).

The signal indicating the tool post indexing surface is also sent to the sequence control section 3, and the sequence control section 3 executes the tool post unumpping operation by generating an unclamping signal (step S3).

On the other hand, the index angle command read from the tool post indexing angle command memory 5 is sent to the tool post indexing control unit 6. The tool post indexing control unit 6 controls the servo motor 9 by the servo motor control unit 7 to turn the tool post 12 to the commanded angle (step S4).

When the turning of the tool rest 12 to the designated angle is completed (step S5), the sequence control unit 3 executes the clamping of the tool rest (step S6).

Then, when the tool post 12 performs the clamping operation by the hydraulic control and the limit switch 11 is turned on, it is determined that the clamping is completed (step S7).

Further, the ON signal from the limit switch 11 is sent to the torque command zero command unit 8, and when the clamping is completed, a torque zero command is issued from the torque command zero command unit 8 to the servo motor control unit 7 (step S8).

When the servo motor 9 stops generating torque by the torque zero command, the index angle of the tool post 12 is fixed according to the accuracy of the index teeth 17a. The motor shaft 9a of the servomotor 9 is minutely rotated via the turret shaft 12a and the speed reduction mechanisms 13, 14, 18, and 19.

As a result, the position detector 10 coupled to the servomotor 9 indicates the actual angle of the commanded tool post indexing surface.

Then, the AND circuit 15 for detecting the tool post actual indexing angle signal indicated by the position detector 10 and the clamp ON signal detected by the limit switch 11 outputs the tool post actual indexing angle signal, and The tool post actual indexing angle is updated and written in the tool post indexing angle command memory 5 at the angular position of the indexing surface (step S9).

Thereafter, similarly, an actual angle corresponding to another tool post indexing command is automatically set in the tool indexing angle command memory 5 as the machining program is executed.

In the above embodiment, the actual indexing angle is set by the tool post indexing command by the machining program.
However, the present invention is not limited to this, and the actual indexing angle may be set in the blade indexing angle command memory 5 by the same operation as described above at the time of blade indexing in the manual operation mode.

[Effects of the Invention] As described above, according to the present invention, every time the tool post indexing is executed, the angular position of the indexing surface held by the holding means is updated based on the actual indexing angle. ,
It can cope with machining errors and aging of the index teeth, eliminating the need for index position adjustment.This ensures accurate and safe meshing and prevents the tooth surfaces of the index teeth from colliding with each other when the tool post is clamped. It is possible to prevent generation of a loud sound.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an indexing control device for a tool post for an NC lathe according to the present invention, FIG. 2 is a diagram showing a drive transmission section from a servo motor to a tool post in the present invention, and FIG. Stored in the program memory in FIG.
FIG. 4 is a flowchart showing an operation of the present invention, FIG. 5 is a diagram showing an indexing surface of a tool post and an indexing angle corresponding to the indexing surface, and FIG. FIG. 9 is a block diagram showing a configuration of a conventional indexing control device for a tool post for an NC lathe. 5: Tool post indexing angle command memory 7: Servo motor control unit 8: Torque command zero command unit 9: Servo motor 10: Position detector 11: Limit switch 12: Tool post

Claims (1)

(57) [Claims] 1. A tool rest control device for turning a tool rest having a plurality of indexing surfaces for holding a tool by means of a servomotor and indexing a desired indexing surface to an indexing position. Angle detecting means for detecting an angular position with respect to the indexing position; clamp state detecting means for detecting a state in which the tool rest is clamped; and angular position of each indexing surface expressed by an angle from the reference plane. Holding means, and output torque control means capable of reducing the output torque of the servomotor to zero, wherein indexing of the tool rest is executed, and the clamp state detecting means detects that the tool rest is clamped. Then, the output torque of the servomotor is set to zero by the output torque control means, and the output torque of the servo motor is maintained by the angular position of the reference plane detected by the angle detection means at this time. Updating the angular position of the indexing surface which is held in the stage, the tool rest indexing control device for NC lathe.